/* ============ 静态信息页 (about/terms/privacy/help/contact) ============
 * 这些页面不加载 feed.css, 故在此声明 :root 变量副本 (与 feed.css 一致),
 * 供本文件及 common.css 的页脚样式引用. 变量与 feed.css 保持同步.
 */
:root {
  --brand: #1a73e8; --brand-dark: #1557b0; --brand-light: #e8f0fe;
  --bg: #f5f6f8; --card: #ffffff;
  --text: #1f2329; --text-2: #646a73; --text-3: #8f959e;
  --border: #e5e6eb; --border-2: #f0f1f3;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-lg: 0 8px 24px rgba(0,0,0,.10);
  --radius: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Segoe UI", "Microsoft YaHei", sans-serif;
  color: var(--text); background: var(--bg); line-height: 1.6;
  -webkit-font-smoothing: antialiased; -webkit-tap-highlight-color: transparent;
  display: flex; flex-direction: column; min-height: 100vh;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { display: block; max-width: 100%; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* ============ 顶部导航 (与 feed.css 同构, 静态页独立维护一份) ============ */
.topbar {
  background: var(--card); border-bottom: 1px solid var(--border);
  height: 56px; display: flex; align-items: center; padding: 0 20px;
  position: sticky; top: 0; z-index: 100;
}
.topbar .brand {
  font-size: 20px; font-weight: 700; color: var(--text);
  margin-right: 24px; letter-spacing: -.2px;
  display: inline-flex; align-items: baseline;
}
.topbar .brand .brand-emph {
  font-size: 24px; font-weight: 800; color: var(--brand);
  margin-right: 1px; letter-spacing: 0;
}
.topbar .nav-links { display: flex; gap: 20px; }
.topbar .nav-links a { font-size: 14px; color: var(--text-2); position: relative; padding: 4px 0; }
.topbar .nav-links a:hover { color: var(--brand); }
.topbar .right { margin-left: auto; display: flex; align-items: center; gap: 10px; }

/* ============ 主体卡片 ============ */
.page {
  width: 100%;
  max-width: 760px;
  margin: 28px auto 0;
  padding: 0 16px;
  flex: 1 0 auto;
}
.page-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 36px;
}
.page-card h1 {
  font-size: 22px; font-weight: 700; color: var(--text);
  letter-spacing: -.2px;
}
.page-card .page-sub {
  margin-top: 6px; font-size: 13px; color: var(--text-3);
  padding-bottom: 18px; margin-bottom: 22px;
  border-bottom: 1px solid var(--border-2);
}

/* ============ 正文排版 ============ */
.prose { font-size: 14px; color: var(--text-2); line-height: 1.85; }
.prose h2 {
  font-size: 16px; font-weight: 600; color: var(--text);
  margin: 22px 0 10px;
}
.prose h2:first-child { margin-top: 0; }
.prose p { margin: 10px 0; }
.prose ul { margin: 10px 0 10px 4px; padding-left: 20px; }
.prose li { margin: 6px 0; }
.prose a { color: var(--brand); }
.prose strong { color: var(--text); font-weight: 600; }
.prose .lead {
  font-size: 15px; color: var(--text); margin: 4px 0 18px;
}
.prose .qa { margin: 14px 0; }
.prose .qa-q {
  font-weight: 600; color: var(--text); margin-bottom: 4px;
}
.prose .qa-a { color: var(--text-2); }

/* ============ 联系页条目 ============ */
.contact-list { list-style: none; padding: 0; margin: 14px 0 0; }
.contact-list li {
  display: flex; align-items: baseline; gap: 12px;
  padding: 12px 0; border-bottom: 1px dashed var(--border-2);
}
.contact-list li:last-child { border-bottom: none; }
.contact-list .cl-label {
  flex-shrink: 0; width: 84px; font-size: 13px; color: var(--text-3);
}
.contact-list .cl-value { font-size: 14px; color: var(--text); }

/* ============ H5 适配 ============ */
body.h5 .topbar { padding: 0 14px; height: 50px; }
body.h5 .topbar .brand { font-size: 18px; margin-right: 14px; }
body.h5 .topbar .brand .brand-emph { font-size: 21px; }
body.h5 .topbar .nav-links { gap: 14px; }
body.h5 .topbar .nav-links a { font-size: 13px; }
body.h5 .page { margin-top: 16px; padding: 0 12px; }
body.h5 .page-card { padding: 22px 18px; }
body.h5 .page-card h1 { font-size: 19px; }
body.h5 .prose { font-size: 13.5px; line-height: 1.8; }
body.h5 .contact-list .cl-label { width: 72px; }