结构 · 11 LINES 复制

<p class="note" style="margin:0 0 10px">// 宽屏：双窗格并排全展开；窄屏：变成两段手风琴，同一份 HTML。</p>
  <div class="cp">
    <details open class="pane">
      <summary>窗格 A · 目录</summary>
      <div class="bd"><div class="fake-text w80"></div><div class="fake-text w60"></div><div class="fake-text w80"></div></div>
    </details>
    <details open class="pane">
      <summary>窗格 B · 正文</summary>
      <div class="bd"><div class="fake-text"></div><div class="fake-text w60"></div><div class="fake-text w80"></div></div>
    </details>
  </div>

样式 · 本 demo 自定义 17 LINES + 共享令牌类 复制

/* ═══ 本 demo 自定义样式 ═══ */

.cp { display: flex; gap: 10px; align-items: flex-start; }
  .cp .pane { flex: 1; border: 1px solid var(--line); }
  .cp summary {
    list-style: none; cursor: pointer; padding: 10px 12px;
    font-family: var(--serif); font-weight: 700; font-size: 13.5px;
    display: flex; justify-content: space-between;
  }
  .cp summary::-webkit-details-marker { display: none; }
  .cp summary::after { content: "−"; font-family: var(--mono); color: var(--accent); }
  .cp details[open] summary::after { content: "+"; }
  .cp .bd { padding: 0 12px 12px; }
  @media (min-width: 560px) {
    .cp details { flex: 1; }
    .cp summary::after { content: "⇕"; }
    .cp details[open] summary::after { content: "⇕"; }
    .cp .bd { display: block !important; }
  }

/* ═══ 共享令牌类 · demo 外壳已内置 ═══ */

.blk {
  background: color-mix(in srgb, var(--ink) 4%, transparent);
  border: 1px solid var(--line); border-radius: 2px;
  display: grid; place-items: center;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .08em; color: var(--ink-2);
  padding: 10px; min-height: 34px;
}
.blk.acc {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border-color: color-mix(in srgb, var(--accent) 45%, transparent); color: var(--accent);
}
.blk.ink { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.tag {
  display: inline-block; font-family: var(--mono); font-size: 10px; letter-spacing: .08em;
  border: 1px solid var(--line); color: var(--ink-2); padding: 2px 8px;
  border-radius: 2px; background: var(--paper-2);
}
.card { background: var(--paper-2); border: 1px solid var(--line); border-radius: 3px; overflow: hidden; }
.card .cv { aspect-ratio: 16/10; background: color-mix(in srgb, var(--accent) 10%, var(--paper-2)); border-bottom: 1px solid var(--line); }
.card .bd { padding: 9px 10px; }
.card .bd .t { font-weight: 600; font-size: 12.5px; }
.card .bd .m { font-family: var(--mono); font-size: 10px; color: var(--ink-3); margin-top: 2px; }
.avatar {
  width: 34px; height: 34px; border-radius: 50%; flex: none;
  background: color-mix(in srgb, var(--accent) 22%, var(--paper-2)); border: 1px solid var(--line);
}
.fake-text { height: 8px; background: color-mix(in srgb, var(--ink) 10%, transparent); border-radius: 1px; }
.fake-text.w60 { width: 60%; } .fake-text.w80 { width: 80%; } .fake-text.w40 { width: 40%; }
.fake-text + .fake-text { margin-top: 6px; }