style.css

:root {
  color-scheme: light;
  --bg: #f5f7fa;
  --panel: #ffffff;
  --ink: #1f2430;
  --ink-2: #5b6472;
  --line: #e2e6ee;
  --accent: #2563eb;
  --accent-ink: #ffffff;
  --accent-soft: #eaf1ff;
  /* 顶部头图渐变：暗色主题覆盖同名变量，避免多处重复书写 */
  --header-grad: linear-gradient(120deg, #1d4ed8, #2563eb 55%, #3b82f6);
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Consolas, Menlo, monospace;
}

/* 手动暗色主题：html[data-theme="dark"]（右上角按钮切换，记忆于 localStorage） */
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1420;
  --panel: #171d2b;
  --ink: #e6eaf2;
  --ink-2: #93a0b4;
  --line: #27303f;
  --accent: #5b8cff;
  --accent-ink: #0b1220;
  --accent-soft: #1b2740;
  --header-grad: linear-gradient(120deg, #16233f, #1e2f55 55%, #233a66);
}

/* 兜底：未手动指定主题时跟随系统深浅色（变量值与上方 data-theme="dark" 保持一致） */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --bg: #0f1420;
    --panel: #171d2b;
    --ink: #e6eaf2;
    --ink-2: #93a0b4;
    --line: #27303f;
    --accent: #5b8cff;
    --accent-ink: #0b1220;
    --accent-soft: #1b2740;
    --header-grad: linear-gradient(120deg, #16233f, #1e2f55 55%, #233a66);
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Roboto, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
}

/* 文案应用前的防闪烁遮罩：由 index.html <head> 预置脚本加类、app.js 应用语言后移除（1.5s 兜底） */
html.i18n-pending body { visibility: hidden; }

/* ---------- header ---------- */
.app-header {
  background: var(--header-grad);
  color: #fff;
}
.header-inner {
  max-width: 1240px;
  margin: 0 auto;
  padding: 20px 24px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.app-header h1 {
  margin: 0;
  font-size: 22px;
  letter-spacing: .3px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.app-header h1 .brand-logo {
  width: 28px;
  height: 28px;
  border-radius: 6px; /* 与 SVG 自带的圆角一致，避免二次裁切 */
  display: block;
  flex: none;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, .25);
}
.app-header h1 .sub { font-size: 13px; font-weight: 400; opacity: .85; }
.header-badges { display: flex; gap: 8px; flex-wrap: wrap; }
/* 头部三个徽标（仓库 / 主题 / 语言）共用底色、描边与悬停反馈 */
.badge {
  background: rgba(255, 255, 255, .16);
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: 999px;
  padding: 3px 10px;
  color: #fff;
  font-size: 12px;
  transition: background-color .15s ease, border-color .15s ease;
}
.badge:hover,
.badge:focus-visible {
  background: rgba(255, 255, 255, .3);
  border-color: rgba(255, 255, 255, .55);
}
.badge-repo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px;
  width: 24px;
  height: 24px;
  box-sizing: border-box;
}
.badge-repo .gh-mark {
  width: 14px;
  height: 14px;
  fill: currentColor;
}
/* 仓库徽标同时作为跳转链接 */
a.badge-repo {
  text-decoration: none;
}
a.badge-repo:hover,
a.badge-repo:focus-visible {
  text-decoration: underline;
}
/* 亮 / 暗主题切换按钮（与仓库徽标同款圆钮） */
button.badge-theme {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  padding: 0;
  cursor: pointer;
}
.badge-theme svg { width: 14px; height: 14px; fill: currentColor; }
/* 亮色显示“月亮”（点击进入暗色）；暗色显示“太阳”（点击回到亮色） */
.theme-icon-sun { display: none; }
html[data-theme="dark"] .theme-icon-moon { display: none; }
html[data-theme="dark"] .theme-icon-sun { display: block; }

/* 界面语言切换（中 / 英）：位于主题按钮与仓库徽标之间 */
button.badge-lang {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  height: 24px;
  padding: 0 9px;
  font-family: inherit;
  font-size: 11px;
  line-height: 1;
  letter-spacing: .3px;
  cursor: pointer;
}
.badge-lang .lang-opt { opacity: .6; }
.badge-lang .lang-sep { opacity: .45; }
html[data-lang="zh"] .badge-lang .lang-opt[data-lang="zh"],
html[data-lang="en"] .badge-lang .lang-opt[data-lang="en"] { opacity: 1; font-weight: 700; }

.chip {
  font-family: var(--mono);
}

/* ---------- layout ---------- */
.app-main { max-width: 1240px; margin: 0 auto; padding: 16px 24px 24px; }

.toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px 18px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 14px;
  margin-bottom: 14px;
}

.indent-seg { display: inline-flex; align-items: center; gap: 6px; }
.seg-label { font-size: 13px; color: var(--ink-2); white-space: nowrap; }

.chip {
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink-2);
  border-radius: 999px;
  font-size: 12px;
  padding: 4px 12px;
  cursor: pointer;
  transition: all .12s ease;
}
.chip:hover { color: var(--ink); border-color: var(--accent); }
.chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
}
.chip.active:hover { color: var(--accent-ink); filter: brightness(1.06); }

.btn {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  border-radius: 8px;
  font-size: 13px;
  padding: 6px 14px;
  cursor: pointer;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: .5; cursor: default; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 600; }
.btn-primary:hover { color: var(--accent-ink); filter: brightness(1.07); }
.btn-sm { padding: 4px 10px; font-size: 12px; border-radius: 7px; }
.btn-ghost { color: var(--ink-2); }

/* ---------- columns ---------- */
.columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 14px;
  align-items: stretch;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  min-height: 420px;
  overflow: hidden;
}

.panel-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}
.panel-head h2 { margin: 0; font-size: 14px; font-weight: 700; }
.head-spacer { flex: 1; }
.hint { color: var(--ink-2); font-size: 12px; font-weight: 400; }

/* 面板头内的弹性分配：
   提示文字可收缩并以省略号截断，标题 / 按钮 / 历史按钮 / “预览中”角标不参与收缩。
   否则角标一出现（悬停历史条目时）就会挤到换行，把行尾的历史下拉甩到第二行。 */
.panel-head .hint {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.panel-head h2,
.panel-head .btn,
.panel-head .hist-wrap { flex: 0 0 auto; }

.editor-wrap { flex: 1; display: flex; min-height: 0; }
#editor {
  flex: 1;
  resize: none;
  border: 0;
  outline: none;
  background: transparent;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.6;
  padding: 14px;
  white-space: pre;
  tab-size: 4;
  min-height: 380px;
}
#editor::placeholder { color: var(--ink-2); opacity: .6; }

.editor-foot {
  padding: 6px 14px;
  border-top: 1px solid var(--line);
  color: var(--ink-2);
  font-size: 12px;
}

/* ---------- preview tree ---------- */
.tree-scroll {
  flex: 1;
  overflow: auto;
  min-height: 300px;
  background: var(--bg);
  margin: 10px;
  border: 1px solid var(--line);
  border-radius: 9px;
}
.tree-rows {
  display: block;
  width: max-content;
  min-width: 100%;
  padding: 8px 4px;
  font-family: var(--mono);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--ink);
}
.trow { display: block; white-space: pre; width: max-content; border-radius: 4px; }
.trow:hover { background: var(--accent-soft); }
.tname { cursor: default; border-radius: 3px; }
.tname.folder { cursor: pointer; }
.tname.folder:hover { text-decoration: underline dotted; }
/* 键盘焦点（节点带 tabindex，可用 Tab + Enter/空格 折叠）：内描边 + 底纹 */
.tname.folder:focus-visible { background: var(--accent-soft); outline: 1px solid var(--accent); outline-offset: -1px; }
.tname.collapsed { color: var(--accent); opacity: .75; font-style: italic; }
.empty-tip { padding: 60px 20px; text-align: center; color: var(--ink-2); }
.empty-tip p { margin: 4px 0; }
.muted { opacity: .7; }

/* ---------- docs ---------- */
.docs {
  margin-top: 16px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 6px 16px;
}
.docs summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 14px;
  padding: 10px 0;
  user-select: none;
}
.docs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 8px 26px;
  padding: 4px 0 14px;
}
.docs h3 { margin: 6px 0 4px; font-size: 13px; color: var(--accent); }
.docs ul, .docs ol { margin: 4px 0; padding-left: 20px; }
.docs li { margin: 3px 0; color: var(--ink-2); }
.docs code {
  font-family: var(--mono);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0 4px;
  font-size: 12px;
}

.app-footer {
  text-align: center;
  color: var(--ink-2);
  font-size: 12px;
  padding: 18px 16px 30px;
}

/* ---------- 历史输入下拉 ---------- */
.hist-wrap { position: relative; display: inline-flex; }
.hist-btn { display: inline-flex; align-items: center; gap: 5px; }
.hist-btn .hist-mark,
.hist-btn .hist-caret { width: 13px; height: 13px; fill: currentColor; opacity: .8; }
.hist-caret { transition: transform .15s ease; }
.hist-btn[aria-expanded="true"] .hist-caret { transform: rotate(180deg); }

.hist-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  z-index: 30;
  /* 宽度随最长条目自适应（内容短就窄），上限比原来收窄，窄屏不溢出 */
  width: max-content;
  min-width: 216px;
  max-width: min(384px, calc(100vw - 28px));
  max-height: min(360px, 62vh);
  overflow: auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: 0 14px 34px rgba(15, 23, 42, .22);
  padding: 6px;
}
.hist-menu[hidden] { display: none; }
.hist-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 4px 8px 6px;
  font-size: 12px;
  color: var(--ink-2);
}
.hist-clear {
  border: 0;
  background: none;
  color: var(--ink-2);
  font-family: inherit;
  font-size: 12px;
  padding: 2px 6px;
  border-radius: 6px;
  cursor: pointer;
}
.hist-clear:hover { color: var(--accent); background: var(--accent-soft); }
.hist-list { list-style: none; margin: 0; padding: 0; }
.hist-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 7px;
  cursor: pointer;
}
.hist-item:hover,
.hist-item:focus-visible { background: var(--accent-soft); outline: none; }
.hist-sum {
  flex: 1 1 auto;
  min-width: 0;
  font-family: var(--mono);
  font-size: 12.5px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
/* 该条历史写入时的缩进样式角标 */
.hist-unit {
  flex: 0 0 auto;
  padding: 1px 7px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 10.5px;
  line-height: 1.5;
  color: var(--ink-2);
  white-space: nowrap;
}
.hist-item:hover .hist-unit,
.hist-item:focus-visible .hist-unit { border-color: var(--accent); color: var(--accent); }

.hist-meta { flex: 0 0 auto; font-size: 11px; color: var(--ink-2); }
.hist-empty { padding: 16px 10px; text-align: center; color: var(--ink-2); font-size: 12.5px; }

/* ---------- 悬停历史条目时的预览状态反馈 ---------- */
/* 两侧面板描边高亮，明确当前看到的是历史预览而非已保存内容 */
.panel.is-preview {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.panel.is-preview .panel-head { border-bottom-color: var(--accent); }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .columns { grid-template-columns: 1fr; }
  .editor-wrap #editor { min-height: 260px; }
  .tree-scroll { max-height: 480px; }
}

/* 窄屏：面板头横向空间紧张，压缩按钮内边距，避免把历史下拉挤到第二行 */
@media (max-width: 560px) {
  .panel-head .btn { padding: 4px 8px; }
}