/* 全局样式 */
:root {
  --primary-color: #3498db;
  --primary-dark: #2980b9;
  --secondary-color: #f39c12;
  --secondary-dark: #e67e22;
  --danger-color: #e74c3c;
  --danger-dark: #c0392b;
  --success-color: #2ecc71;
  --success-dark: #27ae60;
  --text-color: #333;
  --light-text: #666;
  --border-color: #ddd;
  --bg-color: #f8f9fa;
  --white: #fff;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: #f5f5f5;
  padding: 20px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  background-color: var(--white);
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  padding: 30px;
}

header {
  text-align: center;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

header h1 {
  color: var(--primary-color);
  margin-bottom: 10px;
}

header p {
  color: var(--light-text);
}

/* 按钮样式 */
button {
  cursor: pointer;
  border: none;
  border-radius: 4px;
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 500;
  transition: background-color 0.2s, transform 0.1s;
}

button:active {
  transform: translateY(1px);
}

.primary-button {
  background-color: var(--primary-color);
  color: var(--white);
}

.primary-button:hover {
  background-color: var(--primary-dark);
}

.secondary-button {
  background-color: var(--secondary-color);
  color: var(--white);
}

.secondary-button:hover {
  background-color: var(--secondary-dark);
}

.danger-button {
  background-color: var(--danger-color);
  color: var(--white);
}

.danger-button:hover {
  background-color: var(--danger-dark);
}

.danger-button:disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

.icon-button {
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  color: var(--light-text);
  transition: color 0.2s;
}

.icon-button:hover {
  color: var(--text-color);
}

/* 用户信息 */
.user-info {
  display: flex;
  align-items: center;
  margin-bottom: 24px;
  padding: 16px;
  background-color: var(--bg-color);
  border-radius: 8px;
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--primary-color);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  margin-right: 12px;
}

.user-details {
  flex: 1;
}

.user-name {
  font-weight: 600;
  font-size: 18px;
}

.user-stats {
  font-size: 14px;
  color: var(--light-text);
}

.logout-button {
  background: none;
  border: none;
  color: var(--light-text);
  cursor: pointer;
  padding: 4px 8px;
  font-size: 14px;
}

.logout-button:hover {
  color: var(--text-color);
  text-decoration: underline;
}

/* 难度选择器 */
.level-selector {
  display: flex;
  justify-content: center;
  margin-bottom: 30px;
  gap: 10px;
}

.level-button {
  background-color: var(--bg-color);
  color: var(--text-color);
  border: 1px solid var(--border-color);
  padding: 8px 16px;
  border-radius: 20px;
}

.level-button:hover {
  background-color: #e9ecef;
}

.level-button.active {
  background-color: var(--primary-color);
  color: var(--white);
  border-color: var(--primary-color);
}

/* 题目区域 */
.challenge-container {
  margin-bottom: 30px;
  padding: 20px;
  background-color: var(--bg-color);
  border-radius: 8px;
}

.challenge-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.challenge-description {
  margin-bottom: 20px;
  line-height: 1.8;
}

.challenge-section {
  margin-top: 20px;
}

.toggle-button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  background-color: var(--white);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  cursor: pointer;
  margin-bottom: 16px;
}

.toggle-button:hover {
  background-color: #e9ecef;
}

.example-content {
  padding: 16px;
  background-color: var(--white);
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

.example-content pre {
  background-color: #f5f5f5;
  padding: 10px;
  border-radius: 4px;
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
}

/* 编辑区域 */
.editor-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.editor-section, .preview-section {
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
}

.editor-section h3, .preview-section h3 {
  padding: 10px 15px;
  background-color: var(--bg-color);
  margin: 0;
  border-bottom: 1px solid var(--border-color);
}

#editor {
  width: 100%;
  height: 300px;
  padding: 15px;
  border: none;
  resize: none;
  font-family: 'Courier New', Courier, monospace;
  font-size: 14px;
  line-height: 1.5;
}

#editor:focus {
  outline: none;
}

.markdown-preview {
  height: 300px;
  padding: 15px;
  overflow-y: auto;
  background-color: var(--white);
}

/* 按钮组 */
.button-group {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-bottom: 30px;
}

/* 提示容器 */
.hint-container {
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  margin: 20px 0;
  overflow: hidden;
}

.hint-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #e9ecef;
  padding: 10px 15px;
}

.hint-header h4 {
  margin: 0;
  display: flex;
  align-items: center;
}

.hint-header h4 i {
  margin-right: 8px;
  color: var(--secondary-color);
}

.close-button {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--light-text);
  padding: 4px;
}

.close-button:hover {
  color: var(--text-color);
}

.hint-content {
  padding: 15px;
}

/* 验证结果 */
.validation-result {
  margin: 20px 0;
  padding: 15px;
  border-radius: 8px;
}

.validation-result.success {
  background-color: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

.validation-result.error {
  background-color: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

/* 记录部分 */
.records-section {
  margin-top: 40px;
}

.records-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.records-actions {
  display: flex;
  gap: 10px;
}

.records-actions select {
  padding: 8px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  background-color: var(--white);
}

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

.records-table th,
.records-table td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.records-table th {
  background-color: var(--bg-color);
  font-weight: 600;
}

.records-table tr:hover {
  background-color: #f5f5f5;
}

.no-records {
  text-align: center;
  padding: 30px;
  color: var(--light-text);
  background-color: var(--bg-color);
  border-radius: 8px;
}

.status-badge {
  display: inline-block;
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
}

.status-badge.success {
  background-color: #d4edda;
  color: #155724;
}

.status-badge.error {
  background-color: #f8d7da;
  color: #721c24;
}

/* 模态框 */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  justify-content: center;
  align-items: center;
}

.modal-content {
  background-color: var(--white);
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  padding: 24px;
  width: 90%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.record-details {
  max-width: 800px;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.modal-footer {
  margin-top: 24px;
  text-align: right;
}

.input-group {
  margin-bottom: 16px;
}

.input-group input {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 16px;
}

.error-message {
  color: var(--danger-color);
  font-size: 14px;
  margin-top: 4px;
}

/* 记录详情 */
.record-info {
  background-color: var(--bg-color);
  border-radius: 4px;
  padding: 16px;
  margin-bottom: 24px;
}

.info-item {
  margin-bottom: 8px;
}

.info-item .label {
  font-weight: 600;
  margin-right: 8px;
}

.content-section {
  margin-bottom: 24px;
}

.content-section h4 {
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.preview-container {
  margin-top: 16px;
  padding: 16px;
  background-color: var(--bg-color);
  border-radius: 4px;
}

/* 通知 */
.notification {
  position: fixed;
  top: 24px;
  right: 24px;
  padding: 16px;
  border-radius: 4px;
  background-color: var(--white);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  z-index: 1100;
  transform: translateX(120%);
  transition: transform 0.3s ease;
}

.notification.show {
  transform: translateX(0);
}

.notification.success {
  border-left: 4px solid var(--success-color);
}

.notification.error {
  border-left: 4px solid var(--danger-color);
}

.notification-content {
  display: flex;
  align-items: center;
}

.notification-content i {
  margin-right: 12px;
  font-size: 20px;
}

.notification-content i.fa-check-circle {
  color: var(--success-color);
}

.notification-content i.fa-exclamation-circle {
  color: var(--danger-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
  .editor-container {
    grid-template-columns: 1fr;
  }
  
  .challenge-header {
    flex-direction: column;
    gap: 10px;
  }
  
  .records-header {
    flex-direction: column;
    gap: 10px;
  }
  
  .records-actions {
    width: 100%;
  }
  
  .records-table {
    display: block;
    overflow-x: auto;
  }
}