html[data-language="en"] [data-language="zh"],
    html[data-language="zh"] [data-language="en"] { display: none; }
    .languages { display: flex; flex-wrap: wrap; gap: 12px; margin: 0 0 22px; }
    .languages a { padding: 6px 12px; border: 1px solid var(--line); border-radius: 999px; text-decoration: none; }
    .languages a[aria-current="true"] { background: var(--accent-soft); border-color: var(--accent); font-weight: 700; }
    a { overflow-wrap: anywhere; }
    :root {
      color-scheme: light dark;
      --bg: #f3f4f7;
      --card: #ffffff;
      --ink: #1b1e24;
      --muted: #646c78;
      --line: #e1e4ea;
      --accent: #17998f;
      --accent-soft: #e4f4f2;
      --warning: #fff8e7;
      --warning-line: #ead7aa;
    }
    @media (prefers-color-scheme: dark) {
      :root {
        --bg: #101216;
        --card: #191c22;
        --ink: #f3f4f6;
        --muted: #aab0ba;
        --line: #30343c;
        --accent: #54c4ba;
        --accent-soft: #193331;
        --warning: #2c271b;
        --warning-line: #594b2e;
      }
    }
    * { box-sizing: border-box; }
    body {
      margin: 0;
      background: var(--bg);
      color: var(--ink);
      font: 16px/1.68 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", sans-serif;
    }
    main { width: min(900px, calc(100% - 32px)); margin: 0 auto; padding: 48px 0 72px; }
    header, .card { background: var(--card); border: 1px solid var(--line); border-radius: 24px; }
    header {
      padding: 34px;
      background: linear-gradient(135deg, var(--accent-soft), var(--card) 62%);
    }
    .eyebrow { color: var(--muted); font-size: 14px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
    h1 { margin: 8px 0; font-size: clamp(32px, 6vw, 52px); line-height: 1.1; letter-spacing: -.035em; }
    h2 { margin: 0 0 14px; font-size: 23px; }
    h3 { margin: 0; font-size: 17px; line-height: 1.4; }
    p { margin: 7px 0; }
    a { color: var(--ink); text-decoration-color: var(--accent); text-underline-offset: 3px; }
    .meta, .answer { color: var(--muted); }
    .card { margin-top: 18px; padding: 26px 30px; }
    .item { padding: 18px 0; border-top: 1px solid var(--line); }
    .item:first-of-type { border-top: 0; padding-top: 0; }
    .item:last-child { padding-bottom: 0; }
    .actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
    .button { display: inline-block; padding: 11px 15px; border-radius: 999px; background: var(--ink); color: var(--bg); font-weight: 700; text-decoration: none; }
    .warning { background: var(--warning); border-color: var(--warning-line); }
    footer { color: var(--muted); margin-top: 28px; text-align: center; font-size: 14px; }
    @media (max-width: 520px) {
      main { width: min(100% - 20px, 900px); padding-top: 20px; }
      header, .card { border-radius: 18px; padding: 22px; }
    }