/* MARS Trace site: the IDE's own palette, light and dark. */
@font-face { font-family: "JetBrains Mono Web"; src: url("app/fonts/jetbrains-mono/400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "JetBrains Mono Web"; src: url("app/fonts/jetbrains-mono/600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }
:root {
  --bg: #f3f5f8;
  --panel: #fff;
  --text: #26344a;
  --muted: #66728a;
  --line: #e3e8f0;
  --accent: #005fb8;
  --accent-text: #fff;
  --exec: #ffe066;
  --exec-text: #3d3200;
  --done: #8a94a6;
  --write: #c24e00;
  --syn-op: #0000ff;
  --syn-reg: #001080;
  --syn-num: #098658;
  --font: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "JetBrains Mono Web", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15191f;
    --panel: #1d232b;
    --text: #dfe5ee;
    --muted: #97a2b4;
    --line: #2c3440;
    --accent: #4da3ff;
    --accent-text: #08121f;
    --exec: #6b5a12;
    --exec-text: #fff4c2;
    --done: #6f7a8c;
    --write: #ff9d57;
    --syn-op: #6cb6ff;
    --syn-reg: #9cdcfe;
    --syn-num: #b5cea8;
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.65 var(--font); }
a { color: var(--accent); }
html[data-lang="en"] [lang="zh-CN"], html[data-lang="zh-CN"] [lang="en"] { display: none !important; }

.top { position: sticky; top: 0; z-index: 2; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 10px max(16px, calc((100% - 1120px) / 2)); background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 8px; color: var(--text); text-decoration: none; font-size: 17px; }
.brand-icon { display: inline-grid; place-items: center; width: 26px; height: 26px; border-radius: 6px; background: var(--accent); color: var(--accent-text); font: 600 15px var(--mono); }
.top nav { display: flex; align-items: center; gap: 18px; font-size: 14px; }
.top nav a:not(.button) { color: var(--muted); text-decoration: none; }
.top nav a:not(.button):hover { color: var(--text); }
.lang { font: inherit; font-size: 14px; color: var(--muted); background: none; border: 1px solid var(--line); border-radius: 6px; padding: 3px 10px; cursor: pointer; text-decoration: none; }
.lang:hover { color: var(--text); border-color: var(--muted); }

.button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 0 20px; border-radius: 8px; border: 1px solid var(--line); background: var(--panel); color: var(--text); font-weight: 600; text-decoration: none; cursor: pointer; }
.button:hover { border-color: var(--muted); }
.button.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); }
.button.primary:hover { filter: brightness(1.08); }
.button.small { min-height: 34px; padding: 0 14px; font-size: 14px; }
.button:focus-visible, .lang:focus-visible, a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

main { max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; padding: 72px 0 48px; }
.kicker { margin: 0 0 14px; font: 13px var(--mono); color: var(--muted); letter-spacing: 0.02em; }
h1 { margin: 0; font-size: clamp(34px, 5vw, 54px); line-height: 1.12; letter-spacing: -0.02em; }
html[data-lang="zh-CN"] h1 { letter-spacing: 0; line-height: 1.22; }
.lead { margin: 22px 0 28px; max-width: 34em; font-size: 18px; color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 12px; }
.fineprint { margin: 16px 0 0; font-size: 13px; color: var(--muted); }

.trace { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; font: 14px/1 var(--mono); box-shadow: 0 20px 40px -24px rgb(20 30 50 / 0.35); }
.trace-head { display: flex; justify-content: space-between; padding: 10px 14px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.trace-step b { color: var(--text); font-weight: 600; }
.trace-lines { list-style: none; margin: 0; padding: 8px 0; counter-reset: line; }
.trace-lines li { display: grid; grid-template-columns: 2.2em 1fr auto; align-items: center; gap: 8px; padding: 9px 14px 9px 0; counter-increment: line; transition: background-color 0.25s, color 0.25s; }
.trace-lines li::before { content: counter(line); text-align: right; color: var(--done); font-size: 12px; }
.trace-lines code { white-space: pre; font: inherit; }
.trace-lines i { font-style: normal; color: var(--syn-op); }
.trace-lines r { color: var(--syn-reg); }
.trace-lines n { color: var(--syn-num); }
.trace-lines em { font-style: normal; font-size: 12px; color: var(--write); opacity: 0; transition: opacity 0.25s; }
.trace-lines li.done { color: var(--done); }
.trace-lines li.done i, .trace-lines li.done r, .trace-lines li.done n { color: inherit; }
.trace-lines li.done em { opacity: 0.55; }
.trace-lines li.now { background: var(--exec); color: var(--exec-text); }
.trace-lines li.now i, .trace-lines li.now r, .trace-lines li.now n, .trace-lines li.now em { color: inherit; }
.trace-lines li.now em { opacity: 1; font-weight: 600; }
.trace-controls { display: flex; gap: 8px; padding: 10px 14px; border-top: 1px solid var(--line); }
.key { padding: 4px 10px; border: 1px solid var(--line); border-radius: 6px; font-size: 12px; color: var(--muted); }
.key.pressed { border-color: var(--accent); color: var(--accent); }

.shot { margin: 8px 0 72px; }
.shot img { display: block; width: 100%; height: auto; border-radius: 12px; border: 1px solid var(--line); box-shadow: 0 30px 60px -36px rgb(20 30 50 / 0.45); }

h2 { margin: 0 0 24px; font-size: 30px; line-height: 1.25; }
.features { padding-bottom: 64px; }
.grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.grid article { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 22px 24px; }
.grid h3 { margin: 0 0 8px; font-size: 18px; }
.grid p { margin: 0; color: var(--muted); }
.also { margin: 20px 0 0; font-size: 14px; color: var(--muted); }

.learning { border-top: 1px solid var(--line); padding: 56px 0 64px; }
.learning-grid { display: grid; gap: 22px; max-width: 840px; }
.learning h3 { margin: 0 0 6px; font-size: 18px; }
.learning p { margin: 0; color: var(--muted); }

.teachers { display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; align-items: start; padding: 56px 0 80px; border-top: 1px solid var(--line); }
.teachers ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 14px; }
.teachers li { padding-left: 18px; position: relative; color: var(--muted); }
.teachers li::before { content: ""; position: absolute; left: 0; top: 0.7em; width: 7px; height: 7px; border-radius: 2px; background: var(--accent); }
.teachers li b { color: var(--text); }
.contact-card { padding-top: 4px; }
.contact-card p { margin: 0 0 18px; }

footer { max-width: 1120px; margin: 0 auto; padding: 28px 16px 48px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
footer p { margin: 0 0 8px; }
footer .credits { font-size: 12px; }

@media (max-width: 860px) {
  .hero, .teachers { grid-template-columns: 1fr; gap: 32px; }
  .hero { padding-top: 40px; }
  .grid { grid-template-columns: 1fr; }
  .top nav a:not(.button) { display: none; }
}
@media (max-width: 420px) {
  .trace { font-size: 12px; }
  .trace-lines li { grid-template-columns: 1.8em 1fr; }
  .trace-lines em { display: none; }
  .top nav { gap: 10px; }
}