/* ===================================================================
   人工智能训练师 在线考试系统 - 全局现代化设计系统
   支持 PC 宽屏、平板、移动端手机全端自适应
   =================================================================== */

:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;
  --primary-border: #c7d2fe;
  --secondary: #0ea5e9;
  --success: #10b981;
  --success-light: #ecfdf5;
  --danger: #ef4444;
  --danger-light: #fef2f2;
  --warning: #f59e0b;
  --warning-light: #fffbeb;
  --dark: #0f172a;
  --gray-900: #0f172a;
  --gray-800: #1e293b;
  --gray-700: #334155;
  --gray-600: #475569;
  --gray-500: #64748b;
  --gray-400: #94a3b8;
  --gray-300: #cbd5e1;
  --gray-200: #e2e8f0;
  --gray-100: #f1f5f9;
  --gray-50: #f8fafc;
  --white: #ffffff;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--gray-50);
  color: var(--gray-800);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* 容器布局 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 顶部导航栏 */
.header-bar {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.3);
}

.logo-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--gray-900);
}

.logo-subtitle {
  font-size: 12px;
  color: var(--gray-500);
  display: block;
  line-height: 1.2;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* 按钮通用体系 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  line-height: 1.5;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--white);
}
.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.btn-success {
  background-color: var(--success);
  color: var(--white);
}
.btn-success:hover {
  background-color: #059669;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
}

.btn-danger {
  background-color: var(--danger);
  color: var(--white);
}
.btn-danger:hover {
  background-color: #dc2626;
}

.btn-secondary {
  background-color: var(--white);
  color: var(--gray-700);
  border-color: var(--gray-300);
}
.btn-secondary:hover {
  background-color: var(--gray-100);
  border-color: var(--gray-400);
}

.btn-sm {
  padding: 5px 12px;
  font-size: 13px;
}

.btn-lg {
  padding: 12px 28px;
  font-size: 16px;
  border-radius: var(--radius-lg);
}

/* 徽章 */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.5;
}

.badge-primary {
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid var(--primary-border);
}

.badge-success {
  background-color: var(--success-light);
  color: var(--success);
  border: 1px solid #a7f3d0;
}

.badge-warning {
  background-color: var(--warning-light);
  color: #b45309;
  border: 1px solid #fde68a;
}

.badge-danger {
  background-color: var(--danger-light);
  color: var(--danger);
  border: 1px solid #fecaca;
}

.badge-gray {
  background-color: var(--gray-100);
  color: var(--gray-600);
  border: 1px solid var(--gray-300);
}

/* 卡片容器 */
.card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease;
}

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

/* 登录/入场考场首页卡片 */
.welcome-hero {
  min-height: calc(100vh - 120px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 30px 15px;
}

.login-card {
  width: 100%;
  max-width: 480px;
  background: var(--white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--gray-200);
  overflow: hidden;
}

.login-header {
  background: linear-gradient(135deg, #4f46e5 0%, #3b82f6 100%);
  color: white;
  padding: 36px 32px 30px;
  text-align: center;
  position: relative;
}

.login-header h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

.login-header p {
  font-size: 14px;
  opacity: 0.9;
}

.login-body {
  padding: 32px;
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 6px;
}

.form-input, .form-select {
  width: 100%;
  padding: 11px 14px;
  font-size: 15px;
  border: 1.5px solid var(--gray-300);
  border-radius: var(--radius-md);
  color: var(--gray-900);
  background: var(--white);
  transition: all 0.2s ease;
  outline: none;
}

.form-input:focus, .form-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.form-help {
  font-size: 12px;
  color: var(--gray-500);
  margin-top: 5px;
}

/* 考试进行中界面布局 */
.exam-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 24px;
  padding: 24px 0 60px;
}

@media (max-width: 992px) {
  .exam-layout {
    grid-template-columns: 1fr;
  }
}

/* 考试顶栏信息条 */
.exam-bar {
  background: var(--white);
  border-bottom: 2px solid var(--primary-light);
  padding: 12px 0;
  position: sticky;
  top: 0;
  z-index: 90;
  box-shadow: var(--shadow-sm);
}

.exam-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.exam-meta-info {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}

.meta-item {
  font-size: 14px;
  color: var(--gray-600);
}

.meta-item strong {
  color: var(--gray-900);
  font-weight: 600;
}

/* 倒计时钟表 */
.timer-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--primary-light);
  color: var(--primary);
  border: 1.5px solid var(--primary-border);
  padding: 6px 14px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 16px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.5px;
}

.timer-pill.warning {
  background: var(--warning-light);
  color: #b45309;
  border-color: #fde68a;
  animation: pulse 1s infinite;
}

.timer-pill.urgent {
  background: var(--danger-light);
  color: var(--danger);
  border-color: #fecaca;
  animation: blink 0.8s infinite;
}

@keyframes blink {
  50% { opacity: 0.6; }
}

/* 题目卡片列表 */
.question-item {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s, box-shadow 0.2s;
  scroll-margin-top: 140px;
}

.question-item:hover {
  border-color: var(--gray-300);
}

.question-item.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.1);
}

.question-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 18px;
}

.question-num {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-light);
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.question-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--gray-900);
  line-height: 1.6;
  flex: 1;
}

/* 选项列表 */
.options-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.option-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 13px 18px;
  background: var(--white);
  border: 1.5px solid var(--gray-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
  text-align: left;
}

.option-btn:hover {
  background: var(--gray-50);
  border-color: var(--primary-border);
}

.option-btn.selected {
  background: var(--primary-light);
  border-color: var(--primary);
  box-shadow: 0 0 0 1px var(--primary);
}

.option-indicator {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid var(--gray-300);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  color: var(--gray-600);
  background: var(--white);
  flex-shrink: 0;
  transition: all 0.15s;
}

.option-btn.checkbox .option-indicator {
  border-radius: 6px;
}

.option-btn.selected .option-indicator {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.option-text {
  font-size: 15px;
  color: var(--gray-800);
  flex: 1;
}

.option-btn.selected .option-text {
  color: var(--primary);
  font-weight: 500;
}

/* 侧边答题卡面板 */
.exam-sidebar {
  position: sticky;
  top: 90px;
  align-self: start;
}

.answer-sheet-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.sheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--gray-200);
}

.sheet-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--gray-900);
}

.sheet-legend {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12px;
  color: var(--gray-600);
  margin-bottom: 14px;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  margin-right: 4px;
}
.legend-dot.answered { background: var(--success); }
.legend-dot.unanswered { background: var(--gray-200); border: 1px solid var(--gray-300); }

.sheet-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin-bottom: 20px;
}

.sheet-num-btn {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  background: var(--gray-100);
  border: 1px solid var(--gray-300);
  color: var(--gray-700);
  cursor: pointer;
  transition: all 0.15s ease;
}

.sheet-num-btn:hover {
  background: var(--gray-200);
}

.sheet-num-btn.answered {
  background: var(--success-light);
  border-color: #a7f3d0;
  color: #065f46;
  font-weight: 700;
}

.sheet-num-btn.active {
  box-shadow: 0 0 0 2px var(--primary);
  border-color: var(--primary);
}

.sheet-progress-info {
  font-size: 13px;
  color: var(--gray-600);
  margin-bottom: 14px;
  display: flex;
  justify-content: space-between;
}

.progress-bar-bg {
  height: 6px;
  background: var(--gray-200);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 16px;
}

.progress-bar-fill {
  height: 100%;
  background: var(--success);
  transition: width 0.3s ease;
}

/* 考试出分结果页面（学生端） */
.result-container {
  max-width: 680px;
  margin: 40px auto;
  text-align: center;
}

.result-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: 40px 32px;
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--gray-200);
}

.result-badge-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 38px;
}

.result-badge-icon.pass {
  background: var(--success-light);
  color: var(--success);
  border: 3px solid #a7f3d0;
}

.result-badge-icon.fail {
  background: var(--danger-light);
  color: var(--danger);
  border: 3px solid #fecaca;
}

.result-score-title {
  font-size: 15px;
  color: var(--gray-500);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.result-score-number {
  font-size: 64px;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 8px;
  color: var(--gray-900);
}

.result-score-number span {
  font-size: 24px;
  color: var(--gray-500);
  font-weight: 500;
}

.result-status-tag {
  display: inline-block;
  padding: 6px 20px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 28px;
}

.result-details-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  text-align: left;
  background: var(--gray-50);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 28px;
  border: 1px solid var(--gray-200);
}

.detail-block label {
  font-size: 12px;
  color: var(--gray-500);
  display: block;
}

.detail-block value {
  font-size: 15px;
  font-weight: 600;
  color: var(--gray-800);
}

.privacy-notice-box {
  background: var(--warning-light);
  border: 1px solid #fde68a;
  border-radius: var(--radius-md);
  padding: 14px 18px;
  color: #92400e;
  font-size: 13px;
  line-height: 1.6;
  text-align: left;
  margin-bottom: 24px;
}

/* ===================================================================
   后台管理端（ADMIN）专属样式
   =================================================================== */

.admin-nav {
  display: flex;
  gap: 10px;
  border-bottom: 1px solid var(--gray-200);
  margin-bottom: 24px;
}

.admin-nav-item {
  padding: 12px 18px;
  font-size: 15px;
  font-weight: 600;
  color: var(--gray-600);
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.admin-nav-item:hover {
  color: var(--primary);
}

.admin-nav-item.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* 统计仪表盘数字卡片 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin-bottom: 28px;
}

.stat-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 20px;
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.stat-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-500);
  margin-bottom: 6px;
}

.stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--gray-900);
}

.stat-sub {
  font-size: 12px;
  color: var(--gray-400);
  margin-top: 4px;
}

/* 表格样式 */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  background: var(--white);
}

.custom-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  text-align: left;
}

.custom-table th {
  background: var(--gray-50);
  color: var(--gray-700);
  font-weight: 600;
  padding: 12px 16px;
  border-bottom: 1px solid var(--gray-200);
}

.custom-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--gray-100);
  color: var(--gray-800);
}

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

.custom-table tr:hover td {
  background-color: var(--gray-50);
}

/* 模态框 / 弹窗 */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  max-width: 800px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  transform: translateY(10px);
  transition: transform 0.2s ease;
}

.modal-overlay.open .modal-card {
  transform: translateY(0);
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--gray-900);
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--gray-200);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  background: var(--gray-50);
}

/* 答题卡详情预览卡片 (后台查看) */
.student-answer-item {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 18px;
  margin-bottom: 14px;
  background: var(--white);
}

.student-answer-item.correct {
  border-left: 4px solid var(--success);
}

.student-answer-item.wrong {
  border-left: 4px solid var(--danger);
}

.student-answer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.ans-compare-box {
  display: flex;
  gap: 20px;
  margin: 12px 0;
  padding: 10px 14px;
  background: var(--gray-50);
  border-radius: var(--radius-sm);
  font-size: 14px;
}

.analysis-box {
  margin-top: 10px;
  padding: 10px 14px;
  background: #f8fafc;
  border-left: 3px solid var(--primary);
  border-radius: 4px;
  font-size: 13px;
  color: var(--gray-700);
  line-height: 1.5;
}

/* 二维码容器 */
#qrcode-container {
  display: flex;
  justify-content: center;
  padding: 16px;
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-200);
  margin: 16px 0;
}

/* Toast 提示浮窗 */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  background: var(--gray-900);
  color: white;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 14px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 10px;
  animation: slideIn 0.25s ease forwards;
}

.toast.success { background: #065f46; border-left: 4px solid var(--success); }
.toast.danger { background: #991b1b; border-left: 4px solid var(--danger); }
.toast.info { background: #1e293b; border-left: 4px solid var(--secondary); }

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

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}