/* BDMA — shared design tokens and base layout
   Palette: emerald accent (distinct from the SDA crimson course). */

:root {
  --bg:        #0d1117;
  --bg2:       #161b22;
  --bg3:       #1c2128;
  --border:    #30363d;
  --text:      #e6edf3;
  --text2:     #8b949e;
  --accent:    #0f766e;
  --accent-hl: #14b8a6;
  --accent-bg: rgba(20, 184, 166, 0.12);
  --available: #16a34a;
  --avail-bg:  rgba(22, 163, 74, 0.12);
  --past-col:  #6b7280;
  --past-bg:   rgba(107, 114, 128, 0.10);
  --soon-col:  #d97706;
  --soon-bg:   rgba(217, 119, 6, 0.10);
  --amber:     #d97706;
  --green:     #16a34a;
  --green-bg:  rgba(22, 163, 74, 0.12);
  --blue:      #3b82f6;
  --blue-bg:   rgba(59, 130, 246, 0.10);
  --card:      #161b22;
  --shadow:    0 4px 24px rgba(0, 0, 0, 0.4);
}

[data-theme="light"] {
  --bg:        #f6f8fa;
  --bg2:       #ffffff;
  --bg3:       #eaeef2;
  --border:    #d0d7de;
  --text:      #1a1a2e;
  --text2:     #57606a;
  --accent:    #0f766e;
  --accent-hl: #0d9488;
  --accent-bg: rgba(15, 118, 110, 0.10);
  --available: #166534;
  --avail-bg:  rgba(22, 101, 52, 0.08);
  --past-col:  #6b7280;
  --past-bg:   rgba(107, 114, 128, 0.08);
  --soon-col:  #92400e;
  --soon-bg:   rgba(146, 64, 14, 0.08);
  --amber:     #92400e;
  --green:     #166534;
  --green-bg:  rgba(22, 101, 52, 0.08);
  --blue:      #1d4ed8;
  --blue-bg:   rgba(29, 78, 216, 0.08);
  --card:      #ffffff;
  --shadow:    0 4px 24px rgba(0, 0, 0, 0.08);
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background .3s, color .3s;
  min-height: 100vh;
}

/* ---------- NAV ---------- */
nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
  display: flex; align-items: center; justify-content: space-between;
  height: 56px;
  backdrop-filter: blur(12px);
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 600; font-size: .95rem; color: var(--text);
  text-decoration: none; white-space: nowrap;
}
.nav-brand .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent-hl); display: inline-block;
}
.nav-links { display: flex; align-items: center; gap: 1.25rem; }
.nav-links a { font-size: .85rem; color: var(--text2); text-decoration: none; transition: color .2s; }
.nav-links a:hover { color: var(--text); }
.nav-links a.active { color: var(--accent-hl); font-weight: 600; }
.nav-right { display: flex; align-items: center; gap: .75rem; }
.nav-tag {
  font-size: .72rem; font-weight: 500; letter-spacing: .05em;
  padding: 3px 8px; border-radius: 4px;
  background: var(--accent-bg); color: var(--accent-hl);
  border: 1px solid var(--accent-hl); text-transform: uppercase;
}
.theme-toggle {
  background: var(--bg3); border: 1px solid var(--border);
  color: var(--text2); border-radius: 8px;
  padding: 6px 12px; cursor: pointer; font-size: .8rem;
  display: flex; align-items: center; gap: 6px;
  transition: all .2s; font-family: inherit;
}
.theme-toggle:hover { border-color: var(--accent-hl); color: var(--text); }

/* ---------- HERO ---------- */
.hero {
  background: linear-gradient(135deg, var(--bg2) 0%, var(--bg3) 100%);
  border-bottom: 1px solid var(--border);
  padding: 4rem 2rem 3rem; text-align: center;
}
.hero-badge {
  display: inline-block; font-size: .72rem; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--accent-hl); border: 1px solid var(--accent-hl);
  padding: 4px 12px; border-radius: 20px; margin-bottom: 1.25rem;
}
.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem); font-weight: 700;
  line-height: 1.15; margin-bottom: .75rem; letter-spacing: -.02em;
}
.hero h1 span { color: var(--accent-hl); }
.hero-sub {
  font-size: 1.05rem; color: var(--text2); max-width: 600px;
  margin: 0 auto 2rem; line-height: 1.6;
}
.hero-stats { display: flex; justify-content: center; gap: 2.5rem; flex-wrap: wrap; }
.stat { text-align: center; }
.stat-num { font-size: 2rem; font-weight: 700; color: var(--accent-hl); }
.stat-lbl {
  font-size: .78rem; color: var(--text2); text-transform: uppercase;
  letter-spacing: .05em; margin-top: 2px;
}

main { max-width: 1100px; margin: 0 auto; padding: 3rem 2rem 5rem; }

/* ---------- MODULES + CARDS ---------- */
.module { margin-bottom: 3.5rem; }
.module-header {
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 1.25rem; padding-bottom: .75rem;
  border-bottom: 1px solid var(--border); flex-wrap: wrap;
}
.module-num {
  font-size: .7rem; font-weight: 700; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent-hl);
  background: var(--accent-bg); border: 1px solid var(--accent-hl);
  padding: 3px 8px; border-radius: 4px;
}
.module-title { font-size: 1.15rem; font-weight: 600; color: var(--text); }
.module-lectures { font-size: .8rem; color: var(--text2); margin-left: auto; }

.lectures-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1rem;
}
.lecture-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 10px; padding: 1.25rem;
  transition: transform .2s, border-color .2s, box-shadow .2s;
  display: flex; flex-direction: column; gap: 10px;
  text-decoration: none; color: inherit;
  position: relative; overflow: hidden;
}
.lecture-card.available { cursor: pointer; }
.lecture-card.available:hover {
  transform: translateY(-3px);
  border-color: var(--accent-hl);
  box-shadow: var(--shadow);
}
.lecture-card.available::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--accent-hl);
}
.lecture-card.past   { opacity: .55; cursor: default; }
.lecture-card.coming { opacity: .65; cursor: default; }
.card-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.lec-num {
  font-size: .7rem; font-weight: 600; color: var(--text2);
  font-family: 'JetBrains Mono', ui-monospace, monospace;
}
.status-badge {
  font-size: .65rem; font-weight: 600; padding: 2px 8px;
  border-radius: 20px; text-transform: uppercase; letter-spacing: .05em;
  white-space: nowrap;
}
.status-badge.available { background: var(--avail-bg); color: var(--available); border: 1px solid var(--available); }
.status-badge.past      { background: var(--past-bg);  color: var(--past-col);  border: 1px solid var(--past-col); }
.status-badge.coming    { background: var(--soon-bg);  color: var(--soon-col);  border: 1px solid var(--soon-col); }
.card-title { font-size: .95rem; font-weight: 600; line-height: 1.35; }
.card-sub   { font-size: .78rem; color: var(--text2); line-height: 1.4; }
.card-footer {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: auto; padding-top: 8px; border-top: 1px solid var(--border);
  gap: 8px; flex-wrap: wrap;
}
.card-duration { font-size: .72rem; color: var(--text2); }
.card-arrow { font-size: .78rem; color: var(--accent-hl); font-weight: 600; }
.card-links { display: flex; gap: .5rem; }
.card-links a {
  font-size: .72rem; font-weight: 600; text-decoration: none;
  color: var(--accent-hl); border: 1px solid var(--border);
  padding: 3px 9px; border-radius: 6px; transition: border-color .2s;
}
.card-links a:hover { border-color: var(--accent-hl); }

/* ---------- FOOTER ---------- */
footer {
  background: var(--bg2); border-top: 1px solid var(--border);
  padding: 2rem; text-align: center;
  font-size: .8rem; color: var(--text2); line-height: 1.8;
}
footer a { color: var(--accent-hl); text-decoration: none; }
footer a:hover { text-decoration: underline; }

@media (max-width: 760px) {
  nav { padding: 0 .75rem; }
  .nav-brand span:not(.dot) { display: none; }
  .nav-tag { display: none; }
  .nav-links { gap: .6rem; }
  .nav-links a { font-size: .74rem; }
  #themeLabel { display: none; }
  .hero { padding: 2.5rem 1.25rem 2rem; }
  main { padding: 2rem 1.25rem 4rem; }
  .hero-stats { gap: 1.5rem; }
}