:root{
  --radius:16px;
  --radius-sm:12px;
  --shadow: 0 12px 30px rgba(0,0,0,.25);
  --shadow-sm: 0 8px 18px rgba(0,0,0,.18);

  /* 默认：跟随系统（无手动选择时） */
  --bg:#0b1220;
  --bg2:#070b14;
  --card:#0f1a33;
  --text:#e8eefc;
  --muted:#b7c3e3;
  --line:#1c2a55;
  --primary:#4f7cff;
  --primary2:#3a63ff;
  --codebg: rgba(0,0,0,.28);
  --btnbg: rgba(255,255,255,.03);
  --codeText:#e7efff;
}

@media (prefers-color-scheme: light){
  :root{
    --shadow: 0 10px 26px rgba(17,32,72,.12);
    --shadow-sm: 0 8px 18px rgba(17,32,72,.10);

    --bg:#f6f8ff;
    --bg2:#eef2ff;
    --card:#ffffff;
    --text:#0b1220;
    --muted:#4b5a7a;
    --line:#d7def2;
    --primary:#2f63ff;
    --primary2:#1f4fff;
    --codebg: rgba(47,99,255,.06);
    --btnbg: rgba(47,99,255,.06);
    --codeText:#0b1220;
  }
}

:root[data-theme="dark"]{
  --bg:#0b1220;
  --bg2:#070b14;
  --card:#0f1a33;
  --text:#e8eefc;
  --muted:#b7c3e3;
  --line:#1c2a55;
  --primary:#4f7cff;
  --primary2:#3a63ff;
  --codebg: rgba(0,0,0,.28);
  --btnbg: rgba(255,255,255,.03);
  --codeText:#e7efff;
}

:root[data-theme="light"]{
  --bg:#f6f8ff;
  --bg2:#eef2ff;
  --card:#ffffff;
  --text:#0b1220;
  --muted:#4b5a7a;
  --line:#d7def2;
  --primary:#2f63ff;
  --primary2:#1f4fff;
  --codebg: rgba(47,99,255,.06);
  --btnbg: rgba(47,99,255,.06);
  --codeText:#0b1220;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  background:radial-gradient(1200px 600px at 10% -10%, color-mix(in srgb, var(--primary) 22%, transparent), transparent 60%),
             linear-gradient(180deg,var(--bg) 0%,var(--bg2) 100%);
  color:var(--text);
}

.container{max-width:1024px;margin:0 auto;padding:0 18px}

.top{
  position:sticky;top:0;z-index:10;
  background:color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom:1px solid var(--line);
}
.top .container{display:flex;align-items:center;justify-content:space-between;gap:18px;padding:16px 18px}
.brand{display:flex;gap:12px;align-items:center}
.logo{width:42px;height:42px}
h1{font-size:20px;margin:0;letter-spacing:.2px}
.sub{margin:4px 0 0;color:var(--muted);font-size:13px;line-height:1.5}

.actions{display:flex;gap:10px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:10px 12px;
  border:1px solid var(--line);
  border-radius:12px;
  color:var(--text);
  text-decoration:none;
  background:var(--btnbg);
  transition: transform .12s ease, border-color .12s ease, filter .12s ease;
}
.btn:hover{border-color:color-mix(in srgb, var(--primary) 45%, var(--line)); transform: translateY(-1px)}
.btn:active{transform: translateY(0px)}
.btn.primary{background:linear-gradient(135deg,var(--primary),var(--primary2));border-color:transparent;color:#fff}
.btn.primary:hover{filter:brightness(1.04)}

main.container{padding-top:22px;padding-bottom:56px}

.card{
  background:color-mix(in srgb, var(--card) 85%, transparent);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:18px;
  margin:16px 0;
  box-shadow: var(--shadow-sm);
}
.card h2{margin:0 0 12px;font-size:16px}

.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px 18px;margin:0;padding-left:18px}
.grid li{color:var(--muted);line-height:1.7}
.grid b{color:var(--text)}

ol{padding-left:20px}
li{line-height:1.6}

.hint{color:var(--muted);margin:10px 0 0}

/* Code blocks */
.code-wrap{position:relative;margin-top:10px}
.code-head{
  position:absolute;right:10px;top:10px;
  display:flex;gap:8px;align-items:center;
}
.copy-btn{
  font-size:12px;
  padding:7px 10px;
  border-radius:10px;
  border:1px solid var(--line);
  background:color-mix(in srgb, var(--btnbg) 90%, transparent);
  color:var(--text);
  cursor:pointer;
}
.copy-btn:hover{border-color:color-mix(in srgb, var(--primary) 45%, var(--line))}
.copy-btn:active{transform: translateY(1px)}

pre{
  margin:10px 0 0;
  overflow:auto;
  border:1px solid var(--line);
  border-radius:var(--radius-sm);
  background:var(--codebg);
}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono",monospace;font-size:13px}
pre code{display:block;padding:14px 14px;color:var(--codeText);white-space:pre}

.tabs{display:flex;gap:8px;margin:10px 0 12px}
.tab{cursor:pointer;border:1px solid var(--line);background:var(--btnbg);color:var(--text);padding:8px 10px;border-radius:12px}
.tab.active{border-color:color-mix(in srgb, var(--primary) 55%, var(--line));background:color-mix(in srgb, var(--primary) 14%, transparent)}
.tabpanel{display:none}
.tabpanel.active{display:block}

.footer{display:flex;gap:10px;align-items:center;justify-content:center;color:var(--muted);padding:26px 0 0}
.footer a{color:var(--muted)}
.dot{opacity:.6}

.sr-only{
  position:absolute;
  width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0,0,0,0);
  white-space:nowrap;border:0;
}

@media (max-width:760px){
  .top .container{flex-direction:column;align-items:flex-start}
  .grid{grid-template-columns:1fr}
  .code-head{right:8px;top:8px}
}