/* 算法可视化实验室 - Ink & Amber
   配色纪律：中性暖墨黑底 + 单一琥珀强调色，全站锁定，不出现第二种强调色。
   圆角纪律：卡片 10px / 按钮输入 8px / 标签胶囊，其余一律不加圆角。 */
:root {
  color-scheme: dark;
  --bg: #0d0e11;
  --bg-soft: #121317;
  --card: #16181d;
  --card-2: #1c1e24;
  --line: #272a32;
  --text: #ecebe3;
  --muted: #99968a;
  --accent: #e2ac4a;        /* 唯一强调色 */
  --accent-deep: #a97e2f;   /* 同色系深一档，仅用于次级标记 */
  --ok: #7fb069;
  --danger: #d9705f;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Consolas, monospace;
}

/* 亮色模式：跟随系统偏好，仅换 token，层次结构与暗色完全一致。
   画布（canvas 黑板井）两种模式下都保持深色：引擎绘图色按深底绘制。 */
@media (prefers-color-scheme: light) {
  :root {
    color-scheme: light;
    --bg: #f3f2ec;
    --bg-soft: #ebe9e1;
    --card: #fcfbf8;
    --card-2: #f1efe7;
    --line: #d8d4c7;
    --text: #26251f;
    --muted: #6f6b5e;
    --accent: #9c6f21;
    --accent-deep: #7c5a1e;
  }
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  line-height: 1.75;
  font-size: 15px;
}

/* ---------- hero ---------- */
.hero {
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  padding: 68px 24px 54px;
}
.hero-inner { max-width: 1080px; margin: 0 auto; }
.hero-kicker {
  color: var(--accent);
  font-family: var(--mono);
  letter-spacing: .14em;
  font-size: 12px;
  margin-bottom: 16px;
}
.hero h1 {
  font-size: clamp(30px, 5vw, 46px);
  font-weight: 800;
  letter-spacing: .02em;
  color: var(--text);
  margin-bottom: 14px;
}
.hero-sub { color: var(--muted); max-width: 65ch; }
.hero-sub b { color: var(--text); font-weight: 600; }
.hero-stats { display: flex; gap: 20px; margin-top: 24px; flex-wrap: wrap; }
.hero-stats span {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  padding-left: 14px;
  border-left: 1px solid var(--line);
}
.hero-stats span:first-child { border-left: none; padding-left: 0; }
.hero-pz-link {
  display: inline-block;
  margin-top: 26px;
  padding: 10px 22px;
  border-radius: 8px;
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: 14.5px;
  font-weight: 600;
  text-decoration: none;
  transition: background .15s ease, color .15s ease;
}
.hero-pz-link:hover { background: var(--accent); color: #141008; }
.hero-pz-link:active { transform: translateY(1px); }

/* ---------- layout ---------- */
.layout { display: flex; max-width: 1400px; margin: 0 auto; }

.sidebar {
  position: sticky;
  top: 0;
  align-self: flex-start;
  width: 232px;
  flex: 0 0 232px;
  padding: 28px 14px 28px 20px;
  max-height: 100vh;
  overflow-y: auto;
}
.nav-title {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--muted);
  letter-spacing: .18em;
  margin: 0 0 10px 12px;
}
.sidebar a {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 13.5px;
  border-left: 2px solid transparent;
  transition: color .18s ease, background .18s ease;
}
.sidebar a i {
  font-style: normal;
  font-size: 11px;
  color: var(--accent-deep);
  font-family: var(--mono);
  width: 18px;
}
.sidebar a:hover { color: var(--text); background: var(--card); }
.sidebar a.active {
  color: var(--text);
  background: var(--card);
  border-left-color: var(--accent);
}

.content { flex: 1; min-width: 0; padding: 36px 32px 60px; }

/* ---------- algo section ---------- */
.algo { margin-bottom: 72px; scroll-margin-top: 18px; }

.algo-head { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 18px; }
.algo-index {
  font-family: var(--mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.3;
}
.algo-titles { flex: 1; min-width: 0; }
.algo-titles h2 { font-size: 22px; font-weight: 700; }
.algo-titles .en {
  color: var(--muted);
  font-size: 12.5px;
  font-weight: 400;
  font-family: var(--mono);
  margin-left: 8px;
}
.algo-sub { color: var(--muted); font-size: 13.5px; margin-top: 4px; }

/* 策略标签：统一中性描边，不再一策略一色 */
.tag {
  flex: 0 0 auto;
  font-size: 12px;
  padding: 3px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  background: transparent;
  margin-top: 6px;
}

/* ---------- demo card ---------- */
.demo-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}
.demo-card canvas {
  display: block;
  width: 100%;
  aspect-ratio: 960 / 470;
  background: #101114;
}
.controls {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  flex-wrap: wrap;
}
.controls button {
  font: inherit;
  font-size: 13px;
  color: var(--text);
  background: var(--card-2);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 6px 16px;
  cursor: pointer;
  transition: border-color .15s ease, color .15s ease;
}
.controls button:hover { border-color: var(--accent); color: var(--accent); }
.controls button:active { transform: translateY(1px); }
.controls button.primary { border-color: var(--accent); color: var(--accent); }
.speed { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 12.5px; margin-left: 6px; }
.speed input { width: 110px; accent-color: var(--accent); }
.status {
  margin-left: auto;
  font-size: 12.5px;
  color: var(--accent);
  font-family: var(--mono);
  text-align: right;
  min-width: 0;
}

/* ---------- info cards ---------- */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 16px;
}
.info {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px 22px;
  background: var(--card);
}
.info h3 {
  font-size: 15px;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.info h3::before {
  content: "";
  width: 4px;
  height: 16px;
  border-radius: 2px;
  background: var(--accent);
}
.info.case h3::before { background: var(--accent-deep); }
.info h4 { font-size: 13.5px; color: var(--accent); font-weight: 600; margin: 14px 0 6px; }
.info.case h4 { color: var(--accent-deep); }
.info p { color: var(--muted); font-size: 14px; }
.info p b { color: var(--text); font-weight: 600; }

.footer {
  border-top: 1px solid var(--line);
  padding: 26px 8px;
  color: var(--muted);
  font-size: 12.5px;
}

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .layout { flex-direction: column; }
  .sidebar {
    position: static;
    width: 100%;
    max-height: none;
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 16px;
  }
  .nav-title { display: none; }
  .sidebar a { white-space: nowrap; border-left: none; border: 1px solid var(--line); }
  .content { padding: 20px 16px 48px; }
  .info-grid { grid-template-columns: 1fr; }
  .status { margin-left: 0; width: 100%; text-align: left; }
}

/* ---------- reduced motion：关掉平滑滚动与所有位移动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
  .hero-pz-link:active,
  .controls button:active { transform: none; }
}