/* ─── Design Tokens — shared with the lecture archives ──────────────── */
:root, [data-theme="light"] {
  --color-bg:             #fdf9f3;
  --color-surface:        #f9f4ec;
  --color-surface-2:      #f3ece0;
  --color-divider:        #d8ccbb;
  --color-border:         #c9baa5;
  --color-text:           #22180a;
  --color-text-muted:     #6b5740;
  --color-text-faint:     #a8907a;
  --color-primary:        #9e2a1c;
  --color-primary-hover:  #821f14;
  --color-accent:         #8a6500;
  --cat-upanishad:        #1a5c7a;

  --radius-lg: 0.75rem; --radius-xl: 1.25rem; --radius-full: 9999px;
  --shadow-card: 0 2px 10px oklch(0.18 0.06 40 / 0.08), 0 0 0 1px oklch(0.18 0.06 40 / 0.05);
  --shadow-md:   0 14px 40px oklch(0.18 0.06 40 / 0.16);

  --font-bengali: 'Hind Siliguri', 'Noto Sans Bengali', sans-serif;
  --font-display: 'Zodiak', 'Georgia', serif;
  --font-body:    'Satoshi', 'Inter', sans-serif;
  --transition:   220ms cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
  --color-bg:             #120d07;
  --color-surface:        #1a1208;
  --color-surface-2:      #20180c;
  --color-divider:        #2e2010;
  --color-border:         #3d2c18;
  --color-text:           #ede3d5;
  --color-text-muted:     #8a7056;
  --color-text-faint:     #5a4530;
  --color-primary:        #e0584a;
  --color-primary-hover:  #ea6a5d;
  --color-accent:         #c8a040;
  --cat-upanishad:        #5ab8e0;
  --shadow-card: 0 2px 10px oklch(0 0 0 / 0.5), 0 0 0 1px oklch(1 0 0 / 0.04);
  --shadow-md:   0 14px 40px oklch(0 0 0 / 0.6);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
body {
  min-height: 100dvh;
  font-family: var(--font-body);
  color: var(--color-text);
  background:
    radial-gradient(120% 80% at 50% -10%, color-mix(in oklab, var(--color-primary) 8%, transparent), transparent 60%),
    var(--color-bg);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}
svg { display: block; }
a { text-decoration: none; color: inherit; }
h1, h2 { text-wrap: balance; line-height: 1.12; }
.bn, h1, h2, .eyebrow, .landing-sub-bn, .choice-desc, .landing-footer p, .choice-badge {
  font-family: var(--font-bengali), var(--font-body);
}

/* ─── Theme toggle ──────────────────────────────────────────────────── */
.theme-toggle {
  position: fixed; top: 1.25rem; right: 1.25rem; z-index: 10;
  width: 42px; height: 42px; display: grid; place-items: center;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
  transition: var(--transition);
}
.theme-toggle:hover { color: var(--color-primary); transform: translateY(-1px); }

/* ─── Landing layout ────────────────────────────────────────────────── */
.landing {
  min-height: 100dvh;
  display: grid; place-items: center;
  padding: clamp(2rem, 5vw, 5rem) 1.25rem;
}
.landing-inner {
  width: 100%; max-width: 880px;
  text-align: center;
  animation: rise 0.7s cubic-bezier(0.16, 1, 0.3, 1) both;
}
@keyframes rise { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: none; } }

.brand-mark {
  color: var(--color-primary);
  display: grid; place-items: center;
  margin-bottom: 1.5rem;
}
.brand-mark svg { filter: drop-shadow(0 4px 12px color-mix(in oklab, var(--color-primary) 25%, transparent)); }

.eyebrow {
  font-size: 0.8rem; font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  text-transform: none;
  margin-bottom: 1rem;
}
.landing-title {
  font-family: var(--font-bengali);
  font-size: clamp(2.4rem, 1.5rem + 4vw, 4.5rem);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 1rem;
}
.landing-title em {
  font-style: normal;
  color: var(--color-primary);
}
.title-en {
  display: block;
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 500;
  font-size: clamp(1.1rem, 0.8rem + 1.4vw, 1.75rem);
  color: var(--color-text-faint);
  margin-top: 0.35rem;
  letter-spacing: 0.02em;
}
.landing-sub {
  max-width: 560px; margin: 0 auto 0.35rem;
  color: var(--color-text-muted);
  font-size: clamp(0.95rem, 0.9rem + 0.3vw, 1.1rem);
}
.landing-sub-bn {
  color: var(--color-text-faint);
  font-size: 0.95rem;
  margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
}

/* ─── Language choice cards ─────────────────────────────────────────── */
.choice-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: clamp(1rem, 2.5vw, 1.75rem);
  margin-bottom: clamp(3rem, 6vw, 4.5rem);
}
@media (max-width: 620px) {
  .choice-grid { grid-template-columns: 1fr; }
}

.choice-card {
  position: relative;
  display: flex; flex-direction: column; align-items: flex-start;
  text-align: left;
  padding: clamp(1.5rem, 3vw, 2.25rem);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.choice-card::before {
  content: "";
  position: absolute; inset: 0 0 auto 0; height: 4px;
  background: var(--accent, var(--color-primary));
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--transition);
}
.choice-card[data-lang="bn"] { --accent: var(--color-primary); }
.choice-card[data-lang="en"] { --accent: var(--cat-upanishad); }
.choice-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}
.choice-card:hover::before { transform: scaleX(1); }

.choice-badge {
  align-self: flex-start;
  font-size: 0.8rem; font-weight: 700;
  padding: 0.25rem 0.7rem;
  border-radius: var(--radius-full);
  color: #fff; background: var(--accent);
  margin-bottom: 1rem;
}
.choice-title {
  font-size: clamp(1.4rem, 1rem + 1.6vw, 2rem);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.15rem;
}
.choice-roman {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--color-text-faint);
  font-size: 0.95rem;
  margin-bottom: 0.9rem;
}
.choice-desc {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}
.choice-go {
  margin-top: auto;
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-weight: 600;
  color: var(--accent);
}
.choice-go svg { transition: transform var(--transition); }
.choice-card:hover .choice-go svg { transform: translateX(4px); }

/* ─── Footer ────────────────────────────────────────────────────────── */
.landing-footer {
  border-top: 1px solid var(--color-divider);
  padding-top: 2rem;
  color: var(--color-text-faint);
}
.landing-footer p {
  max-width: 620px; margin: 0 auto 1rem;
  font-size: 0.85rem; line-height: 1.7;
}
.landing-footer strong { color: var(--color-text-muted); }
.footer-links {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 0.5rem 1.5rem;
}
.footer-links a {
  font-size: 0.85rem; font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--color-primary); }