:root {
  --fg: #fff;
  --bg: #000;
  --muted: #aaa;
  --primary: #4da3ff;
  --card: #181818;
  --border: #222;
}
@media (prefers-color-scheme: dark) {
  :root {
    --fg: #fff;
    --bg: #000;
    --muted: #aaa;
    --primary: #4da3ff;
    --card: #181818;
    --border: #222;
  }
}
* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Helvetica, Arial, sans-serif;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
.wrap {
  max-width: 860px;
  margin: 0 auto;
  padding: 0px clamp(14px, 4vw, 24px) 100px;
}
.main-title {
  text-align: center;
}
h1,
h2,
h3 {
  line-height: 1.35;
  margin: 1.2em 0 0.6em;
  font-weight: 700;
  color: var(--fg);
}
h1 {
  font-size: clamp(22px, 4.8vw, 30px);
}
h2 {
  font-size: clamp(18px, 4.2vw, 24px);
}
h3 {
  font-size: clamp(16px, 3.8vw, 20px);
}
p {
  margin: 0.7em 0;
  font-size: clamp(15px, 3.8vw, 17px);
}
a {
  color: var(--primary);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
.title {
  margin-top: 8px;
  padding: 14px 16px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
}
.meta {
  color: var(--muted);
  font-size: 13px;
  margin-top: 6px;
}

/* 固定背景色为黑色，不跟随系统主题变化 */
body {
  background: #000;
}

.sub-title {
  color: #37d391;
  font-weight: 400;
}