/* ═══ THEME TOKENS — mirrors main system ═══ */
    :root {
      --bg:          #050814;
      --bg-card:     #0d1b2e;
      --bg-raised:   #111e38;
      --bg-nav:      rgba(5,8,20,.88);
      --border:      #1e3251;
      --border-soft: rgba(30,50,81,.55);
      --border-col:  rgba(30,50,81,.35);
      --text:        #e2e8f0;
      --text-soft:   #94a3b8;
      --accent:      #38bdf8;
      --accent-dim:  rgba(56,189,248,.10);
      --accent-mid:  rgba(56,189,248,.22);
      --green:       #4ade80;
      --green-dim:   rgba(74,222,128,.12);
      --orange:      #fbbf24;
      --purple:      #a78bfa;
      --code-bg:     rgba(56,189,248,.08);
      --code-color:  #38bdf8;
      --shadow:      0 4px 24px rgba(0,0,0,.40);
      --r:           12px;
      --r-sm:        8px;
    }
    [data-theme="light"] {
      --bg:          #f8fafc;
      --bg-card:     #ffffff;
      --bg-raised:   #f1f5f9;
      --bg-nav:      rgba(248,250,252,.90);
      --border:      #e2e8f0;
      --border-soft: rgba(203,213,225,.70);
      --border-col:  rgba(203,213,225,.45);
      --text:        #0f172a;
      --text-soft:   #64748b;
      --accent:      #0284c7;
      --accent-dim:  rgba(2,132,199,.08);
      --accent-mid:  rgba(2,132,199,.18);
      --green:       #15803d;
      --green-dim:   rgba(21,128,61,.10);
      --orange:      #b45309;
      --purple:      #7c3aed;
      --code-bg:     rgba(2,132,199,.07);
      --code-color:  #0284c7;
      --shadow:      0 2px 12px rgba(0,0,0,.08);
    }

    /* ═══ RESET ═══ */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-size: 16px; }
    body {
      font-family: 'Inter', system-ui, -apple-system, sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.72;
      -webkit-font-smoothing: antialiased;
      transition: background .25s, color .25s;
    }
    a { color: var(--accent); text-decoration: none; }
    a:hover { text-decoration: underline; }
    code {
      font-family: 'JetBrains Mono', 'Fira Code', monospace;
      font-size: .82em; padding: 1px 5px; border-radius: 4px;
      background: var(--code-bg); color: var(--code-color);
    }

    /* ═══ NAV ═══ */
    nav {
      position: sticky; top: 0; z-index: 200;
      background: var(--bg-nav);
      backdrop-filter: blur(16px) saturate(1.5);
      -webkit-backdrop-filter: blur(16px) saturate(1.5);
      border-bottom: 1px solid var(--border-soft);
      transition: background .25s, border-color .25s;
    }
    .nav-inner {
      max-width: 1180px; margin: 0 auto; padding: 0 1.5rem;
      height: 56px; display: flex; align-items: center; gap: .75rem;
    }
    .nav-brand {
      font-size: .88rem; font-weight: 700; color: var(--text);
      letter-spacing: .01em; flex-shrink: 0; text-decoration: none;
    }
    .nav-brand span { color: var(--text-soft); font-weight: 400; }
    .nav-sep { color: var(--border); flex-shrink: 0; }
    .nav-title {
      font-size: .8rem; color: var(--text-soft); white-space: nowrap;
      overflow: hidden; text-overflow: ellipsis; flex: 1;
    }
    .nav-right { display: flex; align-items: center; gap: .5rem; flex-shrink: 0; }
    .nav-badge {
      font-size: .58rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase;
      padding: .15em .55em; border-radius: 4px;
      background: var(--green-dim); color: var(--green);
      border: 1px solid rgba(74,222,128,.22);
      white-space: nowrap;
    }
    .theme-btn {
      width: 32px; height: 32px; border-radius: var(--r-sm);
      display: flex; align-items: center; justify-content: center;
      background: var(--bg-raised); border: 1px solid var(--border);
      color: var(--text-soft); cursor: pointer; transition: all .15s;
      font-size: .88rem;
    }
    .theme-btn:hover { color: var(--accent); border-color: var(--accent-mid); }

    /* ═══ SECTION NAV (anchor pills) ═══ */
    .sec-nav {
      background: var(--bg-card); border-bottom: 1px solid var(--border-soft);
      padding: .55rem 0; overflow-x: auto;
    }
    .sec-nav-inner {
      max-width: 1180px; margin: 0 auto; padding: 0 1.5rem;
      display: flex; align-items: center; gap: .3rem;
    }
    .sec-nav a {
      font-size: .72rem; font-weight: 600; letter-spacing: .03em;
      color: var(--text-soft); white-space: nowrap;
      padding: .28rem .65rem; border-radius: 20px;
      border: 1px solid transparent; transition: all .15s;
    }
    .sec-nav a:hover {
      color: var(--accent); border-color: var(--accent-mid);
      background: var(--accent-dim); text-decoration: none;
    }

    /* ═══ PAGE ═══ */
    .page { max-width: 1180px; margin: 0 auto; padding: 3rem 1.5rem 5rem; }

    /* ═══ PAGE HEADER ═══ */
    .page-header {
      margin-bottom: 2.5rem; padding-bottom: 2rem;
      border-bottom: 1px solid var(--border-soft);
    }
    .page-header-label {
      font-size: .67rem; font-weight: 700; letter-spacing: .12em;
      text-transform: uppercase; color: var(--accent);
      margin-bottom: .75rem; display: block;
    }
    .page-header-title {
      font-size: clamp(1.5rem, 3.5vw, 2.2rem); font-weight: 700;
      letter-spacing: -.02em; color: var(--text); line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    /* Metadata grid */
    .meta-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: .75rem;
    }
    .meta-card {
      background: var(--bg-raised); border: 1px solid var(--border);
      border-radius: var(--r-sm); padding: .75rem 1rem;
    }
    .meta-card-label {
      font-size: .65rem; font-weight: 700; letter-spacing: .08em;
      text-transform: uppercase; color: var(--text-soft); margin-bottom: .3rem;
    }
    .meta-card-value {
      font-size: .82rem; font-weight: 500; color: var(--text);
    }
    .meta-card-value code {
      font-size: .78em;
    }
    .meta-disclaimer {
      margin-top: 1rem; padding: .75rem 1rem;
      background: rgba(251,191,36,.06); border: 1px solid rgba(251,191,36,.2);
      border-radius: var(--r-sm);
    }
    .meta-disclaimer p {
      font-size: .8rem; color: var(--text-soft); line-height: 1.6;
    }
    .meta-disclaimer p + p { margin-top: .25rem; }

    /* ═══ BILINGUAL SECTION ═══ */
    .wp-section {
      margin-bottom: 0;
      scroll-margin-top: 110px;
    }
    .wp-section + .wp-section {
      border-top: 1px solid var(--border-soft);
    }

    .sec-header {
      padding: 2rem 0 1.25rem;
      display: flex; align-items: baseline; gap: .75rem;
    }
    .sec-num {
      font-size: .72rem; font-weight: 700; letter-spacing: .06em;
      color: var(--accent); flex-shrink: 0;
      background: var(--accent-dim); border: 1px solid var(--accent-mid);
      padding: .15em .6em; border-radius: 4px;
    }
    .sec-titles {
      display: flex; align-items: baseline; gap: .5rem; flex-wrap: wrap;
    }
    .sec-title-zh {
      font-size: 1.1rem; font-weight: 700; color: var(--text);
    }
    .sec-title-sep { color: var(--text-soft); font-weight: 300; }
    .sec-title-en {
      font-size: .92rem; font-weight: 500; color: var(--text-soft);
    }

    /* Two-column bilingual grid */
    .bilingual {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0;
      border: 1px solid var(--border);
      border-radius: var(--r);
      overflow: hidden;
      margin-bottom: 2rem;
    }
    .col {
      padding: 1.75rem 2rem;
    }
    .col-zh {
      border-right: 1px solid var(--border-col);
    }
    .col-lang-tag {
      font-size: .62rem; font-weight: 700; letter-spacing: .08em;
      text-transform: uppercase; display: inline-block;
      padding: .18em .55em; border-radius: 4px; margin-bottom: 1rem;
    }
    .tag-zh {
      background: rgba(167,139,250,.12); color: var(--purple);
      border: 1px solid rgba(167,139,250,.25);
    }
    .tag-en {
      background: var(--accent-dim); color: var(--accent);
      border: 1px solid var(--accent-mid);
    }

    /* Section content typography */
    .col p { font-size: .9rem; color: var(--text); line-height: 1.78; margin-bottom: .9em; }
    .col p:last-child { margin-bottom: 0; }
    .col strong { font-weight: 600; color: var(--accent); }
    .col em { font-style: italic; color: var(--text-soft); }
    .col ul, .col ol {
      margin: .5em 0 .9em 1.25em; padding: 0;
    }
    .col li {
      font-size: .9rem; color: var(--text); line-height: 1.72;
      margin-bottom: .3em;
    }
    .col li::marker { color: var(--accent); }
    .col h3 {
      font-size: .88rem; font-weight: 700; color: var(--text);
      margin: 1.25em 0 .5em; letter-spacing: .01em;
    }
    .col h3 .subsec-num {
      color: var(--text-soft); font-weight: 500; margin-right: .35em;
    }
    .col code { font-size: .78em; }
    .col .sub-divider {
      border: none; border-top: 1px solid var(--border-soft);
      margin: 1.1em 0;
    }

    /* Cert pair row */
    .cert-row {
      display: grid; grid-template-columns: 1fr 1fr;
      gap: 0; border: 1px solid var(--border);
      border-radius: var(--r); overflow: hidden; margin-bottom: 2rem;
    }
    .cert-cell {
      padding: .9rem 1.5rem;
    }
    .cert-cell + .cert-cell { border-left: 1px solid var(--border-col); }
    .cert-cell-label {
      font-size: .62rem; font-weight: 700; letter-spacing: .08em;
      text-transform: uppercase; color: var(--text-soft); margin-bottom: .35rem;
    }
    .cert-cell-value {
      font-family: 'JetBrains Mono', monospace;
      font-size: .78rem; color: var(--green);
    }

    /* Closing author row */
    .author-row {
      display: grid; grid-template-columns: 1fr 1fr;
      gap: 0; border: 1px solid var(--border);
      border-radius: var(--r); overflow: hidden; margin-bottom: 2rem;
    }
    .author-cell {
      padding: 1.25rem 2rem;
    }
    .author-cell + .author-cell { border-left: 1px solid var(--border-col); }
    .author-label {
      font-size: .65rem; font-weight: 700; letter-spacing: .08em;
      text-transform: uppercase; color: var(--text-soft); margin-bottom: .35rem;
    }
    .author-name {
      font-size: .92rem; font-weight: 600; color: var(--text);
    }

    /* ═══ FOOTER ═══ */
    footer {
      margin-top: 4rem; padding-top: 2rem;
      border-top: 1px solid var(--border-soft);
      text-align: center;
    }
    footer p { font-size: .78rem; color: var(--text-soft); line-height: 1.7; }
    footer a { color: var(--text-soft); }
    footer a:hover { color: var(--accent); }

    /* ═══ RESPONSIVE ═══ */
    @media (max-width: 760px) {
      .bilingual, .cert-row, .author-row {
        grid-template-columns: 1fr;
      }
      .col-zh { border-right: none; border-bottom: 1px solid var(--border-col); }
      .cert-cell + .cert-cell { border-left: none; border-top: 1px solid var(--border-col); }
      .author-cell + .author-cell { border-left: none; border-top: 1px solid var(--border-col); }
      .meta-grid { grid-template-columns: 1fr; }
      .col { padding: 1.25rem 1.25rem; }
    }

    /* ═══ PRINT ═══ */
    @media print {
      nav, .sec-nav, .theme-btn { display: none !important; }
      body { background: #fff; color: #111; }
      .bilingual, .cert-row, .author-row { border: 1px solid #ccc; }
      .col-zh { border-right: 1px solid #ccc; }
    }
  
/* Single-language full-width */
.bilingual { grid-template-columns: 1fr !important; }
.col-zh { border-right: none !important; }
body.lang-zh .col-en, body.lang-en .col-zh { display: none !important; }
.col-lang-tag { display: none !important; }
body.lang-zh .sec-title-en, body.lang-zh .sec-title-sep { display: none !important; }
body.lang-en .sec-title-zh, body.lang-en .sec-title-sep { display: none !important; }
body.lang-en .sec-title-en { font-size: 1.1rem; font-weight: 700; color: var(--text); }
.cert-row, .author-row { grid-template-columns: 1fr !important; }
body.lang-zh .cert-cell:nth-child(2), body.lang-en .cert-cell:nth-child(1) { display: none !important; }
body.lang-zh .cert-cell + .cert-cell, body.lang-en .cert-cell + .cert-cell { border-left: none !important; }
body.lang-zh .author-cell[lang="en"], body.lang-en .author-cell[lang="zh"] { display: none !important; }
body.lang-zh .author-cell + .author-cell, body.lang-en .author-cell + .author-cell { border-left: none !important; }
body.lang-en .meta-disclaimer p:nth-child(1), body.lang-zh .meta-disclaimer p:nth-child(2) { display: none !important; }