:root {
      color-scheme: light;
      --paper: #ffffff;
      --ink: #252525;
      --muted: #666666;
      --line: #e4e4e4;
    }

    * { box-sizing: border-box; }

    html {
      background: var(--paper);
      font-family: "SimSun", "宋体", "Songti SC", "STSong", "Noto Serif CJK SC", serif;
      font-size: 16px;
    }

    body {
      margin: 0;
      background: var(--paper);
      color: var(--ink);
      font-size: 1.125rem;
      line-height: 2;
      overflow-wrap: break-word;
    }

    .page {
      width: min(100% - 48px, 620px);
      margin-inline: auto;
      padding-block: clamp(64px, 12vh, 132px) 40px;
    }

    h1 {
      margin: 0 0 48px;
      font-size: clamp(1.75rem, 5vw, 2.125rem);
      font-weight: 400;
      line-height: 1.6;
      letter-spacing: .04em;
    }

    h2 {
      margin: 0 0 16px;
      font-size: 1.25rem;
      font-weight: 400;
      line-height: 1.8;
    }

    p { margin: 0 0 20px; }

    .note { color: var(--muted); }

    a {
      color: inherit;
      text-underline-offset: .25em;
    }

    a:hover { text-decoration-thickness: 2px; }

    a:focus-visible {
      outline: 2px solid var(--ink);
      outline-offset: 5px;
    }

    .button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 46px;
      margin-top: 12px;
      padding: 6px 25px;
      border: 1px solid #8a8a8a;
      background: transparent;
      color: var(--ink);
      font-size: 1rem;
      line-height: 2;
      text-decoration: none;
    }

    .button:hover { border-color: var(--ink); }

    .back {
      display: inline-block;
      min-height: 44px;
      margin-bottom: 32px;
      padding-block: 6px;
      color: var(--muted);
      font-size: 1rem;
    }

    .article-page h1 { margin-bottom: 28px; }

    .article-list {
      margin: 0;
      padding: 0;
      list-style: none;
    }

    .article-list li {
      padding-block: 18px;
      border-bottom: 1px solid var(--line);
    }

    .article-list:empty { display: none; }
    .article-list:not(:empty) + .empty { display: none; }

    footer {
      margin-top: 72px;
      padding-top: 20px;
      border-top: 1px solid var(--line);
      color: var(--muted);
      font-size: .875rem;
      line-height: 1.8;
    }

    @media (max-width: 480px) {
      .page { width: calc(100% - 40px); }
      h1 { margin-bottom: 36px; }
      footer { margin-top: 56px; }
    }

    @media print {
      .page { width: 100%; padding: 0; }
      .button, .back { display: none; }
    }

    /* 文章正文沿用主页的纯白底色与宋体。 */

    .reading-nav {
      display: flex;
      flex-wrap: wrap;
      gap: 12px 26px;
      margin-bottom: 34px;
    }
    .reading-nav .back { margin: 0; }
    .reading-nav-bottom {
      margin: 52px 0 0;
      padding-top: 20px;
      border-top: 1px solid var(--line);
    }
    .reading-page h1 {
      margin: 0 0 40px;
      font-size: clamp(1.65rem, 4.8vw, 2rem);
      line-height: 1.65;
      letter-spacing: 0;
      text-wrap: pretty;
    }
    .reading-page h2 {
      margin: 46px 0 20px;
      font-size: 1.4rem;
      font-weight: 700;
      line-height: 1.7;
      break-after: avoid;
    }
    .reading-page h3 {
      margin: 32px 0 18px;
      font-size: 1.15rem;
      font-weight: 700;
      line-height: 1.8;
      break-after: avoid;
    }
    .article-body > p {
      margin-bottom: 22px;
      text-align: justify;
      orphans: 3;
      widows: 3;
    }
    .article-body .keywords,
    .article-body .node-reference {
      color: var(--muted);
      font-size: .9375rem;
      line-height: 1.9;
      text-align: left;
    }
    .article-body .node-reference {
      margin-top: 24px;
      padding-left: 16px;
      border-left: 1px solid var(--line);
    }
    .article-list a {
      display: block;
      padding-block: 4px;
      line-height: 1.9;
    }
    .math-inline { white-space: nowrap; }
    .math-svg {
      display: inline-block;
      max-width: none;
      overflow: visible;
    }
    .equation {
      display: grid;
      grid-template-columns: minmax(0, 1fr) auto;
      align-items: center;
      column-gap: 8px;
      margin: 24px 0 28px;
      break-inside: avoid;
    }
    .equation-math {
      min-width: 0;
      overflow-x: auto;
      padding: 10px 4px;
      text-align: center;
      line-height: 1.4;
      scrollbar-width: thin;
    }
    .equation-number {
      white-space: nowrap;
      color: var(--muted);
      font-size: .9375rem;
      font-variant-numeric: tabular-nums;
    }
    .equation-math:focus-visible,
    .table-scroll:focus-visible {
      outline: 1px solid var(--ink);
      outline-offset: 3px;
    }
    .table-scroll { overflow-x: auto; margin: 28px 0; }
    .reading-page table {
      width: 100%;
      min-width: 570px;
      border-collapse: collapse;
      font-size: 1rem;
      line-height: 1.8;
      text-align: left;
    }
    .reading-page th,
    .reading-page td {
      padding: 13px 12px;
      border-bottom: 1px solid var(--line);
      vertical-align: top;
    }
    .reading-page th { font-weight: 700; border-top: 1px solid var(--line); }
    .reading-page td:first-child { min-width: 110px; }
    .reference-list {
      padding-left: 2em;
      font-size: .9375rem;
      line-height: 1.9;
      overflow-wrap: anywhere;
    }
    .reference-list li { padding-left: .35em; margin: 0 0 14px; }

    @media (max-width: 480px) {
      .reading-page h2 { font-size: 1.25rem; }
      .reading-page h3 { font-size: 1.125rem; }
    }
    @media print {
      .reading-nav { display: none; }
      .reading-page table { min-width: 0; }
      .table-scroll, .equation-math { overflow: visible; }
      .equation-math .math-svg { max-width: 100%; height: auto !important; }
    }