:root {
  --bg: #0b0d12;
  --bg-alt: #10131a;
  --surface: #151926;
  --border: #222838;
  --fg: #e7ecf3;
  --muted: #8a93a6;
  --accent: #ff7a45;
  --accent-2: #ffb37a;
  --code-bg: #0a0c11;
  --radius: 10px;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-2); text-decoration: none; }
a:hover { color: var(--accent); }
code, pre { font-family: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace; }
code { background: var(--code-bg); padding: 2px 6px; border-radius: 4px; font-size: 0.92em; }
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 0.9em;
  line-height: 1.55;
}
pre code { background: transparent; padding: 0; }

.hero {
  background:
    radial-gradient(1200px 500px at 20% -10%, rgba(255,122,69,0.18), transparent 60%),
    radial-gradient(1000px 500px at 90% 10%, rgba(255,179,122,0.10), transparent 60%),
    linear-gradient(180deg, #0b0d12 0%, #0b0d12 80%, #0d1018 100%);
  border-bottom: 1px solid var(--border);
}
.nav {
  max-width: 1080px;
  margin: 0 auto;
  padding: 22px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-weight: 800;
  letter-spacing: 0.08em;
  font-size: 18px;
  color: var(--fg);
}
.nav-links a {
  margin-left: 22px;
  color: var(--muted);
  font-size: 14px;
}
.nav-links a:hover { color: var(--fg); }
.nav-links .lang-toggle {
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 6px;
  color: var(--fg);
  font-size: 12px;
}
.nav-links .lang-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.hero-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 60px 24px 90px;
}
.badge {
  display: inline-block;
  padding: 6px 12px;
  font-size: 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  letter-spacing: 0.04em;
}
h1 {
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.15;
  margin: 22px 0 18px;
  letter-spacing: -0.01em;
}
.slogan {
  margin: 18px 0 0;
  font-size: clamp(15px, 1.6vw, 18px);
  font-weight: 600;
  color: var(--accent-2);
  letter-spacing: 0.01em;
}
.tagline {
  font-size: clamp(28px, 4.6vw, 50px);
  font-weight: 800;
  line-height: 1.2;
  margin: 20px 0 20px;
  letter-spacing: -0.005em;
  background: linear-gradient(100deg, #ffd4b3 0%, var(--accent) 55%, #ff9a66 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}
.lede {
  font-size: 18px;
  color: #c8cfdd;
  max-width: 760px;
}
.lede em { color: var(--accent-2); font-style: normal; }
.cta-row {
  margin-top: 28px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 14px;
  border: 1px solid transparent;
  transition: transform 0.08s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn.primary {
  background: var(--accent);
  color: #1a0e07;
}
.btn.ghost {
  border-color: var(--border);
  color: var(--fg);
}
.hero-snippet {
  margin-top: 32px;
  max-width: 760px;
}

.section {
  max-width: 1080px;
  margin: 0 auto;
  padding: 72px 24px;
}
.section.alt {
  background: var(--bg-alt);
  max-width: none;
  padding-left: max(24px, calc((100% - 1080px) / 2));
  padding-right: max(24px, calc((100% - 1080px) / 2));
}
h2 {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  margin: 0 0 8px;
  letter-spacing: -0.005em;
  line-height: 1.2;
  background: linear-gradient(100deg, #ffd4b3 0%, var(--accent) 55%, #ff9a66 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}
h3 { font-size: 16px; margin: 18px 0 10px; color: var(--fg); }
.muted { color: var(--muted); }
.small { font-size: 13px; }

.grid { display: grid; gap: 16px; margin-top: 22px; }
.grid.two { grid-template-columns: repeat(2, 1fr); }
.grid.three { grid-template-columns: repeat(3, 1fr); }
.grid.four { grid-template-columns: repeat(4, 1fr); }
.dl-grid { grid-template-columns: repeat(3, 1fr); }

.loop-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px 18px;
  display: flex;
  flex-direction: column;
  min-width: 0;
  transition: border-color 0.15s ease, transform 0.08s ease;
}
.loop-card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}
.loop-num {
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 11px;
  color: var(--accent);
  letter-spacing: 0.14em;
  margin-bottom: 10px;
  display: block;
}
.loop-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  color: var(--fg);
  letter-spacing: -0.005em;
}
.loop-card p {
  color: var(--muted);
  font-size: 13.5px;
  margin: 0 0 14px;
  flex-grow: 1;
  line-height: 1.55;
}
.loop-card pre {
  margin: 0;
  font-size: 11.5px;
  padding: 12px 14px;
  line-height: 1.55;
}

.feat-label {
  display: block;
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.demo-prompt, .demo-grid { margin-top: 22px; }
.demo-head {
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin-bottom: 8px;
}
.demo-sublabel {
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin: 16px 0 6px;
}
details {
  margin-top: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0 14px;
  background: var(--surface);
}
details[open] { padding-bottom: 14px; }
details summary {
  cursor: pointer;
  padding: 12px 0;
  color: var(--fg);
  font-size: 13px;
  list-style: none;
}
details summary::-webkit-details-marker { display: none; }
details summary::before {
  content: "▸";
  color: var(--accent);
  margin-right: 10px;
  display: inline-block;
  transition: transform 0.15s ease;
}
details[open] summary::before { transform: rotate(90deg); }
details pre { margin-top: 0; }

.demo-observe {
  margin-top: 28px;
  padding: 22px 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.demo-observe h3 { margin-top: 0; }
.demo-observe ul {
  margin: 12px 0 0;
  padding-left: 22px;
  color: #c8cfdd;
  font-size: 14px;
  line-height: 1.65;
}
.demo-observe li { margin-bottom: 10px; }
.demo-observe li:last-child { margin-bottom: 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  color: var(--fg);
  transition: border-color 0.15s ease, transform 0.08s ease;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}
.dl-title { font-weight: 600; font-size: 15px; }
.dl-meta { color: var(--muted); font-size: 12px; margin-top: 6px; font-family: "JetBrains Mono", "SF Mono", Menlo, monospace; }

.feat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 22px;
}
.feat h3 { margin-top: 0; }
.feat p { margin: 0; color: var(--muted); font-size: 14px; }

.footer {
  border-top: 1px solid var(--border);
  background: var(--bg-alt);
  padding: 28px 24px;
  margin-top: 40px;
}
.footer-inner {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 980px) {
  .grid.four { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 820px) {
  .grid.two, .grid.three, .dl-grid { grid-template-columns: 1fr; }
  .nav-links a { margin-left: 14px; }
}
@media (max-width: 560px) {
  .grid.four { grid-template-columns: 1fr; }
}

/* ---- docs ---- */
body.doc { background: var(--bg); }
.doc-nav {
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
}
.doc-nav-inner {
  max-width: 1080px; margin: 0 auto;
  padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between;
  gap: 20px; flex-wrap: wrap;
}
.doc-nav-links { display: flex; align-items: center; flex-wrap: wrap; }
.doc-nav-links a { margin-left: 18px; color: var(--muted); font-size: 13px; }
.doc-nav-links a:first-child { margin-left: 0; }
.doc-nav-links a:hover { color: var(--fg); }
.doc-nav-links a.back-home {
  border: 1px solid var(--border); padding: 4px 10px; border-radius: 6px;
  color: var(--fg); font-size: 12px;
}
.doc-nav-links a.back-home:hover { border-color: var(--accent); color: var(--accent); }
.doc-body {
  max-width: 860px; margin: 0 auto;
  padding: 48px 24px 96px;
}
.doc-crumb {
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 11px; color: var(--muted);
  letter-spacing: 0.08em; margin-bottom: 24px;
}
.doc-crumb a { color: var(--muted); }
.doc-crumb a:hover { color: var(--accent); }
.doc-body h1 {
  font-size: 32px; font-weight: 800; margin: 0 0 24px;
  background: linear-gradient(100deg, #ffd4b3 0%, var(--accent) 55%, #ff9a66 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  display: inline-block;
}
.doc-body h2 {
  font-size: 22px; margin: 40px 0 12px;
  border-bottom: 1px solid var(--border); padding-bottom: 6px;
  background: none; -webkit-text-fill-color: var(--fg); color: var(--fg);
  display: block; font-weight: 700;
}
.doc-body h3 { font-size: 16px; margin: 28px 0 10px; color: var(--fg); }
.doc-body h4 { font-size: 14px; margin: 22px 0 8px; color: var(--fg); }
.doc-body p { margin: 12px 0; color: #c8cfdd; }
.doc-body ul, .doc-body ol { padding-left: 22px; color: #c8cfdd; }
.doc-body li { margin: 4px 0; }
.doc-body blockquote {
  border-left: 3px solid var(--accent);
  margin: 16px 0; padding: 4px 16px;
  background: var(--surface); color: var(--muted);
}
.doc-body table {
  border-collapse: collapse; width: 100%;
  margin: 16px 0; font-size: 13.5px;
}
.doc-body th, .doc-body td {
  border: 1px solid var(--border);
  padding: 8px 12px; text-align: left; vertical-align: top;
}
.doc-body th { background: var(--surface); color: var(--fg); font-weight: 600; }
.doc-body td { color: #c8cfdd; }
.doc-body hr { border: none; border-top: 1px solid var(--border); margin: 32px 0; }
.doc-body img { max-width: 100%; }

.doc-index ul { list-style: none; padding: 0; }
.doc-index li {
  padding: 12px 0; border-bottom: 1px solid var(--border);
}
.doc-index li a { font-weight: 600; color: var(--accent-2); font-size: 15px; }
.doc-index li a:hover { color: var(--accent); }
.doc-index li .desc { display: block; color: var(--muted); font-size: 13px; margin-top: 4px; }
.doc-index li .kind {
  font-family: "JetBrains Mono", "SF Mono", Menlo, monospace;
  font-size: 10.5px; color: var(--accent); letter-spacing: 0.1em;
  text-transform: uppercase; margin-right: 8px;
}

@media (max-width: 820px) {
  .doc-nav-links a { margin-left: 12px; }
}