:root {
  --bg: #ffffff;
  --text: #131314;
  --sub: #8b8b94;
  --sec: #424247;
  --line: rgba(0, 0, 0, 0.08);
  --fill: #f5f5f5;
  --accent: #eb482f;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { background: var(--bg); color: var(--text); }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.75;
}
.top {
  position: sticky;
  top: 0;
  z-index: 2;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.top-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  text-decoration: none;
  font-weight: 650;
  font-size: 15px;
}
.brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  border: 1px solid var(--line);
}
.switch {
  display: flex;
  gap: 6px;
}
.switch a {
  font-size: 13px;
  color: var(--sec);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 999px;
}
.switch a.active {
  background: var(--fill);
  color: var(--text);
  font-weight: 600;
}
.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 28px 20px 64px;
}
header h1 {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.meta {
  margin-top: 10px;
  color: var(--sub);
  font-size: 13px;
}
.meta p { margin: 2px 0; }
article { margin-top: 28px; }
h2 {
  font-size: 17px;
  margin: 28px 0 10px;
}
h3 {
  font-size: 15px;
  margin: 18px 0 8px;
}
p, li { font-size: 15px; color: var(--sec); }
p { margin: 8px 0; }
ul, ol { padding-left: 1.3em; }
li { margin: 6px 0; }
strong { color: var(--text); font-weight: 650; }
a { color: var(--accent); }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 12px 0 18px;
}
th, td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--fill); color: var(--text); font-weight: 600; }
.foot {
  margin-top: 40px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--sub);
}
.foot a { color: var(--sub); }
@media (max-width: 520px) {
  table { display: block; overflow-x: auto; }
}