/* ============ 主题变量 ============ */
:root,
[data-theme="paper"] {
  --bg: #f5f6f3;
  --bg-elevated: #ffffff;
  --text: #22262b;
  --muted: #868d93;
  --accent: #2f5d8a;
  --accent-soft: #2f5d8a22;
  --border: #dde1de;
  --link: #2f5d8a;
}
[data-theme="sepia"] {
  --bg: #f2e8d5;
  --bg-elevated: #f8f0e0;
  --text: #3b2f22;
  --muted: #8a7c63;
  --accent: #7a4a20;
  --accent-soft: #7a4a2022;
  --border: #ddccaa;
  --link: #7a4a20;
}
[data-theme="dark"] {
  --bg: #15171a;
  --bg-elevated: #1c1f23;
  --text: #e7e9ea;
  --muted: #8f969c;
  --accent: #7bb0e8;
  --accent-soft: #7bb0e833;
  --border: #2b2f34;
  --link: #7bb0e8;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  height: 100%;
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  transition: background .2s ease, color .2s ease;
}

button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
input[type="search"], input[type="range"] { font: inherit; }

/* ============ 顶部栏 ============ */
#topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 8px;
  height: 52px; padding: 0 8px;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
}
#doc-title {
  flex: 1; font-size: 15px; font-weight: 600;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
#topbar-actions { display: flex; gap: 2px; }
.icon-btn {
  width: 38px; height: 38px; display: flex; align-items: center; justify-content: center;
  border-radius: 8px; color: var(--text);
}
.icon-btn:hover { background: var(--accent-soft); }
.icon-btn svg { width: 20px; height: 20px; }

/* ============ 布局 ============ */
#layout { display: flex; height: calc(100% - 52px); }

#sidebar {
  position: fixed; top: 52px; bottom: 0; left: 0;
  width: 78vw; max-width: 320px;
  background: var(--bg-elevated);
  border-right: 1px solid var(--border);
  transform: translateX(-100%);
  transition: transform .22s ease;
  z-index: 30;
  display: flex; flex-direction: column;
  padding: 10px;
  overflow-y: auto;
}
body.sidebar-open #sidebar { transform: translateX(0); }

#sidebar-backdrop {
  display: none; position: fixed; inset: 52px 0 0 0; z-index: 25;
  background: rgba(0,0,0,.35);
}
body.sidebar-open #sidebar-backdrop { display: block; }

#search-wrap { margin-bottom: 8px; }
#search-input {
  width: 100%; padding: 8px 10px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--bg); color: var(--text);
}

#file-tree { flex: 1; font-size: 14px; }
#file-tree details { margin-bottom: 2px; }
#file-tree summary {
  cursor: pointer; padding: 6px 4px; border-radius: 6px;
  color: var(--muted); font-weight: 600; list-style: none;
}
#file-tree summary::-webkit-details-marker { display: none; }
#file-tree summary::before { content: "▸ "; }
#file-tree details[open] > summary::before { content: "▾ "; }
#file-tree summary:hover { background: var(--accent-soft); }
#file-tree details { padding-left: 10px; border-left: 1px solid var(--border); margin-left: 4px; }

.file-item {
  padding: 7px 8px; margin: 1px 0; border-radius: 6px;
  cursor: pointer; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.file-item:hover { background: var(--accent-soft); }
.file-item.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

.muted { color: var(--muted); font-size: 12px; }
#sidebar-status { padding: 8px 4px; }

/* ============ 正文 ============ */
#reader { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; }
.note-content {
  max-width: var(--content-width, 640px);
  margin: 0 auto;
  padding: 28px 20px 80px;
  line-height: 1.75;
  font-size: var(--font-size, 17px);
  font-family: "Source Han Serif SC", "Songti SC", "Noto Serif SC", Georgia, serif;
  word-wrap: break-word;
}
.note-content h1, .note-content h2, .note-content h3 {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", sans-serif;
  line-height: 1.35; margin: 1.6em 0 .6em;
}
.note-content h1 { font-size: 1.5em; border-bottom: 1px solid var(--border); padding-bottom: .3em; }
.note-content h2 { font-size: 1.25em; }
.note-content h3 { font-size: 1.1em; color: var(--muted); }
.note-content p { margin: .9em 0; }
.note-content a { color: var(--link); text-decoration: none; border-bottom: 1px solid var(--accent-soft); }
.note-content a.broken-link { color: var(--muted); border-bottom: 1px dashed var(--muted); cursor: default; }
.note-content img { max-width: 100%; border-radius: 6px; display: block; margin: 1em auto; }
.note-content code { background: var(--accent-soft); padding: .1em .35em; border-radius: 4px; font-size: .9em; }
.note-content pre { background: var(--accent-soft); padding: 12px 14px; border-radius: 8px; overflow-x: auto; }
.note-content pre code { background: none; padding: 0; }
.note-content blockquote {
  margin: 1em 0; padding: 2px 16px; border-left: 3px solid var(--accent);
  color: var(--muted);
}
.note-content ul, .note-content ol { padding-left: 1.4em; }
.note-content hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }
.note-content table { border-collapse: collapse; width: 100%; font-size: .92em; }
.note-content th, .note-content td { border: 1px solid var(--border); padding: 6px 10px; text-align: left; }

#welcome { color: var(--muted); padding-top: 10vh; text-align: center; font-family: -apple-system, sans-serif; }
#welcome h1 { color: var(--text); }

/* ============ 显示设置面板 ============ */
.sheet {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 40;
  background: var(--bg-elevated); border-top: 1px solid var(--border);
  border-radius: 16px 16px 0 0;
  padding: 8px 20px 24px;
  transform: translateY(100%);
  transition: transform .22s ease;
  box-shadow: 0 -8px 30px rgba(0,0,0,.15);
}
body.settings-open .sheet { transform: translateY(0); }
.sheet-handle { width: 36px; height: 4px; background: var(--border); border-radius: 2px; margin: 8px auto 12px; }
.sheet h3 { margin: 0 0 14px; font-size: 15px; }
.setting-row { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.setting-row label { width: 68px; font-size: 14px; color: var(--muted); flex-shrink: 0; }
.setting-row input[type="range"] { flex: 1; accent-color: var(--accent); }
.setting-row span { width: 40px; text-align: right; font-size: 13px; color: var(--muted); }
#theme-swatches { display: flex; gap: 8px; flex: 1; }
.swatch {
  flex: 1; padding: 10px 0; border-radius: 8px; border: 1.5px solid var(--border);
  font-size: 13px; text-align: center;
}
.swatch-paper { background: #f5f6f3; color: #22262b; }
.swatch-sepia { background: #f2e8d5; color: #3b2f22; }
.swatch-dark { background: #15171a; color: #e7e9ea; }
.swatch.active { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }
.close-sheet {
  width: 100%; padding: 12px; border-radius: 10px; background: var(--accent);
  color: #fff; font-weight: 600; margin-top: 4px;
}

/* ============ 关系图谱 ============ */
#graph-overlay {
  position: fixed; inset: 0; z-index: 50; background: var(--bg);
  display: none; flex-direction: column;
}
body.graph-open #graph-overlay { display: flex; }
#graph-topbar {
  display: flex; align-items: center; gap: 10px;
  height: 52px; padding: 0 10px; border-bottom: 1px solid var(--border);
  background: var(--bg-elevated);
}
.graph-zoom-controls { display: flex; gap: 2px; }
#graph-status { flex: 1; font-size: 13px; }
#graph-svg {
  flex: 1; width: 100%;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 28px 28px;
  background-position: center;
  opacity: 1;
}
#graph-svg .node { fill: var(--accent); cursor: pointer; }
#graph-svg .node.dim { opacity: .18; }
#graph-svg .node.selected { fill: var(--text); }
#graph-svg .link { stroke: var(--muted); stroke-opacity: .55; }
#graph-svg .link.dim { opacity: .08; }
#graph-svg .link.highlight { stroke: var(--accent); stroke-opacity: .9; }
#graph-svg .node-label { fill: var(--text); font-size: 10px; pointer-events: none; font-family: -apple-system, sans-serif; }
#graph-svg .node-label.dim { opacity: .15; }

#graph-tooltip {
  position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 140%);
  display: flex; align-items: center; gap: 12px;
  background: var(--bg-elevated); border: 1px solid var(--border);
  border-radius: 12px; padding: 10px 10px 10px 16px;
  box-shadow: 0 8px 24px rgba(0,0,0,.2);
  transition: transform .18s ease;
  z-index: 55; max-width: 90vw;
}
#graph-tooltip.visible { transform: translate(-50%, 0); }
#graph-tooltip-name { font-size: 14px; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 55vw; }
#graph-tooltip-open {
  background: var(--accent); color: #fff; padding: 8px 14px; border-radius: 8px;
  font-size: 13px; font-weight: 600; white-space: nowrap;
}

/* ============ 响应式（桌面端更宽敞） ============ */
@media (min-width: 860px) {
  #sidebar { position: sticky; top: 52px; height: calc(100vh - 52px); transform: none; width: 280px; }
  #sidebar-backdrop { display: none !important; }
  #btn-menu { display: none; }
  body.sidebar-open #sidebar { transform: none; }
}