*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg-primary: #050a14;
    --bg-secondary: #0d1525;
    --bg-card: rgba(13, 21, 37, 0.8);
    --bg-card-solid: #0c1530;
    --bg-card-hover: rgba(20, 30, 50, 0.9);
    --bg-input: rgba(4, 10, 24, 0.85);
    --bg-glass: rgba(8, 16, 40, 0.45);
    --bg-nebula-1: rgba(80, 40, 180, 0.08);
    --bg-nebula-2: rgba(0, 140, 200, 0.06);
    --bg-nebula-3: rgba(200, 60, 80, 0.04);
    --text-primary: #e4e8f0;
    --text-secondary: #8892a4;
    --text-muted: #5a6578;
    --border: rgba(255, 255, 255, 0.08);
    --border-bright: rgba(255, 255, 255, 0.15);
    --border-accent: rgba(0, 200, 255, 0.3);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
    --nav-bg: rgba(5, 10, 20, 0.95);
    --dropdown-bg: #0d1525;
    --input-bg: rgba(255, 255, 255, 0.05);
    --code-bg: rgba(0, 0, 0, 0.3);
    --info-bg: rgba(79, 195, 247, 0.08);
    --info-border: rgba(79, 195, 247, 0.3);
    --callout-bg: rgba(255, 193, 7, 0.08);
    --callout-border: rgba(255, 193, 7, 0.3);
    --success-bg: rgba(0, 212, 170, 0.08);
    --success-border: rgba(0, 212, 170, 0.3);

    --accent: #00d4ff;
    --accent-rgb: 0, 212, 255;
    --accent-dim: rgba(0, 212, 255, 0.1);
    --accent-glow: rgba(0, 212, 255, 0.12);
    --cyan: #00e5ff;
    --cyan-dim: rgba(0, 229, 255, 0.1);
    --mars: #ff6b35;
    --mars-rgb: 255, 107, 53;
    --mars-dim: rgba(255, 107, 53, 0.1);
    --success: #3fb950;
    --success-rgb: 63, 185, 80;
    --success-dim: rgba(63, 185, 80, 0.1);
    --danger: #f85149;
    --danger-rgb: 248, 81, 73;
    --danger-dim: rgba(248, 81, 73, 0.1);
    --warning: #d29922;
    --warning-rgb: 210, 153, 34;
    --warning-dim: rgba(210, 153, 34, 0.1);
    --purple: #a371f7;
    --purple-rgb: 163, 113, 247;
    --purple-dim: rgba(163, 113, 247, 0.1);
    --quantum: #7c5cf7;
    --quantum-rgb: 124, 92, 247;
    --quantum-dim: rgba(124, 92, 247, 0.1);
    --nebula: #c84cff;
    --nebula-rgb: 200, 76, 255;
    --nebula-dim: rgba(200, 76, 255, 0.08);
    --teal: #2dd4bf;
    --teal-dim: rgba(45, 212, 191, 0.1);

    --radius: 10px;
    --radius-md: 8px;
    --radius-lg: 14px;
    --radius-xl: 22px;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-out: cubic-bezier(0, 0, 0.2, 1);
    --ease-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', monospace;
    --shadow-card: 0 4px 32px rgba(0, 0, 0, 0.4), 0 1px 4px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(var(--accent-rgb), 0.08);
    --shadow-nebula: 0 0 60px rgba(var(--nebula-rgb), 0.06), 0 0 120px rgba(var(--quantum-rgb), 0.04);
    --canvas-opacity: 1;
}

[data-theme="light"] {
    --bg-primary: #f5f7fa;
    --bg-secondary: #ffffff;
    --bg-card: rgba(255, 255, 255, 0.95);
    --bg-card-solid: #ffffff;
    --bg-card-hover: rgba(255, 255, 255, 1);
    --bg-input: rgba(0, 0, 0, 0.04);
    --bg-glass: rgba(255, 255, 255, 0.6);
    --bg-nebula-1: rgba(80, 40, 180, 0.04);
    --bg-nebula-2: rgba(0, 140, 200, 0.03);
    --bg-nebula-3: rgba(200, 60, 80, 0.02);
    --text-primary: #1a1a2e;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --border: rgba(0, 0, 0, 0.08);
    --border-bright: rgba(0, 0, 0, 0.15);
    --border-accent: rgba(0, 150, 200, 0.3);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    --nav-bg: rgba(255, 255, 255, 0.98);
    --dropdown-bg: #ffffff;
    --input-bg: rgba(0, 0, 0, 0.04);
    --code-bg: rgba(0, 0, 0, 0.05);
    --info-bg: rgba(79, 195, 247, 0.08);
    --info-border: rgba(79, 195, 247, 0.4);
    --callout-bg: rgba(255, 193, 7, 0.08);
    --callout-border: rgba(255, 193, 7, 0.4);
    --success-bg: rgba(0, 212, 170, 0.08);
    --success-border: rgba(0, 212, 170, 0.4);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.06), 0 1px 4px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 30px rgba(var(--accent-rgb), 0.05);
    --shadow-nebula: none;
    --canvas-opacity: 0.7;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    line-height: 1.7;
    padding-top: 60px;
}

#cosmos-canvas {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: var(--canvas-opacity);
    transition: opacity 0.4s ease;
}

::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(var(--quantum-rgb), 0.2); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(var(--accent-rgb), 0.35); }
::selection { background: rgba(var(--accent-rgb), 0.25); color: #fff; }

a { color: var(--accent); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--cyan); }

h1, h2, h3, h4, h5, h6 {
    line-height: 1.3;
    color: var(--text-primary);
    font-weight: 700;
}

h1 { font-size: 2.2rem; margin-bottom: 0.6em; }
h2 { font-size: 1.8rem; margin-bottom: 0.5em; }
h3 { font-size: 1.3rem; margin-bottom: 0.4em; }
h4 { font-size: 1.1rem; margin-bottom: 0.3em; }

p { max-width: 720px; line-height: 1.7; color: var(--text-secondary); }

code, pre {
    font-family: var(--font-mono);
    background: var(--code-bg);
    border-radius: var(--radius-md);
    padding: 2px 6px;
    font-size: 0.9em;
}

pre { padding: 16px; overflow-x: auto; border: 1px solid var(--border); }

/* ─── TOP NAVBAR ─── */
.topnav {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 60px;
    background: var(--nav-bg);
    backdrop-filter: blur(24px) saturate(1.2);
    -webkit-backdrop-filter: blur(24px) saturate(1.2);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    padding: 0 28px;
    z-index: 500;
    transition: background var(--transition);
}

.topnav-brand {
    font-size: 1.15rem;
    font-weight: 800;
    letter-spacing: 4px;
    background: linear-gradient(135deg, var(--cyan) 0%, var(--quantum) 40%, var(--nebula) 70%, var(--mars) 100%);
    background-size: 300% 300%;
    animation: nebulaShift 6s ease infinite;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-transform: uppercase;
    flex-shrink: 0;
    cursor: pointer;
}

.topnav-center {
    display: flex;
    align-items: center;
    gap: 4px;
    margin: 0 auto;
    list-style: none;
}

.topnav-link {
    padding: 8px 16px;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.88rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
    position: relative;
    white-space: nowrap;
}

.topnav-link:hover {
    background: rgba(var(--quantum-rgb), 0.06);
    color: var(--text-primary);
}

.topnav-link.active {
    background: linear-gradient(135deg, rgba(var(--accent-rgb), 0.08), rgba(var(--quantum-rgb), 0.08));
    color: var(--accent);
    font-weight: 600;
}

.topnav-link .nav-icon { font-size: 0.9rem; opacity: 0.6; transition: all var(--transition); }
.topnav-link:hover .nav-icon { opacity: 1; }
.topnav-link.active .nav-icon { opacity: 1; color: var(--accent); }

.topnav-right {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.theme-toggle {
    width: 40px; height: 40px;
    border-radius: var(--radius);
    background: var(--input-bg);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
}

.theme-toggle:hover {
    border-color: rgba(var(--accent-rgb), 0.3);
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.06);
}

.topnav-dropdown {
    position: relative;
}

.topnav-dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(-4px);
    min-width: 200px;
    background: var(--dropdown-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    /* Delay `visibility` until the fade-out has finished, but flip it on
       immediately when opening. A blanket `transition: all` left the menu
       visibility:hidden for the whole 0.25s fade-IN, and a hidden element
       cannot take focus — so the ArrowDown handler's .focus() on the first
       item was silently a no-op for keyboard users. */
    transition: opacity var(--transition),
                transform var(--transition),
                visibility 0s linear 0.25s;
    box-shadow: var(--shadow);
    z-index: 600;
}

.topnav-dropdown:hover .topnav-dropdown-menu,
.topnav-dropdown.open .topnav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
    transition: opacity var(--transition),
                transform var(--transition),
                visibility 0s;
}

.topnav-dropdown-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    /* Only the hover colours animate. `transition: all` also caught the
       `visibility` these items INHERIT from the menu, re-animating it on open
       and leaving each item computed-hidden — hence unfocusable — even after
       the menu itself had turned visible. */
    transition: background var(--transition-fast), color var(--transition-fast);
}

.topnav-dropdown-item:hover {
    background: rgba(var(--accent-rgb), 0.06);
    color: var(--accent);
}

.topnav-dropdown-item.active {
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.08);
}

/* ---- Nav bar refresh (2026-08-06) -------------------------------------
   The bar previously carried 13 top-level items in a fixed-height flex row
   with no wrap, so it overflowed on laptop widths. It is now 6 groups, and
   the rules below cover the new elements plus keyboard/overflow handling. */

/* Dropdown triggers are real <button>s now, so reset UA styling. */
.topnav-center button.topnav-link {
    background: none;
    border: none;
    font-family: inherit;
    font-size: 0.88rem;
    line-height: inherit;
}

/* Keep the bar on one line.

   This element must NEVER become a scroll container. The dropdown menus are
   absolutely positioned at `top: calc(100% + 8px)` — entirely below this box —
   and their containing block (.topnav-dropdown) sits inside it, so any
   overflow value other than `visible` clips every menu away completely. Note
   that setting only `overflow-x` is not enough to avoid this: when one axis is
   non-visible the other computes to `auto`, so an `overflow-x: auto` here
   clipped the menus vertically. `z-index` cannot recover it; clipping is
   applied before stacking.

   The narrow band that previously scrolled is handled by the compact tier
   below and then the hamburger, rather than by clipping. */
.topnav-center {
    flex-wrap: nowrap;
    flex-shrink: 0;
    overflow: visible;
}

.topnav-item { display: flex; align-items: center; }

.nav-caret {
    font-size: 0.6rem;
    opacity: 0.5;
    transition: transform var(--transition-fast);
}
.topnav-dropdown:hover .nav-caret,
.topnav-dropdown.open .nav-caret { transform: rotate(180deg); opacity: 0.9; }

/* Course call-to-action */
a.topnav-link { text-decoration: none; }
a.topnav-link:hover { text-decoration: none; }

.topnav-cta {
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.07);
    border: 1px solid rgba(var(--accent-rgb), 0.28);
    font-weight: 600;
}
.topnav-cta:hover {
    background: rgba(var(--accent-rgb), 0.14);
    border-color: rgba(var(--accent-rgb), 0.5);
    color: var(--accent);
}

.nav-badge {
    font-size: 0.62rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    padding: 1px 6px;
    border-radius: 999px;
    background: var(--accent);
    color: #050a14;
    line-height: 1.5;
}

/* Parent of the active route gets a subtle marker so you can tell which
   group you are inside while the menu is closed. */
.topnav-dropdown.has-active > .topnav-link {
    color: var(--text-primary);
}
.topnav-dropdown.has-active > .topnav-link::after {
    content: '';
    position: absolute;
    left: 16px; right: 16px; bottom: 2px;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--accent), var(--quantum));
}

/* Visible keyboard focus — the old hover-only dropdowns had none. */
.topnav-link:focus-visible,
.topnav-dropdown-item:focus-visible,
.topnav-mobile-link:focus-visible,
.topnav-mobile-cta:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

a.topnav-dropdown-item { text-decoration: none; }

/* After picking an item the pointer is still inside the group, so the :hover
   rule would keep the menu hanging over the page you just navigated to. This
   parks it until the pointer leaves; JS adds the class on item click and drops
   it again on mouseleave. */
.topnav-dropdown.hover-parked:hover .topnav-dropdown-menu {
    opacity: 0;
    visibility: hidden;
}

/* Between the hamburger breakpoint and a comfortable desktop the six groups no
   longer fit at full density. Tighten spacing and drop the decorative icons —
   the bar stays on one line and the dropdowns keep working, which the old
   horizontal-scroll approach could not do. */
@media (max-width: 1100px) {
    .topnav { padding: 0 16px; }
    .topnav-brand { font-size: 1rem; letter-spacing: 2px; }
    .topnav-center { gap: 0; }
    .topnav-center .topnav-link { padding: 8px 10px; }
    .topnav-center .topnav-link .nav-icon { display: none; }
}

.topnav-dropdown-sep {
    border: none;
    border-top: 1px solid var(--border);
    margin: 6px 8px;
}

/* Mobile course CTA */
.topnav-mobile-cta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin: 6px 0 2px;
    padding: 12px 16px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 700;
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.08);
    border: 1px solid rgba(var(--accent-rgb), 0.3);
}
.topnav-mobile-cta:hover { background: rgba(var(--accent-rgb), 0.15); }
.topnav-mobile-link { text-decoration: none; }

@media (prefers-reduced-motion: reduce) {
    .nav-caret, .topnav-dropdown-menu { transition: none; }
}

.topnav-hamburger {
    display: none;
    width: 42px; height: 42px;
    border-radius: var(--radius);
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-primary);
    font-size: 1.2rem;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
}

.topnav-hamburger:hover { border-color: rgba(var(--accent-rgb), 0.3); }

.topnav-mobile-menu {
    display: none;
    position: fixed;
    top: 60px; left: 0; right: 0;
    background: var(--dropdown-bg);
    backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--border);
    padding: 12px;
    z-index: 499;
    flex-direction: column;
    gap: 4px;
    animation: slideDown 0.3s var(--ease-out);
    /* The menu lists every route (~40 links), which is far taller than a phone
       viewport. Being position:fixed it cannot scroll with the page, so it has
       to scroll itself or everything past Study is unreachable. */
    max-height: calc(100vh - 60px);
    overflow-y: auto;
    overscroll-behavior: contain;
}

.topnav-mobile-menu.open { display: flex; }

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

.topnav-mobile-link {
    padding: 12px 16px;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 10px;
}

.topnav-mobile-link.active {
    background: rgba(var(--accent-rgb), 0.06);
    color: var(--accent);
}

.topnav-mobile-section {
    padding: 10px 16px 4px;
    font-size: 0.6rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 700;
    margin-top: 4px;
}

/* ─── KEY ANIMATIONS ─── */
@keyframes nebulaShift {
    0%, 100% { background-position: 0% 50%; }
    25% { background-position: 50% 0%; }
    50% { background-position: 100% 50%; }
    75% { background-position: 50% 100%; }
}

@keyframes quantumPulse {
    0%, 100% { opacity: 1; box-shadow: 0 0 8px rgba(var(--success-rgb), 0.6); }
    50% { opacity: 0.6; box-shadow: 0 0 16px rgba(var(--success-rgb), 0.3); }
}

/* ─── SIDEBAR (LEGACY — HIDDEN) ─── */
.sidebar { display: none !important; }

/* ─── LAYOUT ─── */
.main-content {
    margin-left: 260px;
    flex: 1;
    padding: 28px 36px;
    max-width: 1520px;
    position: relative;
    z-index: 1;
}

.main-content.no-sidebar {
    margin-left: 0;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
    padding: 28px 36px;
}

/* ─── PAGE TRANSITIONS ─── */
.page { display: none; animation: fadeIn 0.3s ease; }
.page.active { display: block; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab { display: none; }
.tab.active { display: block; animation: tabWarp 0.5s var(--ease-out); }

@keyframes tabWarp {
    from { opacity: 0; transform: translateY(16px) scale(0.995); filter: blur(4px); }
    to { opacity: 1; transform: translateY(0) scale(1); filter: blur(0); }
}

.page-header { margin-bottom: 28px; }
.page-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 6px;
    letter-spacing: -0.3px;
    background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
}

.page-header .header-badges {
    display: flex;
    gap: 8px;
    margin-top: 10px;
    flex-wrap: wrap;
}

/* ─── GRIDS ─── */
.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1280px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 1024px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }

/* ─── CARDS ─── */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(16px) saturate(1.1);
    -webkit-backdrop-filter: blur(16px) saturate(1.1);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 22px;
    transition: all var(--transition);
    box-shadow: var(--shadow-card);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 1px;
    background: linear-gradient(135deg, rgba(var(--accent-rgb), 0.15), transparent 40%, transparent 60%, rgba(var(--nebula-rgb), 0.1));
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition);
}

.card:hover {
    border-color: rgba(var(--accent-rgb), 0.2);
    box-shadow: var(--shadow-card), var(--shadow-glow);
    transform: translateY(-1px);
}

.card:hover::before { opacity: 1; }

.card-title {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-muted);
    margin-bottom: 14px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-title .ct-dot {
    width: 5px; height: 5px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 6px rgba(var(--accent-rgb), 0.4);
}

.card-value {
    font-size: 2rem;
    font-weight: 700;
    font-family: var(--font-mono);
    letter-spacing: -0.5px;
}

.card-unit {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-left: 4px;
}

/* ─── STAT CARDS ─── */
.stat-card { position: relative; overflow: hidden; }

.stat-card::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.stat-card.accent::after { background: linear-gradient(90deg, var(--accent), rgba(var(--quantum-rgb), 0.5)); }
.stat-card.mars::after { background: linear-gradient(90deg, var(--mars), rgba(255, 160, 80, 0.4)); }
.stat-card.success::after { background: linear-gradient(90deg, var(--success), rgba(var(--teal-dim), 0.4)); }
.stat-card.danger::after { background: linear-gradient(90deg, var(--danger), rgba(255, 120, 100, 0.4)); }
.stat-card.warning::after { background: linear-gradient(90deg, var(--warning), rgba(255, 200, 60, 0.4)); }
.stat-card.purple::after { background: linear-gradient(90deg, var(--purple), rgba(var(--nebula-rgb), 0.4)); }
.stat-card.quantum::after { background: linear-gradient(90deg, var(--quantum), rgba(var(--nebula-rgb), 0.5)); }
.stat-card.nebula::after { background: linear-gradient(90deg, var(--nebula), rgba(var(--quantum-rgb), 0.5)); }
.stat-card.teal::after { background: linear-gradient(90deg, var(--teal), rgba(var(--accent-rgb), 0.4)); }

/* ─── BADGES ─── */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.68rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: all var(--transition-fast);
}

.badge.success { background: var(--success-dim); color: var(--success); }
.badge.danger { background: var(--danger-dim); color: var(--danger); }
.badge.warning { background: var(--warning-dim); color: var(--warning); }
.badge.accent { background: var(--accent-dim); color: var(--accent); }
.badge.purple { background: var(--purple-dim); color: var(--purple); }
.badge.mars { background: var(--mars-dim); color: var(--mars); }
.badge.quantum { background: var(--quantum-dim); color: var(--quantum); }
.badge.nebula { background: var(--nebula-dim); color: var(--nebula); }
.badge.teal { background: var(--teal-dim); color: var(--teal); }

.badge-pulse { animation: quantumPulse 2s ease-in-out infinite; }

/* ─── FORMS ─── */
.form-group { margin-bottom: 16px; }

.form-group label {
    display: block;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-secondary);
    margin-bottom: 7px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 14px;
}

input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 11px 14px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    transition: all var(--transition);
}

input:hover, select:hover { border-color: var(--border-bright); }

input:focus, select:focus {
    outline: none;
    border-color: rgba(var(--accent-rgb), 0.5);
    box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.08), 0 0 24px rgba(var(--accent-rgb), 0.04);
}

input[type="range"] {
    width: 100%;
    accent-color: var(--accent);
    margin-top: 4px;
    height: 6px;
}

textarea {
    width: 100%;
    padding: 11px 14px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-family: var(--font);
    font-size: 0.9rem;
    line-height: 1.6;
    resize: vertical;
    transition: all var(--transition);
}

textarea:focus {
    outline: none;
    border-color: rgba(var(--accent-rgb), 0.5);
    box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.08);
}

/* ─── BUTTONS ─── */
.btn {
    padding: 11px 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-card-solid);
    color: var(--text-primary);
    font-family: var(--font);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    position: relative;
    overflow: hidden;
}

.btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.08), transparent);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.btn:hover {
    border-color: rgba(var(--accent-rgb), 0.35);
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
}

.btn:hover::after { opacity: 1; }
.btn:active { transform: translateY(0) scale(0.98); }

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #0099cc);
    color: #000;
    border-color: transparent;
    font-weight: 700;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #00e5ff, #00b8d9);
    box-shadow: 0 6px 28px rgba(var(--accent-rgb), 0.3);
}

.btn-mars {
    background: linear-gradient(135deg, var(--mars), #e05520);
    color: #fff;
    border-color: transparent;
    font-weight: 700;
}

.btn-mars:hover {
    background: linear-gradient(135deg, #ff7b45, var(--mars));
    box-shadow: 0 6px 28px rgba(var(--mars-rgb), 0.3);
}

.btn-quantum {
    background: linear-gradient(135deg, var(--quantum), #6340d0);
    color: #fff;
    border-color: transparent;
    font-weight: 700;
}

.btn-quantum:hover {
    background: linear-gradient(135deg, #9070ff, var(--quantum));
    box-shadow: 0 6px 28px rgba(var(--quantum-rgb), 0.3);
}

.btn-sm { padding: 7px 16px; font-size: 0.8rem; }
.btn-group { display: flex; gap: 10px; flex-wrap: wrap; }

/* ─── TABLES ─── */
.table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    max-height: 400px;
    overflow-y: auto;
}

table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }

th {
    text-align: left;
    padding: 12px 16px;
    background: rgba(var(--quantum-rgb), 0.04);
    color: var(--text-muted);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    font-weight: 700;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1;
    backdrop-filter: blur(8px);
}

td {
    padding: 11px 16px;
    border-bottom: 1px solid rgba(var(--quantum-rgb), 0.05);
    font-family: var(--font-mono);
    font-size: 0.8rem;
}

tbody tr { transition: background var(--transition-fast); }
tbody tr:hover td { background: rgba(var(--accent-rgb), 0.03); }

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 0;
    border-bottom: 1px solid rgba(var(--quantum-rgb), 0.05);
}

.result-row:last-child { border-bottom: none; }
.result-label { color: var(--text-secondary); font-size: 0.85rem; }
.result-value { font-family: var(--font-mono); font-weight: 600; font-size: 0.85rem; }

/* ─── CHARTS ─── */
.chart-container { position: relative; width: 100%; height: 320px; }
.chart-container canvas { width: 100% !important; height: 100% !important; }

/* ─── KEY DISPLAY (QKD) ─── */
.key-display {
    display: flex;
    flex-wrap: wrap;
    gap: 2px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    padding: 14px;
    background: var(--code-bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    max-height: 130px;
    overflow-y: auto;
}

.key-bit {
    width: 22px; height: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    font-weight: 700;
    font-size: 0.68rem;
    transition: transform var(--transition-fast);
}

.key-bit:hover { transform: scale(1.4); z-index: 1; }
.key-bit.match { background: var(--success-dim); color: var(--success); }
.key-bit.mismatch { background: var(--danger-dim); color: var(--danger); }

/* ─── ROUTE VISUALIZATION ─── */
.route-visual {
    display: flex;
    align-items: center;
    gap: 0;
    overflow-x: auto;
    padding: 24px 8px;
}

.route-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    min-width: 90px;
    transition: transform var(--transition);
}

.route-node:hover { transform: translateY(-4px); }

.route-node-dot {
    width: 48px; height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    border: 2px solid;
    transition: all var(--transition);
}

.route-node-dot.active { border-color: var(--accent); background: var(--accent-dim); color: var(--accent); box-shadow: 0 0 20px rgba(var(--accent-rgb), 0.2); }
.route-node-dot.store { border-color: var(--warning); background: var(--warning-dim); color: var(--warning); box-shadow: 0 0 20px rgba(var(--warning-rgb), 0.2); }
.route-node-dot.drop { border-color: var(--danger); background: var(--danger-dim); color: var(--danger); box-shadow: 0 0 20px rgba(var(--danger-rgb), 0.2); }
.route-node-dot.delivered {
    border-color: var(--success); background: var(--success-dim); color: var(--success);
    box-shadow: 0 0 20px rgba(var(--success-rgb), 0.3);
    animation: warpArrive 1.5s ease infinite;
}

@keyframes warpArrive {
    0%, 100% { box-shadow: 0 0 20px rgba(var(--success-rgb), 0.3); }
    50% { box-shadow: 0 0 32px rgba(var(--success-rgb), 0.6), 0 0 60px rgba(var(--success-rgb), 0.1); }
}

.route-node-label {
    font-size: 0.58rem;
    color: var(--text-secondary);
    text-align: center;
    max-width: 85px;
    word-wrap: break-word;
    line-height: 1.3;
}

.route-arrow {
    width: 50px;
    height: 2px;
    background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.05), rgba(var(--accent-rgb), 0.5));
    position: relative;
    flex-shrink: 0;
}

.route-arrow::after {
    content: '';
    position: absolute;
    right: -4px; top: -3px;
    width: 8px; height: 8px;
    border-right: 2px solid rgba(var(--accent-rgb), 0.6);
    border-top: 2px solid rgba(var(--accent-rgb), 0.6);
    transform: rotate(45deg);
}

.route-arrow.active {
    background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.05), rgba(var(--accent-rgb), 0.7));
}

/* ─── HERO SECTION ─── */
.hero-section {
    text-align: center;
    padding: 80px 36px 60px;
    background:
        radial-gradient(ellipse 80% 60% at 50% 40%, rgba(var(--quantum-rgb), 0.06), transparent),
        radial-gradient(ellipse 60% 50% at 30% 60%, rgba(var(--nebula-rgb), 0.04), transparent),
        radial-gradient(ellipse 60% 50% at 70% 30%, rgba(var(--accent-rgb), 0.05), transparent),
        var(--bg-glass);
    backdrop-filter: blur(20px) saturate(1.2);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    margin-bottom: 40px;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: -80%; left: -80%;
    width: 260%; height: 260%;
    background:
        radial-gradient(circle at 25% 35%, rgba(var(--quantum-rgb), 0.04), transparent 35%),
        radial-gradient(circle at 75% 65%, rgba(var(--nebula-rgb), 0.03), transparent 35%),
        radial-gradient(circle at 50% 50%, rgba(var(--accent-rgb), 0.02), transparent 50%);
    animation: nebulaRotate 30s linear infinite;
    pointer-events: none;
}

@keyframes nebulaRotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: 6px;
    background: linear-gradient(135deg, var(--cyan), var(--quantum), var(--nebula), var(--mars));
    background-size: 300% 300%;
    animation: nebulaShift 5s ease infinite;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 14px;
    position: relative;
    text-transform: uppercase;
}

.hero-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    max-width: 680px;
    margin: 0 auto;
    line-height: 1.7;
    position: relative;
}

.hero-badge-row {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 22px;
    flex-wrap: wrap;
    position: relative;
}

.hero-badge {
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 0.68rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    border: 1px solid;
    backdrop-filter: blur(8px);
    transition: all var(--transition-fast);
}

.hero-badge:hover { transform: translateY(-2px); }

.hb-accent { border-color: rgba(var(--accent-rgb), 0.3); color: var(--accent); background: rgba(var(--accent-rgb), 0.06); }
.hb-mars { border-color: rgba(var(--mars-rgb), 0.3); color: var(--mars); background: rgba(var(--mars-rgb), 0.06); }
.hb-quantum { border-color: rgba(var(--quantum-rgb), 0.3); color: var(--quantum); background: rgba(var(--quantum-rgb), 0.06); }
.hb-nebula { border-color: rgba(var(--nebula-rgb), 0.3); color: var(--nebula); background: rgba(var(--nebula-rgb), 0.06); }
.hb-success { border-color: rgba(var(--success-rgb), 0.3); color: var(--success); background: rgba(var(--success-rgb), 0.06); }

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin-top: 32px;
    position: relative;
    flex-wrap: wrap;
}

.hero-cta .btn { padding: 14px 32px; font-size: 0.95rem; border-radius: var(--radius-lg); }

/* ─── METRICS BAR ─── */
.metrics-bar {
    display: flex;
    justify-content: center;
    gap: 44px;
    margin-top: 36px;
    flex-wrap: wrap;
    position: relative;
}

.metric-item { text-align: center; }

.metric-value {
    font-size: 1.7rem;
    font-weight: 700;
    font-family: var(--font-mono);
    letter-spacing: -0.5px;
}

.metric-label {
    font-size: 0.6rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-top: 4px;
}

/* ─── SECTION TITLES ─── */
.section-title {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 18px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 10px;
    letter-spacing: -0.2px;
}

.section-icon {
    width: 28px; height: 28px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    background: var(--quantum-dim);
    color: var(--quantum);
    border: 1px solid rgba(var(--quantum-rgb), 0.15);
}

/* ─── TOPOLOGY CANVAS ─── */
.topology-canvas {
    width: 100%;
    height: 300px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--code-bg);
}

/* ─── TOAST NOTIFICATIONS ─── */
.toast-container {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
}

.toast {
    padding: 12px 20px;
    border-radius: var(--radius);
    font-size: 0.8rem;
    font-weight: 600;
    backdrop-filter: blur(16px);
    border: 1px solid;
    animation: toastIn 0.35s var(--ease-bounce), toastOut 0.35s ease 2.65s forwards;
    display: flex;
    align-items: center;
    gap: 8px;
    pointer-events: auto;
}

.toast-success { background: rgba(var(--success-rgb), 0.12); border-color: rgba(var(--success-rgb), 0.25); color: var(--success); }
.toast-info { background: rgba(var(--accent-rgb), 0.12); border-color: rgba(var(--accent-rgb), 0.25); color: var(--accent); }
.toast-error { background: rgba(var(--danger-rgb), 0.12); border-color: rgba(var(--danger-rgb), 0.25); color: var(--danger); }
.toast-quantum { background: rgba(var(--quantum-rgb), 0.12); border-color: rgba(var(--quantum-rgb), 0.25); color: var(--quantum); }

@keyframes toastIn { from { opacity: 0; transform: translateX(50px) scale(0.9); } to { opacity: 1; transform: translateX(0) scale(1); } }
@keyframes toastOut { from { opacity: 1; } to { opacity: 0; transform: translateY(-10px) scale(0.95); } }

/* ─── LIVE TICKER ─── */
.live-ticker {
    display: flex;
    gap: 28px;
    padding: 8px 0;
    margin-bottom: 20px;
    overflow-x: auto;
    scrollbar-width: none;
}

.live-ticker::-webkit-scrollbar { display: none; }

.ticker-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.72rem;
    color: var(--text-secondary);
    white-space: nowrap;
    font-family: var(--font-mono);
}

.ticker-dot {
    width: 5px; height: 5px;
    border-radius: 50%;
    animation: quantumPulse 2s ease-in-out infinite;
}

.mobile-toggle { display: none !important; }

/* ─── INFO BUBBLES ─── */
.info-bubble {
    display: flex;
    gap: 16px;
    padding: 20px;
    background: var(--info-bg);
    border: 1px solid var(--info-border);
    border-radius: 12px;
    margin: 16px 0;
}

.info-bubble-icon { font-size: 1.5rem; flex-shrink: 0; }
.info-bubble-title { font-weight: 600; margin-bottom: 4px; color: var(--text-primary); }
.info-bubble-text { color: var(--text-secondary); line-height: 1.6; }

/* ─── CALLOUTS ─── */
.callout { display: flex; gap: 12px; padding: 16px 20px; border-radius: 10px; margin: 16px 0; }
.callout-fact { background: var(--callout-bg); border-left: 4px solid var(--callout-border); }
.callout-tip { background: var(--success-bg); border-left: 4px solid var(--success-border); }
.callout-warning { background: rgba(var(--warning-rgb), 0.08); border-left: 4px solid rgba(var(--warning-rgb), 0.3); }
.callout-danger { background: rgba(var(--danger-rgb), 0.08); border-left: 4px solid rgba(var(--danger-rgb), 0.3); }
.callout-icon { font-size: 1.3rem; flex-shrink: 0; }
.callout-text { color: var(--text-secondary); line-height: 1.6; }
.callout-title { font-weight: 600; color: var(--text-primary); margin-bottom: 2px; }

/* ─── STEP CARDS ─── */
.steps-container { max-width: 800px; margin: 0 auto; }

.step-card {
    display: flex;
    gap: 24px;
    margin: 32px 0;
    padding: 24px;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.step-card:hover {
    border-color: var(--border-bright);
    box-shadow: var(--shadow);
}

.step-number {
    width: 48px; height: 48px;
    border-radius: 50%;
    background: var(--accent);
    color: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.step-content { flex: 1; }
.step-content h3 { margin-bottom: 6px; }
.step-content p { color: var(--text-secondary); line-height: 1.6; }

/* ─── FEATURE CARDS ─── */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 32px 0;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 28px;
    transition: all 0.3s ease;
}

.feature-card:hover {
    border-color: var(--border-bright);
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.feature-card-icon { font-size: 2rem; margin-bottom: 12px; }
.feature-card h3 { margin-bottom: 8px; }
.feature-card p { color: var(--text-secondary); line-height: 1.6; }

/* ─── EMPTY STATE ─── */
.empty-state {
    text-align: center;
    padding: 48px;
    color: var(--text-muted);
}

.empty-state .icon { font-size: 2.5rem; margin-bottom: 12px; opacity: 0.4; }

/* ─── ANIMATIONS ─── */
.animate-in {
    opacity: 0;
    transform: translateY(16px);
    animation: slideUp 0.5s var(--ease-out) forwards;
}

@keyframes slideUp { to { opacity: 1; transform: translateY(0); } }

.stagger-1 { animation-delay: 0.05s; }
.stagger-2 { animation-delay: 0.1s; }
.stagger-3 { animation-delay: 0.15s; }
.stagger-4 { animation-delay: 0.2s; }
.stagger-5 { animation-delay: 0.25s; }
.stagger-6 { animation-delay: 0.3s; }

/* ─── QUANTUM GRID BACKGROUND ─── */
.quantum-grid-bg {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(var(--quantum-rgb), 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(var(--quantum-rgb), 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    mask-image: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.5), transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.5), transparent 70%);
}

/* ─── PROTOCOL STEPS ─── */
.protocol-steps { position: relative; }

.protocol-step {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 10px 0;
    position: relative;
}

.protocol-step::before {
    content: '';
    position: absolute;
    left: 16px;
    top: 38px;
    bottom: -10px;
    width: 2px;
    background: linear-gradient(180deg, rgba(var(--quantum-rgb), 0.3), rgba(var(--quantum-rgb), 0.05));
}

.protocol-step:last-child::before { display: none; }

.protocol-step-num {
    width: 34px; height: 34px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 700;
    flex-shrink: 0;
    border: 2px solid rgba(var(--quantum-rgb), 0.4);
    color: var(--quantum);
    background: var(--quantum-dim);
}

.protocol-step-content { flex: 1; padding-top: 5px; }
.protocol-step-title { font-weight: 600; font-size: 0.85rem; margin-bottom: 2px; }
.protocol-step-desc { font-size: 0.75rem; color: var(--text-secondary); line-height: 1.5; }

/* ─── LINK BUDGET BAR ─── */
.link-budget-bar {
    display: flex;
    height: 26px;
    border-radius: 8px;
    overflow: hidden;
    margin: 14px 0;
    background: var(--code-bg);
    border: 1px solid var(--border);
}

.lb-bar-segment {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.6rem;
    font-weight: 700;
    font-family: var(--font-mono);
    transition: width 0.6s var(--ease-out);
    min-width: 0;
    overflow: hidden;
    white-space: nowrap;
}

/* ─── PRESENTATION MODE ─── */
body.pres-active { overflow: hidden; }
body.pres-active .sidebar { display: none !important; }
body.pres-active .topnav { display: none !important; }
body.pres-active body { padding-top: 0; }
body.pres-active .main-content {
    margin-left: 0 !important;
    padding: 0 !important;
    width: 100% !important;
    max-width: 100% !important;
}
body.pres-active .live-ticker { display: none !important; }
body.pres-active .mobile-toggle { display: none !important; }
body.pres-active #cosmos-canvas {
    opacity: 0.6;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 0;
    pointer-events: none;
}
body.pres-active .presentation-mode {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 50;
    display: flex;
    flex-direction: column;
}

.pres-overlay {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    z-index: 1;
}

.pres-progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: rgba(255, 255, 255, 0.05);
    z-index: 200;
}

.pres-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--quantum), var(--nebula));
    transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 0 2px 2px 0;
    box-shadow: 0 0 16px rgba(var(--accent-rgb), 0.5), 0 0 40px rgba(var(--quantum-rgb), 0.2);
}

 .pres-slide-container {
     flex: 1;
     display: flex;
     align-items: center;
     justify-content: center;
     padding: 36px 48px 120px;
     max-width: 1440px;
     margin: 0 auto;
     width: 100%;
     overflow-y: auto;
     overscroll-behavior: contain;
 }

.pres-slide {
    width: 100%;
    color: var(--text-primary);
    animation: presSlideIn 0.7s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
}

@keyframes presSlideIn {
    0% { opacity: 0; transform: translateY(40px) scale(0.97); filter: blur(6px); }
    100% { opacity: 1; transform: translateY(0) scale(1); filter: blur(0); }
}

.pres-slide-title { display: none; }

.pres-slide-body h2 {
    font-size: 1.65rem;
    margin-bottom: 24px;
    color: var(--text-primary);
    font-weight: 700;
    letter-spacing: 0.5px;
}

.pres-slide-body h2 .pres-tag {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    padding: 3px 10px;
    border-radius: 20px;
    margin-right: 10px;
    vertical-align: middle;
    background: rgba(var(--accent-rgb), 0.15);
    color: var(--accent);
    border: 1px solid rgba(var(--accent-rgb), 0.3);
}

.pres-slide-body h2 .pres-tag.mars { background: rgba(var(--mars-rgb), 0.15); color: var(--mars); border-color: rgba(var(--mars-rgb), 0.3); }
.pres-slide-body h2 .pres-tag.quantum { background: rgba(var(--quantum-rgb), 0.15); color: var(--quantum); border-color: rgba(var(--quantum-rgb), 0.3); }
.pres-slide-body h2 .pres-tag.success { background: rgba(var(--success-rgb), 0.15); color: var(--success); border-color: rgba(var(--success-rgb), 0.3); }
.pres-slide-body h2 .pres-tag.live { background: rgba(var(--danger-rgb), 0.15); color: var(--danger); border-color: rgba(var(--danger-rgb), 0.3); animation: presPulse 2s infinite; }

.pres-slide-links {
    position: absolute;
    top: 8px;
    right: 8px;
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    justify-content: flex-end;
    max-width: 55%;
    z-index: 10;
}

.pres-link-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.6rem;
    font-weight: 600;
    letter-spacing: 0.8px;
    text-transform: uppercase;
    text-decoration: none;
    padding: 4px 10px;
    border-radius: 16px;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.pres-link-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.pres-link-ref {
    background: rgba(var(--accent-rgb), 0.08);
    color: var(--accent);
    border: 1px solid rgba(var(--accent-rgb), 0.2);
}
.pres-link-ref:hover {
    background: rgba(var(--accent-rgb), 0.15);
    border-color: rgba(var(--accent-rgb), 0.4);
}

.pres-link-demo {
    background: rgba(var(--success-rgb), 0.12);
    color: var(--success);
    border: 1px solid rgba(var(--success-rgb), 0.25);
}
.pres-link-demo:hover {
    background: rgba(var(--success-rgb), 0.2);
    border-color: rgba(var(--success-rgb), 0.45);
}

.pres-link-learn {
    background: rgba(var(--quantum-rgb), 0.08);
    color: var(--quantum);
    border: 1px solid rgba(var(--quantum-rgb), 0.2);
}
.pres-link-learn:hover {
    background: rgba(var(--quantum-rgb), 0.15);
    border-color: rgba(var(--quantum-rgb), 0.4);
}

@keyframes presPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

.pres-hero { text-align: center; padding: 20px 0; }
.pres-hero-title {
    font-size: 5rem;
    font-weight: 900;
    font-family: var(--font-mono);
    letter-spacing: 12px;
    background: linear-gradient(135deg, var(--accent), var(--quantum), var(--nebula), var(--accent));
    background-size: 300% 300%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 20px;
    animation: presGradient 8s ease infinite;
    text-shadow: none;
}

@keyframes presGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.pres-hero-sub {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 720px;
    margin: 0 auto 36px;
    line-height: 1.7;
}

.pres-hero-meta { display: flex; flex-direction: column; gap: 8px; margin-bottom: 28px; }
.pres-meta-item { color: var(--text-muted); font-size: 0.9rem; letter-spacing: 0.5px; }
.pres-hero-links { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.pres-link {
    color: var(--accent);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    padding: 6px 16px;
    border: 1px solid rgba(var(--accent-rgb), 0.3);
    border-radius: var(--radius-md);
    transition: all 0.3s;
}

.pres-link:hover {
    background: rgba(var(--accent-rgb), 0.1);
    box-shadow: 0 0 20px rgba(var(--accent-rgb), 0.15);
}

/* Inline reference links (inside lists/cards/callouts) — subtle underline, not a pill */
.pres-list .pres-link,
.pres-card .pres-link,
.pres-callout .pres-link {
    display: inline;
    font-family: inherit;
    font-size: inherit;
    padding: 0;
    border: none;
    border-bottom: 1px solid rgba(var(--accent-rgb), 0.3);
    border-radius: 0;
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s, border-color 0.2s;
}
.pres-list .pres-link:hover,
.pres-card .pres-link:hover,
.pres-callout .pres-link:hover {
    background: transparent;
    box-shadow: none;
    color: #66e6ff;
    border-bottom-color: #66e6ff;
}

/* Showcase #references clickable rows */
.ref-link {
    color: var(--text-secondary);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    transition: color 0.2s ease, border-color 0.2s ease;
}
.ref-link:hover {
    color: var(--accent-cyan, #00d4ff);
    border-bottom-color: var(--accent-cyan, #00d4ff);
}
.ref-link code { color: inherit; }

.pres-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.pres-grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; }
.pres-grid-4 { display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: 20px; }

.pres-card {
    background: rgba(13, 21, 37, 0.7);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    padding: 20px;
    backdrop-filter: blur(8px);
    transition: border-color 0.3s, box-shadow 0.3s;
}

.pres-card:hover {
    border-color: rgba(var(--accent-rgb), 0.2);
    box-shadow: 0 4px 32px rgba(0, 0, 0, 0.3);
}

.pres-card-title {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--accent);
    margin-bottom: 14px;
}

.pres-card-danger { border-color: rgba(248, 81, 73, 0.2); }
.pres-card-accent { border-color: rgba(var(--accent-rgb), 0.2); }
.pres-card-quantum { border-color: rgba(var(--quantum-rgb), 0.2); }
.pres-card-glow {
    border-color: rgba(var(--accent-rgb), 0.15);
    box-shadow: 0 0 40px rgba(var(--accent-rgb), 0.05), inset 0 0 40px rgba(var(--accent-rgb), 0.02);
}

.pres-table { width: 100%; border-collapse: collapse; font-size: 0.82rem; }
.pres-table th {
    text-align: left;
    padding: 10px 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
}
.pres-table td {
    padding: 8px 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.04);
    color: var(--text-secondary);
}
.pres-table-wide { overflow-x: auto; }

.pres-list { margin: 0; padding-left: 18px; color: var(--text-secondary); font-size: 0.85rem; line-height: 1.8; }
.pres-list li { margin-bottom: 4px; }

.pres-code {
    background: rgba(var(--quantum-rgb), 0.06);
    border: 1px solid rgba(var(--quantum-rgb), 0.12);
    border-radius: var(--radius-md);
    padding: 14px 18px;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    color: var(--quantum);
    line-height: 1.7;
}

.pres-callout {
    background: rgba(var(--accent-rgb), 0.04);
    border: 1px solid rgba(var(--accent-rgb), 0.12);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
    line-height: 1.6;
}

.pres-callout-accent { border-color: rgba(var(--accent-rgb), 0.2); }
.pres-callout-quantum { border-color: rgba(var(--quantum-rgb), 0.2); }

.pres-stat-card {
    background: rgba(13, 21, 37, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 12px;
    padding: 24px 18px;
    text-align: center;
    backdrop-filter: blur(8px);
}

.pres-stat-value {
    font-size: 2.2rem;
    font-weight: 800;
    font-family: var(--font-mono);
    letter-spacing: 1px;
}

.pres-stat-unit {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-top: 6px;
}

.pres-stat-sub { font-size: 0.7rem; color: var(--text-muted); margin-top: 4px; }

.pres-highlight-good { color: var(--success) !important; font-weight: 700; }

.pres-diagram-detail {
    margin-top: 16px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--radius-md);
    background: rgba(13, 21, 37, 0.4);
    backdrop-filter: blur(8px);
    overflow: hidden;
}

.pres-diagram-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    list-style: none;
    transition: color 0.2s, background 0.2s;
    user-select: none;
}

.pres-diagram-toggle:hover {
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.06);
}

.pres-diagram-toggle::before {
    content: '\25B6';
    font-size: 0.55rem;
    transition: transform 0.2s;
}

.pres-diagram-detail[open] > .pres-diagram-toggle::before {
    transform: rotate(90deg);
}

.pres-diagram-detail[open] > .pres-diagram-toggle {
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.pres-diagram-detail > div {
    padding: 12px;
}

.pres-diagram-img {
    background: rgba(5, 10, 20, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--radius-lg);
    padding: 16px;
    overflow: hidden;
    backdrop-filter: blur(8px);
}

.pres-stack { display: flex; flex-direction: column; gap: 6px; }
.pres-stack-layer {
    padding: 12px 18px;
    border: 1px solid;
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    text-align: center;
    backdrop-filter: blur(4px);
}

.pres-tiers { display: flex; flex-direction: column; gap: 10px; }
.pres-tier { display: flex; align-items: center; gap: 16px; }
.pres-tier-badge {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.8rem;
    color: var(--bg-primary);
    flex-shrink: 0;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.pres-tier-content { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.5; }

.pres-demo-badge {
    text-align: center;
    margin-top: 20px;
    padding: 12px;
    background: rgba(var(--accent-rgb), 0.06);
    border: 1px dashed rgba(var(--accent-rgb), 0.25);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
}

.pres-route-hops {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 6px;
    padding: 20px 0;
}

.pres-hop { text-align: center; }

.pres-hop-num {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(var(--accent-rgb), 0.12);
    border: 2px solid var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.8rem;
    color: var(--accent);
    margin: 0 auto 6px;
    box-shadow: 0 0 12px rgba(var(--accent-rgb), 0.2);
}

.pres-hop-label { font-size: 0.72rem; color: var(--text-secondary); }
.pres-hop-label span { font-size: 0.62rem; color: var(--text-muted); display: block; }
.pres-hop-arrow { color: var(--text-muted); font-size: 0.8rem; }

.pres-comparison {
    text-align: center;
    padding: 16px;
    background: rgba(var(--success-rgb), 0.04);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    color: var(--text-secondary);
    border: 1px solid rgba(var(--success-rgb), 0.12);
}

.pres-conclusion { text-align: center; padding: 20px 0; }
.pres-contact { margin-top: 16px; color: var(--text-secondary); font-size: 0.9rem; }
.pres-contact div { margin-bottom: 6px; }

.pres-controls {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 28px;
    background: rgba(5, 10, 20, 0.9);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    z-index: 200;
}

.pres-controls-left, .pres-controls-right { display: flex; align-items: center; gap: 14px; }

.pres-btn {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    padding: 7px 16px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.8rem;
    font-family: inherit;
    transition: all 0.3s;
}

.pres-btn:hover {
    background: rgba(var(--accent-rgb), 0.1);
    color: var(--accent);
    border-color: rgba(var(--accent-rgb), 0.3);
    box-shadow: 0 0 16px rgba(var(--accent-rgb), 0.1);
}
.pres-counter { font-family: var(--font-mono); font-size: 0.8rem; color: var(--text-muted); letter-spacing: 1px; }
.pres-timer { font-family: var(--font-mono); font-size: 0.8rem; color: var(--quantum); }
.pres-mode-toggle {
    display: inline-flex;
    border-radius: 6px;
    overflow: hidden;
    border: 1px solid rgba(0,212,255,0.2);
}
.pres-mode-btn {
    padding: 4px 12px;
    font-size: 0.72rem;
    font-weight: 600;
    background: transparent;
    color: var(--text-muted);
    border: none;
    cursor: pointer;
    font-family: inherit;
    transition: all 0.2s;
}
.pres-mode-btn.active {
    background: rgba(0,212,255,0.15);
    color: #00d4ff;
}
.pres-mode-btn:hover {
    background: rgba(0,212,255,0.08);
    color: var(--text-primary);
}

.pres-shortcuts {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(13, 21, 37, 0.95);
    border: 1px solid rgba(var(--accent-rgb), 0.2);
    border-radius: var(--radius-lg);
    padding: 28px 36px;
    z-index: 300;
    backdrop-filter: blur(20px);
    min-width: 340px;
    box-shadow: 0 8px 48px rgba(0, 0, 0, 0.5);
}

.pres-shortcuts-title { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 2px; color: var(--accent); margin-bottom: 18px; text-align: center; }

.pres-shortcuts-grid {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 8px 18px;
    font-size: 0.85rem;
}

.pres-shortcuts-grid span:nth-child(odd) { font-family: var(--font-mono); color: var(--accent); font-weight: 600; text-align: right; }
.pres-shortcuts-grid span:nth-child(even) { color: var(--text-secondary); }

 .pres-speaker-notes, .pres-full-script {
     position: fixed;
     bottom: 56px;
     left: 50%;
     transform: translateX(-50%);
     background: rgba(10, 16, 30, 0.97);
     border: 1px solid rgba(var(--quantum-rgb), 0.2);
     border-radius: var(--radius-lg);
     padding: 14px 20px;
     max-width: 700px;
     width: 90%;
     max-height: 35vh;
     overflow-y: auto;
     z-index: 500;
     backdrop-filter: blur(24px);
     box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6);
 }

 .pres-full-script {
     max-width: 850px;
     border-color: rgba(210, 153, 34, 0.3);
 }

.pres-notes-title { font-size: 0.65rem; font-weight: 700; color: var(--quantum); text-transform: uppercase; letter-spacing: 2px; margin-bottom: 8px; }
.pres-notes-text { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.7; }

.pres-divider {
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, var(--accent), var(--quantum));
    border-radius: 2px;
    margin: 20px auto;
    opacity: 0.5;
}

.pres-quote {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-style: italic;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.7;
    opacity: 0.8;
}

.pres-emoji {
    font-size: 2rem;
    display: block;
    margin-bottom: 12px;
}

.pres-pill {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    padding: 3px 10px;
    border-radius: 20px;
    margin-right: 6px;
    vertical-align: middle;
}
.pres-pill.accent { background: rgba(var(--accent-rgb), 0.12); color: var(--accent); }
.pres-pill.quantum { background: rgba(var(--quantum-rgb), 0.12); color: var(--quantum); }
.pres-pill.mars { background: rgba(var(--mars-rgb), 0.12); color: var(--mars); }
.pres-pill.success { background: rgba(var(--success-rgb), 0.12); color: var(--success); }
.pres-pill.warning { background: rgba(var(--warning-rgb), 0.12); color: var(--warning); }

.pres-flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    flex-wrap: wrap;
    padding: 12px 0;
}

.pres-flow-step {
    text-align: center;
    padding: 10px 14px;
    background: rgba(var(--accent-rgb), 0.06);
    border: 1px solid rgba(var(--accent-rgb), 0.15);
    border-radius: var(--radius-md);
    min-width: 80px;
}

.pres-flow-step-icon {
    font-size: 1.2rem;
    display: block;
    margin-bottom: 4px;
}

.pres-flow-step-text {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.pres-flow-arrow {
    color: var(--text-muted);
    font-size: 0.7rem;
}

.pres-timeline {
    display: flex;
    flex-direction: column;
    gap: 0;
    position: relative;
    padding-left: 28px;
}

.pres-timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--accent), var(--quantum), var(--nebula));
    opacity: 0.3;
}

.pres-timeline-item {
    position: relative;
    padding: 10px 0 10px 20px;
}

.pres-timeline-dot {
    position: absolute;
    left: -24px;
    top: 14px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 2px solid var(--accent);
}

.pres-timeline-title {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.pres-timeline-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* ─── STUDY RESOURCES ─── */
.study-resource-list { display: flex; flex-direction: column; gap: 6px; }

.study-resource-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all 0.2s;
    cursor: pointer;
}

.study-resource-item:hover {
    background: rgba(var(--accent-rgb), 0.06);
    border-color: rgba(var(--accent-rgb), 0.15);
}

.study-resource-badge {
    font-size: 0.6rem;
    font-weight: 700;
    padding: 2px 7px;
    border-radius: 3px;
    border: 1px solid;
    white-space: nowrap;
    font-family: var(--font-mono);
    letter-spacing: 0.5px;
}

.study-resource-type {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    min-width: 50px;
}

.study-resource-title {
    flex: 1;
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.study-resource-item:hover .study-resource-title { color: var(--accent); }

.study-resource-arrow {
    color: var(--text-muted);
    font-size: 0.8rem;
    opacity: 0.5;
    transition: opacity 0.2s;
}

.study-resource-item:hover .study-resource-arrow { opacity: 1; color: var(--accent); }

.study-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 12px;
}

.study-tool-card {
    display: block;
    padding: 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    text-decoration: none;
    transition: all 0.2s;
}

.study-tool-card:hover {
    background: rgba(var(--accent-rgb), 0.06);
    border-color: rgba(var(--accent-rgb), 0.2);
    transform: translateY(-2px);
}

.study-tool-name { font-weight: 600; font-size: 0.9rem; color: var(--text-primary); margin-bottom: 4px; }
.study-tool-purpose { font-size: 0.78rem; color: var(--text-muted); }

.study-refs-list { display: flex; flex-direction: column; gap: 6px; }

.study-ref-item {
    font-size: 0.82rem;
    color: var(--text-secondary);
    padding: 8px 12px;
    background: var(--input-bg);
    border-left: 3px solid rgba(var(--accent-rgb), 0.3);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    line-height: 1.5;
}

/* ─── RESPONSIVE ─── */
@media (max-width: 768px) {
    .topnav-center { display: none; }
    .topnav-hamburger { display: flex; }
    .topnav-right .theme-toggle { display: none; }

    body { padding-top: 60px; }
    .main-content { margin-left: 0; padding: 20px 14px; padding-top: 16px; }
    .main-content.no-sidebar { padding: 20px 14px; }

    .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
    .hero-title { font-size: 1.8rem !important; letter-spacing: 2px !important; }
    .metrics-bar { gap: 20px !important; }
    .card-value { font-size: 1.4rem; }

    .feature-grid { grid-template-columns: 1fr !important; }
    .step-card { flex-direction: column; gap: 16px; }
    .info-bubble { flex-direction: column; gap: 10px; }
    .callout { gap: 8px; }

    .hero-cta { flex-direction: column; align-items: center; }
    .hero-cta .btn { width: 100%; justify-content: center; }
}

@media (max-width: 900px) {
    .pres-grid-2, .pres-grid-3, .pres-grid-4 { grid-template-columns: 1fr; }
    .pres-hero-title { font-size: 2.5rem; letter-spacing: 6px; }
    .pres-slide-container { padding: 30px 20px 80px; }
    .pres-route-hops { gap: 2px; }
    .pres-flow { gap: 4px; }
    .pres-flow-step { min-width: 60px; padding: 8px 8px; }
    .pres-slide-links { max-width: 70%; top: 4px; right: 4px; }
    .pres-link-btn { font-size: 0.55rem; padding: 3px 7px; }
    .study-tools-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
    html { font-size: 15px; }
    .hero-title { font-size: 1.5rem !important; letter-spacing: 1px !important; }
    .hero-section { padding: 40px 20px 30px; }
    .btn { padding: 10px 18px; font-size: 0.82rem; }
}

/* ─── MOCK DASHBOARD VISUALS ─── */
.mock-browser {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-primary);
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
}
.mock-browser-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}
.mock-browser-dot {
  width: 10px; height: 10px; border-radius: 50%;
}
.mock-browser-dot.r { background: #ef4444; }
.mock-browser-dot.y { background: #f59e0b; }
.mock-browser-dot.g { background: #10b981; }
.mock-browser-url {
  flex: 1;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}
.mock-browser-body {
  padding: 16px;
  min-height: 120px;
}

.mock-layout {
  display: grid;
  grid-template-columns: 180px 1fr;
  min-height: 320px;
  font-size: 0.8rem;
}
.mock-sidebar {
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  padding: 12px 8px;
}
.mock-sidebar-brand {
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 1.5px;
  color: var(--accent);
  padding: 8px 4px 12px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
}
.mock-sidebar-item {
  padding: 6px 8px;
  border-radius: 6px;
  color: var(--text-secondary);
  margin-bottom: 2px;
  font-size: 0.78rem;
  cursor: default;
}
.mock-sidebar-item.active {
  background: rgba(59,130,246,0.12);
  color: var(--accent);
}
.mock-main { padding: 16px; overflow: hidden; }

.mock-stat {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
}
.mock-stat-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 4px;
}
.mock-stat-value {
  font-size: 1.2rem;
  font-weight: 700;
  font-family: var(--font-mono);
}

.mock-terminal {
  background: #0d1321;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.7;
  white-space: pre;
  overflow-x: auto;
  color: #94a3b8;
}
.mock-terminal .t-green { color: #10b981; }
.mock-terminal .t-red { color: #ef4444; }
.mock-terminal .t-yellow { color: #f59e0b; }
.mock-terminal .t-blue { color: #3b82f6; }
.mock-terminal .t-cyan { color: #06b6d4; }
.mock-terminal .t-muted { color: #64748b; }
.mock-terminal .t-bold { font-weight: 700; }

.mock-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.mock-grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; }
.mock-grid-4 { display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: 8px; }
.mock-table { width: 100%; border-collapse: collapse; font-size: 0.75rem; }
.mock-table th { text-align: left; padding: 6px 8px; color: var(--text-muted); font-size: 0.65rem; text-transform: uppercase; letter-spacing: 0.5px; border-bottom: 1px solid var(--border); }
.mock-table td { padding: 6px 8px; color: var(--text-secondary); font-family: var(--font-mono); border-bottom: 1px solid var(--border); }
.mock-page-title { font-size: 1.1rem; font-weight: 600; margin-bottom: 4px; }
.mock-page-sub { font-size: 0.75rem; color: var(--text-muted); margin-bottom: 14px; }
.mock-card-sm {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  margin-bottom: 8px;
}
.mock-card-title { font-size: 0.8rem; font-weight: 600; margin-bottom: 6px; }
.mock-badge {
  display: inline-block;
  padding: 1px 6px;
  border-radius: 999px;
  font-size: 0.6rem;
  font-weight: 600;
}
.mock-badge-green { background: rgba(16,185,129,0.15); color: #10b981; }
.mock-badge-blue { background: rgba(59,130,246,0.15); color: #3b82f6; }
.mock-badge-yellow { background: rgba(245,158,11,0.15); color: #f59e0b; }
.mock-badge-red { background: rgba(239,68,68,0.15); color: #ef4444; }
.mock-bar-chart {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 60px;
}
.mock-bar {
  flex: 1;
  border-radius: 2px 2px 0 0;
  min-width: 3px;
}
.mock-input {
  background: #0d1321;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 8px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  width: 100%;
}
.mock-select {
  background: #0d1321;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 8px;
  color: var(--text-secondary);
  font-size: 0.72rem;
}
.mock-btn {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 6px;
  font-size: 0.7rem;
  font-weight: 500;
}
.mock-btn-primary { background: var(--accent); color: #fff; }
.mock-btn-secondary { background: transparent; border: 1px solid var(--border); color: var(--text-secondary); }

/* ─── UTILITY CLASSES ─── */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-accent { color: var(--accent); }
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }
.p-1 { padding: 8px; }
.p-2 { padding: 16px; }
.p-3 { padding: 24px; }
.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }
.gap-3 { gap: 24px; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.w-full { width: 100%; }
.hidden { display: none; }
.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* ========== QUIZ ENGINE ========== */

.quiz-welcome-hero {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 28px;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-card);
}

.quiz-welcome-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 24px;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.quiz-hero-right {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
    min-width: 260px;
}

.quiz-stat-strip .stat-card {
    padding: 16px;
    text-align: center;
}

/* XP Bar */
.quiz-xp-bar-container {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
}

.quiz-xp-level-badge {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--quantum);
    white-space: nowrap;
    letter-spacing: 0.5px;
}

.quiz-xp-bar-track {
    flex: 1;
    height: 8px;
    background: rgba(124, 92, 247, 0.12);
    border-radius: 4px;
    overflow: hidden;
}

.quiz-xp-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--quantum), var(--nebula));
    border-radius: 4px;
    transition: width 0.6s var(--ease-out);
}

.quiz-xp-text {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
    white-space: nowrap;
}

/* Streak Badge */
.quiz-streak-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(255, 107, 53, 0.12);
    border: 1px solid rgba(255, 107, 53, 0.3);
    border-radius: 20px;
    padding: 6px 14px;
    font-weight: 700;
}

.quiz-streak-fire {
    font-size: 1.1rem;
}

.quiz-streak-count {
    font-size: 1.1rem;
    color: var(--mars);
    font-family: var(--font-mono);
}

.quiz-streak-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Mode Cards Grid */
.quiz-mode-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}

@media (max-width: 1280px) {
    .quiz-mode-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .quiz-mode-grid { grid-template-columns: 1fr; }
    .quiz-welcome-top { flex-direction: column; }
    .quiz-hero-right { align-items: flex-start; width: 100%; }
}

.quiz-mode-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.quiz-mode-header {
    display: flex;
    align-items: center;
    gap: 10px;
}

.quiz-mode-header h3 {
    margin: 0;
    font-size: 1.1rem;
}

.quiz-mode-body {
    margin-top: auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Question Card */
.quiz-question-card {
    max-width: 800px;
    margin: 0 auto;
    animation: quizSlideIn 0.35s var(--ease-out) forwards;
}

@keyframes quizSlideIn {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.quiz-question-meta {
    display: flex;
    gap: 6px;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.quiz-question-number {
    margin-left: auto;
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.quiz-question-text {
    font-size: 1.2rem;
    line-height: 1.6;
    margin-bottom: 1.25rem;
}

/* Options */
.quiz-options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

@media (max-width: 640px) {
    .quiz-options-grid { grid-template-columns: 1fr; }
}

.quiz-option-btn {
    text-align: left;
    padding: 14px 18px;
    min-height: 56px;
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-card-solid);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s var(--ease);
    font-size: 0.95rem;
    color: var(--text-primary);
    position: relative;
}

.quiz-option-btn:hover:not(:disabled) {
    border-color: var(--accent);
    background: rgba(0, 212, 255, 0.06);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(0, 212, 255, 0.1);
}

.quiz-option-btn:active:not(:disabled) {
    transform: scale(0.98);
}

.quiz-option-key {
    font-weight: 700;
    color: var(--accent);
    min-width: 24px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
}

.quiz-option-btn.quiz-option-correct {
    background: rgba(63, 185, 80, 0.12);
    border-color: #3fb950;
    box-shadow: 0 0 20px rgba(63, 185, 80, 0.1);
}

.quiz-option-btn.quiz-option-wrong {
    background: rgba(248, 81, 73, 0.12);
    border-color: #f85149;
    box-shadow: 0 0 20px rgba(248, 81, 73, 0.1);
}

.quiz-option-btn.quiz-option-disabled {
    cursor: default;
    opacity: 0.6;
}

.quiz-option-btn.quiz-option-correct.quiz-option-disabled {
    opacity: 1;
}

/* True/False Grid */
.quiz-tf-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    max-width: 500px;
}

.quiz-tf-btn {
    padding: 18px;
    font-size: 1.15rem;
    font-weight: 700;
    justify-content: center;
}

/* Numeric Input */
.quiz-numeric-input-group {
    display: flex;
    gap: 10px;
    max-width: 350px;
    margin-top: 0.5rem;
}

.quiz-numeric-field {
    font-size: 1.1rem;
    padding: 12px 16px;
    font-family: var(--font-mono);
}

.quiz-input-correct { border-color: #3fb950 !important; color: #3fb950 !important; }
.quiz-input-wrong { border-color: #f85149 !important; color: #f85149 !important; }

/* Feedback */
.quiz-feedback {
    border-radius: var(--radius);
    padding: 16px;
    border-left: 4px solid;
}

.quiz-feedback-correct {
    background: rgba(63, 185, 80, 0.06);
    border-color: #3fb950;
}

.quiz-feedback-wrong {
    background: rgba(248, 81, 73, 0.06);
    border-color: #f85149;
}

.quiz-feedback-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.quiz-feedback-icon {
    font-size: 1.2rem;
}

.quiz-xp-gain {
    margin-left: auto;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--quantum);
    background: rgba(124, 92, 247, 0.12);
    padding: 2px 10px;
    border-radius: 12px;
    animation: quizXpPop 0.4s var(--ease-bounce);
}

@keyframes quizXpPop {
    0% { transform: scale(0.5); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

.quiz-feedback-body {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.quiz-correct-answer {
    margin-top: 8px;
    padding: 6px 12px;
    background: rgba(63, 185, 80, 0.08);
    border-radius: 6px;
    font-weight: 600;
    color: #3fb950;
    font-size: 0.9rem;
}

.quiz-keyboard-hint {
    margin-top: 6px;
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
}

/* Progress Bar */
.quiz-progress-bar-container {
    margin-top: 0.5rem;
}

.quiz-progress-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    font-weight: 600;
}

.quiz-progress-bar-track {
    height: 6px;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 3px;
    overflow: hidden;
}

.quiz-progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--quantum));
    border-radius: 3px;
    transition: width 0.4s var(--ease-out);
}

/* Timer Badge */
.quiz-timer-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border: 1px solid;
    border-radius: 8px;
    font-weight: 700;
    font-size: 1rem;
    font-family: var(--font-mono);
    margin-bottom: 0.5rem;
}

/* Live Streak */
.quiz-live-streak {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--mars);
    margin-left: 12px;
    animation: quizStreakPulse 1.5s ease-in-out infinite;
}

@keyframes quizStreakPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.6; }
}

/* Progress Ring */
.quiz-progress-ring {
    transition: stroke-dashoffset 0.8s var(--ease-out);
}

.quiz-ring-label {
    pointer-events: none;
}

/* Results Card */
.quiz-results-card {
    text-align: center;
}

.quiz-results-header {
    margin-bottom: 1.5rem;
}

.quiz-results-grade {
    margin-top: 0.5rem;
}

.quiz-results-pct {
    font-size: 3.5rem;
    font-weight: 800;
    font-family: var(--font-mono);
    line-height: 1;
}

.quiz-results-grade-label {
    font-size: 1.1rem;
    margin-top: 4px;
}

.quiz-results-score-grid {
    display: flex;
    align-items: center;
    gap: 32px;
    justify-content: center;
    margin: 1.5rem 0;
    text-align: left;
}

.quiz-results-ring {
    flex-shrink: 0;
}

.quiz-results-stats {
    flex: 1;
    max-width: 400px;
}

.quiz-result-stat {
    text-align: center;
    padding: 8px;
}

.quiz-result-value {
    display: block;
    font-size: 1.4rem;
    font-weight: 700;
    font-family: var(--font-mono);
}

.quiz-result-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.quiz-xp-earned {
    text-align: center;
    margin-top: 12px;
    font-size: 1rem;
    font-weight: 700;
    color: var(--quantum);
}

.quiz-results-breakdown {
    margin-top: 1.5rem;
    text-align: left;
}

.quiz-results-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

/* Mini Bar */
.quiz-mini-bar {
    height: 6px;
    background: rgba(255, 255, 255, 0.06);
    border-radius: 3px;
    overflow: hidden;
    width: 80px;
}

.quiz-mini-bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.5s var(--ease-out);
}

/* Heatmap */
.quiz-heatmap-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.quiz-heatmap-row:last-child {
    border-bottom: none;
}

.quiz-heatmap-topic {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 200px;
    flex-shrink: 0;
}

.quiz-heatmap-icon {
    font-size: 1.2rem;
}

.quiz-heatmap-name {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

.quiz-heatmap-cells {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    flex: 1;
}

.quiz-heatmap-cell {
    text-align: center;
    padding: 10px 8px;
    border-radius: var(--radius);
    transition: all 0.2s var(--ease);
    cursor: default;
}

.quiz-heatmap-cell:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.quiz-heatmap-score {
    font-size: 1.1rem;
    font-weight: 700;
    font-family: var(--font-mono);
}

.quiz-heatmap-label {
    font-size: 0.65rem;
    margin-top: 2px;
    opacity: 0.8;
}

.quiz-heatmap-legend {
    display: flex;
    align-items: center;
    gap: 12px;
    justify-content: center;
    margin-bottom: 1rem;
    font-size: 0.8rem;
}

.quiz-heatmap-legend-bar {
    width: 120px;
}

.quiz-heatmap-diff-labels {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 4px;
    padding-left: 0;
}

.quiz-heatmap-diff-labels .quiz-heatmap-cells {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
}

@media (max-width: 768px) {
    .quiz-heatmap-row { flex-direction: column; align-items: flex-start; }
    .quiz-heatmap-topic { min-width: auto; }
    .quiz-heatmap-cells { width: 100%; }
    .quiz-results-score-grid { flex-direction: column; }
}

/* Flashcard */
.quiz-flashcard-container {
    max-width: 700px;
    margin: 0 auto;
}

.quiz-flashcard-progress {
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.quiz-flashcard {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--shadow-card);
}

.quiz-flashcard-front {
    text-align: center;
}

.quiz-flashcard-reveal-btn {
    margin-top: 1.5rem;
}

.quiz-flashcard-actions {
    display: flex;
    gap: 8px;
    justify-content: center;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.quiz-flashcard-back {
    margin-top: 1.5rem;
    animation: quizSlideIn 0.3s var(--ease-out);
}

/* Confetti canvas fix */
#quiz-confetti-canvas {
    position: fixed !important;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 9999;
}

/* Animate-in for cards */
.animate-in {
    /* `forwards` retains the end state (opacity:1); the base `.animate-in` rule
       sets opacity:0, so without a forwards fill every animate-in element snaps
       back to invisible once the animation ends. */
    animation: quizSlideIn 0.35s var(--ease-out) forwards;
}

/* Usage page interface tabs */
.usage-tabs {
    display: flex;
    gap: 12px;
    margin: 28px 0 24px;
}
.usage-tab-btn {
    flex: 1;
    padding: 18px 20px;
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.25s ease;
    text-align: left;
    font-family: inherit;
    color: var(--text-secondary);
}
.usage-tab-btn:hover {
    border-color: var(--border-hover);
    background: var(--accent-dim);
}
.usage-tab-btn.active {
    border-color: var(--accent);
    background: var(--accent-dim);
    color: var(--text-primary);
}
.usage-tab-btn .usage-tab-icon {
    font-size: 1.6rem;
    display: block;
    margin-bottom: 8px;
}
.usage-tab-btn .usage-tab-title {
    font-size: 1rem;
    font-weight: 700;
    display: block;
    margin-bottom: 4px;
}
.usage-tab-btn .usage-tab-desc {
    font-size: 0.78rem;
    color: var(--text-muted);
    line-height: 1.4;
    display: block;
}
.usage-tab-content {
    display: none;
}
.usage-tab-content.active {
    display: block;
    animation: usageFadeIn 0.3s ease;
}
@keyframes usageFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}
.usage-step {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
    align-items: flex-start;
}
.usage-step-num {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 700;
    margin-top: 2px;
}
.usage-step-body h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}
.usage-step-body p {
    font-size: 0.84rem;
    color: var(--text-secondary);
    line-height: 1.6;
}
.usage-guide-box {
    background: linear-gradient(135deg, rgba(59,130,246,0.06), rgba(6,182,212,0.04));
    border: 1px solid rgba(59,130,246,0.15);
    border-left: 4px solid var(--accent);
    border-radius: var(--radius-lg);
    padding: 16px 20px;
    margin: 16px 0;
    font-size: 0.84rem;
    line-height: 1.7;
    color: var(--text-secondary);
}
.usage-guide-box strong {
    color: var(--accent);
}
.usage-guide-box code {
    background: rgba(59,130,246,0.1);
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--accent);
}

.chart-figure {
    margin: 24px 0;
    border: 1px solid rgba(59,130,246,0.12);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--card);
}
.chart-figure img {
    width: 100%;
    height: auto;
    display: block;
}
.chart-figure figcaption {
    padding: 10px 16px;
    font-size: 0.82rem;
    color: var(--text-secondary);
    background: rgba(0,0,0,0.15);
    border-top: 1px solid rgba(59,130,246,0.08);
    line-height: 1.5;
}
.chart-figure figcaption strong {
    color: var(--accent);
}

.chart-figure-half {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
    margin: 24px 0;
}
@media (max-width: 900px) {
    .chart-figure-half { grid-template-columns: 1fr; }
}

.charts-gallery-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 20px;
}
.charts-gallery-grid .chart-figure {
    margin: 0;
}
.charts-gallery-grid .chart-figure figcaption .gallery-ref {
    color: var(--quantum);
    font-size: 0.75rem;
    margin-left: 8px;
}
.chart-figure-gallery {
    display: flex;
    gap: 16px;
    padding: 12px;
}
.chart-gallery-img {
    flex: 0 0 70%;
    min-width: 0;
}
.chart-gallery-img img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0,212,255,0.1);
}
.chart-gallery-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
    justify-content: center;
}
.chart-gallery-caption {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 4px;
}
.chart-gallery-caption strong {
    color: var(--accent);
}
.chart-gallery-caption .gallery-ref {
    color: var(--quantum);
    font-size: 0.75rem;
    margin-left: 8px;
}
.legend-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    margin-top: 6px;
}
.legend-chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.68rem;
    font-weight: 600;
    background: rgba(0,0,0,0.25);
    border: 1px solid rgba(255,255,255,0.06);
}
.legend-chip .chip-dot {
    width: 8px;
    height: 8px;
    border-radius: 2px;
    flex-shrink: 0;
}
@media (max-width: 900px) {
    .chart-figure-gallery {
        flex-direction: column;
    }
    .chart-gallery-img {
        flex: none;
    }
}
.chart-info {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid rgba(59,130,246,0.08);
    display: none;
    flex-direction: column;
    gap: 8px;
}
.chart-info.open { display: flex; }
.chart-toggle {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 8px;
    padding: 5px 12px;
    border: 1px solid rgba(59,130,246,0.2);
    border-radius: 6px;
    background: rgba(59,130,246,0.06);
    color: var(--accent);
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    user-select: none;
    font-family: inherit;
}
.chart-toggle:hover {
    background: rgba(59,130,246,0.12);
    border-color: rgba(59,130,246,0.35);
}
.chart-toggle .toggle-arrow {
    transition: transform 0.2s;
    font-size: 0.65rem;
}
.chart-toggle.open .toggle-arrow {
    transform: rotate(90deg);
}
.chart-card {
    background: rgba(0,0,0,0.2);
    border-radius: 8px;
    padding: 12px 14px;
    border-left: 3px solid;
    line-height: 1.55;
}
.chart-card.challenge { border-left-color: var(--danger); }
.chart-card.purpose { border-left-color: var(--accent); }
.chart-card.impact { border-left-color: var(--success); }
.chart-card-label {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 3px;
}
.chart-card.challenge .chart-card-label { color: var(--danger); }
.chart-card.purpose .chart-card-label { color: var(--accent); }
.chart-card.impact .chart-card-label { color: var(--success); }
.chart-card-text {
    font-size: 0.82rem;
    color: var(--text-secondary);
}

/* =====================================================================
   PRESENTATION VIEW — PREMIUM THEME
   Aligns the in-browser deck with the polished PDF/PPTX slide design:
   Lato display type, deep-space gradient backdrop, blue->cyan accent
   signature, matted chart panels, and refined cards. Everything here is
   scoped under body.pres-active / .pres-* so the rest of the site is
   untouched.
   ===================================================================== */

body.pres-active {
    --pres-blue: #009eff;
    --pres-cyan: #00d4aa;
    --pres-display: 'Lato', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* Deep-space gradient backdrop + vignette so content reads cleanly.
   The cosmos canvas is dimmed to a faint starfield rather than the busy
   planet scene, matching the PDF's quiet starfield. */
body.pres-active #cosmos-canvas { opacity: 0.16 !important; }

body.pres-active .presentation-mode::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -1;
    background:
        radial-gradient(120% 80% at 50% -10%, rgba(0, 158, 255, 0.10), transparent 60%),
        radial-gradient(90% 70% at 50% 120%, rgba(0, 212, 170, 0.07), transparent 55%),
        linear-gradient(180deg, #0a0e1a 0%, #0b1120 55%, #131c33 100%);
}

/* Signature top bar — thin blue->cyan gradient across the viewport. */
body.pres-active .presentation-mode::after {
    content: '';
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
    z-index: 210;
    pointer-events: none;
}

body.pres-active .pres-progress-fill {
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
    box-shadow: 0 0 16px rgba(0, 158, 255, 0.5), 0 0 40px rgba(0, 212, 170, 0.2);
}

/* ---- Typography -------------------------------------------------- */
body.pres-active .pres-hero-title {
    font-family: var(--pres-display);
    font-weight: 900;
    letter-spacing: 10px;
    background: none;
    -webkit-text-fill-color: #f4f8ff;
    color: #f4f8ff;
    text-shadow: 0 0 42px rgba(0, 158, 255, 0.35);
    animation: none;
}

body.pres-active .pres-hero-sub { font-family: var(--pres-display); }

body.pres-active .pres-divider {
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
    opacity: 0.9;
    height: 3px;
    width: 200px;
}

/* Section headings: Lato Black + PDF-style accent underline. */
body.pres-active .pres-slide-body h2 {
    font-family: var(--pres-display);
    font-weight: 900;
    letter-spacing: 0.3px;
    position: relative;
    padding-bottom: 14px;
    margin-bottom: 26px;
}
body.pres-active .pres-slide-body h2::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 180px;
    height: 3px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
}

/* ---- Cards ------------------------------------------------------- */
body.pres-active .pres-card {
    position: relative;
    overflow: hidden;
    background: linear-gradient(180deg, rgba(19, 26, 46, 0.92), rgba(13, 19, 34, 0.92));
    border: 1px solid rgba(0, 158, 255, 0.18);
    box-shadow: 0 10px 34px rgba(0, 0, 0, 0.35);
}
/* Top accent bar, tinted per card variant. */
body.pres-active .pres-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
    opacity: 0.9;
}
body.pres-active .pres-card-danger::before { background: linear-gradient(90deg, #ff4d4d, #ff8c00); }
body.pres-active .pres-card-quantum::before { background: linear-gradient(90deg, #8b5cf6, #c84cff); }
body.pres-active .pres-card-danger { border-color: rgba(255, 77, 77, 0.28); }
body.pres-active .pres-card-quantum { border-color: rgba(139, 92, 246, 0.28); }
body.pres-active .pres-card-title { font-family: var(--pres-display); }

body.pres-active .pres-callout {
    background: rgba(0, 158, 255, 0.06);
    border-color: rgba(0, 158, 255, 0.22);
}

/* ---- Stat cards & flow ------------------------------------------ */
body.pres-active .pres-stat-card {
    position: relative;
    overflow: hidden;
    background: linear-gradient(180deg, rgba(19, 26, 46, 0.92), rgba(13, 19, 34, 0.92));
    border: 1px solid rgba(0, 158, 255, 0.18);
    box-shadow: 0 10px 34px rgba(0, 0, 0, 0.35);
}
body.pres-active .pres-stat-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--pres-blue), var(--pres-cyan));
    opacity: 0.85;
}
body.pres-active .pres-stat-value { font-family: var(--pres-display); font-weight: 900; }

body.pres-active .pres-flow-step {
    background: linear-gradient(180deg, rgba(19, 26, 46, 0.9), rgba(13, 19, 34, 0.9));
    border: 1px solid rgba(0, 158, 255, 0.22);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* ---- Tables ------------------------------------------------------ */
body.pres-active .pres-table th {
    color: var(--pres-cyan);
    border-bottom-color: rgba(0, 158, 255, 0.28);
}
body.pres-active .pres-table tr:hover td { background: rgba(0, 158, 255, 0.03); }

/* ---- Tags -------------------------------------------------------- */
body.pres-active .pres-slide-body h2 .pres-tag {
    font-family: var(--pres-display);
    font-weight: 700;
}

/* ---- Chart panels: matte white, matching the PDF chart slides ---- */
body.pres-active .pres-chart-img {
    background: #ffffff;
    padding: 16px;
    box-shadow: 0 12px 38px rgba(0, 0, 0, 0.4);
}
/* Dark system diagrams sit on a subtle dark panel instead. */
body.pres-active .pres-diagram-fig {
    background: rgba(7, 12, 24, 0.6);
    padding: 12px;
    box-shadow: 0 12px 38px rgba(0, 0, 0, 0.4);
}

/* Closing slide echoes the title treatment. */
body.pres-active .pres-conclusion .pres-hero-title,
body.pres-active .pres-conclusion h1 { font-family: var(--pres-display); }

/* ===== Design Docs tab ===== */
.design-nav-item {
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.88rem;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.15s ease, color 0.15s ease;
}
.design-nav-item:hover { background: rgba(128, 128, 128, 0.12); color: var(--text-primary); }
.design-nav-item.active { background: rgba(0, 212, 255, 0.12); color: var(--accent); font-weight: 600; }
#design-content h1 { font-size: 1.6rem; margin-top: 0.2em; }
#design-content h2 { font-size: 1.25rem; margin-top: 1.4em; border-bottom: 1px solid rgba(128,128,128,0.2); padding-bottom: 0.3em; }
#design-content h3 { font-size: 1.05rem; margin-top: 1.2em; }
#design-content table { border-collapse: collapse; width: 100%; margin: 1em 0; font-size: 0.88rem; }
#design-content th, #design-content td { border: 1px solid rgba(128,128,128,0.25); padding: 6px 10px; text-align: left; }
#design-content th { background: rgba(128,128,128,0.12); }
#design-content code { background: rgba(0, 212, 255, 0.08); padding: 1px 5px; border-radius: 4px; font-size: 0.86em; }
#design-content pre code { display: block; padding: 12px; overflow-x: auto; }
#design-content .mermaid { text-align: center; margin: 1.2em 0; }
/* ===== Mermaid viewer widget (shared: showcase + lessons) ===== */
.mmd-fig {
  border: 1px solid rgba(128, 128, 128, 0.25);
  border-radius: 10px;
  margin: 1.4em 0;
  overflow: hidden;
  background: rgba(128, 128, 128, 0.05);
}
.mmd-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 12px;
  border-bottom: 1px solid rgba(128, 128, 128, 0.2);
  font-size: 0.8rem;
}
.mmd-label {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary, #8892a4);
  font-weight: 600;
}
.mmd-ctrls { display: flex; align-items: center; gap: 6px; }
.mmd-zoom-level {
  font-variant-numeric: tabular-nums;
  color: var(--text-secondary, #8892a4);
  font-size: 0.74rem;
  min-width: 3.2em;
  text-align: right;
}
.mmd-ctrls button {
  background: rgba(0, 212, 255, 0.1);
  color: var(--accent, #00d4ff);
  border: 1px solid rgba(0, 212, 255, 0.35);
  border-radius: 6px;
  font-size: 0.78rem;
  padding: 4px 10px;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s ease;
}
.mmd-ctrls button:hover { background: rgba(0, 212, 255, 0.2); }
.mmd-ctrls button:disabled { opacity: 0.4; cursor: default; }
.mmd-stage {
  position: relative;
  overflow: hidden;
  max-height: 560px;
  min-height: 80px;
  cursor: grab;
  touch-action: none;
  display: flex;
  align-items: flex-start;
  justify-content: flex-start;
  color: var(--text-secondary, #8892a4);
  font-size: 0.85rem;
  /* distinct canvas panel: clearly lighter than page/cards so the
     diagram's bounds are obvious against the site UI */
  background-color: #111e36;
  background-image: radial-gradient(rgba(148, 170, 205, 0.17) 1px, transparent 1px);
  background-size: 22px 22px;
  box-shadow: inset 0 0 0 1px rgba(0, 212, 255, 0.1);
}
[data-theme="light"] .mmd-stage {
  background-color: #e9eff8;
  background-image: radial-gradient(rgba(23, 42, 72, 0.16) 1px, transparent 1px);
  box-shadow: inset 0 0 0 1px rgba(0, 120, 200, 0.12);
}
.mmd-stage.mmd-grabbing { cursor: grabbing; }
/* translate-only pan: no will-change, no scale transform — the SVG is
   re-rasterised at its set width/height so zooming stays vector-crisp */
.mmd-viewport { transform-origin: 0 0; }
.mmd-viewport svg { max-width: none; display: block; }
.mmd-viewport > svg { margin: 0; }
.mmd-src {
  display: none;
  margin: 0;
  padding: 12px 14px;
  overflow-x: auto;
  font-size: 0.8rem;
  line-height: 1.45;
  border-top: 1px solid rgba(128, 128, 128, 0.2);
  background: rgba(0, 0, 0, 0.25);
}
.mmd-fig.show-src .mmd-stage { display: none; }
.mmd-fig.show-src .mmd-src { display: block; }
.mmd-fig .mmd-logo { pointer-events: none; }
#design-content blockquote { border-left: 3px solid var(--accent); margin: 1em 0; padding: 0.2em 1em; color: var(--text-secondary); }
@media (max-width: 900px) {
  #design-layout { grid-template-columns: 1fr !important; }
  #design-nav { position: static !important; }
}