/* ═══════════════════════════════════════════════════════
   QUIZMASTER WEB — Arcade Cosmos Design System
   ═══════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Exo+2:ital,wght@0,400;0,600;0,700;0,900;1,900&family=DM+Sans:wght@400;500;600&family=JetBrains+Mono:wght@500;600&display=swap');

/* ── Design Tokens ───────────────────────────────────── */
:root {
  --bg-top:       #140C35;
  --bg-mid:       #3A2080;
  --bg-low:       #6E308A;
  --bg-end:       #B05585;

  --cyan:         #00D4FF;
  --cyan-dim:     rgba(0, 212, 255, 0.25);
  --magenta:      #FF2D78;
  --gold:         #FFD700;
  --gold-dim:     rgba(255, 215, 0, 0.18);

  --glass-bg:     rgba(255, 255, 255, 0.07);
  --glass-mid:    rgba(255, 255, 255, 0.12);
  --glass-heavy:  rgba(255, 255, 255, 0.16);
  --glass-border: rgba(255, 255, 255, 0.16);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);

  --text-primary:   #FFFFFF;
  --text-secondary: rgba(255, 255, 255, 0.68);
  --text-muted:     rgba(255, 255, 255, 0.4);

  --radius-pill: 100px;
  --radius-card: 20px;
  --radius-chip: 100px;

  --font-display: 'Exo 2', sans-serif;
  --font-body:    'DM Sans', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;

  --ease-spring:  cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-smooth:  cubic-bezier(0.4, 0, 0.2, 1);
  --duration:     0.22s;
  --duration-md:  0.35s;
}

/* ── Reset & Base ────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

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

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background:
    radial-gradient(ellipse 80% 60% at 15% -10%, rgba(90, 40, 220, 0.45) 0%, transparent 60%),
    radial-gradient(ellipse 70% 50% at 90% 110%, rgba(200, 50, 140, 0.4) 0%, transparent 60%),
    radial-gradient(ellipse 50% 40% at 50% 50%, rgba(60, 20, 140, 0.3) 0%, transparent 70%),
    linear-gradient(165deg, var(--bg-top) 0%, var(--bg-mid) 35%, var(--bg-low) 65%, var(--bg-end) 100%);
  background-attachment: fixed;
  min-height: 100vh;
  margin: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Subtle star-field texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
  background-image:
    radial-gradient(1.5px 1.5px at 12% 15%, rgba(255,255,255,0.7) 0%, transparent 100%),
    radial-gradient(1px 1px at 33% 8%, rgba(255,255,255,0.5) 0%, transparent 100%),
    radial-gradient(1px 1px at 55% 22%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 78% 5%, rgba(255,255,255,0.6) 0%, transparent 100%),
    radial-gradient(1px 1px at 92% 18%, rgba(255,255,255,0.5) 0%, transparent 100%),
    radial-gradient(1px 1px at 7% 38%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 45% 42%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1px 1px at 68% 35%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1px 1px at 88% 48%, rgba(255,255,255,0.5) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 22% 62%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1px 1px at 60% 70%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1px 1px at 5% 80%, rgba(255,255,255,0.5) 0%, transparent 100%),
    radial-gradient(1.5px 1.5px at 40% 88%, rgba(255,255,255,0.4) 0%, transparent 100%),
    radial-gradient(1px 1px at 75% 92%, rgba(255,255,255,0.3) 0%, transparent 100%),
    radial-gradient(1px 1px at 95% 75%, rgba(255,255,255,0.5) 0%, transparent 100%);
}

main { position: relative; z-index: 1; }

/* ── Animations ─────────────────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(100%); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

@keyframes logoGlow {
  0%, 100% { filter: drop-shadow(0 6px 24px rgba(0,212,255,0.5)) drop-shadow(0 4px 12px rgba(255,45,120,0.3)); }
  50%       { filter: drop-shadow(0 10px 40px rgba(0,212,255,0.7)) drop-shadow(0 6px 20px rgba(255,45,120,0.5)); }
}

/* ── Glass Utility ──────────────────────────────────── */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

/* ── Header / Navigation ─────────────────────────────── */
header {
  position: sticky;
  top: 0;
  z-index: 200;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 1rem;
  padding: 0.6rem 1.5rem;
  background: rgba(18, 10, 48, 0.78);
  backdrop-filter: blur(28px) saturate(200%);
  -webkit-backdrop-filter: blur(28px) saturate(200%);
  border-bottom: 1px solid var(--glass-border);
  animation: fadeIn 0.4s var(--ease-smooth) both;
}

.header-brand {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.site-logo {
  height: 38px;
  width: auto;
  object-fit: contain;
  display: block;
  animation: logoGlow 4s ease-in-out infinite;
}

/* ── Header Nav Links ────────────────────────────────── */
.header-nav {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 0.25rem;
}

.header-nav::-webkit-scrollbar { display: none; }

.nav-link {
  display: inline-block;
  padding: 0.38rem 0.75rem;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  white-space: nowrap;
  border: 1px solid transparent;
  transition: color     var(--duration) var(--ease-smooth),
              background var(--duration) var(--ease-smooth),
              border-color var(--duration) var(--ease-smooth);
}

.nav-link:hover {
  color: var(--text-primary);
  background: var(--glass-bg);
  border-color: var(--glass-border);
}

.nav-link--active {
  color: var(--text-primary);
  background: var(--glass-mid);
  border-color: var(--glass-border);
  font-weight: 600;
}

/* ── Language Picker ─────────────────────────────────── */
.lang-picker {
  position: relative;
  flex-shrink: 0;
}

/* Remove default marker */
.lang-picker > summary { list-style: none; }
.lang-picker > summary::-webkit-details-marker { display: none; }

.lang-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.38rem 0.75rem;
  border-radius: var(--radius-pill);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  user-select: none;
  transition: background var(--duration) var(--ease-smooth),
              color     var(--duration) var(--ease-smooth),
              border-color var(--duration) var(--ease-smooth);
}

.lang-trigger:hover,
details[open] .lang-trigger {
  background: var(--glass-mid);
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.28);
}

.lang-current-code {
  letter-spacing: 0.04em;
  font-size: 0.78rem;
}

.lang-chevron {
  transition: transform var(--duration) var(--ease-smooth);
  opacity: 0.6;
}

details[open] .lang-chevron {
  transform: rotate(180deg);
  opacity: 1;
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  min-width: 260px;
  background: linear-gradient(150deg, rgba(50, 25, 110, 0.97), rgba(28, 12, 62, 0.98));
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 0.6rem;
  box-shadow: 0 16px 48px rgba(0,0,0,0.55);
  animation: fadeInUp 0.18s var(--ease-smooth) both;
}

.lang-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.3rem;
}

.lang-option {
  display: block;
  padding: 0.45rem 0.6rem;
  border-radius: 10px;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  text-align: center;
  transition: background var(--duration) var(--ease-smooth),
              color     var(--duration) var(--ease-smooth);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

a.lang-option:hover {
  background: var(--glass-mid);
  color: var(--text-primary);
}

.lang-option--active {
  background: rgba(0, 212, 255, 0.16);
  color: var(--cyan);
  border: 1px solid rgba(0, 212, 255, 0.3);
  font-weight: 700;
  cursor: default;
}

/* ── Mobile header ───────────────────────────────────── */
@media (max-width: 639px) {
  header {
    grid-template-columns: auto auto;
    grid-template-rows: auto auto;
    gap: 0 0.75rem;
    padding: 0.6rem 1rem;
  }

  .header-brand { grid-column: 1; grid-row: 1; }
  .lang-picker  { grid-column: 2; grid-row: 1; justify-self: end; }

  .header-nav {
    grid-column: 1 / -1;
    grid-row: 2;
    gap: 0.1rem;
    padding: 0.2rem 0 0.4rem;
    margin: 0 -1rem;
    padding-left: 1rem;
    padding-right: 1rem;
    border-top: 1px solid rgba(255,255,255,0.06);
  }

  .nav-link {
    font-size: 0.8rem;
    padding: 0.3rem 0.65rem;
  }

  .lang-dropdown {
    min-width: 220px;
  }

  .lang-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ── Buttons ────────────────────────────────────────── */
.btn-pill-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.94);
  color: #180F3A;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: transform var(--duration-md) var(--ease-spring),
              box-shadow var(--duration) var(--ease-smooth),
              background var(--duration) var(--ease-smooth);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3), 0 1px 0 rgba(255,255,255,0.5) inset;
  flex: 1;
}

.btn-pill-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 10px 36px rgba(0,0,0,0.35), 0 1px 0 rgba(255,255,255,0.5) inset;
  background: #ffffff;
  color: #180F3A;
}

.btn-pill-primary:active {
  transform: scale(0.97);
}

.btn-pill-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-pill);
  background: var(--glass-bg);
  color: var(--text-primary);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  text-decoration: none;
  border: 1px solid var(--glass-border);
  cursor: pointer;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform var(--duration-md) var(--ease-spring),
              background var(--duration) var(--ease-smooth),
              box-shadow var(--duration) var(--ease-smooth);
  flex: 1;
}

.btn-pill-ghost:hover {
  transform: translateY(-3px) scale(1.02);
  background: var(--glass-mid);
  box-shadow: 0 8px 28px rgba(0,0,0,0.25);
  color: var(--text-primary);
}

.btn-pill-ghost:active {
  transform: scale(0.97);
}

.btn-leaderboard {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-pill);
  background: rgba(0, 212, 255, 0.14);
  color: var(--cyan);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  border: 1px solid rgba(0, 212, 255, 0.32);
  cursor: pointer;
  transition: background var(--duration) var(--ease-smooth),
              transform  var(--duration-md) var(--ease-spring);
}

.btn-leaderboard:hover {
  background: rgba(0, 212, 255, 0.26);
  transform: scale(1.05);
}

.btn-leaderboard svg {
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
}

/* ── Hero / Home ────────────────────────────────────── */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 3.5rem 1.5rem 5rem;
  max-width: 560px;
  margin: 0 auto;
}

.hero-logo {
  width: min(280px, 75vw);
  height: auto;
  margin-bottom: 1.75rem;
  animation: logoGlow 4s ease-in-out infinite, fadeInUp 0.5s var(--ease-smooth) both;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.9rem, 5.5vw, 2.9rem);
  line-height: 1.08;
  margin: 0 0 0.9rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  animation: fadeInUp 0.5s 0.08s var(--ease-smooth) both;
}

.hero-subtitle {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0 0 0.5rem;
  max-width: 420px;
  animation: fadeInUp 0.5s 0.14s var(--ease-smooth) both;
}

.hero-yt-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--cyan);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  margin: 0.75rem 0 2.25rem;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(0, 212, 255, 0.25);
  transition: background var(--duration) var(--ease-smooth),
              border-color var(--duration) var(--ease-smooth);
  animation: fadeInUp 0.5s 0.18s var(--ease-smooth) both;
}

.hero-yt-link:hover {
  background: rgba(0, 212, 255, 0.1);
  border-color: rgba(0, 212, 255, 0.45);
  color: var(--cyan);
}

.hero-yt-link svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  width: 100%;
  max-width: 340px;
  animation: fadeInUp 0.5s 0.22s var(--ease-smooth) both;
}

/* ── Download Hero ────────────────────────────────────── */
.download-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 3rem 1.5rem 5rem;
  max-width: 560px;
  margin: 0 auto;
  animation: fadeInUp 0.5s var(--ease-smooth) both;
}

.download-logo {
  width: min(220px, 60vw);
  height: auto;
  margin-bottom: 1.5rem;
  animation: logoGlow 4s ease-in-out infinite;
}

.download-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
  color: var(--text-primary);
}

.download-stores {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  width: 100%;
  max-width: 320px;
  margin: 2rem 0 0;
}

.store-badge {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.5rem;
  border-radius: var(--radius-pill);
  text-decoration: none;
  font-family: var(--font-body);
  border: 1px solid transparent;
  transition: transform var(--duration-md) var(--ease-spring),
              box-shadow var(--duration) var(--ease-smooth);
  width: 100%;
}

.store-badge__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.store-badge__icon svg {
  width: 30px;
  height: 30px;
}

.store-badge__text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.25;
}

.store-badge__line1 {
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  opacity: 0.75;
}

.store-badge__line2 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.store-badge--apple {
  background: rgba(255, 255, 255, 0.95);
  color: #111;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.28), 0 1px 0 rgba(255,255,255,0.5) inset;
}

.store-badge--apple:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 36px rgba(0, 0, 0, 0.32);
  background: #fff;
  color: #111;
}

.store-badge--google {
  background: var(--glass-mid);
  color: var(--text-primary);
  border-color: var(--glass-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
}

.store-badge--google:hover {
  transform: translateY(-3px) scale(1.02);
  background: var(--glass-heavy);
  box-shadow: 0 14px 36px rgba(0, 0, 0, 0.35);
  color: var(--text-primary);
}

.download-footer {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 1.75rem 0 0;
  max-width: 42ch;
  line-height: 1.6;
}

/* ── Page Header ─────────────────────────────────────── */
.page-header {
  padding: 1.75rem 1.25rem 0.75rem;
  animation: fadeInUp 0.4s var(--ease-smooth) both;
}

.page-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  color: var(--text-primary);
  margin: 0;
  letter-spacing: -0.015em;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  padding: 0.3rem 0.8rem;
  border-radius: var(--radius-pill);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  margin-bottom: 1.25rem;
  transition: all var(--duration) var(--ease-smooth);
}

.back-link:hover {
  background: var(--glass-mid);
  color: var(--text-primary);
}

/* ── Category Filter ─────────────────────────────────── */
.category-filter {
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  padding: 0.6rem 1.25rem 0.4rem;
  scrollbar-width: none;
  -ms-overflow-style: none;
  animation: fadeInUp 0.4s 0.05s var(--ease-smooth) both;
}

.category-filter::-webkit-scrollbar { display: none; }

.category-chip {
  flex-shrink: 0;
  padding: 0.38rem 1.05rem;
  border-radius: var(--radius-chip);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.82rem;
  cursor: pointer;
  border: 1.5px solid var(--glass-border);
  background: var(--glass-bg);
  color: var(--text-secondary);
  white-space: nowrap;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: all var(--duration) var(--ease-smooth);
}

.category-chip:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.3);
  background: var(--glass-mid);
}

.category-chip.active {
  background: #ffffff;
  color: #180F3A;
  border-color: #ffffff;
  box-shadow: 0 2px 14px rgba(255,255,255,0.22);
}

/* ── Quiz Grid ──────────────────────────────────────── */
.quiz-section {
  padding: 0.5rem 1.25rem 5rem;
  animation: fadeInUp 0.4s 0.08s var(--ease-smooth) both;
}

.quiz-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 1.1rem;
}

.quiz-card {
  position: relative;
  border-radius: var(--radius-card);
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, rgba(60,30,120,0.8), rgba(30,15,60,0.9));
  box-shadow: 0 6px 24px rgba(0,0,0,0.4), 0 1px 0 rgba(255,255,255,0.08) inset;
  transition: transform var(--duration-md) var(--ease-spring),
              box-shadow var(--duration) var(--ease-smooth);
  cursor: pointer;
}

.quiz-card:hover {
  transform: translateY(-7px) scale(1.012);
  box-shadow: 0 18px 48px rgba(0,0,0,0.55), 0 1px 0 rgba(255,255,255,0.1) inset;
}

.quiz-card__thumb-link {
  position: absolute;
  inset: 0;
  display: block;
}

.quiz-card__thumb {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.45s var(--ease-smooth);
}

.quiz-card:hover .quiz-card__thumb {
  transform: scale(1.06);
}

.quiz-card__gradient {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to top,
    rgba(12, 5, 35, 0.96) 0%,
    rgba(12, 5, 35, 0.65) 38%,
    rgba(12, 5, 35, 0.18) 68%,
    transparent 100%
  );
}

.quiz-card__glow {
  position: absolute;
  inset: 0;
  border: 1.5px solid rgba(0, 212, 255, 0.25);
  border-radius: var(--radius-card);
  opacity: 0;
  transition: opacity var(--duration) var(--ease-smooth);
  pointer-events: none;
}

.quiz-card:hover .quiz-card__glow {
  opacity: 1;
}

.quiz-card__body {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 1.1rem 1.1rem 1.15rem;
}

.quiz-card__pills {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  margin-bottom: 0.45rem;
}

.pill {
  display: inline-block;
  padding: 0.18rem 0.6rem;
  border-radius: var(--radius-chip);
  font-size: 0.67rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  line-height: 1.4;
}

.pill-category {
  background: rgba(0, 0, 0, 0.5);
  color: var(--cyan);
  border: 1px solid rgba(0, 212, 255, 0.45);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.pill-count {
  background: rgba(0, 0, 0, 0.5);
  color: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.quiz-card__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.96rem;
  line-height: 1.3;
  color: #ffffff;
  margin-bottom: 0.7rem;
  text-shadow: 0 1px 8px rgba(0,0,0,0.6);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.quiz-card__name--link {
  color: inherit;
  text-decoration: none;
}

.quiz-card__name--link:hover {
  text-decoration: underline;
}

/* ── Leaderboard Modal ──────────────────────────────── */
#leaderboard-modal {
  position: fixed;
  inset: 0;
  z-index: 500;
  display: flex;
  align-items: flex-end;
  background: rgba(8, 4, 24, 0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: fadeIn 0.2s var(--ease-smooth) both;
}

#leaderboard-modal[hidden] {
  display: none;
}

.modal-sheet {
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  background: linear-gradient(160deg,
    rgba(52, 25, 110, 0.97) 0%,
    rgba(30, 14, 68, 0.98) 100%
  );
  backdrop-filter: blur(36px) saturate(200%);
  -webkit-backdrop-filter: blur(36px) saturate(200%);
  border-top: 1px solid rgba(255,255,255,0.18);
  border-left: 1px solid rgba(255,255,255,0.1);
  border-right: 1px solid rgba(255,255,255,0.1);
  border-radius: 26px 26px 0 0;
  padding: 1rem 1.25rem 2.5rem;
  max-height: 82vh;
  overflow-y: auto;
  animation: slideUp 0.38s var(--ease-spring) both;
  scrollbar-width: thin;
  scrollbar-color: var(--glass-border) transparent;
}

.modal-handle {
  width: 38px;
  height: 4px;
  background: rgba(255,255,255,0.25);
  border-radius: 2px;
  margin: 0.25rem auto 1.1rem;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.1rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--glass-border);
}

#leaderboard-modal-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--text-primary);
  margin: 0;
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

#leaderboard-close {
  flex-shrink: 0;
  padding: 0.38rem 1rem;
  border-radius: var(--radius-pill);
  background: var(--glass-bg);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all var(--duration) var(--ease-smooth);
}

#leaderboard-close:hover {
  background: var(--glass-mid);
  color: var(--text-primary);
}

/* ── Leaderboard Content ────────────────────────────── */
.leaderboard-list {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.leaderboard-row {
  display: grid;
  grid-template-columns: 2.8rem 1fr auto;
  align-items: center;
  gap: 0.6rem;
  padding: 0.8rem 0.9rem;
  border-radius: 14px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  transition: background var(--duration) var(--ease-smooth);
}

.leaderboard-row:hover {
  background: var(--glass-mid);
}

.leaderboard-row--gold {
  background: var(--gold-dim);
  border-color: rgba(255, 215, 0, 0.32);
}

.leaderboard-row--gold .lb-name,
.leaderboard-row--gold .lb-score {
  color: var(--gold);
}

.lb-rank {
  font-size: 1.45rem;
  text-align: center;
  line-height: 1;
}

.lb-rank-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  text-align: center;
}

.lb-name {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.93rem;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lb-score {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
}

.lb-loading {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem;
  font-size: 0.9rem;
}


/* ── Prose / Content Pages ──────────────────────────── */
.prose-page {
  max-width: 740px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 5rem;
  animation: fadeInUp 0.45s var(--ease-smooth) both;
}

.prose-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--glass-border);
}

.prose-header h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.8rem, 5vw, 2.8rem);
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
  color: var(--text-primary);
}

.prose-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin: 0;
  font-weight: 500;
}

.prose-intro,
.hiw-intro,
.support-intro,
.download-intro {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0.6rem 0 0;
  max-width: 56ch;
}

.prose-body h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin: 2.25rem 0 0.6rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--glass-border);
}

.prose-body h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--cyan);
  margin: 1.5rem 0 0.4rem;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  font-size: 0.82rem;
}

.prose-body p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin: 0 0 1rem;
}

.prose-body ul,
.prose-body ol {
  margin: 0 0 1.1rem 0;
  padding-left: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.prose-body ul li,
.prose-body ol li {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.65;
  padding: 0.6rem 0.85rem 0.6rem 1rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-left: 2.5px solid rgba(0, 212, 255, 0.45);
  border-radius: 10px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.prose-body ul li::before {
  display: none;
}

.prose-body strong {
  color: var(--text-primary);
  font-weight: 600;
}

.prose-body a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 212, 255, 0.35);
  transition: border-color var(--duration) var(--ease-smooth),
              color var(--duration) var(--ease-smooth);
}

.prose-body a:hover {
  color: #fff;
  border-color: rgba(255,255,255,0.5);
}

@media (min-width: 768px) {
  .prose-page {
    padding: 3rem 2rem 6rem;
  }
}

/* ── How It Works ────────────────────────────────────── */
.hiw-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.1rem;
  margin-top: 0.5rem;
}

.hiw-card {
  position: relative;
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-card);
  padding: 1.75rem 1.5rem;
  box-shadow: var(--glass-shadow);
  transition: transform var(--duration-md) var(--ease-spring),
              box-shadow var(--duration) var(--ease-smooth);
}

.hiw-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.45);
}

.hiw-card__icon {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--cyan);
}

.hiw-card__icon svg {
  display: block;
}

.hiw-card__num {
  position: absolute;
  top: 1rem;
  right: 1.1rem;
  width: 1.6rem;
  height: 1.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
}

.hiw-card h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-primary);
  margin: 0 0 0.6rem;
  letter-spacing: -0.01em;
}

.hiw-card p {
  font-size: 0.91rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

/* ── Support Page ────────────────────────────────────── */
.support-grid {
  display: grid;
  gap: 1.25rem;
}

.support-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-card);
  padding: 1.75rem 1.5rem;
  box-shadow: var(--glass-shadow);
}

.support-card h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--text-primary);
  margin: 0 0 1.1rem;
  letter-spacing: -0.01em;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--glass-border);
}

/* Contact info */
.contact-row {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.55rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  font-size: 0.91rem;
  color: var(--text-secondary);
}

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

.contact-label {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  min-width: 3.5rem;
}

.contact-row a {
  color: var(--cyan);
  text-decoration: none;
  transition: opacity var(--duration) var(--ease-smooth);
}

.contact-row a:hover { opacity: 0.75; }

/* FAQ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.faq-item dt {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}

.faq-item dt::before {
  content: 'Q';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.4rem;
  height: 1.4rem;
  border-radius: 50%;
  background: rgba(0, 212, 255, 0.18);
  border: 1px solid rgba(0, 212, 255, 0.35);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 0.05rem;
}

.faq-item dd {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin: 0 0 0 1.9rem;
  padding: 0.5rem 0.75rem;
  background: rgba(255,255,255,0.04);
  border-radius: 10px;
  border-left: 2px solid rgba(255,255,255,0.1);
}

/* Contact form */
.form-field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.form-field label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.form-field input,
.form-field textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  background: rgba(255,255,255,0.07);
  border: 1.5px solid var(--glass-border);
  border-radius: 12px;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.93rem;
  transition: border-color var(--duration) var(--ease-smooth),
              background var(--duration) var(--ease-smooth);
  outline: none;
  -webkit-appearance: none;
}

.form-field input::placeholder,
.form-field textarea::placeholder {
  color: var(--text-muted);
}

.form-field input:focus,
.form-field textarea:focus {
  border-color: var(--cyan);
  background: rgba(0, 212, 255, 0.07);
}

.form-field textarea {
  resize: vertical;
  min-height: 120px;
  line-height: 1.6;
}

.form-field .field-error {
  font-size: 0.78rem;
  color: var(--magenta);
  padding-left: 0.25rem;
}

.form-submit {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 2rem;
  border-radius: var(--radius-pill);
  background: rgba(255,255,255,0.92);
  color: #180F3A;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.92rem;
  border: none;
  cursor: pointer;
  transition: transform var(--duration-md) var(--ease-spring),
              box-shadow var(--duration) var(--ease-smooth);
  box-shadow: 0 4px 18px rgba(0,0,0,0.28);
}

.form-submit:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 28px rgba(0,0,0,0.32);
  background: #fff;
}

.alert-success {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1rem;
  background: rgba(0, 212, 255, 0.12);
  border: 1px solid rgba(0, 212, 255, 0.32);
  border-radius: 12px;
  color: var(--cyan);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 1.1rem;
}

.validation-summary-valid { display: none !important; }

.alert-error {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1rem;
  background: rgba(255, 45, 120, 0.12);
  border: 1px solid rgba(255, 45, 120, 0.32);
  border-radius: 12px;
  color: var(--magenta);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 1.1rem;
}

@media (min-width: 900px) {
  .hiw-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ── Error Pages ─────────────────────────────────────── */
.error-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 70vh;
  text-align: center;
  padding: 2rem;
  animation: fadeInUp 0.5s var(--ease-smooth) both;
}

.error-code {
  font-family: var(--font-display);
  font-size: clamp(5rem, 18vw, 9rem);
  font-weight: 900;
  color: transparent;
  background: linear-gradient(135deg, var(--cyan), var(--magenta));
  -webkit-background-clip: text;
  background-clip: text;
  line-height: 1;
  margin-bottom: 0.5rem;
  opacity: 0.4;
}

/* ── Scrollbar ──────────────────────────────────────── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 3px; }

/* ── Focus & Accessibility ──────────────────────────── */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

.visually-hidden-focusable:not(:focus):not(:focus-within) {
  clip: rect(0,0,0,0);
  clip-path: inset(50%);
  height: 1px;
  overflow: hidden;
  position: absolute;
  white-space: nowrap;
  width: 1px;
}

/* ── Bootstrap overrides ────────────────────────────── */
.text-danger { color: var(--magenta) !important; }

/* ── Responsive ─────────────────────────────────────── */
@media (min-width: 640px) {
  .hero-actions {
    flex-direction: row;
    max-width: 460px;
  }

  .btn-pill-primary,
  .btn-pill-ghost {
    flex: 1;
  }
}

@media (min-width: 768px) {
  header {
    padding: 0.7rem 2rem;
  }

  .site-logo { height: 44px; }

  .hero {
    padding: 4.5rem 2rem 6rem;
  }

  .category-filter {
    padding: 0.75rem 2rem 0.5rem;
  }

  .quiz-section {
    padding: 0.75rem 2rem 5rem;
  }

  .page-header {
    padding: 2rem 2rem 0.75rem;
  }

  #leaderboard-modal {
    align-items: center;
  }

  .modal-sheet {
    border-radius: 26px;
    border: 1px solid rgba(255,255,255,0.16);
    max-height: 88vh;
  }
}

@media (min-width: 1100px) {
  .quiz-grid {
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.35rem;
  }
}