/* =========================================================
   EXAMDECK — shared design system
   Deep navy console theme. One primary signal color (amber)
   for all interactive UI. Four muted subject colors are used
   ONLY as small structural labels (dot + left border) on
   course cards/pages — they encode which course, not decor.
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700&family=Inter:wght@400;500;600;700&display=swap');

:root{
  --bg: #0A0E1A;
  --surface: #121A2B;
  --surface-2: #1A2338;
  --border: #232E47;
  --text: #EAF0FA;
  --text-muted: #93A0B8;
  --accent: #FFB454;       /* primary signal — buttons, links, focus */
  --accent-ink: #241804;   /* text placed on top of accent fill */
  --ok: #37D6C4;           /* correct / success */
  --bad: #FF6B6B;          /* incorrect */
  --chm: #37D6C4;
  --eng: #6FA8DC;
  --mth: #B39DDB;
  --phy: #FF8A65;
  --radius: 10px;
  --mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin:0;
  background: var(--bg);
  background-image:
    linear-gradient(180deg, rgba(255,180,84,0.05) 0%, rgba(255,180,84,0) 300px),
    repeating-linear-gradient(0deg, rgba(255,255,255,0.018) 0px, rgba(255,255,255,0.018) 1px, transparent 1px, transparent 3px);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.6;
  min-height: 100vh;
}

@media (prefers-reduced-motion: reduce){
  *{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

h1,h2,h3{
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 .5em;
}
h1{ font-size: clamp(1.9rem, 4vw, 3rem); line-height: 1.1; }
h2{ font-size: clamp(1.3rem, 2.6vw, 1.8rem); }
p{ color: var(--text-muted); margin: 0 0 1em; }
a{ color: var(--accent); text-decoration: none; }
a:hover{ text-decoration: underline; }

.eyebrow{
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent);
  display:flex; align-items:center; gap:.5em;
}
.eyebrow::before{ content:''; width:6px; height:6px; border-radius:50%; background: var(--accent); box-shadow: 0 0 8px var(--accent); }

.wrap{ max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ---------- nav ---------- */
.nav{
  position: sticky; top:0; z-index: 40;
  background: rgba(10,14,26,0.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav .wrap{ display:flex; align-items:center; justify-content:space-between; height:64px; }
.brand{ font-family: var(--mono); font-weight:700; font-size:1.05rem; color:var(--text); display:flex; align-items:center; gap:.5em; }
.brand .dot{ width:8px; height:8px; border-radius:50%; background:var(--accent); box-shadow:0 0 10px var(--accent); }
.navlinks{ display:flex; align-items:center; gap:22px; font-family: var(--mono); font-size:.85rem; }
.navlinks a{ color: var(--text-muted); }
.navlinks a:hover{ color: var(--text); text-decoration:none; }
.navlinks a.current{ color: var(--accent); }
.btn-nav{
  border:1px solid var(--border); padding:8px 16px; border-radius: var(--radius);
  color: var(--text) !important;
}
.btn-nav:hover{ border-color: var(--accent); text-decoration:none !important; }
.navtoggle{ display:none; }

/* ---------- buttons ---------- */
.btn{
  font-family: var(--mono);
  font-size:.85rem;
  font-weight:600;
  letter-spacing:.02em;
  padding: 12px 22px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  display: inline-flex; align-items:center; gap:.6em;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
}
.btn:focus-visible, a:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible, button:focus-visible{
  outline: 2px solid var(--accent); outline-offset: 2px;
}
.btn-primary{ background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover{ transform: translateY(-1px); box-shadow: 0 8px 24px rgba(255,180,84,.25); text-decoration:none; }
.btn-ghost{ background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover{ border-color: var(--accent); color: var(--accent); text-decoration:none; }
.btn:disabled{ opacity:.45; cursor:not-allowed; transform:none !important; box-shadow:none !important; }
.btn-block{ width:100%; justify-content:center; }

/* ---------- hero ---------- */
.hero{ padding: 84px 0 56px; border-bottom: 1px solid var(--border); }
.hero .lede{ font-size: 1.05rem; max-width: 640px; }
.hero-actions{ display:flex; gap:14px; flex-wrap:wrap; margin-top: 28px; }
.bootline{ font-family: var(--mono); font-size:.78rem; color: var(--text-muted); margin-bottom: 18px; }
.bootline b{ color: var(--ok); }

/* voice banner */
.voice-banner{
  margin-top: 30px;
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 16px 18px;
  display:flex; align-items:center; gap:14px; flex-wrap:wrap;
}
.voice-banner .pulse{
  width:38px; height:38px; border-radius:50%;
  border:1px solid var(--accent);
  display:flex; align-items:center; justify-content:center;
  color: var(--accent); flex-shrink:0;
}
.voice-banner .pulse.playing{ animation: pulse 1.4s ease-in-out infinite; }
@keyframes pulse{ 0%,100%{ box-shadow:0 0 0 0 rgba(255,180,84,.35);} 50%{ box-shadow:0 0 0 10px rgba(255,180,84,0);} }
.voice-banner .vb-text{ flex:1; min-width:200px; font-size:.9rem; color:var(--text-muted); }
.voice-banner .vb-text b{ color:var(--text); }

/* ---------- section ---------- */
.section{ padding: 56px 0; }
.section-head{ display:flex; align-items:flex-end; justify-content:space-between; gap:16px; margin-bottom: 28px; flex-wrap:wrap; }

/* ---------- course grid/cards ---------- */
.grid{ display:grid; grid-template-columns: repeat(3,1fr); gap:18px; }
.card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--card-accent, var(--accent));
  border-radius: var(--radius);
  padding: 22px;
  transition: transform .15s ease, border-color .15s ease;
  display:block; color:var(--text);
}
.card:hover{ transform: translateY(-3px); text-decoration:none; border-color: var(--card-accent, var(--accent)); }
.card .code{ font-family: var(--mono); font-size:.72rem; letter-spacing:.12em; color: var(--card-accent, var(--accent)); display:flex; align-items:center; gap:.5em; margin-bottom:10px; }
.card .code .dot{ width:6px; height:6px; border-radius:50%; background: var(--card-accent, var(--accent)); }
.card h3{ font-family:var(--sans); font-size:1.08rem; margin-bottom:6px; }
.card p{ font-size:.88rem; margin-bottom:0; }

/* ---------- misc panels ---------- */
.panel{ background: var(--surface); border:1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.panel + .panel{ margin-top: 16px; }

.pill{ font-family: var(--mono); font-size:.7rem; letter-spacing:.08em; text-transform:uppercase; padding:4px 10px; border-radius:100px; border:1px solid var(--border); color:var(--text-muted); display:inline-block; }

/* ---------- forms ---------- */
label{ display:block; font-family: var(--mono); font-size:.78rem; color: var(--text-muted); margin-bottom:6px; letter-spacing:.03em; }
input[type=text], input[type=email], input[type=password], textarea, select{
  width:100%; background: var(--bg); border:1px solid var(--border); color: var(--text);
  padding: 12px 14px; border-radius: var(--radius); font-family: var(--sans); font-size:.95rem;
  margin-bottom: 18px;
}
textarea{ resize: vertical; min-height: 90px; }
.field-note{ font-size:.78rem; color:var(--text-muted); margin-top:-12px; margin-bottom:18px; }

/* ---------- footer ---------- */
footer{ border-top:1px solid var(--border); padding: 32px 0; margin-top: 60px; }
footer .wrap{ display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:12px; }
footer p{ font-size:.8rem; margin:0; }

/* ---------- music player ---------- */
.player{
  background: var(--surface); border:1px solid var(--border); border-radius: var(--radius);
  padding: 18px; position: sticky; top: 84px;
}
.player h3{ font-size:.95rem; margin-bottom:4px; }
.player .sub{ font-size:.78rem; color:var(--text-muted); margin-bottom:16px; }
.track-list{ display:flex; flex-direction:column; gap:8px; margin-bottom:16px; }
.track-btn{
  text-align:left; background: var(--bg); border:1px solid var(--border); color:var(--text);
  padding: 10px 12px; border-radius:8px; font-family: var(--sans); font-size:.85rem; cursor:pointer;
  display:flex; align-items:center; gap:10px;
}
.track-btn:hover{ border-color: var(--accent); }
.track-btn.active{ border-color: var(--accent); color: var(--accent); }
.track-btn .n{ font-family: var(--mono); font-size:.72rem; color: var(--text-muted); }
.player-frame{ width:100%; aspect-ratio:16/9; border-radius:8px; overflow:hidden; border:1px solid var(--border); background:#000; }
.player-frame iframe{ width:100%; height:100%; border:0; }
.player-empty{ display:flex; align-items:center; justify-content:center; height:100%; color:var(--text-muted); font-size:.8rem; font-family:var(--mono); }

/* ---------- layout helpers ---------- */
.two-col{ display:grid; grid-template-columns: 1fr 320px; gap:22px; align-items:start; }
.stack{ display:flex; flex-direction:column; gap:14px; }
.row{ display:flex; gap:14px; flex-wrap:wrap; }

/* ---------- quiz ---------- */
.progress-track{ height:6px; background:var(--surface-2); border-radius:100px; overflow:hidden; margin-bottom:28px; }
.progress-fill{ height:100%; background:var(--accent); border-radius:100px; transition: width .25s ease; }
.q-card{ background:var(--surface); border:1px solid var(--border); border-radius: var(--radius); padding:26px; }
.q-count{ font-family:var(--mono); font-size:.75rem; color:var(--text-muted); margin-bottom:10px; }
.q-text{ font-size:1.15rem; margin-bottom:20px; color:var(--text); }
.options{ display:flex; flex-direction:column; gap:10px; }
.option{
  display:flex; align-items:center; gap:12px; padding:13px 15px; border-radius:8px;
  border:1px solid var(--border); background:var(--bg); cursor:pointer; font-size:.95rem;
}
.option:hover{ border-color: var(--accent); }
.option input{ accent-color: var(--accent); }
.option.chosen{ border-color: var(--accent); background: rgba(255,180,84,.06); }
.quiz-actions{ display:flex; justify-content:space-between; margin-top:24px; }

/* results */
.score-block{ text-align:center; padding: 36px 20px; }
.score-num{ font-family:var(--mono); font-size:3.2rem; font-weight:700; color:var(--accent); }
.score-sub{ font-family:var(--mono); font-size:.85rem; color:var(--text-muted); letter-spacing:.06em; }
.review-item{ background:var(--surface); border:1px solid var(--border); border-left:3px solid var(--bad); border-radius: var(--radius); padding:18px; margin-bottom:12px; }
.review-item.correct{ border-left-color: var(--ok); }
.review-item .tag{ font-family:var(--mono); font-size:.7rem; letter-spacing:.08em; text-transform:uppercase; }
.review-item.correct .tag{ color:var(--ok); }
.review-item.wrong .tag{ color:var(--bad); }
.review-item p{ margin:6px 0; font-size:.88rem; }
.review-item .ans-you{ color: var(--text); }
.review-item .ans-correct{ color: var(--ok); }
.review-item .explain{ color:var(--text-muted); font-style:italic; }

/* ---------- comments ---------- */
.comment{ display:flex; gap:12px; padding:16px 0; border-bottom:1px solid var(--border); }
.comment .avatar{ width:36px; height:36px; border-radius:50%; background:var(--surface-2); border:1px solid var(--border); display:flex; align-items:center; justify-content:center; font-family:var(--mono); font-size:.8rem; color:var(--accent); flex-shrink:0; }
.comment .meta{ font-family:var(--mono); font-size:.72rem; color:var(--text-muted); margin-bottom:4px; }
.comment .body{ font-size:.92rem; }
.sticker-tray{ display:flex; gap:8px; flex-wrap:wrap; margin-bottom:14px; }
.sticker-btn{ font-size:1.3rem; background:var(--bg); border:1px solid var(--border); border-radius:8px; width:44px; height:44px; cursor:pointer; }
.sticker-btn:hover{ border-color:var(--accent); }
.sticker-btn.active{ border-color:var(--accent); background:rgba(255,180,84,.08); }
.sticker-inline{ font-size:1.1rem; margin-left:6px; }

/* ---------- lock / paywall ---------- */
.lock-card{ text-align:center; padding: 48px 24px; }
.lock-card .icon{ font-family:var(--mono); font-size:.75rem; letter-spacing:.1em; color:var(--bad); margin-bottom:14px; }

/* ---------- utility ---------- */
.muted{ color: var(--text-muted); }
.mono{ font-family: var(--mono); }
.center{ text-align:center; }
.mt-0{ margin-top:0; }
.small{ font-size:.82rem; }
.hidden{ display:none !important; }

@media (max-width: 860px){
  .grid{ grid-template-columns: repeat(2,1fr); }
  .two-col{ grid-template-columns: 1fr; }
  .player{ position: static; }
}
@media (max-width: 560px){
  .grid{ grid-template-columns: 1fr; }
  .navlinks{ display:none; }
  .hero{ padding: 56px 0 40px; }
  .quiz-actions{ flex-direction:column; gap:12px; }
}