:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --border: #e5e7eb;
  --text: #111827;
  --muted: #6b7280;
  /* 品牌色取自新 logo（圆规）渐变：#3E44D9 靛蓝 → #6549D5 紫罗兰 → #9444DA 紫 */
  --primary: #6549d5;
  --primary-hover: #5a41c4;
  --primary-soft: #f0effc;
  --primary-soft-border: #d8d3f5;
  --primary-ink: #4c3dbe;
  --warn-bg: #fff7e6;
  --warn-border: #ffd591;
  --warn-text: #ad6800;
  --danger: #dc2626;
  --radius: 12px;
  /* 设计令牌：字体 / 动效（redesign skill 规范值） */
  --font-sans: "Manrope", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "MiSans", "Microsoft YaHei", sans-serif;
  --ease: cubic-bezier(0.32, 0.72, 0, 1);
  --dur-micro: 200ms;
  --dur-surface: 500ms;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
}

/* 键盘焦点环：可访问性必需，不做样式取舍 */
:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

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

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  background: rgba(0,0,0,.06);
  padding: 2px 4px;
  border-radius: 4px;
  font-size: .9em;
}

/* ---------- 顶栏 ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 24px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}
.brand { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.brand-logo { font-size: 20px; color: var(--primary); }
.brand-name { font-size: 16px; font-weight: 700; }
.brand-sub { font-size: 12px; color: var(--muted); }

.badge {
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 999px;
  white-space: nowrap;
}
.badge-warn { background: var(--warn-bg); color: var(--warn-text); border: 1px solid var(--warn-border); }
.badge-ok { background: #f0fdf4; color: #15803d; border: 1px solid #bbf7d0; }

/* ---------- 主体 ---------- */
.container { max-width: 880px; margin: 0 auto; padding: 24px 16px 64px; }

.banner {
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 16px;
}
.banner-warn { background: var(--warn-bg); border: 1px solid var(--warn-border); color: var(--warn-text); }
.banner-info { background: #f8fafc; border: 1px solid var(--border); color: #4b5563; font-size: 12px; }
.banner-info strong { color: var(--text); }
.banner-info a { color: var(--primary-ink); }

/* 浮动帮助按钮（对标大角几何） */
.fab-help {
  position: fixed; right: 16px; bottom: 16px; z-index: 30;
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--panel); border: 1px solid var(--border);
  box-shadow: 0 4px 16px rgba(15,23,42,.08);
  color: #4b5563; font-size: 17px; font-weight: 700; font-family: inherit;
  cursor: pointer;
  transition: color var(--dur-micro) var(--ease), border-color var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease), box-shadow var(--dur-micro) var(--ease);
}
.fab-help:hover { color: var(--primary); border-color: var(--primary); box-shadow: 0 6px 20px rgba(101,73,213,.14); }
.fab-help:active { transform: scale(.94); }

.actions { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 24px; }

.btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--dur-micro) var(--ease);
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-ghost { background: var(--panel); border-color: var(--border); color: var(--text); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }
.btn-danger { background: none; border-color: var(--border); color: var(--danger); padding: 4px 12px; font-size: 12px; }
.btn-danger:hover { border-color: var(--danger); }
.btn-sm { padding: 4px 8px; font-size: 12px; }

/* 按压物理反馈：全局统一 */
.btn:not(:disabled):active,
.tool:not(:disabled):active,
.ai-tab:active,
.hero-action:active,
.hero-ai-send:not(:disabled):active,
.hero-ai-img:active,
.qs-close:active,
.nav-toggle:active { transform: scale(.96); }

/* ---------- 文件列表面板 ---------- */
.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.panel-title {
  font-size: 14px;
  font-weight: 600;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.muted { color: var(--muted); font-weight: 400; font-size: 12px; }

/* ---------- 我的画板：卡片网格（对标大角几何） ---------- */
.file-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(216px, 1fr));
  gap: 16px;
}
.file-card {
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  background: #fff;
  display: flex;
  flex-direction: column;
  transition: all var(--dur-surface) var(--ease);
}
.file-card:hover {
  box-shadow: 0 12px 32px rgba(15,23,42,.10);
  transform: translateY(-2px);
  border-color: var(--primary-soft-border);
}
.file-thumb {
  position: relative;
  aspect-ratio: 16 / 11;
  background: #f8fafc;
  cursor: pointer;
}
.file-thumb svg { display: block; width: 100%; height: 100%; }
.file-open-layer {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(15, 23, 42, .26);
  opacity: 0;
  transition: opacity var(--dur-micro) var(--ease);
}
.file-card:hover .file-open-layer { opacity: 1; }
.file-open-layer span {
  background: #fff;
  color: var(--primary);
  font-weight: 600;
  font-size: 12px;
  padding: 8px 16px;
  border-radius: 999px;
  box-shadow: 0 2px 8px rgba(15, 23, 42, .18);
}
.file-badge {
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 6px;
  padding: 2px 8px;
  backdrop-filter: blur(4px);
}
.file-badge.mode-2d { background: rgba(223, 247, 237, .92); color: #019974; }
.file-badge.mode-3d { background: rgba(245, 243, 255, .92); color: #6d28d9; }
.file-info { padding: 12px 16px 4px; min-width: 0; }
.file-name { font-weight: 600; font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.file-name input {
  width: 100%;
  font: inherit;
  border: 1px solid var(--primary);
  border-radius: 6px;
  padding: 2px 6px;
  outline: none;
}
.file-time { color: var(--muted); font-size: 12px; margin-top: 2px; }
.file-actions { display: flex; flex-wrap: wrap; gap: 6px; padding: 8px 12px 12px; }
.file-actions .btn { flex: 1 1 auto; min-width: 0; font-size: 12px; padding: 4px 8px; text-align: center; }
.file-actions .btn-danger { color: #b91c1c; }
.file-actions .btn-danger:hover { background: #fef2f2; }

.empty { padding: 48px 16px; text-align: center; color: var(--muted); font-size: 14px; line-height: 1.8; }

.footer { margin-top: 26px; font-size: 12px; color: var(--muted); line-height: 1.8; }

/* ---------- 编辑器页 ---------- */
.editor-layout { display: flex; flex-direction: column; height: 100dvh; }
.editor-topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.editor-topbar .back { border: none; background: none; font-size: 14px; color: var(--text); cursor: pointer; padding: 4px 8px; border-radius: 6px; transition: background var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease); }
.editor-topbar .back:hover { background: var(--bg); }
.editor-topbar .back:active { transform: scale(.96); }
#docName { font-size: 14px; font-weight: 600; border: 1px solid transparent; border-radius: 6px; padding: 4px 8px; min-width: 120px; max-width: 320px; }
#docName:hover, #docName:focus { border-color: var(--border); outline: none; background: #fff; }
.editor-status { margin-left: auto; display: flex; align-items: center; gap: 10px; font-size: 12px; color: var(--muted); }
.dot { width: 8px; height: 8px; border-radius: 50%; background: #22c55e; display: inline-block; }
.dot.busy { background: #f59e0b; animation: pulse 1s infinite; }
.dot.err { background: var(--danger); }
@keyframes pulse { 50% { opacity: .3; } }

#editorHost { flex: 1; position: relative; background: #fff; }
#editorHost iframe { width: 100%; height: 100%; border: none; display: block; }

.loading-mask {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; gap: 16px;
  align-items: center; justify-content: center;
  background: rgba(255,255,255,.92);
  color: var(--muted); font-size: 14px; z-index: 5;
}
/* 骨架屏：形状贴近真实编辑器布局，替代圆形 spinner */
.skel-board { width: min(420px, 80vw); display: flex; flex-direction: column; gap: 16px; }
.skel-canvas { height: 180px; border-radius: 12px; background: var(--border); animation: skel 1.4s var(--ease) infinite; }
.skel-row { display: flex; gap: 12px; }
.skel-chip { width: 64px; height: 28px; border-radius: 8px; background: var(--border); animation: skel 1.4s var(--ease) infinite; }
.skel-chip:nth-child(2) { animation-delay: .15s; }
.skel-chip:nth-child(3) { animation-delay: .3s; }
.loading-text { margin: 0; }
@keyframes skel { 50% { opacity: .45; } }

.error-mask {
  position: absolute; inset: 0;
  display: none; flex-direction: column; gap: 12px;
  align-items: center; justify-content: center;
  background: #fff; z-index: 6; padding: 40px; text-align: center;
}
.error-mask.show { display: flex; }
.error-mask h3 { font-size: 16px; color: var(--danger); }
.error-mask p { font-size: 12px; color: var(--muted); line-height: 1.9; max-width: 520px; }

@media (max-width: 640px) {
  .file-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; }
  .file-actions .btn { font-size: 12px; }
}

/* ---------- 路线B · 自建画板页 ---------- */
.board-page { display: flex; flex-direction: column; height: 100dvh; overflow: hidden; }

/* showNavigation:false 时 JSXGraph 仍会留下一个覆盖全画板的透明导航 div
   （z-index:100），会挡住 FAB / 底部抽屉等浮层，直接隐藏 */
.JXG_navigation { display: none !important; }

.board-page .topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  position: static;
}
.board-page .topbar .ghost {
  border: none; background: none; font-size: 14px; color: var(--text);
  cursor: pointer; padding: 4px 8px; border-radius: 6px; text-decoration: none;
  transition: background var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease);
}
.board-page .topbar .ghost:hover { background: var(--bg); text-decoration: none; }
.board-page .topbar .ghost:active { transform: scale(.96); }
.board-page .flex-spacer { flex: 1; }
.board-page .btn { padding: 6px 12px; font-size: 12px; }
.board-page .btn.small { padding: 4px 8px; font-size: 12px; }

.doc-name {
  font-size: 14px; font-weight: 600;
  border: 1px solid transparent; border-radius: 6px;
  padding: 4px 8px; min-width: 140px; max-width: 300px;
  font-family: inherit;
}
.doc-name:hover, .doc-name:focus { border-color: var(--border); outline: none; background: #fff; }
.save-status { font-size: 12px; color: var(--muted); }

/* ---------- 画板设置 ---------- */
.settings-wrap { position: relative; }
.settings-pop {
  position: absolute; top: calc(100% + 8px); right: 0; z-index: 60;
  width: 236px; padding: 8px 16px 12px;
  background: #fff; border: 1px solid var(--border); border-radius: 12px;
  box-shadow: 0 12px 32px rgba(15, 23, 42, .14);
}
.settings-pop.hidden { display: none; }
.settings-title { font-size: 14px; font-weight: 700; padding: 8px 0 4px; }
.settings-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 8px 0; font-size: 12px; }
.settings-row + .settings-row { border-top: 1px solid #f1f5f9; }
.settings-sub { display: block; font-size: 12px; color: var(--muted); font-style: normal; margin-top: 2px; }
.settings-note { margin-top: 8px; padding-top: 8px; border-top: 1px solid #f1f5f9; font-size: 12px; color: var(--muted); }

/* 动画播放面板（滑动条自动播放） */
.anim-select {
  max-width: 118px; border: 1px solid var(--border); border-radius: 6px;
  padding: 4px 6px; font-size: 12px; font-family: inherit; color: var(--text);
  background: #fff; cursor: pointer;
}
.anim-play { display: flex; width: 100%; margin-top: 10px; align-items: center; justify-content: center; }
.switch {
  appearance: none; -webkit-appearance: none;
  width: 36px; height: 20px; border-radius: 999px; background: #cbd5e1;
  position: relative; cursor: pointer; transition: background var(--dur-micro) var(--ease); flex: none; margin: 0;
}
.switch::after {
  content: ''; position: absolute; top: 2px; left: 2px;
  width: 16px; height: 16px; border-radius: 50%; background: #fff;
  transition: transform var(--dur-micro) var(--ease); box-shadow: 0 1px 3px rgba(0, 0, 0, .25);
}
.switch:checked { background: var(--primary); }
.switch:checked::after { transform: translateX(16px); }
.seg-bg { display: flex; gap: 6px; }
.bg-swatch {
  width: 26px; height: 26px; border-radius: 8px;
  border: 2px solid var(--border); cursor: pointer; padding: 0;
  transition: border-color var(--dur-micro) var(--ease), box-shadow var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease);
}
.bg-swatch:hover { transform: scale(1.06); }
.bg-swatch:active { transform: scale(.94); }
.bg-swatch.active { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(1, 184, 139, .22); }
.bg-white { background: #fff; }
.bg-beige { background: #faf5ec; }
.bg-dark { background: #0f172a; }
@media (max-width: 640px) {
  .settings-pop { width: 220px; }
}

/* 嵌入面板（iframe / JS 内嵌第三方网页与笔记） */
.embed-pop { width: 320px; }
.embed-modes { display: flex; gap: 6px; padding: 4px 0 8px; }
.embed-modes button {
  flex: 1; padding: 4px 6px; font-size: 12px; cursor: pointer;
  border: 1px solid var(--border); border-radius: 8px; background: #fff; color: var(--text);
}
.embed-modes button.active { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
.embed-num {
  max-width: 96px; border: 1px solid var(--border); border-radius: 6px;
  padding: 3px 6px; font-size: 12px; font-family: inherit; color: var(--text); background: #fff; text-align: right;
}
.embed-code {
  width: 100%; box-sizing: border-box; margin-top: 8px; padding: 8px; resize: vertical;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11px; line-height: 1.55;
  color: var(--text); background: var(--bg); border: 1px solid var(--border); border-radius: 8px;
}
.embed-acts { display: flex; gap: 6px; margin-top: 8px; }
.embed-acts .btn { flex: 1; justify-content: center; }

/* LaTeX / TikZ 导出面板 */
.tikz-list { display: flex; flex-direction: column; gap: 6px; padding-top: 4px; }
.tikz-list .btn { width: 100%; justify-content: center; }
.tikz-desc { margin-top: 8px; padding-top: 8px; border-top: 1px solid #f1f5f9; font-size: 11px; line-height: 1.6; color: var(--muted); }

.toolbar {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 16px;
  background: #fbfcfd;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.toolbar-label { font-size: 12px; color: var(--muted); margin-right: 2px; }
.toolbar-sep { width: 1px; height: 20px; background: var(--border); margin: 0 6px; }
.tool {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 8px;
  padding: 4px 12px;
  font-size: 12px;
  cursor: pointer;
  font-family: inherit;
  color: var(--text);
  transition: all var(--dur-micro) var(--ease);
}
.tool:hover { border-color: var(--primary); color: var(--primary); }
.tool.active { background: var(--primary); border-color: var(--primary); color: #fff; }
.tool.hidden { display: none; }
.tool:disabled { opacity: .45; cursor: default; }
.tool:disabled:hover { border-color: var(--border); color: var(--text); }
.tool-hint {
  font-size: 12px; color: var(--muted);
  margin-left: auto; padding-left: 12px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  max-width: 260px;
}
.float-input {
  position: fixed; z-index: 230;
  display: flex; align-items: center; gap: 6px;
  background: #fff; border: 1px solid var(--border); border-radius: 12px;
  padding: 8px; box-shadow: 0 10px 28px rgba(15, 23, 42, .2);
}
.float-input input {
  border: 1px solid var(--border); border-radius: 6px;
  padding: 6px 8px; font-size: 14px; width: 170px;
  font-family: inherit; outline: none;
}
.float-input input:focus { border-color: var(--primary); }
/* 交点筛选浮层：多交点时让用户明确选一个（大角几何「交点筛选」的对位实现） */
.float-choice {
  position: fixed; z-index: 235; width: 200px;
  background: #fff; border: 1px solid var(--border); border-radius: 12px;
  padding: 8px; box-shadow: 0 10px 28px rgba(15, 23, 42, .2);
  display: flex; flex-direction: column; gap: 6px;
}
.float-choice-title { font-size: 12px; color: var(--muted); padding: 0 2px; }
.float-choice-item {
  display: flex; align-items: baseline; justify-content: space-between; gap: 8px;
  border: 1px solid var(--border); background: #fff; border-radius: 8px;
  padding: 6px 9px; font-size: 13px; cursor: pointer; font-family: inherit; color: var(--text);
  transition: all var(--dur-micro) var(--ease); text-align: left;
}
.float-choice-item:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
.float-choice-item .fc-sub { font-size: 11px; color: var(--muted); }
#fn-input {
  width: 180px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 5px 10px;
  font-size: 14px;
  font-family: inherit;
  outline: none;
}
#fn-input:focus { border-color: var(--primary); }
.fn-range {
  width: 62px; flex: none;
  border: 1px solid var(--border); border-radius: 8px;
  padding: 5px 6px; font-size: 13px; font-family: inherit;
  color: var(--text); background: #fff; outline: none;
}
.fn-range:focus { border-color: var(--primary); }

.board-main { flex: 1; display: flex; min-height: 0; }
.board-box { flex: 1; min-width: 0; background: #fff; }
/* 注意：不能把 JXGraph 的 html 文本层（.JXGtext 点标签 / .JXGinfobox 坐标提示）撑成 100%——
   JXGraph 1.14 用 inset + clip-path 定位标签，强制全尺寸会让所有点标签不可见 */
.board-box > div:not(.JXGtext):not(.JXGinfobox) { width: 100%; height: 100%; }

/* AI 面板 */
.hidden { display: none !important; }
.ai-panel {
  width: 320px;
  border-left: 1px solid var(--border);
  background: var(--panel);
  display: flex; flex-direction: column;
  min-height: 0;
}
.ai-head {
  font-size: 14px; font-weight: 700;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 8px;
  flex-wrap: wrap; /* 三个 tab + 模型选择 + 关闭钮在窄面板/手机上自动换行，避免溢出 */
  row-gap: 6px;
}
.ai-head .ai-title { flex: 1; min-width: 0; }
.ai-close {
  display: none;
  border: none; background: none; cursor: pointer;
  color: var(--muted); padding: 4px; border-radius: 6px;
  line-height: 0;
  transition: background var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease);
}
.ai-close:hover { background: var(--bg); color: var(--text); }
.ai-close:active { transform: scale(.94); }
#ai-fab { display: none; }
.ai-model {
  font-size: 12px;
  font-family: inherit;
  max-width: 60%;
  padding: 4px 6px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  outline: none;
  cursor: pointer;
}
.ai-model:focus { border-color: var(--primary); }
.ai-img-preview {
  display: flex; align-items: center; gap: 8px;
  margin: 0 12px; padding: 4px 8px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  background: #fff;
}
.ai-img-preview.hidden { display: none; }
.ai-img-preview img {
  height: 36px; width: 36px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--border);
}
.ai-img-name {
  flex: 1; min-width: 0;
  font-size: 12px; color: var(--muted);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.ai-log { flex: 1; overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 8px; }
.ai-msg {
  font-size: 14px; line-height: 1.7;
  padding: 8px 12px;
  border-radius: 12px;
  max-width: 92%;
  white-space: pre-wrap;
  word-break: break-word;
}
.ai-msg.user { align-self: flex-end; background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.ai-msg.ai { align-self: flex-start; background: #f1f3f5; color: var(--text); border-bottom-left-radius: 4px; }
.ai-input-row { display: flex; gap: 8px; padding: 8px 12px; border-top: 1px solid var(--border); }
.ai-input-row textarea {
  flex: 1;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 14px;
  font-family: inherit;
  resize: none;
  outline: none;
  line-height: 1.5;
}
.ai-input-row textarea:focus { border-color: var(--primary); }
.ai-btns { display: flex; flex-direction: column; gap: 6px; }
.ai-btns .btn { align-self: flex-end; }
.ai-tip { font-size: 12px; color: var(--muted); padding: 0 12px 8px; line-height: 1.6; }

/* AI 面板 tab 切换（对话 / 对象） */
.ai-view { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.ai-view.hidden { display: none; }
.ai-tabs { display: flex; gap: 4px; }
.ai-tab {
  border: 1px solid var(--border); background: #fff; border-radius: 8px;
  padding: 4px 10px; font-size: 12px; cursor: pointer; font-family: inherit; color: var(--muted);
  display: inline-flex; align-items: center; gap: 4px; white-space: nowrap;
  transition: all var(--dur-micro) var(--ease);
}
.ai-tab.active { background: var(--primary); border-color: var(--primary); color: #fff; }
.obj-count {
  background: var(--bg); border-radius: 8px; padding: 0 5px;
  font-size: 12px; line-height: 16px; min-width: 16px; text-align: center;
}
.ai-tab.active .obj-count { background: rgba(255, 255, 255, .25); }

/* 对象面板 */
.obj-toolbar { display: flex; align-items: center; gap: 8px; padding: 8px 12px 8px; }
.obj-hint { flex: 1; font-size: 12px; color: var(--muted); line-height: 1.5; }
.obj-list { flex: 1; overflow-y: auto; padding: 0 12px; display: flex; flex-direction: column; gap: 4px; }
.obj-empty { font-size: 12px; color: var(--muted); text-align: center; padding: 24px 0; }
.obj-row {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px;
  background: #fff; cursor: pointer; font-size: 12px;
  transition: border-color var(--dur-micro) var(--ease), background var(--dur-micro) var(--ease);
}
.obj-row:hover { border-color: var(--primary); }
.obj-row.selected { border-color: var(--primary); background: var(--primary-soft); }
.obj-row.hidden-obj { opacity: .5; }
.obj-dot { width: 10px; height: 10px; border-radius: 50%; flex: none; border: 1px solid rgba(0,0,0,.12); }
.obj-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.obj-type { font-size: 12px; color: var(--muted); flex: none; }
.obj-act {
  border: none; background: none; cursor: pointer; color: var(--muted);
  padding: 3px 4px; border-radius: 5px; line-height: 0; flex: none;
  transition: background var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease);
}
.obj-act:hover { background: var(--bg); color: var(--text); }
.obj-act svg { width: 14px; height: 14px; }

/* 对象属性区 */
.obj-props { border-top: 1px solid var(--border); padding: 8px 12px 12px; display: flex; flex-direction: column; gap: 8px; }
.obj-props.hidden { display: none; }
.obj-props-title { font-size: 12px; font-weight: 600; }
.obj-props-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.obj-props-label { font-size: 12px; color: var(--muted); width: 32px; flex: none; }
.obj-colors { display: flex; gap: 6px; }
.obj-color { width: 20px; height: 20px; border-radius: 50%; border: 2px solid #fff; box-shadow: 0 0 0 1px var(--border); cursor: pointer; padding: 0; transition: box-shadow var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease); }
.obj-color:hover { transform: scale(1.1); }
.obj-color.active { box-shadow: 0 0 0 2px var(--primary); }
.obj-seg { display: flex; gap: 4px; }
.obj-seg button {
  border: 1px solid var(--border); background: #fff; border-radius: 6px;
  padding: 3px 9px; font-size: 12px; cursor: pointer; font-family: inherit; color: var(--text);
  transition: all var(--dur-micro) var(--ease);
}
.obj-seg button.active { border-color: var(--primary); color: var(--primary); background: var(--primary-soft); }
.obj-props-row input {
  flex: 1; min-width: 0; border: 1px solid var(--border); border-radius: 8px;
  padding: 5px 8px; font-size: 12px; font-family: inherit; outline: none;
}
.obj-props-row input:focus { border-color: var(--primary); }
.obj-props-range { gap: 6px; }
.obj-props-range .btn { flex: none; }
.obj-props-pick.hidden { display: none; }
.obj-props-pick .obj-seg { flex-wrap: wrap; }
.obj-range-tag { font-size: 12px; color: var(--muted); flex: none; }
.obj-props-row input.obj-num {
  flex: 1 1 52px; min-width: 52px; max-width: 84px;
  border: 1px solid var(--border); border-radius: 6px;
  padding: 4px 6px; font-size: 12px; font-family: inherit;
  color: var(--text); background: #fff; outline: none;
}
.obj-props-row input.obj-num:focus { border-color: var(--primary); }
.obj-props-actions { gap: 6px; }
.obj-props-actions .btn { flex: 1; }
.obj-props-cmd { flex: 1; min-width: 0; font-size: 12px; color: var(--muted); line-height: 1.6; word-break: break-all; }
.btn.danger { color: #C62828; border-color: #f3c1c1; }
.btn.danger:hover { border-color: #C62828; color: #C62828; }

/* 作图记录（Construction Protocol 回放） */
.rec-toolbar { display: flex; align-items: center; gap: 6px; padding: 8px 12px 8px; flex-wrap: wrap; }
.rec-toolbar .btn:disabled { opacity: .4; cursor: not-allowed; }
.rec-step { font-size: 12px; color: var(--muted); margin-left: auto; font-variant-numeric: tabular-nums; white-space: nowrap; }
.rec-speed {
  font-size: 12px; font-family: inherit; padding: 3px 4px;
  border: 1px solid var(--border); border-radius: 8px; background: #fff; color: var(--text); cursor: pointer;
}
.rec-hint { font-size: 12px; color: var(--muted); padding: 0 12px 8px; line-height: 1.6; }
.rec-list { flex: 1; overflow-y: auto; padding: 0 12px 12px; display: flex; flex-direction: column; gap: 3px; }
.rec-empty { font-size: 12px; color: var(--muted); text-align: center; padding: 24px 0; }
.rec-row {
  display: flex; align-items: baseline; gap: 8px;
  padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px;
  background: #fff; cursor: pointer; font-size: 12px; line-height: 1.5;
  transition: border-color var(--dur-micro) var(--ease), background var(--dur-micro) var(--ease);
}
.rec-row:hover { border-color: var(--primary); }
.rec-row.active { border-color: var(--primary); background: var(--primary-soft); }
.rec-row.done { color: var(--muted); }
.rec-row.pending { opacity: .55; }
.rec-no {
  flex: none; min-width: 20px; text-align: center;
  font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums;
  background: var(--bg); border-radius: 6px; padding: 1px 4px;
}
.rec-row.active .rec-no { background: var(--primary); color: #fff; }
.rec-desc { flex: 1; min-width: 0; }

/* 右键上下文菜单 */
.ctx-menu {
  position: fixed; z-index: 240; min-width: 150px;
  background: #fff; border: 1px solid var(--border); border-radius: 12px;
  box-shadow: 0 12px 32px rgba(15, 23, 42, .22);
  padding: 8px; display: flex; flex-direction: column; gap: 1px;
}
.ctx-menu.hidden { display: none; }
.ctx-item {
  display: flex; align-items: center; gap: 8px;
  border: none; background: none; padding: 8px 12px; border-radius: 6px;
  font-size: 12px; cursor: pointer; text-align: left; color: var(--text);
  font-family: inherit; width: 100%;
  transition: background var(--dur-micro) var(--ease);
}
.ctx-item:hover { background: #f1f5f9; }
.ctx-item.danger { color: #C62828; }
.ctx-item.danger:hover { background: #fdecec; }
.ctx-sep { height: 1px; background: var(--border); margin: 4px 2px; }
.ctx-colors { display: flex; gap: 6px; padding: 8px 12px 8px; }
.ctx-color { width: 18px; height: 18px; border-radius: 50%; border: 2px solid #fff; box-shadow: 0 0 0 1px var(--border); cursor: pointer; padding: 0; transition: box-shadow var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease); }
.ctx-color:hover { box-shadow: 0 0 0 2px var(--primary); transform: scale(1.1); }

/* 编辑器（路线A）顶栏模型选择 */
.ai-model-top {
  font-size: 12px;
  font-family: inherit;
  max-width: 220px;
  padding: 5px 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  outline: none;
  cursor: pointer;
}
.ai-model-top:focus { border-color: var(--primary); }

/* Toast */
.toast {
  position: fixed;
  left: 50%; bottom: 28px;
  transform: translateX(-50%);
  background: rgba(31,35,41,.92);
  color: #fff;
  font-size: 12px;
  padding: 8px 16px;
  border-radius: 999px;
  z-index: 220;
  box-shadow: 0 4px 16px rgba(0,0,0,.18);
}
.toast.hidden { display: none; }

/* ---------- 首页（landing） ---------- */
/* 平铺背景：移除整页紫蓝渐变（AI 渐变指纹），底色与全站一致 */
.landing { background: var(--bg); }

.site-nav {
  display: flex; align-items: center; gap: 18px;
  padding: 0 24px; height: 64px;
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 40;
}
/* 毛玻璃放在 ::before 上：backdrop-filter 会让自己成为 fixed 子元素的包含块，
   挂在伪元素上才不会把移动端全屏菜单限制在导航条内 */
.site-nav::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background: rgba(255,255,255,.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.site-brand { display: flex; align-items: center; gap: 9px; color: var(--text); position: relative; z-index: 50; }
.site-brand:hover { text-decoration: none; }
.site-logo { width: 30px; height: 30px; display: block; flex: none; }
.site-name { font-size: 18px; font-weight: 700; letter-spacing: .5px; color: var(--text); }
.site-links { display: flex; gap: 2px; margin-left: 12px; }
.site-links a {
  color: #4b5563; font-size: 14px; padding: 8px 12px; border-radius: 8px;
  transition: color var(--dur-micro) var(--ease), background var(--dur-micro) var(--ease);
}
.site-links a:hover { color: var(--primary); text-decoration: none; background: var(--primary-soft); }
.site-links a.active { color: var(--primary); font-weight: 600; }
.nav-toggle {
  display: none; margin-left: auto; width: 38px; height: 38px;
  align-items: center; justify-content: center;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--panel); color: var(--text); cursor: pointer;
  position: relative; z-index: 50;
  transition: border-color var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease);
}
.nav-toggle:hover { border-color: var(--primary); color: var(--primary); }
/* 汉堡两条线：点击时旋转平移成 X，不做整图替换 */
.nav-toggle-line {
  position: absolute; left: 50%; width: 18px; height: 2px;
  background: currentColor; border-radius: 2px;
  transform: translateX(-50%);
  transition: top var(--dur-surface) var(--ease), transform var(--dur-surface) var(--ease);
}
.nav-toggle-line:nth-child(1) { top: 14px; }
.nav-toggle-line:nth-child(2) { top: 22px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) { top: 18px; transform: translateX(-50%) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) { top: 18px; transform: translateX(-50%) rotate(-45deg); }
.nav-toggle svg { display: none; }
.site-cta {
  margin-left: auto; white-space: nowrap;
  border-radius: 999px; padding: 8px 16px; font-weight: 600; font-size: 14px;
  position: relative; z-index: 50;
}
.nav-toggle + .site-cta { margin-left: 0; }

/* 窄屏顶栏：禁止品牌名竖排折行，整体收紧间距保证一行放得下 */
@media (max-width: 640px) {
  .site-nav { gap: 7px; }
  .site-brand { gap: 6px; }
  .site-logo { width: 25px; height: 25px; }
  .site-name { font-size: 16px; white-space: nowrap; flex: none; }
  .site-cta { padding: 7px 11px; font-size: 13px; }
  .auth-anchor .btn.is-user { max-width: 108px; padding: 3px 10px 3px 3px; }
  .auth-anchor .btn.is-user .auth-name { font-size: 12px; }
}

/* 首屏 */
.hero {
  position: relative;
  max-width: 1080px;
  margin: 0 auto;
  padding: 80px 24px 64px;
  text-align: center;
  overflow: hidden;
}
.hero-decor { position: absolute; inset: 0; pointer-events: none; }
.deco { position: absolute; opacity: .55; }
/* 装饰统一为品牌靛紫单色系 + 中性描边，移除多色相混用 */
.deco-circle {
  width: 170px; height: 170px; border-radius: 50%;
  background: var(--primary-soft);
  top: 30px; left: 5%;
}
.deco-ring {
  width: 120px; height: 120px; border-radius: 50%;
  border: 1.5px solid #cbd5e1;
  top: 90px; right: 12%;
}
.deco-triangle {
  width: 0; height: 0;
  border-left: 36px solid transparent; border-right: 36px solid transparent;
  border-bottom: 62px solid var(--primary-soft-border);
  top: 150px; right: 8%;
  transform: rotate(12deg);
}
.deco-square {
  width: 62px; height: 62px; border-radius: 16px;
  background: var(--primary-soft-border);
  bottom: 150px; left: 9%;
  transform: rotate(-14deg);
}
.deco-blob {
  width: 150px; height: 150px; border-radius: 50%;
  background: var(--primary-soft);
  bottom: 40px; right: 6%; opacity: .5;
}
.deco-dot {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--primary); top: 230px; right: 20%; opacity: .3;
}
.deco-grid {
  inset: 0;
  background-image: radial-gradient(rgba(100,116,139,.14) 1px, transparent 1px);
  background-size: 24px 24px;
  opacity: .5;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
}
/* hero 标题：浅色主题左到右文字渐变（规范唯一允许的渐变），收紧字距，680px 断行 */
.hero-title {
  font-size: clamp(36px, 6vw, 60px);
  font-weight: 700;
  letter-spacing: -0.02em;
  max-width: 680px;
  margin-inline: auto;
  text-wrap: balance;
  background: linear-gradient(90deg, #000000 0%, #666666 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.hero-sub {
  margin-top: 12px;
  font-size: clamp(16px, 2.4vw, 18px);
  color: var(--muted);
  max-width: 680px;
  margin-inline: auto;
  line-height: 1.7;
  text-wrap: pretty;
}

.hero-ai {
  position: relative;
  max-width: 720px;
  margin: 24px auto 0;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 16px 48px rgba(15,23,42,.08);
  text-align: left;
  padding: 16px 16px 12px;
  transition: border-color var(--dur-micro) var(--ease), box-shadow var(--dur-surface) var(--ease);
}
.hero-ai:focus-within {
  border-color: var(--primary-soft-border);
  box-shadow: 0 16px 48px rgba(101,73,213,.14);
}
.hero-ai textarea {
  width: 100%;
  border: none; outline: none; resize: none;
  font: inherit; font-size: 16px; line-height: 1.7;
  background: transparent; color: var(--text);
  min-height: 68px;
}
.hero-ai-bar { display: flex; align-items: center; gap: 8px; margin-top: 8px; }
.hero-ai-left { display: flex; align-items: center; gap: 8px; min-width: 0; }
.ai-model {
  border: none; background: transparent;
  font: inherit; font-size: 12px; color: var(--muted);
  padding: 4px 2px; cursor: pointer; max-width: 220px;
  transition: color var(--dur-micro) var(--ease);
}
.ai-model:hover { color: var(--primary); }
.ai-model:focus-visible { outline: 2px solid var(--primary); outline-offset: 1px; border-radius: 6px; }
.hero-ai-img {
  width: 36px; height: 36px; flex: none;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--panel); color: #6b7280; cursor: pointer;
  transition: all var(--dur-micro) var(--ease);
}
.hero-ai-img:hover { border-color: var(--primary); color: var(--primary); }
.hero-ai-img svg { width: 17px; height: 17px; }
.hero-ai-send {
  margin-left: auto; flex: none;
  width: 38px; height: 38px; border-radius: 50%;
  border: none; background: var(--primary); color: #fff;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: all var(--dur-micro) var(--ease);
}
.hero-ai-send:hover:not(:disabled) { background: var(--primary-hover); transform: translateY(-1px); }
.hero-ai-send:disabled { background: #d1d5db; cursor: not-allowed; }
.hero-ai-send svg { width: 17px; height: 17px; }
.hero-ai-status { margin-top: 8px; font-size: 12px; line-height: 1.7; color: var(--muted); }
.hero-ai-status.pending { color: var(--primary-ink); }
.hero-ai-status.error { color: var(--danger); }
.hero-ai .ai-img-preview { margin: 8px 0 0; }
.hero-ai .ai-img-preview .btn { white-space: nowrap; }

.hero-actions {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px;
  max-width: 720px; margin: 24px auto 0;
}
.hero-action {
  display: flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 54px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 16px;
  cursor: pointer;
  font-family: inherit;
  transition: all var(--dur-micro) var(--ease);
  text-align: center;
}
.hero-action:hover { border-color: var(--primary); box-shadow: 0 8px 24px rgba(101,73,213,.16); transform: translateY(-1px); }
.hero-action svg { width: 24px; height: 24px; color: var(--primary); flex: none; }
.hero-action-text { display: flex; align-items: center; gap: 8px; }
.hero-action-text strong { font-size: 14px; font-weight: 500; color: var(--text); }
.hero-action-text em { font-style: normal; font-size: 12px; color: var(--muted); }
.hero-warn { margin-top: 24px; text-align: left; }

/* 通用 section */
.section { max-width: 1080px; margin: 0 auto; padding: 64px 24px; }
.section-head { display: flex; align-items: baseline; gap: 12px; }
.section-title { font-size: 20px; font-weight: 700; margin-bottom: 24px; text-wrap: balance; }
.section-head .section-title { margin-bottom: 0; }

/* 快速入门（白色面板，对标大角几何） */
.qs-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 16px 48px rgba(15,23,42,.06);
  padding: 24px;
}
.qs-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.qs-head .section-title { margin-bottom: 0; }
.qs-close {
  width: 32px; height: 32px; flex: none;
  display: inline-flex; align-items: center; justify-content: center;
  border: none; border-radius: 8px; background: none;
  font-size: 18px; line-height: 1; color: var(--muted); cursor: pointer;
  transition: background var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease), transform var(--dur-micro) var(--ease);
}
.qs-close:hover { background: var(--bg); color: var(--text); }
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.step {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px 16px;
  transition: border-color var(--dur-micro) var(--ease), box-shadow var(--dur-surface) var(--ease);
}
.step:hover { border-color: var(--primary-soft-border); box-shadow: 0 8px 24px rgba(15,23,42,.06); }
.step-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--primary); color: #fff;
  font-size: 14px; font-weight: 700; margin-bottom: 12px;
}
.step h3 { font-size: 14px; font-weight: 600; margin-bottom: 8px; }
.step p { font-size: 12px; color: var(--muted); line-height: 1.8; }

/* 模板与案例 */
.tpl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.tpl-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  display: flex; flex-direction: column;
  transition: all var(--dur-surface) var(--ease);
}
.tpl-card:hover { border-color: var(--primary); box-shadow: 0 12px 32px rgba(15,23,42,.08); transform: translateY(-2px); }
.tpl-thumb { background: #f8fafc; }
.tpl-thumb svg { display: block; width: 100%; height: auto; }
.tpl-body { padding: 16px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.tpl-cat {
  align-self: flex-start;
  font-size: 12px; color: var(--primary-ink);
  background: var(--primary-soft); border: 1px solid var(--primary-soft-border);
  padding: 2px 8px; border-radius: 999px;
}
.tpl-title { font-size: 14px; font-weight: 600; }
.tpl-desc { font-size: 12px; color: var(--muted); line-height: 1.7; flex: 1; }
.tpl-foot { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 4px; }
.tpl-author { font-size: 12px; color: var(--muted); }

/* 关于 */
.about-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  display: flex; flex-direction: column; gap: 12px;
}
.about-card p { font-size: 14px; color: var(--text); line-height: 1.9; }

.site-footer {
  max-width: 1080px; margin: 48px auto 0;
  padding: 24px 24px 32px;
  border-top: 1px solid var(--border);
  font-size: 12px; color: var(--muted); line-height: 2;
  text-align: center;
}

/* 跳到主要内容（键盘可访问性） */
.skip-link {
  position: absolute; left: 16px; top: -48px;
  z-index: 100;
  background: var(--primary); color: #fff;
  padding: 8px 16px; border-radius: 8px;
  font-size: 14px; font-weight: 600;
  transition: top var(--dur-micro) var(--ease);
}
.skip-link:focus { top: 12px; text-decoration: none; }

/* 滚动入场：JS 运行时才附加 data-reveal（无 JS 时内容直接可见，防白屏） */
[data-reveal] {
  opacity: 0;
  transform: translateY(48px);
  filter: blur(6px);
  transition: opacity 800ms var(--ease), transform 800ms var(--ease), filter 800ms var(--ease);
}
[data-reveal].revealed { opacity: 1; transform: none; filter: none; }
@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; filter: none; transition: none; }
}

/* ---------- 响应式：平板 ---------- */
@media (max-width: 1024px) {
  .steps { grid-template-columns: repeat(2, 1fr); }
  .tpl-grid { grid-template-columns: repeat(2, 1fr); }
  .hero { padding-top: 56px; }
  .deco-circle { left: -30px; }
  .deco-triangle { right: -10px; }
}

/* ---------- 响应式：手机（画板页 AI 抽屉 + 首页全屏菜单） ---------- */
@media (max-width: 860px) {
  .board-main { flex-direction: column; }
  .ai-panel {
    position: fixed; left: 0; right: 0; bottom: 0;
    width: auto; height: min(72vh, 560px);
    border-left: none;
    border-top: 1px solid var(--border);
    border-radius: 16px 16px 0 0;
    box-shadow: 0 -8px 32px rgba(15,23,42,.16);
    transform: translateY(102%);
    transition: transform var(--dur-surface) var(--ease);
    z-index: 205;
  }
  .ai-panel.open { transform: none; }
  .ai-panel .ai-close { display: inline-flex; }
  #ai-fab {
    display: inline-flex; align-items: center; gap: 6px;
    position: fixed; right: 14px; bottom: 18px;
    z-index: 210;
    background: var(--primary); color: #fff;
    border: none; border-radius: 999px;
    padding: 8px 16px; font-size: 14px; font-weight: 600;
    font-family: inherit; cursor: pointer;
    box-shadow: 0 8px 24px rgba(101,73,213,.32);
    transition: all var(--dur-micro) var(--ease);
  }
  #ai-fab:hover { background: var(--primary-hover); }
  #ai-fab:active { transform: scale(.96); }

  /* 首页导航：全屏毛玻璃菜单，链接错峰入场（替代普通下拉） */
  .site-nav { padding: 0 16px; gap: 10px; }
  .nav-toggle { display: inline-flex; }
  .site-links {
    position: fixed; inset: 0; z-index: 45;
    display: flex; flex-direction: column; justify-content: center;
    gap: 8px; margin-left: 0; padding: 24px;
    background: rgba(255,255,255,.86);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    opacity: 0; pointer-events: none;
    transition: opacity var(--dur-surface) var(--ease);
  }
  .site-links.open { opacity: 1; pointer-events: auto; }
  .site-links a {
    width: 100%;
    font-size: 20px; font-weight: 600;
    padding: 12px 16px; border-radius: 12px;
    opacity: 0; transform: translateY(48px);
    transition: opacity var(--dur-surface) var(--ease), transform var(--dur-surface) var(--ease), background var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease);
  }
  .site-links.open a { opacity: 1; transform: none; }
  .site-links.open a:nth-child(1) { transition-delay: 100ms; }
  .site-links.open a:nth-child(2) { transition-delay: 150ms; }
  .site-links.open a:nth-child(3) { transition-delay: 200ms; }
  .site-links.open a:nth-child(4) { transition-delay: 250ms; }
  .site-links a:hover { background: var(--primary-soft); }
  .site-cta { margin-left: 0; padding: 8px 16px; }
  .hero-actions { grid-template-columns: 1fr; max-width: 420px; }
}

@media (max-width: 640px) {
  .hero { padding: 40px 16px 48px; }
  .hero-decor { display: none; }
  .hero-action { justify-content: flex-start; }
  .hero-ai-bar { flex-wrap: wrap; }
  .hero-ai-left { flex: 1; }
  .hero-ai-send { margin-left: auto; }

  .section { padding: 48px 16px; }
  .steps { grid-template-columns: 1fr; }
  .tpl-grid { grid-template-columns: 1fr; }
  .file-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .qs-panel { padding: 16px; }

  /* 画板页顶栏收窄 */
  .board-page .topbar { padding: 8px 12px; gap: 6px; }
  .doc-name { min-width: 100px; max-width: none; flex: 1; }
  .save-status { display: none; }
  .board-page .topbar .btn { padding: 6px 12px; font-size: 12px; }

  /* 工具条横滑 */
  .toolbar { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
  .toolbar::-webkit-scrollbar { display: none; }
  #fn-input { width: 130px; flex: none; }
  .fn-range { width: 54px; flex: none; }

  /* 编辑器顶栏 */
  .editor-topbar { gap: 8px; padding: 8px 12px; }
  #docName { max-width: none; flex: 1; min-width: 0; }
  .ai-model-top { max-width: 150px; }
}

/* ============ 账号登录 / 云端画板（靛紫主题） ============ */
#authBtn.is-user { background: var(--primary-soft, #F0EFFC); color: var(--primary, #6549D5); border-color: var(--primary-border, #D8D3F5); }

/* 登录弹窗 */
.auth-modal { position: fixed; inset: 0; z-index: 3000; display: flex; align-items: center; justify-content: center; }
.auth-modal.hidden { display: none; }
.auth-backdrop { position: absolute; inset: 0; background: rgba(28, 25, 64, 0.42); backdrop-filter: blur(2px); }
.auth-card {
  position: relative; width: min(380px, 92vw); background: #fff; border-radius: 16px;
  padding: 28px 26px 22px; box-shadow: 0 24px 60px rgba(60, 50, 140, 0.25);
  border: 1px solid var(--primary-border, #D8D3F5);
}
.auth-x { position: absolute; top: 10px; right: 12px; width: 30px; height: 30px; border: 0; background: transparent; font-size: 22px; line-height: 1; color: #94a0c0; cursor: pointer; border-radius: 8px; }
.auth-x:hover { background: #f1f0fb; color: var(--primary, #6549D5); }
.auth-tabs { display: flex; gap: 6px; margin-bottom: 18px; background: #f3f2fb; padding: 4px; border-radius: 10px; }
.auth-tab { flex: 1; border: 0; background: transparent; padding: 8px 0; border-radius: 8px; font-size: 14px; font-weight: 600; color: #6b6f86; cursor: pointer; }
.auth-tab.active { background: #fff; color: var(--primary, #6549D5); box-shadow: 0 1px 3px rgba(60, 50, 140, 0.12); }
.auth-field { display: block; margin-bottom: 14px; }
.auth-field span { display: block; font-size: 13px; color: #5b607a; margin-bottom: 6px; }
.auth-field input { width: 100%; box-sizing: border-box; padding: 11px 12px; border: 1px solid #d9dcec; border-radius: 10px; font-size: 14px; outline: none; transition: border-color .15s, box-shadow .15s; }
.auth-field input:focus { border-color: var(--primary, #6549D5); box-shadow: 0 0 0 3px rgba(101, 73, 213, 0.14); }
.auth-err { color: #d23f57; font-size: 13px; min-height: 18px; margin: 2px 0 10px; }
.auth-submit { width: 100%; padding: 11px; font-size: 15px; }
.auth-hint { margin: 14px 0 0; font-size: 12px; line-height: 1.6; color: #8b90a6; }

/* 登录后下拉菜单 */
.auth-menu { position: absolute; top: calc(100% + 8px); right: 0; min-width: 168px; background: #fff; border: 1px solid #e6e7f2; border-radius: 12px; box-shadow: 0 12px 30px rgba(60, 50, 140, 0.16); padding: 6px; z-index: 60; }
.auth-menu.hidden { display: none; }
.auth-menu-head { padding: 8px 10px; font-size: 12px; color: #8b90a6; border-bottom: 1px solid #f0f0f7; margin-bottom: 4px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.auth-menu-item { display: block; width: 100%; text-align: left; border: 0; background: transparent; padding: 9px 10px; border-radius: 8px; font-size: 14px; color: #3a3f57; cursor: pointer; }
.auth-menu-item:hover { background: #f3f2fb; color: var(--primary, #6549D5); }

/* 云端画板区 */
#cloudSection .section-head { flex-wrap: wrap; gap: 10px; }
.cloud-list { display: flex; flex-direction: column; gap: 8px; margin-top: 14px; }
.cloud-row { display: flex; align-items: center; gap: 12px; padding: 12px 14px; background: #fff; border: 1px solid #ebeaf4; border-radius: 12px; }
.cloud-name { flex: 1; text-align: left; border: 0; background: transparent; font-size: 15px; font-weight: 600; color: #2b2f47; cursor: pointer; padding: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.cloud-name:hover { color: var(--primary, #6549D5); }
.cloud-mode { font-size: 11px; font-weight: 700; padding: 2px 7px; border-radius: 6px; }
.cloud-mode.mode-2d { background: #E0E7FF; color: #3E44D9; }
.cloud-mode.mode-3d { background: #FCE7F3; color: #B83280; }
.cloud-time { font-size: 12px; color: #9aa0b8; min-width: 120px; }
.cloud-del { white-space: nowrap; }
.cloud-loading { padding: 18px; color: #9aa0b8; font-size: 14px; }

/* ---------- 账号二级弹窗（改密 / 删号） ---------- */
.auth-title { margin: 4px 0 16px; font-size: 18px; font-weight: 700; color: #2b2f47; }
.auth-warn { margin: 0 0 16px; padding: 12px 14px; background: #fff4f5; border: 1px solid #f7d3d8; border-radius: 10px; color: #b42334; font-size: 13px; line-height: 1.6; }
.auth-menu-item.danger { color: #d23f57; }
.auth-menu-item.danger:hover { background: #fdeef0; color: #d23f57; }
/* 删号提交按钮：实心红，区别于幽灵样式的全局 .btn-danger */
.auth-card .btn-danger { background: #d23f57; border-color: #d23f57; color: #fff; }
.auth-card .btn-danger:hover { background: #bd3349; border-color: #bd3349; }
.auth-card .btn-danger:disabled { opacity: 0.6; cursor: not-allowed; }

/* ---------- 忘记密码 / 重置结果 ---------- */
.auth-alt { margin: 12px 0 0; text-align: center; font-size: 13px; }
.auth-alt a { color: var(--primary, #6549D5); text-decoration: none; }
.auth-alt a:hover { text-decoration: underline; }
.auth-reset-result { margin-top: 14px; padding: 14px; background: #f4f3fd; border: 1px solid #e4e1f7; border-radius: 10px; font-size: 13px; line-height: 1.6; }
.auth-reset-url { margin: 8px 0 12px; padding: 10px 12px; background: #fff; border: 1px dashed #c9c3ef; border-radius: 8px; word-break: break-all; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px; color: #3a3f57; }

/* ---------- 第三方登录（OAuth） ---------- */
.auth-oauth { margin-top: 14px; }
.auth-oauth.hidden { display: none; }
.auth-oauth-sep { display: flex; align-items: center; gap: 10px; color: #9aa0b8; font-size: 12px; margin: 4px 0 10px; }
.auth-oauth-sep::before, .auth-oauth-sep::after { content: ''; flex: 1; height: 1px; background: #e6e7f2; }
.auth-oauth-btn { display: block; width: 100%; margin-top: 8px; padding: 10px 12px; border: 1px solid #d9dcec; background: #fff; border-radius: 10px; font-size: 14px; font-weight: 600; color: #3a3f57; cursor: pointer; transition: border-color .15s, background .15s; }
.auth-oauth-btn:hover { border-color: var(--primary, #6549D5); background: #f7f6fe; }

/* ---------- 会员中心 / 会员徽章 ---------- */
.mb-status { margin: 4px 0 16px; padding: 12px 14px; background: #f7f6fe; border: 1px solid #e6e3f7; border-radius: 10px; font-size: 14px; color: #4a4f6b; }
.mb-vip { color: #b8860b; font-weight: 700; }
.auth-vip { display: inline-flex; align-items: center; margin-left: 8px; padding: 1px 8px; font-size: 12px; font-weight: 700; line-height: 1.6; color: #fff; background: linear-gradient(135deg, #C9A227, #E6C35C); border-radius: 999px; vertical-align: middle; }
.auth-vip.hidden { display: none; }

/* ---------- 画板页登录墙 ---------- */
.login-wall { position: fixed; inset: 0; z-index: 2000; display: flex; align-items: center; justify-content: center; background: rgba(28, 25, 64, 0.55); backdrop-filter: blur(4px); opacity: 1; visibility: visible; transition: opacity .28s var(--ease), visibility .28s var(--ease); }
.login-wall.hidden { opacity: 0; visibility: hidden; pointer-events: none; display: flex; }
.login-wall-card { width: min(380px, 90vw); padding: 32px 28px; background: #fff; border-radius: 18px; box-shadow: 0 24px 60px rgba(60, 50, 140, 0.25); text-align: center; }
.login-wall-brand { justify-content: center; margin-bottom: 14px; }
.login-wall-brand .site-name { font-size: 18px; font-weight: 800; color: #2b2f47; }
.login-wall-title { margin: 6px 0 8px; font-size: 20px; font-weight: 800; color: #2b2f47; }
.login-wall-sub { margin: 0 0 20px; font-size: 13px; line-height: 1.7; color: #6b6f86; }
.login-wall #wallLogin { width: 100%; padding: 12px; font-size: 15px; }

/* ---------- 管理后台 ---------- */
.admin-wrap { max-width: 920px; margin: 0 auto; padding: 32px 20px 64px; }
.admin-title { font-size: 24px; font-weight: 800; color: #2b2f47; margin: 0 0 6px; }
.admin-sub { color: #6b6f86; font-size: 14px; margin: 0 0 24px; }
.admin-card { background: #fff; border: 1px solid #ebeaf4; border-radius: 14px; padding: 20px; margin-bottom: 22px; box-shadow: 0 6px 18px rgba(60, 50, 140, 0.06); }
.admin-card h3 { margin: 0 0 14px; font-size: 16px; font-weight: 700; color: #2b2f47; }
.admin-row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; margin-bottom: 12px; }
.admin-row input { padding: 9px 11px; border: 1px solid #d9dcec; border-radius: 9px; font-size: 14px; }
.admin-row input[type="number"] { width: 90px; }
.admin-note { font-size: 13px; color: #8b90a6; min-height: 18px; margin: 6px 0 0; }
.admin-note.ok { color: #2f9e63; }
.admin-note.err { color: #d23f57; }
.code-chip { display: inline-block; margin: 4px 6px 4px 0; padding: 5px 10px; background: #f4f3fd; border: 1px solid #e4e1f7; border-radius: 8px; font-family: ui-monospace, Menlo, monospace; font-size: 13px; letter-spacing: .5px; user-select: all; }
.admin-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.admin-table th, .admin-table td { text-align: left; padding: 9px 10px; border-bottom: 1px solid #f0f0f7; }
.admin-table th { color: #8b90a6; font-weight: 600; background: #fafaff; }
.admin-table tr:hover td { background: #fafaff; }
.pill { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 12px; font-weight: 600; }
.pill.admin { background: #EFE7FF; color: #6d28d9; }
.pill.user { background: #E0E7FF; color: #3E44D9; }
.pill.vip { background: #FFF4D6; color: #b8860b; }
.pill.free { background: #f0f0f7; color: #6b6f86; }


/* ---------- 顶栏账号锚点 / 头像（首页 + 画板页通用） ---------- */
.auth-anchor { position: relative; display: inline-flex; align-items: center; flex: none; }
.avatar-dot {
  width: 24px; height: 24px; border-radius: 50%; flex: none;
  background: linear-gradient(135deg, #3E44D9, #9444DA);
  color: #fff; font-size: 12px; font-weight: 700;
  display: inline-flex; align-items: center; justify-content: center;
}
.auth-anchor .btn.is-user {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 3px 12px 3px 3px; border-radius: 999px;
  border-color: var(--border); background: #fff;
  max-width: 180px;
}
.auth-anchor .btn.is-user:hover { border-color: var(--primary); }
.auth-anchor .btn.is-user .auth-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 13px; }
.auth-anchor .auth-vip { position: absolute; top: -7px; right: -4px; z-index: 1; }

/* ---------- 画板顶栏「导出 / 导入」下拉 ---------- */
.export-menu { width: 240px; padding: 6px 8px 10px; max-height: calc(100vh - 90px); overflow: auto; }
.export-menu-title {
  font-size: 11px; font-weight: 700; color: #8b90a6; letter-spacing: .5px;
  padding: 10px 8px 4px; text-transform: uppercase;
}
.export-menu-item {
  display: flex; width: 100%; align-items: baseline; justify-content: space-between; gap: 8px;
  border: 0; background: transparent; padding: 8px 10px; border-radius: 8px;
  font-size: 13px; color: #3a3f57; cursor: pointer; text-align: left; font-family: inherit;
  transition: background var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease);
}
.export-menu-item:hover { background: #f3f2fb; color: var(--primary, #6549D5); }
.export-menu-item:active { transform: scale(.98); }

/* 顶栏分组间距：把「视图类(设置/动画) | 文件类(同步/保存/导出) | 分享类(嵌入/LaTeX) | 账号」隔开 */
.board-page .topbar .settings-wrap { flex: none; }
.board-page .topbar > .auth-anchor { margin-left: 2px; }
@media (max-width: 900px) {
  .export-menu { right: 0; }
  .auth-anchor .btn.is-user { max-width: 120px; }
}