:root {
  --bg: #060912;
  --panel: rgba(14, 20, 35, 0.86);
  --line: rgba(255, 255, 255, 0.14);
  --text: #f5f8ff;
  --muted: #aebbd4;
  --brand: #f5c04f;
  --active: #82a7ff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: 'Manrope', ui-sans-serif, system-ui, -apple-system, sans-serif;
  background:
    radial-gradient(circle at 20% 0%, rgba(103, 131, 255, 0.20), transparent 34%),
    radial-gradient(circle at 80% 10%, rgba(245, 192, 79, 0.16), transparent 32%),
    linear-gradient(180deg, #0c1222 0%, #060912 56%, #03050a 100%);
}

.themes-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  border-bottom: 1px solid var(--line);
  background: rgba(6, 9, 18, 0.7);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 100;
}
.back-link {
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  transition: color .18s;
}
.back-link:hover { color: var(--text); }

.btn-demo {
  background: var(--brand);
  color: #0a0a0a;
  border: none;
  border-radius: 999px;
  padding: 10px 20px;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  text-decoration: none;
  transition: opacity .18s, transform .18s;
}
.btn-demo:hover { opacity: 0.88; transform: translateY(-1px); }
.btn-demo.lg { padding: 14px 32px; font-size: 16px; }

.page-shell { width: min(1380px, calc(100vw - 36px)); margin: 0 auto; }
.hero {
  padding: 54px 0 26px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 30px;
  align-items: end;
}
.eyebrow { color: var(--brand); font-weight: 800; letter-spacing: .12em; text-transform: uppercase; font-size: 13px; }
h1 { margin: 12px 0 10px; font-size: clamp(36px, 5vw, 74px); line-height: .94; letter-spacing: -0.055em; font-family: 'Plus Jakarta Sans', sans-serif; }
.hero p { margin: 0; max-width: 840px; color: var(--muted); font-size: clamp(16px, 1.45vw, 21px); line-height: 1.55; }

.theme-nav, .mode-buttons { display: flex; gap: 10px; flex-wrap: wrap; }
.theme-nav { justify-content: flex-end; }
.theme-btn, .mode-btn {
  border: 1px solid var(--line);
  background: rgba(255,255,255,.06);
  color: var(--text);
  border-radius: 999px;
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
  font-size: 14px;
  font-family: inherit;
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}
.theme-btn:hover, .mode-btn:hover { transform: translateY(-1px); background: rgba(255,255,255,.10); }
.theme-btn.active, .mode-btn.active {
  border-color: var(--active);
  background: color-mix(in srgb, var(--active) 24%, rgba(255,255,255,.07));
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--active) 55%, transparent) inset;
}

.stage-card {
  border: 1px solid var(--line);
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(255,255,255,.08), rgba(255,255,255,.025));
  padding: 14px;
  box-shadow: 0 26px 85px rgba(0,0,0,.46);
}
.stage {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border-radius: 20px;
  background: #050812;
  isolation: isolate;
}
.bg, .full-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.full-video { z-index: 1; background: #000; }
.flashboard {
  position: absolute;
  top: 7.1%;
  left: 3.55%;
  width: 93%;
  height: auto;
  z-index: 2;
  filter: drop-shadow(0 10px 18px rgba(0,0,0,.35));
}
.card-preview {
  position: absolute;
  left: 14.5%;
  bottom: 5.5%;
  width: 16.2%;
  z-index: 3;
  filter: drop-shadow(0 14px 22px rgba(0,0,0,.42));
}
.card-preview.right { left: auto; right: 13.2%; }
.foreground {
  position: absolute;
  left: 50%;
  bottom: 3%;
  width: 21%;
  aspect-ratio: 1;
  transform: translateX(-50%);
  z-index: 3;
  object-fit: contain;
  pointer-events: none;
  filter: drop-shadow(0 15px 25px rgba(0,0,0,.40));
}
.overlay-top {
  position: absolute;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(0,0,0,.28) 0%, rgba(0,0,0,0) 18%),
    linear-gradient(0deg, rgba(0,0,0,.18) 0%, rgba(0,0,0,0) 20%);
}
.mock-title, .mock-count {
  position: absolute;
  top: 2.1%;
  z-index: 5;
  font-weight: 900;
  font-size: clamp(12px, 1.6vw, 25px);
  text-shadow: 0 2px 10px rgba(0,0,0,.7);
  font-family: 'Plus Jakarta Sans', sans-serif;
}
.mock-title { left: 2.5%; }
.mock-count { right: 2.5%; }
.video-note {
  position: absolute;
  left: 16px;
  bottom: 14px;
  z-index: 3;
  background: rgba(0,0,0,.54);
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 999px;
  padding: 7px 11px;
  color: rgba(255,255,255,.86);
  font-size: 13px;
}
.mode-panel {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  margin-top: 16px;
  flex-wrap: wrap;
}
.theme-copy h2 { margin: 0 0 5px; font-size: 29px; letter-spacing: -0.02em; font-family: 'Plus Jakarta Sans', sans-serif; }
.theme-copy p { margin: 0; color: var(--muted); line-height: 1.45; }

.showcase-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin: 30px 0 0; }
.mini-card { border: 1px solid var(--line); border-radius: 18px; overflow: hidden; background: var(--panel); cursor: pointer; transition: transform .18s, border-color .18s; }
.mini-card:hover { transform: translateY(-3px); border-color: rgba(255,255,255,.28); }
.mini-card img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; display: block; }
.mini-card div { padding: 14px; }
.mini-card strong { display: block; margin-bottom: 5px; font-family: 'Plus Jakarta Sans', sans-serif; }
.mini-card span { color: var(--muted); font-size: 14px; line-height: 1.35; }

.cta-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin: 40px 0 60px;
  padding: 28px 32px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: linear-gradient(135deg, rgba(245,192,79,.08), rgba(130,167,255,.06));
}
.cta-strip p { margin: 0; font-size: 18px; font-weight: 600; font-family: 'Plus Jakarta Sans', sans-serif; }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; align-items: start; }
  .theme-nav { justify-content: flex-start; }
  .showcase-grid { grid-template-columns: 1fr; }
  .card-preview { width: 22%; left: 7%; }
  .card-preview.right { right: 7%; }
  .foreground { width: 25%; }
  .cta-strip { flex-direction: column; text-align: center; }
}