/* DevHub product site: plain CSS, no build step. */
:root {
  --bg: #0d1210;
  --bg-alt: #111815;
  --surface: #151d19;
  --surface-2: #1a2420;
  --line: #24302b;
  --text: #e8eee9;
  --muted: #95a39b;
  --accent: #b8f04a;
  --accent-ink: #0f1511;
  --accent-soft: rgba(184, 240, 74, 0.12);
  --blue: #7aa7ff;
  --amber: #f4c25b;
  --violet: #b99bff;
  --shadow: 0 30px 80px -30px rgba(0, 0, 0, 0.7);
  --radius: 14px;
  --mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  color-scheme: dark;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8f5;
    --bg-alt: #eef2ec;
    --surface: #ffffff;
    --surface-2: #f3f6f1;
    --line: #dde4dc;
    --text: #121a15;
    --muted: #5b6a61;
    --accent: #4f8a0b;
    --accent-ink: #ffffff;
    --accent-soft: rgba(79, 138, 11, 0.1);
    --blue: #2f62d6;
    --amber: #a86d00;
    --violet: #6b45d1;
    --shadow: 0 30px 70px -35px rgba(20, 40, 25, 0.35);
    color-scheme: light;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 var(--sans);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.08em 0.38em;
  white-space: nowrap;
}
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.02em; margin: 0; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.3rem); margin-bottom: 1rem; }
h3 { font-size: 1.05rem; margin-bottom: 0.45rem; }
p { margin: 0 0 1rem; }

.wrap { width: min(1120px, 100% - 40px); margin-inline: auto; }
.narrow { width: min(820px, 100% - 40px); }
.muted { color: var(--muted); }
.center { text-align: center; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; z-index: 99; background: var(--accent); color: var(--accent-ink); padding: 8px 12px; border-radius: 8px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

/* Top bar */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 1.08rem; }
.brand:hover { text-decoration: none; }
.tag {
  font: 600 0.62rem/1 var(--mono); letter-spacing: 0.08em;
  border: 1px solid var(--line); color: var(--muted);
  padding: 4px 6px; border-radius: 5px;
}
.nav { display: flex; align-items: center; gap: 22px; font-size: 0.92rem; }
.nav a { color: var(--muted); }
.nav a:hover { color: var(--text); text-decoration: none; }
.nav .nav-gh {
  color: var(--text); border: 1px solid var(--line); padding: 6px 12px; border-radius: 9px; background: var(--surface);
}

/* Hero */
.hero {
  position: relative;
  padding: 88px 0 40px;
  background:
    radial-gradient(900px 420px at 50% -10%, var(--accent-soft), transparent 70%),
    linear-gradient(var(--bg), var(--bg));
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 20%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 20%, #000 20%, transparent 75%);
  opacity: 0.45;
}
.hero-inner { position: relative; text-align: center; display: flex; flex-direction: column; align-items: center; }
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.82rem; color: var(--muted);
  border: 1px solid var(--line); background: var(--surface);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 26px;
}
.pill:hover { color: var(--text); text-decoration: none; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
h1 { font-size: clamp(2.2rem, 5.6vw, 3.9rem); max-width: 16ch; letter-spacing: -0.035em; margin-bottom: 1.2rem; }
.accent { color: var(--accent); }
.lead { font-size: clamp(1.02rem, 1.6vw, 1.18rem); color: var(--muted); max-width: 680px; }
.lead.small { font-size: 1.02rem; max-width: 760px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin: 14px 0 36px; }
.cta.left { justify-content: flex-start; margin-bottom: 0; }
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 12px 20px; border-radius: 11px; font-weight: 600; font-size: 0.97rem;
  border: 1px solid transparent; transition: transform .15s ease, background .15s ease, border-color .15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.btn svg.fill { fill: currentColor; stroke: none; }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { filter: brightness(1.06); }
.btn-ghost { background: var(--surface); color: var(--text); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--muted); }
.facts {
  list-style: none; padding: 0; margin: 0;
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1px;
  background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  width: min(860px, 100%);
}
.facts li { background: var(--surface); padding: 16px 14px; display: flex; flex-direction: column; gap: 2px; }
.facts strong { font-family: var(--mono); font-size: 0.98rem; }
.facts span { color: var(--muted); font-size: 0.82rem; }

/* Screenshot */
.shot-section { padding: 30px 0 30px; }
.window {
  margin: 0 auto; max-width: 1024px;
  border: 1px solid var(--line); border-radius: 14px; overflow: hidden;
  background: #111; box-shadow: var(--shadow);
}
.window-bar {
  display: flex; align-items: center; gap: 7px; padding: 10px 14px;
  background: #171d1a; border-bottom: 1px solid #26302b;
}
.window-bar span { width: 11px; height: 11px; border-radius: 50%; background: #3a4440; }
.window-bar span:nth-child(1) { background: #ff5f57; }
.window-bar span:nth-child(2) { background: #febc2e; }
.window-bar span:nth-child(3) { background: #28c840; }
.window-bar em {
  margin-left: 12px; font: 0.76rem var(--mono); font-style: normal; color: #8c9991;
  background: #0f1412; border: 1px solid #26302b; padding: 3px 12px; border-radius: 6px;
}
.caption { text-align: center; color: var(--muted); font-size: 0.82rem; margin-top: 14px; }

/* Sections */
.section { padding: 84px 0; }
.section.alt { background: var(--bg-alt); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.eyebrow {
  font: 600 0.74rem/1 var(--mono); letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 14px;
}
.why { padding: 56px 0 24px; text-align: center; }
.q-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 26px 0 22px; text-align: left; }
.q { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.q-n { font: 600 0.78rem var(--mono); color: var(--accent); }
.q p { margin: 6px 0 0; font-weight: 600; }

.grid { display: grid; gap: 16px; }
.features { grid-template-columns: repeat(3, 1fr); margin-top: 30px; }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; transition: border-color .2s ease, transform .2s ease;
}
.card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); transform: translateY(-2px); }
.card p { color: var(--muted); font-size: 0.93rem; margin: 0; }
.ico {
  width: 38px; height: 38px; border-radius: 10px; display: grid; place-items: center;
  background: var(--accent-soft); margin-bottom: 14px;
}
.ico svg { width: 20px; height: 20px; fill: none; stroke: var(--accent); stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }
.ico svg .fillc { fill: var(--accent); }

/* Steps */
.steps { list-style: none; padding: 0; margin: 30px 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.steps li { display: flex; gap: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.steps p { color: var(--muted); font-size: 0.93rem; margin: 0; }
.step-n {
  flex: none; width: 30px; height: 30px; border-radius: 50%;
  display: grid; place-items: center; font: 700 0.86rem var(--mono);
  background: var(--accent); color: var(--accent-ink);
}
.code-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.code { background: #0b0f0d; border: 1px solid #222b27; border-radius: var(--radius); overflow: hidden; }
.code-head { padding: 10px 16px; border-bottom: 1px solid #222b27; font: 0.76rem var(--mono); color: #8c9991; }
.code pre { margin: 0; padding: 16px 18px; overflow-x: auto; }
.code pre code {
  background: none; border: 0; padding: 0; white-space: pre;
  font-size: 0.84rem; line-height: 1.75; color: #dfe8e1;
}
.code .c { color: #6f7f76; }

/* Security */
.sec { grid-template-columns: repeat(3, 1fr); margin: 28px 0 22px; }
.sec-item { border-left: 2px solid var(--accent); padding: 4px 0 4px 18px; }
.sec-item p { color: var(--muted); font-size: 0.93rem; margin: 0; }
.note {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 20px; font-size: 0.9rem; color: var(--muted); margin: 0;
}
.note strong { color: var(--text); }

/* Roadmap */
.timeline { list-style: none; margin: 34px 0 0; padding: 0 0 0 28px; position: relative; max-width: 860px; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px; background: var(--line); }
.timeline li { position: relative; padding: 0 0 30px 10px; }
.timeline li:last-child { padding-bottom: 0; }
.timeline li::before {
  content: ""; position: absolute; left: -27px; top: 5px; width: 14px; height: 14px; border-radius: 50%;
  background: var(--bg-alt); border: 2px solid var(--muted);
}
.timeline li.done::before { background: var(--accent); border-color: var(--accent); }
.timeline li.active::before { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 35%, var(--bg-alt)); }
.timeline li.planned::before { border-style: dashed; }
.timeline li.ai::before { border-color: var(--violet); }
.timeline h3 { margin-top: 8px; }
.timeline p { color: var(--muted); font-size: 0.94rem; margin: 0; max-width: 72ch; }
.timeline li.ai {
  background: var(--surface); border: 1px dashed color-mix(in srgb, var(--violet) 60%, var(--line));
  border-radius: var(--radius); padding: 16px 18px 18px; margin: 0 0 30px 0;
}
.timeline li.ai::before { left: -27px; top: 21px; }
.badge {
  display: inline-block; font: 600 0.7rem/1 var(--mono); letter-spacing: 0.04em; text-transform: uppercase;
  padding: 5px 8px; border-radius: 6px;
}
.b-done { background: var(--accent-soft); color: var(--accent); }
.b-active { background: color-mix(in srgb, var(--blue) 15%, transparent); color: var(--blue); }
.b-planned { background: color-mix(in srgb, var(--violet) 16%, transparent); color: var(--violet); }
.b-future { background: var(--surface-2); color: var(--muted); border: 1px solid var(--line); }

/* Open source */
.os-grid { display: grid; grid-template-columns: 1.15fr 1fr; gap: 40px; align-items: start; }
.stack { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.stack dl { margin: 10px 0 0; display: grid; grid-template-columns: auto 1fr; gap: 10px 18px; font-size: 0.92rem; }
.stack dt { color: var(--muted); font: 0.8rem/1.9 var(--mono); }
.stack dd { margin: 0; }

/* Chinese section */
.zh-list { padding-left: 1.2rem; color: var(--muted); }
.zh-list li { margin: 0.4rem 0; }
.zh-list strong { color: var(--text); }

/* Footer */
.footer { border-top: 1px solid var(--line); padding: 36px 0 44px; }
.footer-inner { display: grid; grid-template-columns: 1fr auto; gap: 14px 24px; align-items: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.footer-brand .muted { font-weight: 400; font-size: 0.9rem; }
.footer-links { display: flex; flex-wrap: wrap; gap: 20px; font-size: 0.92rem; }
.footer-links a { color: var(--muted); }
.footer-links a:first-child { color: var(--accent); }
.fine { grid-column: 1 / -1; color: var(--muted); font-size: 0.8rem; margin: 0; }

/* Responsive */
@media (max-width: 960px) {
  .features, .sec { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .os-grid { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .nav a:not(.nav-gh):not([lang]) { display: none; }
  .nav { gap: 14px; }
  .hero { padding: 56px 0 28px; }
  .facts { grid-template-columns: repeat(2, 1fr); }
  .q-grid, .features, .sec, .code-grid { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-brand .muted { display: none; }
  .window-bar em { display: none; }
  code { white-space: normal; word-break: break-word; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn, .card { transition: none; }
}