/* ============================================================
   行测学习工作台 - 公共样式
   移动端优先，PC 端次要兼容，轻量化
   ============================================================ */

* { margin:0; padding:0; box-sizing:border-box; -webkit-tap-highlight-color:transparent; }

:root {
  --primary:#4F7DF3;
  --primary-dark:#3A5FC9;
  --primary-light:#E8F0FE;
  --success:#16A34A;
  --danger:#DC2626;
  --warn:#F59E0B;
  --bg:#F5F6FA;
  --card:#fff;
  --text:#1F2937;
  --text-light:#6B7280;
  --border:#E5E7EB;
  --radius:12px;
  --shadow:0 1px 3px rgba(0,0,0,.06);
  --nav-w:200px;
  --nav-h:56px;
  --safe-bottom:env(safe-area-inset-bottom);
}

html,body { height:100%; }
body {
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",sans-serif;
  background:var(--bg); color:var(--text); font-size:15px; line-height:1.6;
  -webkit-font-smoothing:antialiased;
}

a { color:var(--primary); text-decoration:none; }
button { font-family:inherit; cursor:pointer; border:none; outline:none; }
input,textarea,select { font-family:inherit; font-size:16px; outline:none; }
/* 键盘焦点可见（WCAG 可访问性） */
button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible, a:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* 滚动条隐藏 */
::-webkit-scrollbar { width:4px; height:4px; }
::-webkit-scrollbar-thumb { background:#ccc; border-radius:2px; }

/* ============================================================
   布局：左侧导航（PC 固定显示，移动端抽屉）
   ============================================================ */
.app { display:flex; min-height:100vh; }

.sidebar {
  width:var(--nav-w); background:#fff; border-right:1px solid var(--border);
  position:fixed; top:0; left:0; bottom:0; z-index:100;
  display:flex; flex-direction:column;
  transition:transform .25s ease;
}
.sidebar .logo { padding:20px 16px; font-size:18px; font-weight:700; color:var(--primary); border-bottom:1px solid var(--border); display:flex; align-items:center; gap:8px; }
.sidebar .logo svg { width:28px; height:28px; }
.nav { flex:1; overflow-y:auto; padding:12px 0; }
.nav a {
  display:flex; align-items:center; gap:12px; padding:12px 20px;
  color:var(--text-light); font-size:14px; border-left:3px solid transparent;
  transition:all .15s;
}
.nav a:hover { background:var(--primary-light); color:var(--primary); }
.nav a.active { background:var(--primary-light); color:var(--primary); border-left-color:var(--primary); font-weight:600; }
.nav a svg { width:20px; height:20px; flex-shrink:0; }
.nav .nav-section { padding:8px 20px 4px; font-size:11px; color:#9CA3AF; text-transform:uppercase; letter-spacing:.5px; }

.sidebar .nav-footer { padding:12px 20px; border-top:1px solid var(--border); font-size:12px; color:var(--text-light); }

.main { flex:1; margin-left:var(--nav-w); display:flex; flex-direction:column; min-height:100vh; }

.content { padding:16px; flex:1; width:100%; }
/* PC 端内容区限宽居中，避免表格/表单在宽屏下拉得过散 */
@media (min-width:769px) {
  .content { max-width:1100px; margin:0 auto; }
}

/* 顶部栏（移动端） */
.topbar {
  display:none; height:var(--nav-h); background:var(--primary); color:#fff;
  position:sticky; top:0; z-index:50; align-items:center; padding:0 12px;
  gap:12px;
}
.topbar .menu-btn { background:none; color:#fff; padding:8px; display:flex; }
.topbar .menu-btn svg { width:24px; height:24px; }
.topbar .topbar-title { flex:1; font-size:17px; font-weight:600; }
.topbar .topbar-right { display:flex; gap:8px; }

/* 遮罩 */
.overlay { display:none; position:fixed; top:0; left:0; right:0; bottom:0; background:rgba(0,0,0,.4); z-index:99; }
.overlay.show { display:block; }

/* ============================================================
   卡片 / 列表 / 表单
   ============================================================ */
.card { background:var(--card); border-radius:var(--radius); padding:16px; margin-bottom:12px; box-shadow:var(--shadow); }

.section-title { font-size:16px; font-weight:700; margin:0 0 12px; display:flex; align-items:center; gap:8px; }
.section-title svg { width:20px; height:20px; color:var(--primary); }

.grid { display:grid; gap:12px; }
.grid-2 { grid-template-columns:repeat(2,1fr); }
.grid-3 { grid-template-columns:repeat(3,1fr); }
.grid-5 { grid-template-columns:repeat(5,1fr); }
.grid-6 { grid-template-columns:repeat(6,1fr); }

.stat-card { background:#fff; border-radius:var(--radius); padding:14px; text-align:center; box-shadow:var(--shadow); }
.stat-card .num { font-size:22px; font-weight:700; color:var(--primary); }
.stat-card .label { font-size:12px; color:var(--text-light); margin-top:4px; }

.btn {
  display:inline-flex; align-items:center; justify-content:center; gap:6px;
  padding:10px 20px; border-radius:8px; font-size:14px; font-weight:500;
  min-height:44px; transition:all .15s;
}
.btn-primary { background:var(--primary); color:#fff; }
.btn-primary:active { background:var(--primary-dark); }
.btn-outline { background:#fff; color:var(--primary); border:1px solid var(--primary); }
.btn-danger { background:var(--danger); color:#fff; }
.btn-ghost { background:transparent; color:var(--text-light); }
.btn-sm { padding:6px 12px; min-height:32px; font-size:12px; }
.btn-block { display:flex; width:100%; }

.form-group { margin-bottom:14px; }
.form-label { display:block; font-size:14px; margin-bottom:6px; color:var(--text); }
.form-input, .form-select, .form-textarea {
  width:100%; padding:12px; border:1px solid var(--border); border-radius:8px;
  font-size:16px; background:#fff; color:var(--text);
}
.form-input:focus, .form-select:focus, .form-textarea:focus { border-color:var(--primary); }
.form-textarea { min-height:80px; resize:vertical; }
.form-hint { font-size:12px; color:var(--text-light); margin-top:4px; }
.form-error { color:var(--danger); font-size:13px; margin-top:6px; }

/* 题目卡片 */
.question-card { background:#fff; border-radius:var(--radius); padding:16px; margin-bottom:12px; box-shadow:var(--shadow); }
.question-card .q-meta { display:flex; gap:8px; margin-bottom:10px; flex-wrap:wrap; }
.tag { display:inline-block; padding:2px 8px; border-radius:4px; font-size:11px; }
.tag-cat { background:var(--primary-light); color:var(--primary); }
.tag-type { background:#F3F4F6; color:var(--text-light); }
.question-card .q-image { margin-bottom:14px; text-align:center; background:#fafbfc; border-radius:8px; padding:10px; border:1px solid #eee; overflow-x:auto; }
.question-card .q-image svg { max-width:100%; height:auto; }
.question-card .q-text { font-size:15px; line-height:1.7; margin-bottom:14px; white-space:pre-wrap; }
.options { display:flex; flex-direction:column; gap:8px; }
.option {
  display:flex; gap:10px; padding:12px; border:1px solid var(--border); border-radius:8px;
  cursor:pointer; transition:all .15s; font-size:14px; background:#fff;
}
.option:active { background:#F9FAFB; }
.option.selected { border-color:var(--primary); background:var(--primary-light); }
.option.correct { border-color:var(--success); background:#F0FDF4; }
.option.wrong { border-color:var(--danger); background:#FEF2F2; }
.option .opt-label { width:24px; height:24px; border-radius:50%; background:#F3F4F6; display:flex; align-items:center; justify-content:center; font-weight:600; flex-shrink:0; font-size:13px; }
.option.selected .opt-label { background:var(--primary); color:#fff; }
.option.correct .opt-label { background:var(--success); color:#fff; }
.option.wrong .opt-label { background:var(--danger); color:#fff; }
.option .opt-text { flex:1; word-break:break-all; }

.analysis-box { margin-top:12px; padding:12px; background:#FFFBEB; border-radius:8px; border-left:3px solid var(--warn); font-size:13px; line-height:1.6; }
.analysis-box .ans-tag { font-weight:600; color:var(--success); margin-right:6px; }

/* 空状态 */
.empty { text-align:center; padding:40px 20px; color:var(--text-light); }
.empty svg { width:48px; height:48px; margin-bottom:12px; opacity:.4; }

/* 弹窗 */
.modal-mask { display:none; position:fixed; inset:0; background:rgba(0,0,0,.5); z-index:200; align-items:center; justify-content:center; padding:16px; }
.modal-mask.show { display:flex; }
.modal { background:#fff; border-radius:var(--radius); width:100%; max-width:400px; max-height:85vh; overflow-y:auto; }
.modal-head { padding:16px; border-bottom:1px solid var(--border); font-size:16px; font-weight:600; display:flex; justify-content:space-between; align-items:center; }
.modal-body { padding:16px; }
.modal-foot { padding:12px 16px; border-top:1px solid var(--border); display:flex; gap:8px; justify-content:flex-end; }
.modal-close { background:none; font-size:20px; color:var(--text-light); }

/* Toast */
.toast { position:fixed; top:50%; left:50%; transform:translate(-50%,-50%); background:rgba(0,0,0,.8); color:#fff; padding:10px 20px; border-radius:8px; font-size:14px; z-index:300; opacity:0; transition:opacity .2s; pointer-events:none; }
.toast.show { opacity:1; }

/* 进度条 */
.progress { height:8px; background:#E5E7EB; border-radius:4px; overflow:hidden; }
.progress-bar { height:100%; background:var(--primary); border-radius:4px; transition:width .3s; }

/* 日历热力图 */
.heatmap { display:grid; grid-template-columns:repeat(7,1fr); gap:3px; }
.heatmap .cell { aspect-ratio:1; border-radius:3px; background:#F3F4F6; }
.heatmap .cell.l1 { background:#DBEAFE; }
.heatmap .cell.l2 { background:#93C5FD; }
.heatmap .cell.l3 { background:#3B82F6; }
.heatmap .cell.l4 { background:#1D4ED8; }

/* 题目网格：强制单列全宽，防止任何情况下变成多列 */
.question-grid { display:block !important; gap:0; }
.question-card { width:100%; box-sizing:border-box; }

/* 响应式：移动端 < 768px — 全部单列平铺 */
@media (max-width:768px) {
  :root { --nav-w:240px; }
  .sidebar {
    width:85%; transform:translateX(-105%);
    box-shadow:4px 0 24px rgba(0,0,0,.25);
    transition:transform .3s ease;
  }
  .sidebar.open { transform:translateX(0); }
  .overlay { z-index:99; }
  .overlay.show { display:block; }
  .main { margin-left:0; width:100%; max-width:100vw !important; }
  .topbar { display:flex; }
  .grid, .grid-2, .grid-3, .grid-5, .grid-6 { grid-template-columns:1fr !important; display:grid !important; }
  .content { padding:12px; max-width:100%; width:100%; }
  .app { display:block; }
  body { overflow-x:hidden; }
  .card, .stat-card { width:100%; }
  .stat-card .num { font-size:18px; }
  .modal { max-width:100%; }
  .btn { min-height:44px; }
  [style*="grid-template-columns"] { grid-template-columns:1fr !important; }
  img, svg { max-width:100%; height:auto; }
}

@media (min-width:769px) {
  .grid-2 { grid-template-columns:repeat(3,1fr); }
}

/* iOS 底部安全区 */
.bottom-safe { padding-bottom:calc(12px + var(--safe-bottom)); }

/* 头像 */
.avatar { border-radius:50%; object-fit:cover; background:#E5E7EB; }
.avatar-lg { width:80px; height:80px; }
.avatar-md { width:48px; height:48px; }
.avatar-sm { width:32px; height:32px; }

/* 加载 */
.loading { text-align:center; padding:20px; color:var(--text-light); }
.loading::after { content:''; display:inline-block; width:18px; height:18px; border:2px solid #E5E7EB; border-top-color:var(--primary); border-radius:50%; animation:spin .6s linear infinite; vertical-align:middle; margin-left:6px; }
@keyframes spin { to { transform:rotate(360deg); } }

/* 简单图表 */
.bar-chart { display:flex; align-items:flex-end; gap:4px; height:120px; padding:8px 0; }
.bar-chart .bar-col { flex:1; display:flex; flex-direction:column; align-items:center; gap:4px; height:100%; justify-content:flex-end; }
.bar-chart .bar { width:60%; background:var(--primary); border-radius:3px 3px 0 0; min-height:2px; transition:height .3s; }
.bar-chart .bar-label { font-size:10px; color:var(--text-light); }