:root {
  --orange: #F4511E; --orange-soft: rgba(244,81,30,.10);
  --ink: #111111; --bg: #ffffff; --bg-alt: #F3F1EC; --panel: #ffffff;
  --text: #111111; --muted: #6B6B6B; --line: #E4E1DA;
  --code-bg: #15131f; --code-text: #e8e6f0;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 8px 24px rgba(0,0,0,.05);
}
:root[data-theme="dark"] {
  --ink: #f5f5f5; --bg: #0e0e12; --bg-alt: #16161c; --panel: #16161c;
  --text: #f0f0f2; --muted: #a0a0a8; --line: #2a2a33;
  --code-bg: #0a0a0f; --code-text: #e8e6f0; --shadow: none;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: 'Inter', -apple-system, 'Helvetica Neue', Arial, sans-serif; color: var(--text); background: var(--bg); line-height: 1.55; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
code, pre, kbd { font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace; }
img { max-width: 100%; }

/* header */
.top { position: sticky; top: 0; z-index: 50; background: var(--bg); border-bottom: 1px solid var(--line); }
.top-inner { max-width: 1240px; margin: 0 auto; padding: 0 24px; height: 64px; display: flex; align-items: center; gap: 28px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .02em; font-size: 15px; white-space: nowrap; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand em { font-style: normal; font-weight: 600; color: var(--muted); border-left: 1px solid var(--line); padding-left: 10px; margin-left: 2px; }
.logo-dark { display: none; } :root[data-theme="dark"] .logo-dark { display: block; } :root[data-theme="dark"] .logo-light { display: none; }
.nav { display: flex; gap: 4px; margin-left: 12px; }
.nav a { padding: 8px 12px; border-radius: 8px; font-weight: 500; font-size: 14px; color: var(--muted); }
.nav a:hover, .nav a.active { color: var(--text); background: var(--bg-alt); }
.top-actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }
.theme-toggle { border: 1px solid var(--line); background: transparent; color: var(--text); width: 36px; height: 36px; border-radius: 8px; cursor: pointer; font-size: 16px; }
.menu-toggle { display: none; border: 1px solid var(--line); background: transparent; color: var(--text); width: 40px; height: 36px; border-radius: 8px; font-size: 18px; margin-left: auto; }

/* buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; background: var(--orange); color: #fff; font-weight: 700; padding: 12px 20px; border-radius: 10px; font-size: 15px; border: 1px solid var(--orange); }
.btn:hover { filter: brightness(.95); }
.btn-small { padding: 8px 14px; font-size: 13px; border-radius: 8px; }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--line); }
.btn-light { background: #fff; color: #111; border-color: #fff; }
.btn-ghost-light { background: transparent; color: #fff; border-color: rgba(255,255,255,.4); }

/* shell */
.shell { max-width: 1240px; margin: 0 auto; padding: 0 24px; }
.shell.docs { display: grid; grid-template-columns: 240px minmax(0, 1fr) 200px; gap: 40px; padding-top: 32px; padding-bottom: 80px; }
.shell.docs .content { display: contents; }
.shell.page .content { max-width: 820px; padding: 40px 0 80px; }
.sidebar { position: sticky; top: 88px; align-self: start; max-height: calc(100vh - 110px); overflow: auto; padding-right: 8px; }
.sb-group { margin-bottom: 22px; }
.sb-title { font-size: 11px; letter-spacing: .14em; font-weight: 700; color: var(--muted); text-transform: uppercase; margin-bottom: 8px; }
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar li a { display: block; padding: 6px 10px; border-radius: 7px; font-size: 14px; color: var(--muted); }
.sidebar li a:hover { color: var(--text); background: var(--bg-alt); }
.sidebar li a.active { color: var(--orange); background: var(--orange-soft); font-weight: 600; }
.toc { position: sticky; top: 88px; align-self: start; font-size: 13px; }
.toc-title { font-size: 11px; letter-spacing: .14em; font-weight: 700; color: var(--muted); text-transform: uppercase; margin-bottom: 8px; }
.toc a { display: block; padding: 4px 0 4px 10px; border-left: 2px solid var(--line); color: var(--muted); }
.toc a:hover, .toc a.active { color: var(--text); border-left-color: var(--orange); }

/* prose */
.prose { min-width: 0; }
.prose h1 { font-size: 36px; line-height: 1.1; letter-spacing: -.02em; font-weight: 800; margin: 0 0 16px; }
.prose h2 { font-size: 24px; letter-spacing: -.01em; font-weight: 800; margin: 44px 0 12px; padding-top: 16px; border-top: 2px solid var(--ink); }
.prose h3 { font-size: 17px; font-weight: 700; margin: 28px 0 8px; }
.prose p, .prose li { font-size: 15.5px; color: var(--text); }
.prose > p:first-of-type { font-size: 17px; color: var(--muted); }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 4px 0; }
.prose a { color: var(--orange); font-weight: 500; }
.prose code { background: var(--bg-alt); border: 1px solid var(--line); padding: 1px 6px; border-radius: 5px; font-size: 13px; }
.prose pre { background: var(--code-bg); color: var(--code-text); padding: 16px 18px; border-radius: 10px; overflow: auto; font-size: 13px; line-height: 1.55; }
.prose pre code { background: none; border: 0; padding: 0; color: inherit; font-size: inherit; }
.prose table { width: 100%; border-collapse: collapse; font-size: 14px; margin: 14px 0 20px; }
.prose th, .prose td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose th { font-size: 12px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); border-bottom: 2px solid var(--ink); }
.prose blockquote { margin: 0; padding: 12px 16px; background: var(--orange-soft); border-left: 3px solid var(--orange); border-radius: 0 8px 8px 0; }
.prose input[type=checkbox] { margin-right: 8px; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 32px 0; }
.prompt-box { border: 1.5px solid var(--ink); border-radius: 12px; overflow: hidden; margin: 20px 0; }
.prompt-bar { display: flex; justify-content: space-between; align-items: center; padding: 10px 14px; background: var(--bg-alt); font-size: 12px; letter-spacing: .1em; font-weight: 700; color: var(--muted); }
.copy-btn { background: var(--orange); color: #fff; border: 0; border-radius: 7px; padding: 7px 12px; font-weight: 700; font-size: 13px; cursor: pointer; letter-spacing: 0; }
.prompt-box pre { margin: 0; border-radius: 0; max-height: 520px; white-space: pre-wrap; }

/* landing */
.eyebrow { color: var(--orange); font-size: 12px; letter-spacing: .18em; font-weight: 700; text-transform: uppercase; margin-bottom: 14px; }
.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; padding: 72px 0 56px; }
.hero h1 { font-size: 52px; line-height: 1.04; letter-spacing: -.025em; font-weight: 800; margin: 0 0 18px; }
.hero p { font-size: 18px; color: var(--muted); max-width: 540px; margin: 0 0 26px; }
.hero-cta, .cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-code { background: var(--code-bg); color: var(--code-text); border-radius: 14px; overflow: hidden; box-shadow: var(--shadow); }
.code-bar { display: flex; justify-content: space-between; padding: 10px 16px; background: rgba(255,255,255,.06); font: 600 12px 'JetBrains Mono', monospace; letter-spacing: .04em; color: #c9c7d6; }
.pill { background: #1f7a3a; color: #fff; padding: 2px 8px; border-radius: 999px; font-size: 11px; }
.hero-code pre { margin: 0; padding: 18px 20px; font-size: 13px; line-height: 1.6; overflow: auto; }
.hero-code .hl { color: #ffb38a; font-weight: 600; } .hero-code .dim { color: #7a7890; }
.section { padding: 56px 0; }
.section.alt { position: relative; }
.section.alt:before { content: ""; position: absolute; inset: 0 -100vw; background: var(--bg-alt); z-index: -1; }
.section h2 { font-size: 34px; letter-spacing: -.02em; font-weight: 800; margin: 0 0 28px; line-height: 1.1; }
.cards4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.card { display: block; border: 1.5px solid var(--ink); border-radius: 14px; padding: 22px; background: var(--panel); transition: transform .15s; }
.card:hover { transform: translateY(-2px); }
.card .n { color: var(--orange); font-weight: 800; font-size: 18px; margin-bottom: 8px; }
.card h3 { margin: 0 0 8px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 14.5px; }
.levels { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.level { background: var(--panel); border: 1.5px solid var(--line); border-radius: 14px; padding: 24px; position: relative; }
.level.hot { border-color: var(--orange); }
.level .lv { font-size: 11px; letter-spacing: .14em; font-weight: 700; color: var(--muted); text-transform: uppercase; }
.level.hot .lv { color: var(--orange); }
.level h3 { margin: 6px 0 8px; font-size: 20px; }
.level p { color: var(--muted); font-size: 14.5px; margin: 0 0 12px; }
.level ul { margin: 0; padding-left: 18px; font-size: 13.5px; font-family: 'JetBrains Mono', monospace; color: var(--text); }
.level li { margin: 3px 0; }
.level .eff { display: inline-block; margin-top: 16px; font-size: 12px; font-weight: 700; padding: 4px 10px; border-radius: 999px; background: var(--bg-alt); border: 1px solid var(--line); }
.level.hot .eff { background: var(--orange-soft); border-color: transparent; color: var(--orange); }
.steps { counter-reset: s; list-style: none; padding: 0; margin: 0 0 28px; display: grid; grid-template-columns: 1fr 1fr; gap: 10px 32px; }
.steps li { counter-increment: s; position: relative; padding: 14px 0 14px 54px; border-bottom: 1px solid var(--line); font-size: 15.5px; }
.steps li:before { content: counter(s, decimal-leading-zero); position: absolute; left: 0; top: 10px; width: 38px; height: 38px; border-radius: 50%; background: var(--ink); color: var(--bg); display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 14px; }
.steps li code { background: var(--bg-alt); border: 1px solid var(--line); padding: 1px 6px; border-radius: 5px; font-size: 13px; }
.who { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.who div { border-top: 2px solid var(--ink); padding-top: 14px; }
.who h3 { margin: 0 0 8px; font-size: 17px; }
.who p { margin: 0; color: var(--muted); font-size: 14.5px; }
.cta-band { background: var(--ink); color: var(--bg); border-radius: 16px; padding: 44px 48px; display: flex; justify-content: space-between; align-items: center; gap: 32px; margin-bottom: 72px; }
:root[data-theme="dark"] .cta-band { background: #1f1f27; color: #fff; }
.cta-band h2 { margin: 0 0 8px; font-size: 28px; }
.cta-band p { margin: 0; opacity: .8; }

/* reference */
.ref-head { padding: 28px 0 8px; }
.ref-head h1 { font-size: 32px; margin: 0 0 6px; letter-spacing: -.02em; }
.ref-head p { margin: 0; color: var(--muted); }
.ref-head a { color: var(--orange); }

/* footer */
.foot { border-top: 1px solid var(--line); margin-top: 40px; }
.foot-inner { max-width: 1240px; margin: 0 auto; padding: 36px 24px 44px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; font-size: 13.5px; color: var(--muted); line-height: 1.8; }
.foot strong { color: var(--text); }
.foot a:hover { color: var(--orange); }
.foot-legal { text-align: right; }

/* responsive */
@media (max-width: 1024px) {
  .shell.docs { grid-template-columns: 220px minmax(0, 1fr); }
  .toc { display: none; }
  .cards4 { grid-template-columns: 1fr 1fr; }
  .hero { grid-template-columns: 1fr; padding-top: 48px; }
  .hero h1 { font-size: 40px; }
  .foot-inner { grid-template-columns: 1fr 1fr; } .foot-legal { text-align: left; }
}
@media (max-width: 760px) {
  .nav, .top-actions { display: none; }
  .menu-toggle { display: block; }
  .top.open .nav { display: flex; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg); border-bottom: 1px solid var(--line); padding: 12px 16px; }
  .shell { padding: 0 16px; }
  .shell.docs { grid-template-columns: 1fr; gap: 16px; }
  .sidebar { position: static; max-height: none; display: grid; grid-template-columns: 1fr 1fr; gap: 8px; padding: 12px; border: 1px solid var(--line); border-radius: 12px; }
  .cards4, .levels, .who, .steps { grid-template-columns: 1fr; }
  .hero h1 { font-size: 34px; } .section h2 { font-size: 28px; }
  .cta-band { flex-direction: column; align-items: flex-start; padding: 28px 24px; }
  .prose h1 { font-size: 30px; }
  .prose table { display: block; overflow-x: auto; }
}