/* ================================================================
   lectures.css  — extends home.css, same design tokens
   ================================================================ */

/* ── Hero ────────────────────────────────────────────────────── */
.lec-hero {
  position: relative; z-index: 1;
  padding: 130px 5% 90px;
  text-align: center;
  background:
    radial-gradient(ellipse 80% 55% at 50% -5%,  rgba(163,230,53,0.12) 0%, transparent 65%),
    radial-gradient(ellipse 45% 35% at 88% 88%,  rgba(99,102,241,0.08) 0%, transparent 55%),
    var(--bg);
  overflow: hidden;
}
.lec-hero::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.022) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.022) 1px, transparent 1px);
  background-size: 56px 56px;
  pointer-events: none;
}
.lec-hero-inner { position: relative; z-index: 1; }

.lec-hero .hero-eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 5px 16px;
  background: var(--lime-dim); border: 1px solid var(--lime-border);
  border-radius: 50px; font-size: 0.78rem; font-weight: 600;
  color: var(--lime); letter-spacing: 0.5px;
  margin-bottom: 28px;
  animation: fade-up 0.5s ease both;
}
.lec-hero h1 {
  font-family: var(--font-h);
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 800; letter-spacing: -3.5px;
  line-height: 1; margin-bottom: 20px;
  animation: fade-up 0.6s 0.1s ease both;
}
.lec-hero h1 em { color: var(--lime); font-style: normal; }
.lec-hero p {
  max-width: 520px; margin: 0 auto 36px;
  color: var(--text-muted); font-size: 1.05rem; line-height: 1.75;
  animation: fade-up 0.6s 0.18s ease both;
}
.lec-hero-btns {
  display: flex; justify-content: center; gap: 14px;
  flex-wrap: wrap; margin-bottom: 48px;
  animation: fade-up 0.6s 0.26s ease both;
}

.lec-stats {
  display: inline-flex; align-items: center;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 50px; padding: 8px 6px;
  animation: fade-up 0.6s 0.34s ease both;
}
.lstat { display: flex; flex-direction: column; align-items: center; padding: 4px 28px; }
.lstat-n {
  font-family: var(--font-h); font-size: 1.4rem;
  font-weight: 800; color: var(--lime); line-height: 1;
}
.lstat-l {
  font-size: 0.68rem; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 1px; margin-top: 3px;
}
.lstat-div { width: 1px; height: 32px; background: var(--border); }

/* ── Quick nav ───────────────────────────────────────────────── */
.quick-nav {
  position: sticky; top: 66px; z-index: 100;
  background: rgba(10,12,16,0.92);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  padding: 0 5%;
  display: flex; gap: 2px; flex-wrap: nowrap;
  overflow-x: auto;
}
.quick-nav::-webkit-scrollbar { display: none; }
.qn-btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 14px 18px;
  font-family: var(--font-h); font-size: 0.82rem; font-weight: 700;
  color: var(--text-muted); white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color var(--t), border-color var(--t);
  flex-shrink: 0;
}
.qn-btn:hover, .qn-btn.active { color: var(--lime); border-bottom-color: var(--lime); }

/* ── Section wrapper ─────────────────────────────────────────── */
.lec-sec {
  position: relative; z-index: 1;
  padding: 90px 5% 80px;
}
.lec-sec.bg-dark  { background: var(--bg); }
.lec-sec.bg-alt   { background: var(--bg2); }

.lec-sec-head {
  max-width: 1200px; margin: 0 auto 44px;
  display: flex; align-items: flex-end;
  justify-content: space-between; flex-wrap: wrap; gap: 20px;
}
.lec-sec-left h2 {
  font-family: var(--font-h);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 800; letter-spacing: -1.5px;
  line-height: 1.08; margin: 6px 0 8px;
}
.lec-sec-left p { color: var(--text-muted); font-size: 0.9rem; max-width: 480px; line-height: 1.65; }

.yt-cta-small {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 18px;
  background: rgba(255,0,0,0.1); border: 1px solid rgba(255,0,0,0.22);
  border-radius: 50px; font-family: var(--font-h);
  font-size: 0.82rem; font-weight: 700; color: #f87171;
  white-space: nowrap;
  transition: background var(--t);
}
.yt-cta-small:hover { background: rgba(255,0,0,0.2); }

/* ── Playlist grid ───────────────────────────────────────────── */
.pl-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 18px;
}

/* ── Playlist card ───────────────────────────────────────────── */
.pl-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex; flex-direction: column;
  transition: border-color var(--t), transform var(--t), box-shadow var(--t);
  cursor: pointer;
}
.pl-card:hover {
  border-color: var(--lime-border);
  transform: translateY(-5px);
  box-shadow: 0 14px 52px rgba(163,230,53,0.09);
}

/* thumbnail area */
.pl-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg3);
  flex-shrink: 0;
}
.pl-ytthumb {
  width: 100%; height: 100%;
  object-fit: cover; display: block;
  transition: transform 0.4s var(--ease);
}
.pl-card:hover .pl-ytthumb { transform: scale(1.04); }

/* play overlay */
.pl-overlay {
  position: absolute; inset: 0;
  background: rgba(10,12,16,0.55);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 10px; z-index: 2;
  transition: background var(--t);
}
.pl-card:hover .pl-overlay { background: rgba(10,12,16,0.35); }
.pl-overlay.hidden { opacity: 0; pointer-events: none; }

.pl-ring {
  width: 52px; height: 52px; border-radius: 50%;
  background: rgba(255,255,255,0.12);
  border: 2px solid rgba(255,255,255,0.4);
  display: flex; align-items: center; justify-content: center;
  transition: background var(--t), border-color var(--t), transform var(--t);
}
.pl-card:hover .pl-ring {
  background: rgba(255,0,0,0.7);
  border-color: transparent;
  transform: scale(1.1);
}
.pl-overlay > span {
  font-family: var(--font-h); font-size: 0.75rem;
  font-weight: 700; color: #fff; letter-spacing: 0.5px;
}

/* badge */
.pl-badge {
  position: absolute; top: 10px; left: 10px; z-index: 3;
  background: var(--lime); color: #0a0c10;
  font-family: var(--font-h); font-size: 0.62rem; font-weight: 800;
  letter-spacing: 1.5px; text-transform: uppercase;
  padding: 3px 10px; border-radius: 50px;
}

/* iframe inside thumb (shown after click) */
.pl-iframe-wrap {
  position: absolute; inset: 0; z-index: 4;
  display: none;
}
.pl-iframe-wrap.active { display: block; }
.pl-iframe-wrap iframe {
  width: 100%; height: 100%; border: none;
}

/* card body */
.pl-body {
  padding: 16px 18px 20px;
  display: flex; flex-direction: column; gap: 5px; flex: 1;
}
.pl-cat {
  font-size: 0.68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 2px;
  color: var(--lime);
}
.pl-title {
  font-family: var(--font-h); font-size: 0.96rem;
  font-weight: 700; color: var(--text); line-height: 1.3;
}
.pl-sub {
  font-size: 0.78rem; color: var(--text-muted); margin-top: 2px;
}

/* ── Divider band ────────────────────────────────────────────── */
.divider-band {
  position: relative; z-index: 1;
  background: var(--lime);
  padding: 20px 5%;
}
.divider-band-inner {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
}
.db-icon { font-size: 1.3rem; }
.divider-band-inner > span {
  flex: 1; font-family: var(--font-h);
  font-size: 0.88rem; font-weight: 700;
  color: #0a0c10;
}
.db-link {
  font-family: var(--font-h); font-size: 0.85rem; font-weight: 800;
  color: #0a0c10; background: rgba(0,0,0,0.12);
  padding: 7px 18px; border-radius: 50px;
  transition: background var(--t);
}
.db-link:hover { background: rgba(0,0,0,0.22); }

/* ── Channel band ────────────────────────────────────────────── */
.channel-band {
  position: relative; z-index: 1;
  padding: 100px 5%;
  background: var(--bg2);
}
.channel-band-inner {
  max-width: 1100px; margin: 0 auto;
  display: grid; grid-template-columns: 1fr 1.4fr;
  gap: 64px; align-items: start;
}
.channel-band-left h2 {
  font-family: var(--font-h);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800; letter-spacing: -2px;
  line-height: 1.05; margin: 8px 0 14px;
}
.channel-band-left h2 em { color: var(--lime); font-style: normal; }
.channel-band-left p { color: var(--text-muted); font-size: 0.95rem; line-height: 1.7; margin-bottom: 28px; }
.channel-band-btns { display: flex; gap: 12px; flex-wrap: wrap; }

/* more playlists list */
.more-pl-list {
  display: flex; flex-direction: column; gap: 12px;
}
.mpl-item {
  display: flex; align-items: center; gap: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  transition: border-color var(--t), transform var(--t);
}
.mpl-item:hover { border-color: var(--lime-border); transform: translateX(5px); }
.mpl-icon { font-size: 1.5rem; flex-shrink: 0; }
.mpl-name {
  font-family: var(--font-h); font-size: 0.9rem; font-weight: 700;
  margin-bottom: 3px;
}
.mpl-desc { font-size: 0.75rem; color: var(--text-muted); }
.mpl-arrow {
  margin-left: auto; font-size: 1.1rem;
  color: var(--text-muted); flex-shrink: 0;
  transition: transform var(--t), color var(--t);
}
.mpl-item:hover .mpl-arrow { transform: translateX(4px); color: var(--lime); }

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 900px) {
  .channel-band-inner { grid-template-columns: 1fr; gap: 40px; }
}
@media (max-width: 640px) {
  .lec-hero { padding: 110px 4% 70px; }
  .lec-hero h1 { letter-spacing: -2px; }
  .lec-sec { padding: 68px 4% 60px; }
  .lec-stats { flex-direction: column; border-radius: 16px; }
  .lstat-div { width: 60%; height: 1px; }
  .lstat { padding: 10px 20px; }
  .pl-grid { grid-template-columns: 1fr; }
  .channel-band { padding: 70px 4%; }
  .lec-sec-head { flex-direction: column; align-items: flex-start; }
}