/* ── Day-drive theme (sáng) ────────────────────────────────────── */
:root {
  --asphalt: #f6f4ee;         /* nền giấy sáng ấm */
  --asphalt-2: #ffffff;
  --card: #ffffff;
  --card-edge: #e3ded2;
  --lane: #e0a800;            /* vàng vạch kẻ đường, đậm để đủ tương phản */
  --lane-bright: #f5c518;     /* vàng tươi cho nền badge/nút */
  --lane-dim: #b58900;
  --ink: #23272e;
  --ink-dim: #7a8190;
  --ok: #1f9d55;
  --bad: #d64541;
  --radius: 14px;
  --font-display: "Bricolage Grotesque", sans-serif;
  --font-body: "Be Vietnam Pro", sans-serif;
}

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

body {
  font-family: var(--font-body);
  background:
    radial-gradient(1200px 500px at 80% -10%, rgba(224, 168, 0, 0.08), transparent 60%),
    radial-gradient(900px 400px at 0% 110%, rgba(31, 157, 85, 0.05), transparent 60%),
    var(--asphalt);
  color: var(--ink);
  min-height: 100vh;
  padding-bottom: 48px;
}

/* ── Topbar ────────────────────────────────────────────────────── */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 28px;
  border-bottom: 1px solid var(--card-edge);
  background: linear-gradient(180deg, rgba(224,168,0,.07), rgba(255,255,255,.6));
}

.brand { display: flex; align-items: center; gap: 14px; }

.brand-badge {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.5rem;
  color: #23272e;
  background: var(--lane-bright);
  border-radius: 10px;
  padding: 8px 12px;
  letter-spacing: -0.03em;
  box-shadow: 0 4px 14px rgba(224,168,0,.3);
}

.brand-text h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}
.brand-text p { color: var(--ink-dim); font-size: 0.82rem; margin-top: 2px; }

.scorebox { text-align: right; }
.scorebox-label { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--ink-dim); }
.scorebox-value {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.7rem;
  color: var(--lane-dim);
}
.scorebox-value small { color: var(--ink-dim); font-size: 0.9rem; margin-left: 4px; }

/* ── Layout ────────────────────────────────────────────────────── */
.layout {
  display: grid;
  grid-template-columns: minmax(380px, 7fr) minmax(340px, 5fr);
  gap: 22px;
  padding: 22px 28px;
  align-items: start;
}
@media (max-width: 980px) { .layout { grid-template-columns: 1fr; } }

/* ── Video pane ────────────────────────────────────────────────── */
.video-pane {
  background: var(--asphalt-2);
  border: 1px solid var(--card-edge);
  border-radius: var(--radius);
  padding: 16px;
  position: sticky;
  top: 16px;
  box-shadow: 0 6px 24px rgba(35,39,46,.06);
}
@media (max-width: 980px) { .video-pane { position: static; } }

.video-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 12px;
}
.q-number {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.4rem;
}
.q-number span { color: var(--lane); }
.q-meta { color: var(--ink-dim); font-size: 0.85rem; }

.video-frame {
  position: relative;
  border-radius: 10px;
  overflow: hidden;
  background: #000;
  border: 1px solid var(--card-edge);
}
.video-frame video { width: 100%; aspect-ratio: 16 / 9; display: block; background: #000; }

/* vạch kẻ đường trang trí dưới video */
.lane-strip {
  height: 6px;
  background: repeating-linear-gradient(90deg,
    var(--lane) 0 36px, transparent 36px 64px);
  opacity: 0.85;
}

.video-actions { display: flex; gap: 10px; margin-top: 14px; }
.video-actions .btn { flex: 1; }

.reveal {
  margin-top: 14px;
  padding: 14px 16px;
  border-radius: 10px;
  background: rgba(224,168,0,.07);
  border: 1px dashed rgba(181,137,0,.45);
  animation: fadeUp .35s ease;
}
.reveal h3 {
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: .12em;
  color: var(--lane-dim); margin-bottom: 4px;
}
.reveal p { font-size: 0.9rem; color: var(--ink); margin-bottom: 10px; line-height: 1.5; }
.reveal p:last-child { margin-bottom: 0; }

/* ── Quiz pane ─────────────────────────────────────────────────── */
.qcard {
  background: var(--card);
  border: 1px solid var(--card-edge);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 14px;
  animation: fadeUp .35s ease both;
  box-shadow: 0 4px 16px rgba(35,39,46,.05);
}
.qcard:nth-child(2) { animation-delay: .05s; }
.qcard:nth-child(3) { animation-delay: .10s; }
.qcard:nth-child(4) { animation-delay: .15s; }

.qcard-label {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--lane-dim);
  background: rgba(224,168,0,.1);
  border: 1px solid rgba(224,168,0,.35);
  padding: 3px 9px;
  border-radius: 99px;
  margin-bottom: 8px;
}
.qcard-title { font-weight: 600; font-size: 0.98rem; margin-bottom: 12px; line-height: 1.45; }

.opt {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 9px;
  border: 1px solid var(--card-edge);
  background: var(--asphalt);
  cursor: pointer;
  margin-bottom: 8px;
  font-size: 0.9rem;
  line-height: 1.45;
  transition: border-color .15s, background .15s, transform .1s;
}
.opt:hover { border-color: var(--lane-dim); transform: translateX(2px); }
.opt input { margin-top: 3px; accent-color: var(--lane); flex-shrink: 0; }

.opt.selected { border-color: var(--lane); background: rgba(224,168,0,.1); }
.opt.correct  { border-color: var(--ok);  background: rgba(31,157,85,.1); }
.opt.wrong    { border-color: var(--bad); background: rgba(214,69,65,.1); }
.opt.disabled { pointer-events: none; }

.qcard-result { font-size: 0.82rem; font-weight: 600; margin-top: 4px; }
.qcard-result.ok  { color: var(--ok); }
.qcard-result.bad { color: var(--bad); }

.quiz-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.q-score {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  padding: 8px 16px;
  border-radius: 99px;
  border: 1px solid var(--card-edge);
  background: var(--card);
  box-shadow: 0 3px 10px rgba(35,39,46,.06);
  animation: fadeUp .3s ease;
}
.q-score strong { color: var(--lane-dim); }

/* ── Buttons ───────────────────────────────────────────────────── */
.btn {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.88rem;
  padding: 10px 18px;
  border-radius: 9px;
  border: 1px solid var(--card-edge);
  cursor: pointer;
  transition: transform .1s, box-shadow .15s, background .15s;
}
.btn:active { transform: scale(.97); }
.btn.primary {
  background: var(--lane-bright);
  border-color: var(--lane-bright);
  color: #23272e;
  box-shadow: 0 4px 14px rgba(224,168,0,.3);
}
.btn.primary:hover { box-shadow: 0 6px 20px rgba(224,168,0,.45); }
.btn.ghost { background: var(--card); color: var(--ink); }
.btn.ghost:hover { background: rgba(224,168,0,.08); border-color: var(--lane-dim); }
.btn.tiny { font-size: 0.75rem; padding: 5px 10px; }
.btn:disabled { opacity: .45; cursor: not-allowed; }

/* ── Navigation grid ───────────────────────────────────────────── */
.navgrid-wrap { padding: 6px 28px 0; }
.navgrid-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-dim);
}

.navgrid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(46px, 1fr));
  gap: 7px;
}
.navcell {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.85rem;
  padding: 9px 0;
  text-align: center;
  border-radius: 8px;
  border: 1px solid var(--card-edge);
  background: var(--card);
  color: var(--ink-dim);
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.navcell:hover { border-color: var(--lane-dim); color: var(--ink); }
.navcell.active { border-color: var(--lane); color: var(--lane-dim); box-shadow: 0 0 0 3px rgba(224,168,0,.2); }
.navcell.full    { background: rgba(31,157,85,.12); border-color: rgba(31,157,85,.5);  color: var(--ok); }
.navcell.partial { background: rgba(224,168,0,.12); border-color: rgba(224,168,0,.5);  color: var(--lane-dim); }
.navcell.zero    { background: rgba(214,69,65,.1);  border-color: rgba(214,69,65,.45); color: var(--bad); }

.hidden { display: none !important; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: none; }
}