:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-alt: #f5f7f9;
  --bg-code: #0f172a;
  --fg: #16202b;
  --fg-muted: #55636f;
  --border: #dde3e9;
  --accent: #0b7f86;
  --accent-fg: #ffffff;
  --accent-soft: #e6f4f4;
  --warn-bg: #fff6e5;
  --warn-border: #e6b455;
  --radius: 10px;
  --maxw: 960px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1419;
    --bg-alt: #151d24;
    --bg-code: #060a0e;
    --fg: #e6edf3;
    --fg-muted: #9aa8b4;
    --border: #26313b;
    --accent: #3fd0d4;
    --accent-fg: #06171a;
    --accent-soft: #12292c;
    --warn-bg: #2a2213;
    --warn-border: #7a6023;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}

a { color: var(--accent); }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* header */
.topbar {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 5;
}
.topbar .wrap {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 58px;
  flex-wrap: wrap;
}
.brand {
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--fg);
  font-size: 17px;
}
.topbar nav { margin-left: auto; display: flex; gap: 18px; align-items: center; flex-wrap: wrap; }
.topbar nav a { color: var(--fg-muted); text-decoration: none; font-size: 14px; }
.topbar nav a:hover { color: var(--accent); }
.lang { border-left: 1px solid var(--border); padding-left: 18px; }

/* hero */
.hero { padding: 56px 0 8px; }
h1 {
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
}
.lede { font-size: 19px; color: var(--fg-muted); max-width: 46em; margin: 0 0 28px; }
.lede strong { color: var(--fg); font-weight: 600; }

.cta { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; margin-bottom: 10px; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-fg);
  text-decoration: none;
  font-weight: 600;
  padding: 12px 22px;
  border-radius: var(--radius);
  border: 1px solid transparent;
}
.btn:hover { filter: brightness(1.08); }
.btn.secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--border);
}
.meta { color: var(--fg-muted); font-size: 14px; margin: 4px 0 0; }

figure { margin: 34px 0 0; }
figure img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
figcaption { color: var(--fg-muted); font-size: 13px; margin-top: 8px; }

/* sections */
section { padding: 46px 0; border-top: 1px solid var(--border); margin-top: 46px; scroll-margin-top: 70px; }
section:first-of-type { border-top: 0; }
h2 { font-size: 26px; letter-spacing: -0.01em; margin: 0 0 6px; }
h3 { font-size: 17px; margin: 0 0 6px; }
.sub { color: var(--fg-muted); margin: 0 0 26px; }

.cards { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(270px, 1fr)); }
.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  background: var(--bg-alt);
}
.card p { margin: 0; color: var(--fg-muted); font-size: 15px; }

/* table */
.tablewrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
table { border-collapse: collapse; width: 100%; font-size: 15px; min-width: 640px; }
th, td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--border); white-space: nowrap; }
th { background: var(--bg-alt); font-size: 13px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--fg-muted); }
tbody tr:last-child td { border-bottom: 0; }
td.c { text-align: center; }

/* lists */
ul.feat { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
ul.feat li { padding-left: 22px; position: relative; color: var(--fg-muted); font-size: 15px; }
ul.feat li::before { content: "\2022"; color: var(--accent); position: absolute; left: 4px; font-weight: 700; }
ul.feat b { color: var(--fg); font-weight: 600; }

/* code */
pre {
  background: var(--bg-code);
  color: #d8e2ec;
  padding: 16px 18px;
  border-radius: var(--radius);
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.6;
  border: 1px solid var(--border);
}
code { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace; }
p code, li code, td code {
  background: var(--accent-soft);
  color: inherit;
  padding: 1px 5px;
  border-radius: 5px;
  font-size: 0.9em;
}
pre .c { color: #7c8a99; }

/* steps */
ol.steps { padding-left: 20px; margin: 0 0 22px; }
ol.steps li { margin-bottom: 8px; color: var(--fg-muted); }
ol.steps b { color: var(--fg); }

/* notice */
.notice {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-left-width: 4px;
  border-radius: var(--radius);
  padding: 16px 20px;
}
.notice p { margin: 0 0 10px; font-size: 15px; }
.notice p:last-child { margin-bottom: 0; }

/* faq */
.faq details {
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
.faq details:first-of-type { border-top: 1px solid var(--border); }
.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  display: flex;
  gap: 12px;
  align-items: baseline;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before { content: "+"; color: var(--accent); font-weight: 700; }
.faq details[open] summary::before { content: "\2212"; }
.faq .answer { color: var(--fg-muted); font-size: 15px; margin: 10px 0 2px 24px; }

/* footer */
footer {
  border-top: 1px solid var(--border);
  margin-top: 46px;
  padding: 30px 0 50px;
  color: var(--fg-muted);
  font-size: 14px;
}
footer a { color: var(--fg-muted); }
footer p { margin: 0 0 8px; }

@media (max-width: 640px) {
  .hero { padding-top: 34px; }
  section { padding: 34px 0; margin-top: 34px; }
  .topbar nav a.hide-sm { display: none; }
}