/* ===== 题库管理系统 - 全局样式 ===== */

:root {
  --primary: #10B981;
  --primary-dark: #059669;
  --primary-light: #D1FAE5;
  --bg: #F8FAFC;
  --sidebar-bg: #0F172A;
  --sidebar-hover: #1E293B;
  --card-bg: #FFFFFF;
  --text-primary: #1E293B;
  --text-secondary: #64748B;
  --text-light: #94A3B8;
  --border: #E2E8F0;
  --success: #22C55E;
  --warning: #F59E0B;
  --error: #EF4444;
  --info: #3B82F6;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
  --transition: 200ms ease-out;
  --sidebar-text: #E2E8F0;
  --sidebar-text-secondary: #94A3B8;
  --sidebar-border: #1E293B;
  --sidebar-width: 240px;
  --font-sans: 'Inter', system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html { font-size: 16px; line-height: 1.6; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

/* ===== 布局 ===== */
.app-layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  color: #E2E8F0;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition);
}

.sidebar-brand {
  padding: 24px 20px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-brand .brand-icon {
  width: 36px;
  height: 36px;
  background: var(--primary);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: #fff;
}

.sidebar-brand h1 {
  font-size: 16px;
  font-weight: 600;
  color: #F1F5F9;
  letter-spacing: -0.02em;
}

.sidebar-brand .brand-sub {
  font-size: 11px;
  color: var(--text-light);
  margin-top: 2px;
}

.sidebar-nav {
  flex: 1;
  padding: 12px 10px;
  overflow-y: auto;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: #94A3B8;
  font-size: 14px;
  cursor: pointer;
  transition: all var(--transition);
  margin-bottom: 2px;
  user-select: none;
}

.nav-item:hover {
  background: var(--sidebar-hover);
  color: #E2E8F0;
}

.nav-item.active {
  background: var(--primary);
  color: #fff;
  font-weight: 500;
}

.nav-item .nav-icon {
  width: 20px;
  text-align: center;
  font-size: 16px;
}

.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  transition: margin-left var(--transition);
}

.page-header {
  background: #fff;
  padding: 20px 32px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
}

.page-header h2 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
}

.page-body {
  padding: 24px 32px;
  max-width: 1400px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-dark); }

.btn-secondary {
  background: #fff;
  color: var(--text-primary);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--bg); }

.btn-danger {
  background: var(--error);
  color: #fff;
}
.btn-danger:hover { background: #DC2626; }

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}
.btn-ghost:hover {
  background: var(--bg);
  color: var(--text-primary);
  transform: none;
  box-shadow: none;
}

/* ===== 卡片 ===== */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 20px;
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.stat-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
}

.stat-icon.green { background: #D1FAE5; color: #059669; }
.stat-icon.blue { background: #DBEAFE; color: #2563EB; }
.stat-icon.amber { background: #FEF3C7; color: #D97706; }
.stat-icon.purple { background: #EDE9FE; color: #7C3AED; }

.stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.1;
}

.stat-label {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* ===== 表格 ===== */
.table-wrap {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 12px 16px;
  text-align: left;
  font-size: 14px;
  border-bottom: 1px solid var(--border);
}

th {
  background: var(--bg);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

tr:hover td { background: #F8FAFC; }

tr:last-child td { border-bottom: none; }

/* ===== 表单 ===== */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.form-control {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  color: var(--text-primary);
  background: #fff;
  transition: border-color var(--transition);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(16,185,129,0.1);
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748B' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}

textarea.form-control {
  resize: vertical;
  min-height: 80px;
}

/* ===== 模态框 ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15,23,42,0.5);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 150ms ease-out;
}

.modal {
  background: #fff;
  border-radius: var(--radius);
  width: 90%;
  max-width: 560px;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: slideUp 200ms ease-out;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 17px;
  font-weight: 600;
}

.modal-body { padding: 24px; }

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

/* ===== 徽章 ===== */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
}

.badge-green { background: #D1FAE5; color: #065F46; }
.badge-blue { background: #DBEAFE; color: #1E40AF; }
.badge-amber { background: #FEF3C7; color: #92400E; }
.badge-red { background: #FEE2E2; color: #991B1B; }
.badge-purple { background: #EDE9FE; color: #5B21B6; }
.badge-gray { background: #F1F5F9; color: #475569; }

/* ===== 搜索栏 ===== */
.toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.search-box {
  position: relative;
  flex: 1;
  min-width: 200px;
}

.search-box input {
  width: 100%;
  padding: 8px 12px 8px 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(16,185,129,0.1);
}

.search-box::before {
  content: "🔍";
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 14px;
}

/* ===== 进度条 ===== */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 4px;
  transition: width 0.3s ease;
}

/* ===== 分页 ===== */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  margin-top: 20px;
}

.pagination .page-btn {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #fff;
  cursor: pointer;
  font-size: 13px;
  transition: all var(--transition);
}

.pagination .page-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.pagination .page-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ===== Toast ===== */
.toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 14px;
  box-shadow: var(--shadow-md);
  animation: slideIn 200ms ease-out;
}

.toast-success { background: var(--success); }
.toast-error { background: var(--error); }
.toast-warning { background: var(--warning); }
.toast-info { background: var(--info); }

/* ===== 考试界面 ===== */
.exam-container {
  max-width: 800px;
  margin: 0 auto;
}

.exam-timer {
  position: sticky;
  top: 73px;
  background: #fff;
  padding: 12px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  z-index: 40;
}

.timer-display {
  font-size: 24px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text-primary);
}

.timer-display.warning { color: var(--warning); }
.timer-display.danger { color: var(--error); }

.question-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}

.question-card .q-number {
  font-size: 18px;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 8px;
}

.question-card .q-content {
  font-size: 23px;
  line-height: 1.7;
  margin-bottom: 12px;
}

.question-card .q-image {
  margin-bottom: 16px;
  text-align: center;
}

.question-card .q-image img {
  max-width: 100%;
  max-height: 300px;
  border-radius: 8px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: transform 0.2s;
}

.question-card .q-image img:hover {
  transform: scale(1.02);
}

.question-card .q-image img.fullscreen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  object-fit: contain;
  max-height: 100vh;
  max-width: 100vw;
  z-index: 10000;
  background: rgba(0,0,0,0.85);
  border: none;
  border-radius: 0;
  cursor: zoom-out;
}

.image-upload-area {
  border: 2px dashed var(--border);
  border-radius: 8px;
  padding: 16px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: 12px;
  background: var(--bg);
}

.image-upload-area:hover {
  border-color: var(--primary);
  background: var(--primary-light);
}

.image-upload-area.uploading {
  opacity: 0.6;
  cursor: wait;
}

.image-upload-area.has-image {
  border-style: solid;
  border-color: var(--primary);
  padding: 8px;
}

.image-upload-area .preview-img {
  max-width: 100%;
  max-height: 200px;
  border-radius: 6px;
}

.image-upload-area .upload-hint {
  color: var(--text-secondary);
  font-size: 13px;
}

.image-upload-area .remove-btn {
  margin-top: 8px;
  color: var(--error);
  cursor: pointer;
  font-size: 13px;
}

.image-upload-area .remove-btn:hover {
  text-decoration: underline;
}

.option-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.option-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 21px;
}

.option-item:hover {
  border-color: var(--primary);
  background: #F0FDF4;
}

.option-item.selected {
  border-color: var(--primary);
  background: var(--primary-light);
}

.option-item.correct {
  border-color: var(--success);
  background: #F0FDF4;
}

.option-item.wrong {
  border-color: var(--error);
  background: #FEF2F2;
}

.option-label {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 600;
  flex-shrink: 0;
}

.option-item.selected .option-label {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
}

/* ===== 移动端汉堡菜单 ===== */
.mobile-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border: none;
  background: transparent;
  font-size: 22px;
  cursor: pointer;
  color: var(--text-primary);
}

.sidebar-close {
  display: none;
  position: absolute;
  top: 16px;
  right: 16px;
  width: 32px;
  height: 32px;
  align-items: center;
  justify-content: center;
  border: none;
  background: rgba(255,255,255,0.1);
  border-radius: 8px;
  color: #94A3B8;
  font-size: 18px;
  cursor: pointer;
}

/* ===== 空状态 ===== */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-secondary);
}

.empty-state .empty-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.empty-state h3 {
  font-size: 18px;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.empty-state p {
  font-size: 14px;
  max-width: 400px;
  margin: 0 auto;
}

/* ===== 动画 ===== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(100px); }
  to { opacity: 1; transform: translateX(0); }
}

.fade-enter-active { animation: fadeIn 150ms ease-out; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .main-content {
    margin-left: 0;
  }

  .mobile-toggle {
    display: flex;
  }

  .sidebar-close {
    display: flex;
  }

  .page-body {
    padding: 16px;
  }

  .page-header {
    padding: 16px;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .toolbar {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (max-width: 1024px) and (min-width: 769px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== 登录页面 ===== */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #0F172A 100%);
  padding: 20px;
}

.login-card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 40px;
  width: 100%;
  max-width: 420px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.login-brand {
  text-align: center;
}

.login-brand h1 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 4px;
}

.login-card .form-group {
  margin-bottom: 16px;
}

.login-card .form-control {
  padding: 10px 14px;
  font-size: 14px;
}

.login-card a {
  text-decoration: none;
}

.login-card a:hover {
  text-decoration: underline;
}