:root {
  --bg: #f5f6f7;
  --surface: #fff;
  --text: #17191c;
  --muted: #61666d;
  --line: #d9dde2;
  --accent: #ffcf00;
  --code: #111317;
  --code-text: #f5f7f9;
  --max: 1180px;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}
.wrap {
  width: min(var(--max), calc(100% - 32px));
  margin: 0 auto;
}
.hero {
  background: #fff;
  border-bottom: 1px solid var(--line);
  padding: 64px 0 40px;
}
.eyebrow,
.step {
  display: inline-block;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 1rem;
}
.eyebrow {
  border-bottom: 5px solid var(--accent);
  padding-bottom: 5px;
}
.hero h1 {
  font-size: clamp(2.2rem, 6vw, 4.8rem);
  line-height: 1.02;
  max-width: 920px;
  margin: 18px 0;
}
.lead {
  max-width: 850px;
  color: var(--muted);
  font-size: 1.15rem;
}
.hero-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 28px;
}
.hero-grid div {
  border: 1px solid var(--line);
  padding: 14px;
  background: var(--surface);
}
.hero-grid strong,
.hero-grid span {
  display: block;
}
.hero-grid span {
  color: var(--muted);
  margin-top: 4px;
}
.layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 28px;
  padding: 30px 0 60px;
}
.toc {
  position: sticky;
  top: 18px;
  align-self: start;
  background: #fff;
  border: 1px solid var(--line);
  padding: 18px;
  max-height: calc(100vh - 36px);
  overflow: auto;
}
.toc strong {
  display: block;
  margin-bottom: 10px;
}
.toc a {
  display: block;
  color: var(--muted);
  text-decoration: none;
  padding: 5px 0;
  font-size: 0.92rem;
}
.toc a:hover {
  color: var(--text);
}
article {
  min-width: 0;
}
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: clamp(22px, 4vw, 38px);
  margin-bottom: 22px;
  scroll-margin-top: 20px;
}
.card h2 {
  font-size: clamp(1.55rem, 3vw, 2.25rem);
  line-height: 1.2;
  margin: 0.35rem 0 1rem;
}
.card h3 {
  margin-top: 1.7rem;
}
.step {
  background: var(--accent);
  padding: 4px 8px;
}
code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}
pre {
  background: var(--code);
  color: var(--code-text);
  padding: 18px;
  overflow: auto;
  border-radius: 2px;
  line-height: 1.5;
}
p code,
li code,
summary code {
  background: #eef0f2;
  padding: 2px 5px;
  border-radius: 3px;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
}
th,
td {
  text-align: left;
  border: 1px solid var(--line);
  padding: 11px;
  vertical-align: top;
}
th {
  background: #f0f1f2;
}
.note,
.warning,
.checkpoint {
  border-left: 5px solid var(--accent);
  padding: 14px 16px;
  margin: 18px 0;
  background: #fff9d9;
}
.warning {
  border-left-color: #111;
  background: #f0f1f2;
}
.checkpoint {
  font-weight: 600;
}
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.two-col > div {
  border: 1px solid var(--line);
  padding: 18px;
}
.two-col h3 {
  margin-top: 0;
}
.checklist {
  list-style: none;
  padding: 0;
}
.checklist li {
  padding: 7px 0;
}
.checklist li::before {
  content: "✓";
  display: inline-block;
  margin-right: 10px;
  font-weight: 900;
}
.final-card {
  border-top: 8px solid var(--accent);
}
details {
  border-top: 1px solid var(--line);
  padding: 14px 0;
}
summary {
  cursor: pointer;
  font-weight: 700;
}
a {
  color: #202b38;
}
footer {
  border-top: 1px solid var(--line);
  background: #fff;
  padding: 28px 0;
  color: var(--muted);
}
@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
  }
  .toc {
    position: relative;
    top: auto;
    max-height: none;
  }
  .hero-grid {
    grid-template-columns: 1fr 1fr;
  }
}
@media (max-width: 560px) {
  .wrap {
    width: min(var(--max), calc(100% - 20px));
  }
  .hero {
    padding-top: 40px;
  }
  .hero-grid,
  .two-col {
    grid-template-columns: 1fr;
  }
  .card {
    padding: 20px;
  }
  th,
  td {
    padding: 8px;
    font-size: 0.9rem;
  }
}