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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 15px;
}

/* 头部样式 */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.header h1 {
    color: #333;
    margin-bottom: 25px;
    font-size: 24px;
    font-weight: 600;
    text-align: center;
    letter-spacing: 1px;
}

/* 主要控制按钮 */
.main-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin-bottom: 25px;
}

.control-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 16px 12px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.control-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
}

.control-btn:active {
    transform: translateY(0);
}

.control-btn .btn-icon {
    font-size: 20px;
}

.control-btn .btn-text {
    font-size: 13px;
}

.control-btn.primary {
    background: linear-gradient(135deg, #4CAF50, #45a049);
    color: white;
}

.control-btn.secondary {
    background: linear-gradient(135deg, #FF9800, #f57c00);
    color: white;
}

.control-btn.accent {
    background: linear-gradient(135deg, #E91E63, #c2185b);
    color: white;
}

.control-btn.info {
    background: linear-gradient(135deg, #2196F3, #1976D2);
    color: white;
}

/* 进度区域 */
.progress-section {
    margin-bottom: 20px;
}

.mode-info {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
    flex-wrap: wrap;
    justify-content: space-between;
}

.mode-badge {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.day-info {
    font-size: 14px;
    color: #666;
    font-weight: 500;
    flex: 1;
}

/* 每日目标设置 */
.daily-goal-setting {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.8);
    padding: 8px 12px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    border: 1px solid #e0e0e0;
}

.goal-label {
    font-size: 12px;
    font-weight: 500;
    color: #666;
}

.goal-input {
    width: 60px;
    padding: 6px 8px;
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 500;
    text-align: center;
}

.goal-btn {
    padding: 6px 12px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.goal-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.4);
}

.progress-bar {
    width: 100%;
    height: 12px;
    background: #f0f0f0;
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 12px;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #4CAF50, #45a049);
    border-radius: 6px;
    transition: width 0.6s ease;
    box-shadow: 0 0 10px rgba(76, 175, 80, 0.5);
}

.today-progress {
    font-size: 14px;
    color: #666;
    text-align: center;
}

.learned-count {
    color: #4CAF50;
    font-weight: 600;
    font-size: 16px;
}

/* 日期导航 */
.day-navigation {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.nav-btn {
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.8);
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    color: #666;
    cursor: pointer;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: #f8f9fa;
    border-color: #667eea;
    color: #667eea;
}

/* 内容区域 */
.content-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 25px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.section-header {
    text-align: center;
    margin-bottom: 25px;
}

.section-title {
    font-size: 20px;
    font-weight: 600;
    color: #333;
    margin-bottom: 6px;
}

.section-title.review {
    color: #E91E63;
}

.section-subtitle {
    font-size: 14px;
    color: #999;
}

/* 单词容器 */
.word-container {
    display: grid;
    gap: 16px;
}

/* 单词卡片 */
.word-card {
    background: white;
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 1px solid #f0f0f0;
}

.word-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.word-card h2 {
    font-size: 22px;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
    letter-spacing: 1px;
}

.word-card .syllable {
    font-size: 14px;
    color: #999;
    margin-bottom: 12px;
    font-style: italic;
}

.word-card .meaning {
    font-size: 16px;
    color: #666;
    margin-bottom: 20px;
    line-height: 1.5;
}

.word-card .meaning.hidden {
    display: none;
}

/* 卡片操作按钮 */
.word-card .actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.word-card button {
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.word-card button.play {
    background: linear-gradient(135deg, #2196F3, #1976D2);
    color: white;
}

.word-card button.learned-btn {
    background: linear-gradient(135deg, #4CAF50, #45a049);
    color: white;
}

.word-card button.unlearned-btn {
    background: linear-gradient(135deg, #FF9800, #f57c00);
    color: white;
}

.word-card button:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* 复习信息 */
.today-review-info {
    text-align: center;
    margin-bottom: 20px;
    padding: 15px;
    background: rgba(233, 30, 99, 0.1);
    border-radius: 12px;
    border: 1px solid rgba(233, 30, 99, 0.2);
}

.review-count {
    color: #E91E63;
    font-weight: 600;
    font-size: 18px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 15px 10px;
    }
    
    .header {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 20px;
        margin-bottom: 20px;
    }
    
    .main-controls {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }
    
    .control-btn {
        padding: 14px 10px;
    }
    
    .control-btn .btn-text {
        font-size: 12px;
    }
    
    .mode-info {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .daily-goal-setting {
        width: 100%;
        justify-content: flex-end;
    }
    
    .content-section {
        padding: 20px;
    }
    
    .word-card {
        padding: 16px;
    }
    
    .word-card h2 {
        font-size: 20px;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 18px;
    }
    
    .main-controls {
        grid-template-columns: 1fr;
    }
    
    .control-btn {
        flex-direction: row;
        justify-content: center;
        padding: 12px 15px;
    }
    
    .control-btn .btn-icon {
        font-size: 16px;
    }
    
    .daily-goal-setting {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
        padding: 12px;
    }
    
    .goal-input {
        width: 100%;
    }
    
    .goal-btn {
        width: 100%;
    }
    
    .word-card h2 {
        font-size: 18px;
    }
    
    .word-card button {
        padding: 10px 16px;
        font-size: 13px;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.word-card {
    animation: fadeIn 0.5s ease-out;
}

/* 加载动画 */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px;
    color: #666;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #999;
}

.empty-state .icon {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state .message {
    font-size: 16px;
    line-height: 1.5;
}