:root {
  color-scheme: dark;
  --bg: #06100d;
  --surface: #0b1713;
  --surface-2: #101e19;
  --line: #263a32;
  --text: #f0f4ea;
  --muted: #9aaba3;
  --acid: #c9f45a;
  --mint: #6ce3b9;
  --cyan: #67d5f3;
  --coral: #ff7a72;
  --mono: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  --serif: "Noto Serif SC", "Songti SC", SimSun, serif;
  --sans: Inter, "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  background:
    linear-gradient(rgba(108, 227, 185, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(108, 227, 185, .035) 1px, transparent 1px),
    radial-gradient(circle at 80% 10%, rgba(108, 227, 185, .09), transparent 28%),
    var(--bg);
  background-size: 56px 56px, 56px 56px, auto, auto;
  color: var(--text);
  font-family: var(--sans);
}

button, a { font: inherit; }
a { color: inherit; text-decoration: none; }
button { color: inherit; }

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 4vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(6, 16, 13, .9);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
}

.brand-mark {
  display: grid;
  width: 30px;
  height: 30px;
  place-items: center;
  border: 1px solid var(--acid);
  border-radius: 50%;
  color: var(--acid);
}

.site-header nav { display: flex; align-items: center; gap: 28px; color: var(--muted); font-size: 14px; }
.site-header nav a:hover { color: var(--text); }
.github-link { padding: 9px 14px; border: 1px solid var(--line); border-radius: 999px; }

main { width: min(1520px, calc(100% - 32px)); margin: 0 auto; }
.hero {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  align-items: end;
  gap: 48px;
  padding: clamp(52px, 8vw, 112px) clamp(0px, 3vw, 44px) 48px;
}

.eyebrow, .panel-label, .section-kicker {
  color: var(--acid);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 20px 0 0;
  font-family: var(--serif);
  font-size: clamp(52px, 7vw, 104px);
  font-weight: 500;
  letter-spacing: -.06em;
  line-height: .95;
}

em { color: var(--acid); font-style: normal; }
.hero > p { max-width: 620px; margin: 0 0 8px; color: var(--muted); font-size: clamp(16px, 1.35vw, 20px); line-height: 1.9; }

.lab { overflow: hidden; border: 1px solid var(--line); border-radius: 18px; background: rgba(9, 20, 16, .94); box-shadow: 0 30px 90px rgba(0, 0, 0, .25); }
.lab-toolbar { display: flex; justify-content: space-between; border-bottom: 1px solid var(--line); }
.scenario-tabs { display: flex; }
.scenario-tab {
  display: grid;
  min-width: 230px;
  gap: 6px;
  padding: 18px 24px;
  border: 0;
  border-right: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  text-align: left;
  cursor: pointer;
}
.scenario-tab small { font-family: var(--mono); font-size: 12px; letter-spacing: .14em; }
.scenario-tab span { font-size: 15px; font-weight: 700; }
.scenario-tab.is-active { background: var(--acid); color: #10170b; }
.step-readout { display: flex; align-items: center; gap: 20px; padding: 0 26px; font-family: var(--mono); font-size: 12px; letter-spacing: .1em; }
.step-readout span { color: var(--muted); }

.lab-grid { display: grid; grid-template-columns: minmax(240px, .78fr) minmax(480px, 1.42fr) minmax(290px, .9fr); min-height: 650px; }
.explain-panel, .visual-panel, .inspect-panel { padding: clamp(24px, 2.5vw, 40px); }
.explain-panel, .visual-panel { border-right: 1px solid var(--line); }
.phase { margin: 32px 0 10px; color: var(--cyan); font-family: var(--mono); font-size: 12px; letter-spacing: .08em; }
.explain-panel h2 { margin: 0; font-family: var(--serif); font-size: clamp(30px, 2.8vw, 48px); font-weight: 500; line-height: 1.16; }
.step-copy { min-height: 116px; margin: 24px 0 0; color: var(--muted); font-size: 16px; line-height: 1.9; }

.why-box, .rule-card { margin-top: 24px; border: 1px solid var(--line); background: var(--surface-2); }
.why-box { padding: 18px; border-left: 3px solid var(--acid); }
.why-box span, .rule-card span { color: var(--acid); font-family: var(--mono); font-size: 12px; font-weight: 700; letter-spacing: .15em; }
.why-box p { margin: 8px 0 0; font-size: 14px; line-height: 1.75; }
.rule-card { display: grid; gap: 10px; padding: 18px; }
.rule-card code { color: var(--muted); font-family: var(--mono); font-size: 12px; }

.panel-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; }
.panel-head h2 { margin: 8px 0 0; font-family: var(--serif); font-size: 28px; font-weight: 500; }
.legend { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 14px; color: var(--muted); font-size: 12px; }
.legend span { display: flex; align-items: center; gap: 6px; }
.legend i { width: 9px; height: 9px; border-radius: 50%; }
.current-dot { background: var(--acid); }
.compare-dot { background: var(--cyan); }

.tree-stage { position: relative; height: 360px; margin: 18px 0 12px; }
.tree-lines { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.tree-lines line { stroke: #395148; stroke-width: .65; vector-effect: non-scaling-stroke; transition: stroke 400ms ease; }
.tree-lines line.is-active { stroke: var(--cyan); stroke-width: 1.25; }
.tree-node {
  position: absolute;
  display: grid;
  width: 64px;
  height: 64px;
  place-items: center;
  transform: translate(-50%, -50%);
  border: 1px solid #49645a;
  border-radius: 50%;
  background: #0d1b16;
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 700;
  transition: left 400ms ease, top 400ms ease, background 400ms ease, border-color 400ms ease, color 400ms ease, transform 400ms ease;
}
.tree-node small { position: absolute; top: -18px; color: var(--muted); font-size: 12px; font-weight: 400; }
.tree-node.is-compare { border-color: var(--cyan); color: var(--cyan); box-shadow: 0 0 0 5px rgba(103, 213, 243, .08); }
.tree-node.is-current { z-index: 2; border-color: var(--acid); background: var(--acid); color: #0b1308; box-shadow: 0 0 0 7px rgba(201, 244, 90, .1); transform: translate(-50%, -50%) scale(1.08); }

.array-section { border-top: 1px solid var(--line); padding-top: 18px; }
.array-caption { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 15px; }
.array-caption span { color: var(--acid); font-family: var(--mono); font-size: 12px; font-weight: 700; letter-spacing: .12em; }
.array-caption code { overflow: hidden; color: var(--muted); font-family: var(--mono); font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.heap-array { display: grid; grid-template-columns: repeat(7, minmax(42px, 1fr)); gap: 7px; }
.array-cell { position: relative; display: grid; min-height: 62px; place-items: center; border: 1px solid var(--line); background: var(--surface); font-family: var(--mono); font-size: 17px; font-weight: 700; transition: all 400ms ease; }
.array-cell small { position: absolute; top: 4px; left: 6px; color: #71827a; font-size: 12px; font-weight: 400; }
.array-cell.is-compare { border-color: var(--cyan); color: var(--cyan); }
.array-cell.is-current { border-color: var(--acid); background: var(--acid); color: #0b1308; }

.inspect-panel { display: flex; min-width: 0; flex-direction: column; justify-content: space-between; gap: 30px; }
.metrics { display: grid; grid-template-columns: repeat(2, 1fr); gap: 9px; margin: 22px 0 0; }
.metrics div { padding: 13px; border: 1px solid var(--line); background: var(--surface-2); }
.metrics dt { color: var(--muted); font-family: var(--mono); font-size: 12px; text-transform: uppercase; }
.metrics dd { margin: 8px 0 0; color: var(--cyan); font-family: var(--mono); font-size: 18px; font-weight: 700; }
.metrics .output-metric { grid-column: 1 / -1; }
.output-metric dd { color: var(--coral); }

.code-block { overflow: hidden; border: 1px solid var(--line); border-radius: 8px; background: #07100e; }
.code-head { display: flex; justify-content: space-between; padding: 12px 14px; border-bottom: 1px solid var(--line); font-family: var(--mono); font-size: 12px; letter-spacing: .1em; }
.code-head span { color: var(--muted); }
.code-head strong { color: var(--acid); }
.code-block ol { margin: 0; padding: 8px 0; list-style-position: inside; }
.code-block li { overflow: hidden; padding: 7px 12px; color: #71827a; font-family: var(--mono); font-size: 12px; line-height: 1.45; text-overflow: ellipsis; white-space: nowrap; transition: all 400ms ease; }
.code-block li::marker { color: #46574f; }
.code-block li.is-active { background: rgba(201, 244, 90, .08); color: var(--text); }
.code-block li.is-active::marker { color: var(--acid); }

.controls { display: flex; min-height: 82px; align-items: center; justify-content: space-between; gap: 24px; padding: 14px 22px; border-top: 1px solid var(--line); background: #08130f; }
.step-dots { display: flex; gap: 8px; }
.step-dot { width: 28px; height: 3px; border: 0; background: #2c4037; transition: background 400ms ease; }
.step-dot.is-past { background: var(--mint); }
.step-dot.is-active { background: var(--acid); }
.control-buttons { display: flex; gap: 9px; }
.control-buttons button { min-height: 42px; padding: 0 17px; border: 1px solid var(--line); border-radius: 5px; background: transparent; cursor: pointer; }
.control-buttons button:hover:not(:disabled) { border-color: var(--muted); }
.control-buttons button:disabled { cursor: not-allowed; opacity: .35; }
.control-buttons .auto-button { border-color: var(--mint); color: var(--mint); }
.control-buttons .auto-button.is-playing { background: var(--mint); color: #07110d; }
.control-buttons .next-button { border-color: var(--acid); background: var(--acid); color: #0b1308; font-weight: 700; }

.principle { padding: clamp(72px, 9vw, 130px) clamp(0px, 3vw, 44px); }
.principle > h2 { max-width: 900px; margin: 18px 0 54px; font-family: var(--serif); font-size: clamp(42px, 6vw, 78px); font-weight: 500; letter-spacing: -.045em; line-height: 1.08; }
.principle-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); }
.principle-grid > div { min-height: 220px; padding: 28px; border-right: 1px solid var(--line); }
.principle-grid > div:last-child { border-right: 0; }
.principle-grid span { color: var(--acid); font-family: var(--mono); font-size: 12px; }
.principle-grid h3 { margin: 28px 0 12px; font-family: var(--serif); font-size: 26px; font-weight: 500; }
.principle-grid p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.8; }
.article-link { display: inline-block; margin-top: 32px; padding-bottom: 5px; border-bottom: 1px solid var(--acid); color: var(--acid); }

@media (max-width: 1160px) {
  .lab-grid { grid-template-columns: minmax(240px, .8fr) minmax(500px, 1.4fr); }
  .inspect-panel { grid-column: 1 / -1; flex-direction: row; border-top: 1px solid var(--line); }
  .inspect-panel > * { width: 50%; }
}

@media (max-width: 780px) {
  .site-header { position: static; }
  .site-header nav a:not(.github-link) { display: none; }
  main { width: min(100% - 20px, 1520px); }
  .hero { grid-template-columns: 1fr; gap: 24px; }
  .lab-toolbar, .scenario-tabs, .controls, .inspect-panel { flex-direction: column; }
  .scenario-tabs { width: 100%; }
  .scenario-tab { width: 100%; min-width: 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .step-readout { justify-content: space-between; padding: 14px 20px; }
  .lab-grid { display: block; }
  .explain-panel, .visual-panel { border-right: 0; border-bottom: 1px solid var(--line); }
  .inspect-panel > * { width: 100%; }
  .tree-stage { height: 330px; }
  .tree-node { width: 54px; height: 54px; font-size: 15px; }
  .panel-head, .array-caption { align-items: flex-start; flex-direction: column; }
  .legend { justify-content: flex-start; }
  .array-caption code { max-width: 100%; }
  .heap-array { gap: 4px; }
  .array-cell { min-height: 54px; font-size: 14px; }
  .controls { align-items: stretch; }
  .control-buttons { display: grid; grid-template-columns: 1fr 1fr; }
  .step-dots { justify-content: center; }
  .principle-grid { grid-template-columns: 1fr; }
  .principle-grid > div { border-right: 0; border-bottom: 1px solid var(--line); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; }
}
.scheduler-lab{overflow:hidden;margin-top:72px;border:1px solid #385047;border-radius:18px;background:#091411;box-shadow:0 30px 90px #0005}.scheduler-head{display:grid;grid-template-columns:1.1fr .9fr;align-items:end;gap:48px;padding:34px 38px;border-bottom:1px solid var(--line)}.scheduler-head h2{margin:12px 0 0;font:500 clamp(36px,4vw,62px)/1.08 var(--serif)}.scheduler-head p{margin:0;color:var(--muted);font-size:15px;line-height:1.85}.scheduler-tabs{display:grid;grid-template-columns:repeat(4,1fr);border-bottom:1px solid var(--line)}.scheduler-tab{min-height:58px;border:0;border-right:1px solid var(--line);background:#0b1713;color:var(--muted);font-size:13px;cursor:pointer}.scheduler-tab:last-child{border-right:0}.scheduler-tab:hover{color:var(--text);background:#12211b}.scheduler-tab.is-active,.scheduler-tab[aria-pressed=true]{color:#10170b;background:var(--acid);font-weight:700}.scheduler-grid{display:grid;grid-template-columns:300px minmax(560px,1fr) 330px;min-height:650px}.scheduler-copy,.scheduler-state,.scheduler-inspect{min-width:0;padding:28px}.scheduler-copy,.scheduler-state{border-right:1px solid var(--line)}.scheduler-copy>span,.scheduler-state header span{color:var(--cyan);font:700 12px var(--mono);letter-spacing:.08em}.scheduler-copy h3{margin:14px 0;font:500 32px/1.25 var(--serif)}.scheduler-copy>p{margin:0;color:var(--muted);font-size:15px;line-height:1.8}.scheduler-copy>div{margin-top:20px;padding:14px 15px;border-left:2px solid var(--cyan);background:var(--surface-2)}.scheduler-copy>div.schedule-why{border-left-color:var(--acid)}.scheduler-copy b{color:var(--cyan);font:700 12px var(--mono)}.scheduler-copy .schedule-why b{color:var(--acid)}.scheduler-copy div p{margin:7px 0 0;color:#c8d5cf;font-size:13px;line-height:1.7}.scheduler-state{background:radial-gradient(circle at 50% 15%,rgba(103,213,243,.07),transparent 24rem),#091512}.scheduler-state header{display:flex;justify-content:space-between;gap:18px}.scheduler-state header h3{margin:7px 0 0;font:500 25px var(--serif)}.scheduler-state header strong{color:var(--acid);font:700 13px var(--mono)}.message-columns{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-top:22px}.message-columns article{min-height:230px;padding:13px;border:1px solid var(--line);border-radius:8px;background:#0d1b16}.message-columns h4{margin:0 0 10px;color:var(--mint);font:700 12px var(--mono)}.message-columns ol,.schedule-events{margin:0;padding:0;list-style:none}.message-columns li{display:grid;grid-template-columns:1fr auto;gap:8px;margin-top:7px;padding:9px;border:1px solid #33483f;border-radius:6px;background:#12221c;font-size:12px;line-height:1.45}.message-columns li small{color:var(--muted);font:12px var(--mono)}.message-columns li.is-picked{border-color:var(--acid);box-shadow:inset 3px 0 var(--acid)}.heap-strip{display:flex;align-items:center;gap:14px;margin-top:12px;padding:12px 14px;border:1px solid var(--line);border-radius:7px;background:#07110e}.heap-strip span{color:var(--cyan);font:700 12px var(--mono)}.heap-strip code{overflow:auto;color:#d9e5df;font:12px var(--mono);white-space:nowrap}.schedule-events{margin-top:12px}.schedule-events li{margin-top:6px;padding:8px 10px;border-left:3px solid #526e63;background:#102019;color:#bed0c8;font-size:12px}.schedule-events li.is-error{border-left-color:var(--coral);color:#ffd0cc}.scheduler-inspect{display:flex;flex-direction:column;background:#08130f}.scheduler-inspect dl{display:grid;gap:8px;margin:0}.scheduler-inspect dl div{display:grid;grid-template-columns:1fr auto;gap:10px;padding:10px;border:1px solid var(--line);background:var(--surface-2)}.scheduler-inspect dt{color:var(--muted);font-size:12px}.scheduler-inspect dd{margin:0;text-align:right;font:700 12px var(--mono)}.schedule-code{margin-top:auto;overflow:hidden;border:1px solid var(--line);border-radius:7px;background:#06100d}.schedule-code>div{display:flex;justify-content:space-between;gap:10px;padding:10px 12px;border-bottom:1px solid var(--line);color:var(--muted);font:12px var(--mono)}.schedule-code>div strong{color:var(--acid)}#schedule-code-lines{margin:0;padding:12px 10px 12px 42px;overflow:auto;color:#82968d;font:12px/1.65 var(--mono);white-space:pre}#schedule-code-lines li{min-width:max-content;padding:2px 6px}#schedule-code-lines li.is-active{color:var(--text);background:#193027;box-shadow:inset 2px 0 var(--acid)}.scheduler-controls{display:grid;grid-template-columns:150px 1fr auto;align-items:end;gap:18px;padding:16px 22px;border-top:1px solid var(--line);background:#08130f}.scheduler-controls label{display:grid;gap:6px;color:var(--muted);font:600 12px var(--mono)}.scheduler-controls select{min-height:38px;padding:0 10px;border:1px solid #40584e;border-radius:5px;background:#0e1c17;color:var(--text);font-size:13px}.scheduler-controls>div:nth-child(2){display:flex;justify-content:center;gap:7px;padding-bottom:12px}.scheduler-controls .step-dot{width:12px;height:12px;border:1px solid #557268;border-radius:50%;background:transparent}.scheduler-controls .step-dot.is-past{background:#477768}.scheduler-controls .step-dot.is-active{border-color:var(--acid);background:var(--acid)}.scheduler-controls>div:last-child{display:flex;gap:8px}.scheduler-controls button{min-height:42px;padding:0 14px;border:1px solid #425b51;border-radius:5px;background:#102019;color:var(--text);font-size:13px;cursor:pointer}.scheduler-controls button:hover:not(:disabled){border-color:var(--mint)}.scheduler-controls button:disabled{opacity:.35;cursor:not-allowed}.scheduler-controls .auto-button.is-playing,.scheduler-controls .auto-button[aria-pressed=true]{color:#07110d;background:var(--mint)}.scheduler-controls .next-button{color:#0b1308;background:var(--acid);font-weight:700}button:focus-visible,select:focus-visible,a:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}
@media(max-width:1160px){.scheduler-grid{grid-template-columns:280px 1fr}.scheduler-inspect{grid-column:1/-1;display:grid;grid-template-columns:.7fr 1.3fr;gap:20px;border-top:1px solid var(--line)}.schedule-code{margin-top:0}}@media(max-width:780px){.scheduler-head{grid-template-columns:1fr;gap:20px;padding:28px 22px}.scheduler-tabs{grid-template-columns:1fr 1fr}.scheduler-grid{display:block}.scheduler-copy,.scheduler-state{border-right:0;border-bottom:1px solid var(--line)}.scheduler-inspect{display:flex}.message-columns{grid-template-columns:1fr}.message-columns article{min-height:0}.scheduler-controls{grid-template-columns:1fr}.scheduler-controls>div:nth-child(2){order:-1}.scheduler-controls>div:last-child{display:grid;grid-template-columns:1fr 1fr}}@media(max-width:480px){.scheduler-tabs{grid-template-columns:1fr}.scheduler-copy,.scheduler-state,.scheduler-inspect{padding:20px}.scheduler-controls>div:last-child{grid-template-columns:1fr}}