:root {
  color-scheme: light;
  --bg: #f4f6f9;
  --bg-elevated: #ffffff;
  --surface: #ffffff;
  --surface-hover: #eef1f7;
  --border: #cfd6e4;
  --border-subtle: #e4e9f2;
  --border-focus: #94a3b8;
  --text: #141824;
  --text-secondary: #5c6477;
  --accent: #2563eb;
  --accent-muted: rgba(37, 99, 235, 0.12);
  --focus: #1d4ed8;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 12px 40px rgba(15, 23, 42, 0.1);
  --radius: 10px;
  --radius-sm: 7px;
  --font: "Segoe UI", system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "Cascadia Code", "Consolas", "SFMono-Regular", ui-monospace, monospace;
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --topbar-h: 48px;
  --sidebar-w: 260px;
  --note-body: #3b4354;
  --md-h2: #0f172a;
  --md-h3: #1e293b;
  --md-h4: #334155;
  --md-h56: #475569;
  --md-strong: #0f172a;
  --md-a-hover: #1d4ed8;
  --md-bq-fg: #475569;
  --md-bq-bg: rgba(37, 99, 235, 0.06);
  --md-code-bg: rgba(15, 23, 42, 0.06);
  --md-pre-bg: #1e293b;
  --md-pre-fg: #e2e8f0;
  --skip-fg: #ffffff;
  --hint-warn-fg: #9a3412;
  --hint-warn-bg: rgba(254, 243, 199, 0.75);
  --hint-warn-border: rgba(245, 158, 11, 0.45);
  --loading-bg: rgba(255, 255, 255, 0.95);
  --toc-active-bg: rgba(37, 99, 235, 0.1);
  --selection-bg: rgba(37, 99, 235, 0.2);
  --scrollbar-thumb: rgba(15, 23, 42, 0.18);
  --scrollbar-thumb-hover: rgba(15, 23, 42, 0.32);
  --scrollbar-track: transparent;
  --copy-btn-bg: rgba(255, 255, 255, 0.1);
  --copy-btn-hover: rgba(255, 255, 255, 0.2);
  --empty-icon: rgba(37, 99, 235, 0.15);
  --details-bg: rgba(37, 99, 235, 0.025);
  --details-border: rgba(37, 99, 235, 0.1);
  --progress-bg: var(--accent);
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0c0e14;
  --bg-elevated: #12151e;
  --surface: #161a24;
  --surface-hover: #1c2230;
  --border: #2a3142;
  --border-subtle: #222836;
  --border-focus: #3d4658;
  --text: #e6eaf2;
  --text-secondary: #9aa3b5;
  --accent: #7eb0ff;
  --accent-muted: rgba(126, 176, 255, 0.14);
  --focus: #9ec0ff;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --note-body: #d0d8e4;
  --md-h2: #eef1f6;
  --md-h3: #e2e7f0;
  --md-h4: #d8dde8;
  --md-h56: #c8d0dc;
  --md-strong: #f0f3f8;
  --md-a-hover: #a8c8ff;
  --md-bq-fg: #c8d0e0;
  --md-bq-bg: rgba(126, 176, 255, 0.06);
  --md-code-bg: rgba(0, 0, 0, 0.35);
  --md-pre-bg: #0a0c12;
  --md-pre-fg: #e2e8f0;
  --skip-fg: #0a0c10;
  --hint-warn-fg: #fecaca;
  --hint-warn-bg: rgba(248, 113, 113, 0.1);
  --hint-warn-border: rgba(248, 113, 113, 0.25);
  --loading-bg: rgba(18, 21, 30, 0.94);
  --toc-active-bg: rgba(126, 176, 255, 0.12);
  --selection-bg: rgba(126, 176, 255, 0.25);
  --scrollbar-thumb: rgba(255, 255, 255, 0.15);
  --scrollbar-thumb-hover: rgba(255, 255, 255, 0.28);
  --copy-btn-bg: rgba(255, 255, 255, 0.08);
  --copy-btn-hover: rgba(255, 255, 255, 0.15);
  --empty-icon: rgba(126, 176, 255, 0.15);
  --details-bg: rgba(126, 176, 255, 0.025);
  --details-border: rgba(126, 176, 255, 0.08);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

*, *::before, *::after { box-sizing: border-box; }

.muted { color: var(--text-secondary); }

::selection {
  background: var(--selection-bg);
}

html, body { height: 100%; overflow: hidden; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--scrollbar-track); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: var(--scrollbar-thumb-hover); }
@supports (scrollbar-width: thin) {
  * { scrollbar-width: thin; scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track); }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 15px;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute; left: 0.75rem; top: 0.75rem;
  padding: 0.4rem 0.7rem; background: var(--accent); color: var(--skip-fg);
  font-weight: 600; font-size: 0.85rem; border-radius: var(--radius-sm);
  z-index: 100; transform: translateY(-160%); transition: transform 0.2s var(--ease);
}
.skip-link:focus { transform: translateY(0); outline: 2px solid var(--focus); outline-offset: 2px; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ── 阅读进度条 ── */
.reading-progress {
  position: fixed; top: 0; left: 0; width: 0%; height: 3px;
  background: var(--progress-bg); z-index: 200;
  transition: width 0.1s linear; pointer-events: none; opacity: 0;
}
.reading-progress.is-visible { opacity: 1; }

/* ── 顶栏 ── */
.app {
  height: 100vh; display: flex; flex-direction: column;
  overflow: hidden;
}

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  gap: 0.5rem;
  height: var(--topbar-h);
  padding: 0 max(0.75rem, env(safe-area-inset-right)) 0 max(0.75rem, env(safe-area-inset-left));
  border-bottom: 1px solid var(--border-subtle);
  background: var(--surface);
  position: sticky; top: 0; z-index: 40;
  flex-shrink: 0;
}

.topbar-left {
  display: flex; align-items: center; gap: 0.6rem;
  flex: 1; min-width: 0;
}

.logo {
  font-weight: 800; font-size: 1rem; letter-spacing: -0.04em;
  color: var(--accent); flex-shrink: 0;
  user-select: none;
}

.topbar-left .search-field {
  flex: 1; max-width: 420px; min-width: 140px;
}

.search-field {
  position: relative; width: 100%;
}

.search-hit {
  width: 100%; text-align: left;
  padding: 0.45rem 0.65rem;
  border: none; border-bottom: 1px solid var(--border-subtle);
  background: transparent; color: var(--text);
  font: inherit; font-size: 0.8rem; line-height: 1.35;
  cursor: pointer;
  display: block;
  transition: background 0.1s var(--ease);
}
.search-hit:hover { background: var(--surface-hover); }
.search-hit:focus-visible { outline: none; background: var(--surface-hover); box-shadow: inset 0 0 0 2px var(--accent); }
.search-hit.is-focused { background: var(--surface-hover); }

.search-hit-title {
  display: block; font-weight: 600; font-size: 0.78rem;
  color: var(--text-secondary); margin-bottom: 0.2rem;
}
.search-hit-snippet {
  color: var(--text);
  overflow: hidden;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
}
.search-hit-kind {
  font-weight: 600; font-size: 0.72rem; color: var(--text-secondary);
}

.notes-list li button.search-hit-continue {
  padding-top: 0.38rem;
  box-shadow: inset 3px 0 0 var(--border-subtle);
}
.notes-list li button.search-hit-continue .search-hit-title-skip {
  display: none;
}
.search-hit-snippet .muted {
  font-size: 0.76rem;
}
.search-hit-snippet mark, .search-hit-title mark {
  background: rgba(37, 99, 235, 0.2); color: var(--accent);
  padding: 0 0.05em; border-radius: 2px;
}
html[data-theme="dark"] .search-hit-snippet mark,
html[data-theme="dark"] .search-hit-title mark {
  background: rgba(126, 176, 255, 0.22);
}

.search-icon {
  position: absolute; left: 0.6rem; top: 50%; transform: translateY(-50%);
  color: var(--text-secondary); pointer-events: none;
  transition: color 0.15s var(--ease);
}
.search-field:focus-within .search-icon { color: var(--accent); }

.search-input {
  width: 100%; padding: 0.35rem 1.8rem 0.35rem 2rem;
  border: 1px solid var(--border); border-radius: 999px;
  background: var(--bg); color: var(--text); font: inherit; font-size: 0.85rem;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.search-input::placeholder { color: var(--text-secondary); opacity: 0.65; }
.search-input:hover { border-color: var(--border-focus); }
.search-input:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-muted);
}

.search-clear {
  position: absolute; right: 0.4rem; top: 50%; transform: translateY(-50%);
  border: none; background: none; color: var(--text-secondary); cursor: pointer;
  padding: 0.15rem; border-radius: 4px; display: flex;
  transition: color 0.12s var(--ease);
}
.search-clear:hover { color: var(--text); }

.topbar-right { display: flex; gap: 0.15rem; align-items: center; flex-shrink: 0; }
.repo-link { text-decoration: none; }

.topbar-btn {
  width: 34px; height: 34px; border-radius: 7px;
  border: none; background: transparent; color: var(--text-secondary);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background 0.12s var(--ease), color 0.12s var(--ease);
  flex-shrink: 0;
}
.topbar-btn:hover { background: var(--surface-hover); color: var(--text); }
.topbar-btn:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--accent); }
.topbar-btn[hidden] { display: none !important; }

.theme-toggle .theme-icon-sun { display: none; }
.theme-toggle .theme-icon-moon { display: block; }
html[data-theme="dark"] .theme-toggle .theme-icon-sun { display: block; }
html[data-theme="dark"] .theme-toggle .theme-icon-moon { display: none; }

.hint {
  margin: 0; min-height: 0; font-size: 0.82rem; color: var(--text-secondary);
  padding: 0 max(0.75rem, env(safe-area-inset-left));
}
.hint:empty { display: none; }
.hint.is-warn {
  color: var(--hint-warn-fg); padding: 0.4rem 0.65rem;
  background: var(--hint-warn-bg); border-radius: var(--radius-sm);
  border: 1px solid var(--hint-warn-border); margin: 0.5rem 0.75rem;
}

/* ── 主布局 ── */
.layout {
  display: flex; flex: 1; min-height: 0; overflow: hidden;
}

/* ── 侧栏 ── */
.sidebar {
  width: var(--sidebar-w); flex-shrink: 0;
  display: flex; flex-direction: column;
  border-right: 1px solid var(--border-subtle);
  background: var(--surface);
  transition: width 0.25s var(--ease), margin-left 0.25s var(--ease);
  overflow: hidden;
}

.sidebar.is-collapsed {
  width: 0; margin-left: 0;
  border-right: none;
}

.sidebar.is-collapsed .notes-list,
.sidebar.is-collapsed .filter-empty,
.sidebar.is-collapsed .search-options {
  opacity: 0; pointer-events: none;
}

.sidebar.is-collapsed .sidebar-head {
  opacity: 0;
}

.sidebar-head {
  display: flex; align-items: center; gap: 0.4rem;
  padding: 0.55rem 0.65rem;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.sidebar-title {
  font-weight: 600; font-size: 0.85rem; color: var(--text);
  flex: 1;
}

.badge {
  font-size: 0.65rem; font-weight: 600; font-variant-numeric: tabular-nums;
  background: var(--bg); border: 1px solid var(--border);
  padding: 0.1rem 0.4rem; border-radius: 999px; color: var(--text-secondary);
}

.sidebar-toggle-btn {
  margin-right: 0.1rem;
}

.filter-empty {
  margin: 0; font-size: 0.82rem; padding: 0.6rem 0.65rem;
}

.search-options {
  flex-shrink: 0;
  padding: 0.45rem 0.65rem 0.5rem;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.72rem;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.search-options-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.5rem;
}
.search-options-label {
  flex: 0 0 auto;
  font-weight: 600;
  color: var(--text);
  font-size: 0.72rem;
  margin-right: 0.1rem;
}
.search-option-radio,
.search-option-check {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
  cursor: pointer;
  user-select: none;
}
.search-option-radio input,
.search-option-check input {
  margin: 0;
  accent-color: var(--accent);
}

.notes-list {
  list-style: none; margin: 0; padding: 0;
  overflow-y: auto; flex: 1; min-height: 0;
  -webkit-overflow-scrolling: touch;
}

.notes-list li { margin: 0; }

.notes-list li button {
  width: 100%; text-align: left;
  padding: 0.55rem 0.65rem;
  border: none; border-bottom: 1px solid var(--border-subtle);
  background: transparent; color: var(--text);
  font: inherit; font-size: 0.85rem; line-height: 1.4;
  cursor: pointer;
  transition: background 0.12s var(--ease);
}
.notes-list li:last-child button { border-bottom: none; }
.notes-list li button:hover { background: var(--surface-hover); }
.notes-list li button:focus-visible {
  outline: none; background: var(--surface-hover);
  box-shadow: inset 0 0 0 2px var(--accent);
}
.notes-list li button.active {
  background: var(--accent-muted);
  box-shadow: inset 3px 0 0 var(--accent);
}
.notes-list li button.is-focused {
  background: var(--surface-hover);
}

.note-title-main {
  display: block; font-weight: 500; word-break: break-word;
}

.note-title-main mark {
  background: rgba(37, 99, 235, 0.18); color: var(--accent);
  padding: 0 0.05em; border-radius: 2px;
}
html[data-theme="dark"] .note-title-main mark {
  background: rgba(126, 176, 255, 0.18);
}

.search-highlight {
  background: var(--search-hl); color: inherit;
  padding: 0.1em 0; border-radius: 2px;
}
.search-highlight.is-current {
  background: var(--search-hl-strong);
}
:root { --search-hl: rgba(37, 99, 235, 0.15); --search-hl-strong: rgba(37, 99, 235, 0.45); }
html[data-theme="dark"] { --search-hl: rgba(126, 176, 255, 0.18); --search-hl-strong: rgba(126, 176, 255, 0.45); }

.list-error, .list-empty {
  list-style: none; padding: 0.8rem 0.65rem; margin: 0;
  color: var(--text-secondary); font-size: 0.82rem; line-height: 1.5;
}

/* ── 预览区 ── */
.preview-wrap {
  display: flex; flex-direction: column;
  flex: 1; min-width: 0; min-height: 0;
  position: relative;
}

.preview-toolbar {
  padding: 0.45rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex; align-items: center; justify-content: space-between;
  gap: 0.5rem; flex-shrink: 0;
  background: var(--surface);
}

.preview-heading {
  margin: 0; font-size: 0.9rem; font-weight: 600; line-height: 1.35;
  flex: 1; min-width: 0;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

.preview-title-text { color: var(--text); }
.preview-title-text.is-placeholder { color: var(--text-secondary); font-weight: 400; }

.search-nav {
  display: flex; align-items: center; gap: 0.25rem; flex-shrink: 0;
}
.search-nav-count {
  font-size: 0.72rem; font-variant-numeric: tabular-nums;
  color: var(--text-secondary); white-space: nowrap; min-width: 3.5em; text-align: center;
}
.search-nav-btn {
  width: 24px; height: 24px; border-radius: 5px;
  border: none; background: transparent; color: var(--text-secondary);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background 0.12s var(--ease), color 0.12s var(--ease);
}
.search-nav-btn:hover { background: var(--surface-hover); color: var(--text); }
.search-nav-btn:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--accent); }
.note-share-btn { flex-shrink: 0; }
.toolbar-text-btn {
  width: auto;
  min-width: 7.2em;
  height: 24px;
  padding: 0 0.55rem;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  background: var(--surface);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.toolbar-text-btn:hover {
  border-color: var(--border);
}

.reading-meta {
  display: flex; gap: 0.6rem; align-items: center; flex-shrink: 0; white-space: nowrap;
}
.reading-time, .word-count {
  font-size: 0.72rem; font-variant-numeric: tabular-nums;
  color: var(--text-secondary);
}

.preview-body {
  display: flex; flex: 1; min-height: 0; overflow: hidden;
}

.note-preview-scroll {
  flex: 1; min-width: 0;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.note-preview-scroll.is-loading .note-preview {
  opacity: 0.35; pointer-events: none;
}

.note-preview {
  padding: 1.1rem 1.4rem 2rem;
  font-size: 0.9375rem; line-height: 1.72;
  color: var(--note-body); outline: none;
  transition: opacity 0.2s var(--ease);
}

.note-preview :is(h1,h2,h3,h4) { scroll-margin-top: 12px; }

/* ── 空状态 ── */
.empty-state {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 4rem 1rem; text-align: center; min-height: 50vh;
  animation: fadeInUp 0.4s var(--ease);
}
.empty-state-icon { color: var(--empty-icon); margin-bottom: 1rem; }
.empty-state-title { margin: 0 0 0.35rem; font-size: 1rem; font-weight: 600; color: var(--text); }
.empty-state-hint { margin: 0; font-size: 0.82rem; color: var(--text-secondary); max-width: 250px; line-height: 1.5; }
.home-state {
  max-width: 760px;
  margin: 0 auto;
  padding: 0.5rem 0.2rem 1.5rem;
}
.home-state h1 {
  margin: 0 0 0.4rem;
  font-size: 1.45rem;
  line-height: 1.35;
  color: var(--text);
}
.home-state p {
  margin: 0 0 0.6rem;
  color: var(--text-secondary);
  line-height: 1.7;
}
.home-state-links {
  display: flex;
  gap: 0.55rem;
  flex-wrap: wrap;
  margin-top: 0.45rem;
}
.home-state-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.35rem 0.62rem;
  color: var(--text);
  background: var(--surface);
  font-size: 0.8rem;
}
.home-state-links a:hover { background: var(--surface-hover); }
.home-note-list {
  margin-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  padding-top: 0.75rem;
}
.home-note-list h2 {
  margin: 0 0 0.4rem;
  font-size: 0.95rem;
  color: var(--text);
}
.home-note-list ul {
  margin: 0;
  padding-left: 1.1rem;
}
.home-note-list li { margin: 0.28rem 0; }
.home-note-list a { color: var(--accent); }

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── 目录面板 ── */
.toc-panel {
  width: 220px; flex-shrink: 0;
  border-left: 1px solid var(--border-subtle);
  background: var(--surface);
  display: flex; flex-direction: column;
  overflow: hidden;
}

.toc-head {
  display: flex; align-items: center; gap: 0.35rem;
  padding: 0.5rem 0.65rem;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.toc-title { font-size: 0.8rem; font-weight: 650; color: var(--text); }
.toc-count { font-size: 0.65rem; font-variant-numeric: tabular-nums; color: var(--text-secondary); }
.toc-toggle-btn {
  margin-left: auto;
  width: 24px; height: 24px;
  border: none; border-radius: 6px;
  background: transparent; color: var(--text-secondary);
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: background 0.12s var(--ease), color 0.12s var(--ease), transform 0.2s var(--ease);
}
.toc-toggle-btn:hover { background: var(--surface-hover); color: var(--text); }
.toc-toggle-btn:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--accent); }
.toc-panel.is-collapsed .toc-toggle-btn { transform: rotate(-90deg); }

.toc-body {
  flex: 1; overflow-y: auto; padding: 0.35rem 0.4rem 0.5rem;
  -webkit-overflow-scrolling: touch;
}
.toc-panel.is-collapsed .toc-body { display: none; }

.toc-list { margin: 0; padding: 0; }

/* 一级标题（h2）作为可折叠分组 */
.toc-group { margin-bottom: 0.15rem; }

.toc-group-header {
  display: flex; align-items: center; gap: 0;
  padding: 0.35rem 0.35rem;
  border: none; background: transparent;
  font: inherit; font-size: 0.8rem; font-weight: 600;
  color: var(--text); width: 100%;
  cursor: pointer; border-radius: 5px;
  text-align: left;
  transition: background 0.12s var(--ease), color 0.12s var(--ease);
  -webkit-tap-highlight-color: transparent;
}
.toc-group-header:hover { background: var(--surface-hover); }
.toc-group-header:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--accent); }

.toc-group-text {
  flex: 1; min-width: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}

.toc-group-chevron {
  width: 20px; height: 20px; flex-shrink: 0;
  padding: 3px;
  color: var(--text-secondary);
  transition: transform 0.2s var(--ease);
  cursor: pointer;
}
.toc-group-chevron:hover { color: var(--text); }
.toc-group.is-open > .toc-group-header .toc-group-chevron { transform: rotate(90deg); }

.toc-group-header.is-active {
  color: var(--accent);
}

.toc-group-children {
  display: none; padding-left: 0.5rem;
}
.toc-group.is-open > .toc-group-children { display: block; }

.toc-link {
  display: block; width: 100%; text-align: left;
  border: none; background: transparent;
  font: inherit; font-size: 0.78rem; line-height: 1.35;
  color: var(--text-secondary);
  padding: 0.3rem 0.35rem; border-radius: 5px; cursor: pointer;
  transition: background 0.12s var(--ease), color 0.12s var(--ease);
  -webkit-tap-highlight-color: transparent;
}
.toc-link:hover { color: var(--text); background: var(--surface-hover); }
.toc-link:focus-visible { outline: none; box-shadow: 0 0 0 2px var(--accent); }
.toc-link.is-active {
  color: var(--accent); font-weight: 600;
  background: var(--toc-active-bg);
}

.toc-empty { margin: 0; font-size: 0.75rem; line-height: 1.4; padding: 0.5rem; }

[hidden] { display: none !important; }

.preview-loading {
  position: absolute; bottom: 0.75rem; right: 0.75rem;
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.35rem 0.65rem; font-size: 0.75rem;
  color: var(--text-secondary); background: var(--loading-bg);
  border: 1px solid var(--border); border-radius: 999px;
  box-shadow: var(--shadow-md); z-index: 2; backdrop-filter: blur(6px);
  animation: fadeIn 0.2s var(--ease);
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.spinner {
  width: 12px; height: 12px;
  border: 2px solid var(--border); border-top-color: var(--accent);
  border-radius: 50%; animation: spin 0.65s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Markdown 样式 ── */
.md-body h1 {
  margin: 1.2rem 0 0.5rem; font-size: 1.3rem; font-weight: 700;
  letter-spacing: -0.02em; line-height: 1.35; color: var(--text);
  border-bottom: 1px solid var(--border-subtle); padding-bottom: 0.3rem;
}
.md-body h1:first-child { margin-top: 0; }

.md-body h2 {
  margin: 1.1rem 0 0.45rem; font-size: 1.12rem; font-weight: 650;
  letter-spacing: -0.015em; line-height: 1.4; color: var(--md-h2);
  display: flex; align-items: center; gap: 0.45rem;
}
.md-body h2 .section-group-toggle-btn {
  margin-left: 0.2rem;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  border-radius: 999px;
  padding: 0.15rem 0.5rem;
  font-size: 0.72rem;
  line-height: 1.4;
  cursor: pointer;
}
.md-body h2 .section-group-toggle-btn:hover {
  color: var(--text);
  background: var(--surface-hover);
}

.md-body h3 {
  margin: 0.9rem 0 0.35rem; font-size: 1rem; font-weight: 600; color: var(--md-h3);
}

.md-body h4, .md-body h5, .md-body h6 {
  margin: 0.75rem 0 0.3rem; font-size: 0.93rem; font-weight: 600; color: var(--md-h4);
}
.md-body h5, .md-body h6 { color: var(--md-h56); }

.md-body p { margin: 0.5rem 0; }

.md-body a {
  color: var(--accent); text-decoration: underline;
  text-decoration-thickness: 1px; text-underline-offset: 3px;
  transition: color 0.12s var(--ease);
}
.md-body a:hover { color: var(--md-a-hover); }

.md-body strong { font-weight: 650; color: var(--md-strong); }

.md-body hr {
  margin: 1.2rem 0; border: none; height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.md-body ul, .md-body ol { margin: 0.45rem 0; padding-left: 1.5rem; }
.md-body li { margin: 0.25rem 0; }
.md-body li::marker { color: var(--text-secondary); }

.md-body blockquote {
  margin: 0.65rem 0; padding: 0.5rem 0.8rem 0.5rem 0.9rem;
  border-left: 3px solid var(--accent); background: var(--md-bq-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; color: var(--md-bq-fg);
}
.md-body blockquote p { margin: 0.3rem 0; }

.md-body table {
  width: 100%; margin: 0.75rem 0; border-collapse: collapse;
  font-size: 0.86rem; display: block; overflow-x: auto;
  border-radius: var(--radius-sm); border: 1px solid var(--border);
}
.md-body table thead { background: var(--surface-hover); }
.md-body th, .md-body td {
  padding: 0.4rem 0.6rem; border: 1px solid var(--border-subtle);
  text-align: left; vertical-align: top;
}

.md-body code {
  font-family: var(--mono); font-size: 0.84em;
  background: var(--md-code-bg); padding: 0.12em 0.35em;
  border-radius: 4px; border: 1px solid var(--border-subtle);
}

.md-body pre {
  margin: 0.65rem 0; padding: 0.75rem 0.9rem;
  background: var(--md-pre-bg); color: var(--md-pre-fg);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  overflow: auto; font-size: 0.8rem; line-height: 1.55; position: relative;
}
.md-body pre code { background: none; border: none; padding: 0; font-size: inherit; color: inherit; }

.code-copy-btn {
  position: absolute; top: 0.4rem; right: 0.4rem;
  padding: 0.25rem 0.4rem; border: none; border-radius: 5px;
  background: var(--copy-btn-bg); color: var(--md-pre-fg); cursor: pointer;
  font-size: 0.7rem; font-family: var(--font); opacity: 0;
  transition: opacity 0.15s var(--ease), background 0.15s var(--ease);
  display: inline-flex; align-items: center; gap: 0.25rem; z-index: 1;
}
.md-body pre:hover .code-copy-btn { opacity: 1; }
.code-copy-btn:hover { background: var(--copy-btn-hover); }
.code-copy-btn.is-copied { opacity: 1; color: #4ade80; }

.md-body img { max-width: 100%; height: auto; border-radius: var(--radius-sm); margin: 0.4rem 0; }

/* ── details/summary 样式 ── */
.md-body details {
  margin: 0.3rem 0; border: 1px solid var(--details-border);
  border-radius: var(--radius-sm); background: var(--details-bg);
  overflow: hidden; transition: border-color 0.2s var(--ease);
}
.md-body details[open] { border-color: var(--border-subtle); }

.md-body details summary {
  padding: 0.5rem 0.7rem; cursor: pointer; font-weight: 500; font-size: 0.88rem;
  color: var(--text-secondary);
  transition: color 0.12s var(--ease), background 0.12s var(--ease);
  user-select: none; -webkit-tap-highlight-color: transparent;
  list-style: none; display: flex; align-items: flex-start; gap: 0.35rem;
}
.md-body details summary::-webkit-details-marker { display: none; }
.md-body details summary::marker { content: ""; }
.md-body details summary::before {
  content: ""; display: inline-block; width: 0; height: 0;
  border-left: 5px solid var(--text-secondary);
  border-top: 4px solid transparent; border-bottom: 4px solid transparent;
  margin-top: 0.4em; flex-shrink: 0;
  transition: transform 0.2s var(--ease);
}
.md-body details[open] summary::before { transform: rotate(90deg); }
.md-body details summary:hover { color: var(--text); background: var(--surface-hover); }
.md-body .meta-desc-details {
  margin-top: 0.2rem;
}
.md-body .meta-desc-details .meta-desc-body > p {
  margin: 0.15rem 0;
}

.md-body details > ul,
.md-body details > ol {
  padding-left: 2rem;
  margin: 0.3rem 0.7rem 0.5rem;
}

.md-body details > p {
  padding: 0 0.7rem;
}

.md-body details > :last-child {
  margin-bottom: 0.5rem;
}

/* ── 浮动按钮 ── */
.fab {
  position: fixed;
  bottom: max(1.25rem, env(safe-area-inset-bottom, 0px));
  right: max(1.25rem, env(safe-area-inset-right, 0px));
  width: 44px; height: 44px; border-radius: 50%;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-md);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease), background 0.12s var(--ease);
  z-index: 50; opacity: 0; transform: translateY(10px); pointer-events: none;
}
.fab.is-visible { opacity: 1; transform: translateY(0); pointer-events: auto; }
.fab:hover { background: var(--surface-hover); }
.fab:active { transform: scale(0.93); }

/* ── Toast ── */
.toast {
  position: fixed; bottom: max(4rem, calc(env(safe-area-inset-bottom, 0px) + 3.5rem));
  left: 50%; transform: translateX(-50%) translateY(120%);
  padding: 0.45rem 0.85rem; background: var(--md-pre-bg); color: var(--md-pre-fg);
  border-radius: 999px; font-size: 0.78rem; font-weight: 500;
  box-shadow: var(--shadow-md); z-index: 100; opacity: 0;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
  pointer-events: none; white-space: nowrap;
}
.toast.is-visible { opacity: 1; transform: translateX(-50%) translateY(0); }

.note-preview.is-entering { animation: contentFadeIn 0.3s var(--ease); }
@keyframes contentFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ── 移动端 ── */
@media (max-width: 768px) {
  :root { --sidebar-w: 100vw; }

  .layout { flex-direction: column; }

  .sidebar {
    width: 100%; border-right: none;
    border-bottom: 1px solid var(--border-subtle);
    flex-shrink: 0;
    max-height: 40vh;
  }

  .sidebar.is-collapsed {
    width: 100%; height: 0; max-height: 0; border-bottom: none;
    overflow: hidden;
  }

  .preview-wrap { min-height: 0; flex: 1; overflow: hidden; }

  .preview-body { flex-direction: column; }

  .toc-panel {
    width: 100%; border-left: none; border-top: 1px solid var(--border-subtle);
    flex-shrink: 0;
  }
  .toc-panel.is-collapsed { width: 100%; }

  .toc-body { max-height: 30vh; }

  .note-preview { padding: 0.9rem 1rem 1.5rem; }

  .preview-toolbar { padding: 0.4rem 0.75rem; }

  .fab { display: flex; }
}

@media (min-width: 769px) {
  .fab { display: none; }

  .toc-panel { max-height: none; }
  .toc-panel.is-collapsed { width: 68px; }
  .toc-panel.is-collapsed .toc-count { display: none; }
  .toc-panel.is-collapsed .toc-head {
    justify-content: space-between;
    gap: 0.2rem;
    padding: 0.5rem 0.4rem;
  }
  .toc-panel.is-collapsed .toc-title {
    display: inline;
    font-size: 0.72rem;
    white-space: nowrap;
  }
  .toc-panel.is-collapsed .toc-toggle-btn { margin-left: 0; flex-shrink: 0; }
}

.footer {
  padding: 0.5rem 0.75rem; border-top: 1px solid var(--border-subtle);
  font-size: 0.72rem; text-align: center; flex-shrink: 0;
}

/* ── 打印 ── */
@media print {
  .topbar, .sidebar, .toc-panel, .toc-head, .fab, .reading-progress,
  .preview-loading, .code-copy-btn, .skip-link, .toast, .footer { display: none !important; }
  body { background: white; color: black; font-size: 12pt; }
  .preview-wrap { overflow: visible; }
  .note-preview-scroll { overflow: visible; }
  .md-body pre { background: #f5f5f5; color: #333; border: 1px solid #ddd; }
  .md-body a { color: inherit; text-decoration: underline; }
  .md-body details { border: none; }
}