/* css/app.css —— 小学数学家庭教辅 · 布局与主题（深色黑板 / 浅色两种主题） */
:root {
  --bg: #10151b;
  --bg-2: #161d26;
  --bg-3: #1d2733;
  --panel: #141b23;
  --line: #26313d;
  --line-2: #33404f;
  --text: #e6edf5;
  --text-dim: #9aa9b9;
  --accent: #4da3ff;
  --accent-2: #2f7fd6;
  --ok: #3ecf8e;
  --warn: #f5c451;
  --danger: #ef5f6b;
  --num: #4da3ff;
  --geo: #3ecf8e;
  --stat: #c58af9;
  --prac: #f5a25d;
  --shadow: 0 8px 24px rgba(0, 0, 0, .38);
  --radius: 10px;
  --topbar-h: 52px;
  --status-h: 24px;
  /* 面板收起时保留的固定行高（一行标题栏） */
  --row-h: 42px;
  --panel-anim: 220ms cubic-bezier(.4, 0, .2, 1);
  --font: "Segoe UI", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  --mono: "Cascadia Mono", Consolas, "Courier New", monospace;
}
html[data-theme="light"] {
  --bg: #eef2f7;
  --bg-2: #f7f9fc;
  --bg-3: #e4eaf2;
  --panel: #ffffff;
  --line: #d3dbe5;
  --line-2: #bcc7d4;
  --text: #1b2430;
  --text-dim: #5d6b7c;
  --shadow: 0 8px 20px rgba(20, 30, 45, .12);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 14px;
  color: var(--text);
  background: var(--bg);
  overflow: hidden;
  -webkit-text-size-adjust: 100%;
}
.ic { vertical-align: -3px; flex: none; }
.spacer { flex: 1 1 auto; }
.muted { color: var(--text-dim); }
.small { font-size: 12px; }
.hint { color: var(--text-dim); font-size: 12px; }

/* ================= 整体框架 ================= */
.app { display: flex; flex-direction: column; height: 100vh; }
.topbar {
  height: var(--topbar-h);
  flex: none;
  display: flex; align-items: center; gap: 10px;
  padding: 0 10px;
  background: linear-gradient(180deg, var(--bg-3), var(--bg-2));
  border-bottom: 1px solid var(--line);
  z-index: 40;
}
.brand { display: flex; align-items: center; gap: 8px; padding-right: 6px; }
.brand-logo {
  width: 30px; height: 30px; border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), #7c5cff);
  color: #fff; font-weight: 700; font-size: 18px;
  display: grid; place-items: center;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 14px; letter-spacing: .3px; }
.brand-text small { font-size: 11px; color: var(--text-dim); }
.topbar-mid { display: flex; align-items: center; gap: 10px; flex: 1 1 auto; min-width: 0; }
.topbar-right { display: flex; align-items: center; gap: 6px; }

.body { flex: 1 1 auto; display: flex; min-height: 0; position: relative; }
/* 展开/收起时让"说明区 ↔ 画布 ↔ 训练题"平滑联动：黑板随动压缩/扩展 */
.inspector, .quiz-drawer { transition: height var(--panel-anim); overflow: hidden; }
/* 动画进行中禁用画布指针事件，避免动画期间误画；结束后由 JS 重新校准画布尺寸 */
.app[data-anim="1"] .canvas-wrap { pointer-events: none; }
@media (prefers-reduced-motion: reduce) {
  .inspector, .quiz-drawer { transition: none; }
}
.main { flex: 1 1 auto; display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.statusbar {
  height: var(--status-h); flex: none;
  display: flex; align-items: center; gap: 12px;
  padding: 0 12px; font-size: 11.5px; color: var(--text-dim);
  background: var(--bg-2); border-top: 1px solid var(--line);
}

/* ================= 通用控件 ================= */
button { font-family: inherit; font-size: 13px; color: inherit; }
.icon-btn {
  width: 32px; height: 32px; border-radius: 8px;
  display: inline-grid; place-items: center;
  background: transparent; border: 1px solid transparent; cursor: pointer;
}
.icon-btn:hover { background: var(--bg-3); border-color: var(--line-2); }
.icon-btn.sm { width: 26px; height: 26px; border-radius: 7px; }
.icon-btn[aria-pressed="true"], .icon-btn.active { background: var(--accent); color: #fff; border-color: var(--accent-2); }
.btn {
  border: 1px solid var(--line-2); background: var(--bg-3); color: var(--text);
  padding: 6px 12px; border-radius: 8px; cursor: pointer; white-space: nowrap;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent-2); color: #fff; font-weight: 600; }
.btn.primary:hover { background: var(--accent-2); }
.btn.ghost { background: transparent; }
.btn.danger { border-color: var(--danger); color: var(--danger); background: transparent; }
.btn.danger:hover { background: var(--danger); color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.mini-btn {
  border: 1px solid var(--line-2); background: var(--bg-2); color: var(--text-dim);
  border-radius: 6px; padding: 3px 8px; font-size: 11.5px; cursor: pointer;
}
.mini-btn:hover { color: var(--text); border-color: var(--accent); }
.mini-btn[aria-pressed="true"] { background: var(--accent); color: #fff; border-color: var(--accent-2); }
.field { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--text-dim); }
.field.inline { flex-direction: row; align-items: center; gap: 6px; white-space: nowrap; }
.field.checkbox { flex-direction: row; align-items: center; gap: 6px; color: var(--text); }
select, input[type="text"], input[type="number"], input[type="search"], textarea {
  background: var(--bg); border: 1px solid var(--line-2); color: var(--text);
  border-radius: 8px; padding: 6px 8px; font-family: inherit; font-size: 13px; min-width: 0;
}
input:focus, select:focus, textarea:focus, button:focus-visible, .tree:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 1px;
}
.row { display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-end; margin-bottom: 12px; }
.kbd-list { line-height: 2; font-size: 12px; color: var(--text-dim); }
kbd {
  font-family: var(--mono); font-size: 11px; padding: 1px 5px; margin: 0 1px;
  border: 1px solid var(--line-2); border-bottom-width: 2px; border-radius: 4px;
  background: var(--bg-3); color: var(--text);
}

/* ================= 搜索 ================= */
.global-search { position: relative; flex: 1 1 320px; max-width: 460px; display: flex; align-items: center; }
.global-search .gs-icon, .sidebar-search .gs-icon {
  position: absolute; left: 9px; top: 50%; transform: translateY(-50%);
  color: var(--text-dim); display: flex;
}
.global-search input, .sidebar-search input { width: 100%; padding-left: 32px; }
.search-results {
  position: absolute; top: 110%; left: 0; right: 0; max-height: 60vh; overflow: auto;
  background: var(--panel); border: 1px solid var(--line-2); border-radius: var(--radius);
  box-shadow: var(--shadow); z-index: 60; padding: 4px;
}
.sr-item { padding: 7px 9px; border-radius: 7px; cursor: pointer; display: flex; gap: 8px; align-items: baseline; }
.sr-item[aria-selected="true"], .sr-item:hover { background: var(--bg-3); }
.sr-path { font-size: 11px; color: var(--text-dim); flex: none; }
.sr-title { font-size: 13px; }
.sr-empty { padding: 10px; color: var(--text-dim); font-size: 12px; }

/* ================= 孩子档案 ================= */
.profile-switch { position: relative; }
.profile-switch .btn { display: flex; align-items: center; gap: 6px; max-width: 190px; }
.profile-switch .btn b { font-weight: 600; }
.menu {
  position: absolute; top: 108%; left: 0; min-width: 240px; display: none;
  background: var(--panel); border: 1px solid var(--line-2); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 5px; z-index: 60;
}
.menu[data-open="true"] { display: block; }
.menu-item { display: flex; align-items: center; gap: 8px; padding: 7px 9px; border-radius: 7px; cursor: pointer; font-size: 13px; }
.menu-item:hover { background: var(--bg-3); }
.menu-item .grow { flex: 1 1 auto; }
.menu-sep { height: 1px; background: var(--line); margin: 5px 2px; }
.menu-item .tag { font-size: 11px; color: var(--text-dim); }

/* ================= 年级切换 ================= */
.grade-tabs { display: flex; gap: 3px; background: var(--bg); padding: 3px; border-radius: 9px; border: 1px solid var(--line); }
.grade-tabs button {
  border: none; background: transparent; color: var(--text-dim); cursor: pointer;
  padding: 5px 9px; border-radius: 7px; font-size: 12.5px; position: relative;
}
.grade-tabs button:hover { color: var(--text); background: var(--bg-3); }
.grade-tabs button[aria-selected="true"] { background: var(--accent); color: #fff; font-weight: 600; }
.grade-tabs button .dot {
  position: absolute; right: 4px; top: 4px; width: 5px; height: 5px; border-radius: 50%; background: var(--ok);
}

/* ================= 左侧目录 ================= */
.sidebar {
  width: 310px; flex: none; display: flex; flex-direction: column;
  background: var(--panel); border-right: 1px solid var(--line); min-height: 0;
  transition: width .16s ease;
}
.app[data-sidebar="closed"] .sidebar { width: 0; overflow: hidden; border-right: none; }
.sidebar-head { display: flex; align-items: center; gap: 6px; padding: 8px 10px 4px; }
.sidebar-title { font-size: 12px; font-weight: 600; color: var(--text-dim); letter-spacing: .5px; flex: 1 1 auto; }
.sidebar-actions { display: flex; gap: 4px; }
.sidebar-search { position: relative; display: flex; align-items: center; padding: 4px 10px 8px; }
.tree { flex: 1 1 auto; overflow: auto; padding: 2px 6px 10px; }
.tree-node { user-select: none; }
.tree-row {
  display: flex; align-items: center; gap: 5px; padding: 5px 7px; border-radius: 7px;
  cursor: pointer; font-size: 13px; line-height: 1.3;
}
.tree-row:hover { background: var(--bg-3); }
.tree-row .chev { width: 14px; flex: none; color: var(--text-dim); display: flex; transition: transform .12s ease; }
.tree-row .chev[data-open="true"] { transform: rotate(90deg); }
.tree-row .label { flex: 1 1 auto; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tree-row .count { font-size: 11px; color: var(--text-dim); flex: none; }
.tree-row.grade { font-weight: 700; font-size: 13.5px; }
.tree-row.term { color: var(--text-dim); font-size: 12.5px; padding-left: 14px; }
.tree-row.chapter { font-weight: 600; padding-left: 22px; }
.tree-children { margin-left: 10px; border-left: 1px dashed var(--line); }
.tree-row.point { padding-left: 30px; }
.tree-row.point[aria-selected="true"] { background: var(--accent); color: #fff; }
.tree-row.point[aria-selected="true"] .count, .tree-row.point[aria-selected="true"] .tag { color: #eaf3ff; }
.tree-row.point:focus-visible { outline: 2px solid var(--accent); }
.tag {
  font-size: 10px; padding: 0 5px; border-radius: 4px; border: 1px solid var(--line-2);
  color: var(--text-dim); flex: none;
}
.tag.d-num { border-color: var(--num); color: var(--num); }
.tag.d-geo { border-color: var(--geo); color: var(--geo); }
.tag.d-stat { border-color: var(--stat); color: var(--stat); }
.tag.d-prac { border-color: var(--prac); color: var(--prac); }
.tag.t-重点 { border-color: var(--warn); color: var(--warn); }
.tag.t-易错 { border-color: var(--danger); color: var(--danger); }
.sidebar-foot {
  display: flex; align-items: center; gap: 8px; padding: 6px 10px;
  border-top: 1px solid var(--line); font-size: 11.5px; color: var(--text-dim);
}

/* ================= 说明区（三档） ================= */
.inspector {
  flex: none; position: relative; display: flex; flex-direction: column;
  background: var(--panel); border-bottom: 1px solid var(--line);
  height: 25%; min-height: 42px;
}
.app[data-inspector="collapsed"] .inspector,
.app[data-inspector="fullscreen"] .inspector { height: var(--row-h); }
.inspector-bar {
  height: 42px; flex: none; display: flex; align-items: center; gap: 8px; padding: 0 8px 0 4px;
  border-bottom: 1px solid var(--line);
}
.ins-toggle {
  display: flex; align-items: center; gap: 6px; background: transparent; border: none;
  cursor: pointer; padding: 4px 6px; border-radius: 7px; flex: 1 1 auto; min-width: 0; text-align: left;
}
.ins-toggle:hover { background: var(--bg-3); }
.ins-chevron { display: flex; color: var(--text-dim); transition: transform .12s ease; }
.ins-chevron[data-open="true"] { transform: rotate(90deg); }
.ins-title { font-weight: 600; font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ins-meta { font-size: 11.5px; color: var(--text-dim); flex: none; }
.ins-tags { display: flex; gap: 4px; flex: none; }
.ins-modes { display: flex; gap: 2px; flex: none; }
.ins-modes .icon-btn[aria-pressed="true"] { background: var(--accent); color: #fff; }
.inspector-body { flex: 1 1 auto; overflow: auto; padding: 10px 12px 8px; display: flex; flex-direction: column; }
.app[data-inspector="collapsed"] .inspector-body,
.app[data-inspector="fullscreen"] .inspector-body { display: none; }
.ins-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 10px; }
.card { background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); padding: 9px 11px; }
.card h3 { margin: 0 0 6px; font-size: 12px; color: var(--text-dim); font-weight: 600; letter-spacing: .4px; }
.card.tips { border-color: rgba(245, 196, 81, .35); }
.ins-text { font-size: 13.5px; line-height: 1.7; }
.ins-list { margin: 0; padding-left: 18px; font-size: 13px; line-height: 1.75; }
.ins-list li { margin-bottom: 3px; }
.ins-foot { display: flex; align-items: center; gap: 8px; padding-top: 9px; margin-top: auto; flex-wrap: wrap; }
.ins-resizer {
  position: absolute; left: 0; right: 0; bottom: -3px; height: 7px; cursor: row-resize; z-index: 5;
}
.ins-resizer:hover, .ins-resizer.dragging { background: rgba(77, 163, 255, .35); }
/* 收起/全屏档不提供拖拽：提示"不可拖"，避免误以为能调整 */
.ins-resizer[aria-disabled="true"] { cursor: default; }
.ins-resizer[aria-disabled="true"]:hover { background: transparent; }

/* ================= 画布区（三列：左工具栏 | 画布 | 右工具栏，互不遮挡） ================= */
.stage { flex: 1 1 auto; position: relative; min-height: 0; overflow: hidden; display: flex; align-items: stretch; }
.canvas-wrap { flex: 1 1 auto; position: relative; min-width: 0; min-height: 0; overflow: hidden; }
.canvas-layers { position: absolute; inset: 0; }
.layer { position: absolute; inset: 0; display: block; }
.scene-layer { touch-action: none; }
.overlay-layer { pointer-events: none; }
.overlay-ui { position: absolute; inset: 0; pointer-events: none; }
.overlay-ui > * { pointer-events: auto; }
.mz-text-editor {
  position: absolute; min-width: 130px; min-height: 34px; resize: both;
  background: rgba(0, 0, 0, .35); border: 1px dashed var(--accent); border-radius: 6px;
  font-family: var(--font); line-height: 1.3; padding: 3px 6px; z-index: 20; color: #fff;
}
.stage-bar {
  position: absolute; left: 0; right: 0; bottom: 0; height: 32px;
  display: flex; align-items: center; gap: 6px; padding: 0 8px;
  background: linear-gradient(180deg, rgba(10, 14, 20, .05), rgba(10, 14, 20, .68));
  font-size: 11.5px; z-index: 10;
}
.chip { color: #e2ecf8; background: rgba(20, 27, 35, .78); border: 1px solid var(--line-2); border-radius: 6px; padding: 2px 7px; }
.chip.saving { color: var(--warn); }
.chip.saved { color: var(--ok); }

/* ================= 工具栏 ================= */
.toolrail {
  flex: none; width: 184px; z-index: 12; display: flex; flex-direction: column;
  background: var(--bg-2); border-right: 1px solid var(--line); min-height: 0;
  transition: width .16s ease;
}
.toolrail.right { border-right: none; border-left: 1px solid var(--line); width: 176px; }
.toolrail[data-collapsed="true"] { width: 48px; }
.toolrail.right[data-collapsed="true"] { width: 48px; }
.rail-body { flex: 1 1 auto; overflow: auto; padding: 8px 7px 10px; display: flex; flex-direction: column; gap: 8px; }
.toolrail[data-collapsed="true"] .rail-body { padding: 8px 6px 10px; align-items: center; }
.rail-toggle {
  position: absolute; top: 8px; width: 26px; height: 26px; border-radius: 7px; z-index: 11;
  background: rgba(20, 27, 35, .86); border: 1px solid var(--line-2); cursor: pointer; color: var(--text-dim);
  display: grid; place-items: center;
}
.rail-toggle.left { left: 8px; }
.rail-toggle.right { right: 8px; }
.rail-toggle:hover { color: var(--text); border-color: var(--accent); }
.rail-group { display: flex; flex-direction: column; gap: 4px; }
.rail-group-title { font-size: 10.5px; color: var(--text-dim); letter-spacing: .5px; padding-left: 3px; }
.toolrail[data-collapsed="true"] .rail-group-title { display: none; }
.tool-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; }
.toolrail[data-collapsed="true"] .tool-grid { grid-template-columns: 1fr; }
.tool-btn {
  display: flex; align-items: center; gap: 6px; padding: 6px 7px; border-radius: 8px;
  background: transparent; border: 1px solid transparent; cursor: pointer; font-size: 12px; text-align: left;
  min-width: 0;
}
.tool-btn .lbl { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
.toolrail[data-collapsed="true"] .tool-btn { justify-content: center; padding: 6px 4px; }
.tool-btn:hover { background: var(--bg-3); border-color: var(--line-2); }
.tool-btn[aria-pressed="true"] { background: var(--accent); border-color: var(--accent-2); color: #fff; }
.tool-btn .lbl { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.toolrail[data-collapsed="true"] .tool-btn .lbl { display: none; }
.shape-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px; }
.toolrail[data-collapsed="true"] .shape-grid { grid-template-columns: 1fr; }
.shape-chip {
  display: flex; flex-direction: column; align-items: center; gap: 2px; padding: 4px 2px;
  border-radius: 8px; border: 1px dashed var(--line-2); cursor: grab; background: var(--bg-2);
  font-size: 10px; color: var(--text-dim); min-width: 0;
}
.shape-chip:hover { border-color: var(--accent); color: var(--text); border-style: solid; }
.shape-chip .prev { width: 100%; height: 38px; display: flex; align-items: center; justify-content: center; }
.shape-chip .prev svg { width: 100%; height: 100%; }
.toolrail[data-collapsed="true"] .shape-chip .name { display: none; }
.swatches { display: grid; grid-template-columns: repeat(6, 1fr); gap: 4px; }
.toolrail[data-collapsed="true"] .swatches { grid-template-columns: repeat(2, 1fr); }
.swatch {
  width: 100%; aspect-ratio: 1/1; border-radius: 6px; border: 2px solid transparent; cursor: pointer;
}
.swatch[aria-pressed="true"] { border-color: #fff; box-shadow: 0 0 0 2px var(--accent); }
.swatch.transparent {
  background-image: linear-gradient(45deg, #999 25%, transparent 25%, transparent 75%, #999 75%), linear-gradient(45deg, #999 25%, transparent 25%, transparent 75%, #999 75%);
  background-size: 10px 10px; background-position: 0 0, 5px 5px; background-color: #fff;
}
.size-row { display: flex; align-items: center; gap: 6px; }
.size-row input[type="range"] { flex: 1 1 auto; min-width: 0; accent-color: var(--accent); }
.custom-item {
  display: flex; align-items: center; gap: 5px; padding: 4px 5px; border-radius: 7px;
  border: 1px solid var(--line); background: var(--bg-2); font-size: 12px; cursor: grab;
}
.custom-item:hover { border-color: var(--accent); }
.custom-item img { width: 34px; height: 26px; object-fit: cover; border-radius: 4px; background: #223; flex: none; }
.custom-item .nm { flex: 1 1 auto; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.custom-item .mini-btn { padding: 1px 5px; font-size: 11px; }
.empty-tip { font-size: 11.5px; color: var(--text-dim); padding: 4px; line-height: 1.6; }

/* ================= 训练题抽屉 ================= */
.quiz-drawer {
  flex: none; position: relative; background: var(--panel); border-top: 1px solid var(--line);
  display: flex; flex-direction: column; height: var(--row-h);
}
.quiz-drawer[data-open="true"] { height: 34%; }
.quiz-resizer { position: absolute; left: 0; right: 0; top: -3px; height: 7px; cursor: row-resize; z-index: 6; }
.quiz-resizer:hover, .quiz-resizer.dragging { background: rgba(77, 163, 255, .35); }
.quiz-resizer[aria-disabled="true"] { cursor: default; }
.quiz-resizer[aria-disabled="true"]:hover { background: transparent; }
.quiz-head { display: flex; align-items: center; gap: 10px; padding: 4px 8px; flex-wrap: wrap; min-height: var(--row-h); }
.quiz-toggle { display: flex; align-items: center; gap: 6px; background: transparent; border: none; cursor: pointer; padding: 4px 6px; border-radius: 7px; }
.quiz-toggle:hover { background: var(--bg-3); }
.quiz-controls { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.quiz-body {
  flex: 1 1 auto; overflow: auto; padding: 4px 12px 14px;
  display: none;
  opacity: 0;
  transition: opacity 140ms ease;
}
.quiz-drawer[data-open="true"] .quiz-body { display: block; opacity: 1; }
.quiz-empty { color: var(--text-dim); font-size: 13px; padding: 14px 4px; }
.quiz-list { margin: 0; padding-left: 22px; }
.quiz-item { margin: 0 0 12px; padding: 9px 11px; background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); }
.quiz-item .q-head { display: flex; align-items: center; gap: 6px; margin-bottom: 6px; flex-wrap: wrap; }
.quiz-item .q-type { font-size: 11px; padding: 1px 6px; border-radius: 5px; background: var(--bg-3); color: var(--text-dim); }
.quiz-item .q-diff { font-size: 11px; padding: 1px 6px; border-radius: 5px; }
.q-diff.basic { color: var(--ok); border: 1px solid var(--ok); }
.q-diff.improve { color: var(--warn); border: 1px solid var(--warn); }
.q-diff.challenge { color: var(--danger); border: 1px solid var(--danger); }
.q-autotag { font-size: 11px; color: var(--warn); }
.quiz-item .q-text { font-size: 14.5px; line-height: 1.75; }
.quiz-item .q-svg { margin: 8px 0; background: #f7f9fc; border-radius: 8px; padding: 6px; max-width: 320px; }
.quiz-item .q-svg svg { width: 100%; height: auto; display: block; }
.q-options { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0 0; }
.q-option {
  border: 1px solid var(--line-2); background: var(--bg); border-radius: 8px;
  padding: 5px 12px; cursor: pointer; font-size: 13.5px; min-width: 84px; text-align: left;
}
.q-option:hover { border-color: var(--accent); }
.q-option[aria-pressed="true"] { border-color: var(--accent); background: rgba(77, 163, 255, .16); }
.q-option.correct { border-color: var(--ok); background: rgba(62, 207, 142, .16); }
.q-option.wrong { border-color: var(--danger); background: rgba(239, 95, 107, .16); }
.q-input-row { display: flex; gap: 8px; align-items: center; margin: 8px 0 0; flex-wrap: wrap; }
.q-input-row input { min-width: 160px; }
.q-feedback { font-size: 12.5px; margin-top: 4px; }
.q-feedback.ok { color: var(--ok); }
.q-feedback.no { color: var(--danger); }
.q-answer {
  margin-top: 8px; padding: 8px 10px; border-radius: 8px;
  background: rgba(62, 207, 142, .1); border: 1px dashed rgba(62, 207, 142, .5);
  font-size: 13px; line-height: 1.7;
}
.q-answer .lbl { color: var(--ok); font-weight: 600; margin-right: 4px; }
.q-explain { color: var(--text-dim); margin-top: 3px; }
.q-actions { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }
.quiz-notice { color: var(--warn); font-size: 12.5px; padding: 6px 4px; }
.quiz-notice.judge { color: var(--accent); border: 1px dashed var(--accent); border-radius: 8px; padding: 6px 9px; margin: 4px 0 8px; }
.quiz-src { color: var(--text-dim); font-size: 12px; padding: 4px 2px 8px; border-bottom: 1px dashed var(--line); margin-bottom: 10px; }
.q-srctag {
  font-size: 11px; padding: 1px 6px; border-radius: 5px;
  border: 1px solid var(--accent); color: var(--accent);
}

/* ================= 提示 / 弹窗 ================= */
.toasts { position: fixed; right: 14px; bottom: 40px; display: flex; flex-direction: column; gap: 8px; z-index: 200; }
.toast {
  background: var(--panel); border: 1px solid var(--line-2); border-left: 3px solid var(--accent);
  border-radius: 8px; padding: 9px 12px; box-shadow: var(--shadow); font-size: 13px; max-width: 340px;
  animation: slideIn .16s ease;
}
.toast.ok { border-left-color: var(--ok); }
.toast.warn { border-left-color: var(--warn); }
.toast.err { border-left-color: var(--danger); }
@keyframes slideIn { from { transform: translateX(20px); opacity: 0; } to { transform: none; opacity: 1; } }

.modal { position: fixed; inset: 0; background: rgba(4, 8, 12, .6); display: grid; place-items: center; z-index: 300; padding: 18px; }
.modal[hidden] { display: none; }
.modal-panel {
  width: 100%; max-width: 620px; max-height: 88vh; display: flex; flex-direction: column;
  background: var(--panel); border: 1px solid var(--line-2); border-radius: 14px; box-shadow: var(--shadow);
}
.modal-panel.wide { max-width: 780px; }
.modal-panel.narrow { max-width: 430px; }
.modal-panel header { display: flex; align-items: center; gap: 8px; padding: 12px 14px; border-bottom: 1px solid var(--line); }
.modal-panel header h2 { margin: 0; font-size: 15px; flex: 1 1 auto; }
.modal-body { padding: 14px; overflow: auto; }
.modal-body.help { line-height: 1.75; font-size: 13.5px; }
.modal-body h3.sec { font-size: 13px; margin: 16px 0 6px; color: var(--accent); }
.modal-foot { display: flex; justify-content: flex-end; gap: 8px; padding: 10px 14px; border-top: 1px solid var(--line); }
.help-steps { padding-left: 20px; margin: 0 0 8px; }
.help-steps li { margin-bottom: 8px; }
.fix-list { padding-left: 20px; margin: 0; }
.fix-list li { margin-bottom: 6px; color: var(--text-dim); }
.fix-list li b { color: var(--text); }
.code {
  background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 10px;
  font-family: var(--mono); font-size: 12px; color: var(--text-dim); overflow: auto; max-height: 220px; margin: 0;
  white-space: pre-wrap;
}
.grade-check { display: flex; gap: 8px; flex-wrap: wrap; font-size: 12.5px; }
.grade-check label { display: flex; align-items: center; gap: 3px; color: var(--text); }

/* ================= 打印 ================= */
.print-area { display: none; }
@media print {
  body { overflow: visible; background: #fff; color: #000; }
  .topbar, .sidebar, .stage, .statusbar, .toasts, .modal, .quiz-drawer, .toolrail { display: none !important; }
  .print-area { display: block !important; padding: 0; font-size: 12pt; color: #000; }
  .print-area h1 { font-size: 18pt; margin: 0 0 6pt; }
  .print-area h2 { font-size: 13pt; margin: 12pt 0 4pt; border-bottom: 1px solid #999; padding-bottom: 2pt; }
  .print-area .meta { color: #444; font-size: 10pt; margin-bottom: 8pt; }
  .print-area ol, .print-area ul { padding-left: 18pt; }
  .print-area li { margin-bottom: 6pt; page-break-inside: avoid; }
  .print-area .pa-answer { color: #0a6; font-weight: 600; }
  .print-area .pa-svg svg { width: 90mm; height: auto; border: 1px solid #ccc; }
  .print-area .pa-quiz { page-break-before: always; }
}

/* ================= 响应式 ================= */
@media (max-width: 1240px) {
  .sidebar { width: 268px; }
  .toolrail { width: 150px; }
  .toolrail.right { width: 162px; }
}
@media (max-width: 1024px) {
  .brand-text { display: none; }
  .sidebar { position: absolute; z-index: 30; height: 100%; }
  .app[data-sidebar="open"] .sidebar { box-shadow: var(--shadow); }
  .toolrail { width: 48px; }
  .toolrail.right { width: 48px; }
}
@media (max-width: 820px) {
  .quiz-drawer[data-open="true"] { height: 46%; }
  .stage-bar .chip { display: none; }
}