:root {
  --accent: #ff9429;
  --bg: #ffffff;
  --panel: #f4f4f6;
  --chip: rgba(118, 118, 128, 0.12);
  --text: #1d1d1f;
  --muted: #6e6e73;
  --hairline: rgba(0, 0, 0, 0.1);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --panel: #1c1c1e;
    --chip: rgba(118, 118, 128, 0.24);
    --text: #f5f5f7;
    --muted: #98989d;
    --hairline: rgba(255, 255, 255, 0.14);
  }
}
html[data-lang="zh"] [data-l="en"], html[data-lang="en"] [data-l="zh"] { display: none !important; }
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
.nav {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border-bottom: 0.5px solid var(--hairline);
}
.nav-inner {
  max-width: 760px; margin: 0 auto; padding: 12px 20px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; font-weight: 700; }
.brand img { width: 28px; height: 28px; border-radius: 7px; }
.nav-links { display: flex; align-items: center; gap: 18px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; }
.nav-links a[aria-current="page"] { color: var(--text); font-weight: 600; }
.lang-toggle {
  border: 0; cursor: pointer; font: inherit; font-size: 13px; font-weight: 600;
  color: var(--text); background: var(--chip);
  height: 28px; padding: 0 12px; border-radius: 999px;
}
main { max-width: 760px; margin: 0 auto; padding: 40px 20px 72px; }
h1 { font-size: 34px; line-height: 1.2; margin: 0 0 12px; letter-spacing: -0.02em; }
h2 { font-size: 22px; margin: 44px 0 12px; padding-top: 4px; letter-spacing: -0.01em; }
h3 { font-size: 17px; margin: 28px 0 8px; }
p, ul { margin: 0 0 14px; }
ul { padding-left: 1.3em; }
li { margin: 4px 0; }
li::marker { color: var(--accent); }
a { color: var(--accent); }
strong { font-weight: 650; }
.meta { color: var(--muted); font-size: 14px; margin-bottom: 28px; }
.summary {
  background: var(--panel);
  border-left: 3px solid var(--accent);
  border-radius: 14px;
  padding: 16px 20px;
  margin: 0 0 8px;
}
footer { border-top: 0.5px solid var(--hairline); color: var(--muted); font-size: 13px; }
footer .inner { max-width: 760px; margin: 0 auto; padding: 24px 20px 40px; display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between; }
footer a { color: var(--muted); text-decoration: none; margin-right: 16px; }
@media (max-width: 420px) { .nav-links { gap: 12px; } }