/* 單字卡學習系統 - 前台樣式 */

.fls-frontend {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

/* 統計面板 */
.fls-frontend-stats {
    display: flex;
    justify-content: space-around;
    background: #f8f9fa;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.fls-stat-item {
    text-align: center;
    flex: 1;
}

.fls-stat-number {
    display: block;
    font-size: 2.5em;
    font-weight: bold;
    color: #007cba;
    margin-bottom: 5px;
}

.fls-stat-label {
    display: block;
    font-size: 0.9em;
    color: #666;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* 學習控制面板 */
.fls-learning-controls {
    text-align: center;
    margin-bottom: 30px;
}

/* 按鈕樣式 */
.fls-btn {
    display: inline-block;
    padding: 12px 24px;
    margin: 5px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
}

.fls-btn-primary {
    background-color: #007cba;
    color: white;
}

.fls-btn-primary:hover {
    background-color: #005a87;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,124,186,0.3);
}

.fls-btn-secondary {
    background-color: #6c757d;
    color: white;
}

.fls-btn-secondary:hover {
    background-color: #545b62;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(108,117,125,0.3);
}

.fls-btn-audio {
    background-color: #28a745;
    color: white;
}

.fls-btn-audio:hover {
    background-color: #1e7e34;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(40,167,69,0.3);
}

/* 學習區域 */
.fls-learning-area {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    border: 1px solid #e9ecef;
}

/* 進度條 */
.fls-progress-bar {
    background-color: #e9ecef;
    border-radius: 10px;
    height: 8px;
    margin-bottom: 30px;
    position: relative;
    overflow: hidden;
}

.fls-progress-fill {
    background: linear-gradient(90deg, #007cba, #00a0d2);
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
    width: 0%;
}

.fls-progress-text {
    position: absolute;
    top: -25px;
    right: 0;
    font-size: 14px;
    color: #666;
    font-weight: 500;
}

/* 單字卡樣式 */
.fls-flashcard {
    min-height: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
    position: relative;
}

.fls-flashcard-front h2,
.fls-flashcard-back h2 {
    font-size: 3em;
    margin-bottom: 30px;
    color: #007cba;
    font-weight: 300;
    letter-spacing: 1px;
}

.fls-flashcard-actions {
    margin-top: 30px;
}

.fls-translation {
    margin: 20px 0;
}

.fls-translation p {
    font-size: 1.5em;
    color: #333;
    margin: 10px 0;
    line-height: 1.4;
}

.fls-example {
    background-color: #f8f9fa;
    border-left: 4px solid #007cba;
    padding: 15px 20px;
    margin: 20px 0;
    border-radius: 0 6px 6px 0;
}

.fls-example strong {
    color: #007cba;
    font-size: 0.9em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.fls-example p {
    font-size: 1.1em;
    color: #555;
    margin: 8px 0 0 0;
    font-style: italic;
}

/* 品質評分區域 */
.fls-quality-section {
    margin-top: 40px;
}

.fls-quality-title {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
}

.fls-quality-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
    margin-top: 15px;
}

.fls-quality-btn {
    padding: 10px 15px;
    font-size: 14px;
    border-radius: 6px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.fls-quality-0,
.fls-quality-1 {
    background-color: #dc3545;
    color: white;
}

.fls-quality-0:hover,
.fls-quality-1:hover {
    background-color: #c82333;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(220,53,69,0.3);
}

.fls-quality-2 {
    background-color: #fd7e14;
    color: white;
}

.fls-quality-2:hover {
    background-color: #e8650e;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(253,126,20,0.3);
}

.fls-quality-3 {
    background-color: #ffc107;
    color: #212529;
}

.fls-quality-3:hover {
    background-color: #e0a800;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(255,193,7,0.3);
}

.fls-quality-4,
.fls-quality-5 {
    background-color: #28a745;
    color: white;
}

.fls-quality-4:hover,
.fls-quality-5:hover {
    background-color: #1e7e34;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(40,167,69,0.3);
}

/* 學習底部 */
.fls-learning-footer {
    margin-top: 30px;
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #e9ecef;
}

/* 載入和無卡片狀態 */
.fls-loading,
.fls-no-cards {
    text-align: center;
    padding: 60px 20px;
}

.fls-loading {
    font-size: 1.2em;
    color: #666;
}

.fls-loading:after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #007cba;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 10px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.fls-no-cards h3 {
    color: #28a745;
    font-size: 2em;
    margin-bottom: 15px;
}

.fls-no-cards p {
    font-size: 1.1em;
    color: #666;
    margin-bottom: 25px;
}

/* 消息提示 */
.fls-message {
    margin: 20px 0;
    padding: 12px 16px;
    border-radius: 6px;
    border-left: 4px solid;
}

.fls-message.success {
    background-color: #d4edda;
    border-color: #28a745;
    color: #155724;
}

.fls-message.error {
    background-color: #f8d7da;
    border-color: #dc3545;
    color: #721c24;
}

/* 響應式設計 */
@media (max-width: 768px) {
    .fls-frontend {
        padding: 15px;
    }
    
    .fls-frontend-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .fls-stat-item {
        padding: 10px 0;
        border-bottom: 1px solid #dee2e6;
    }
    
    .fls-stat-item:last-child {
        border-bottom: none;
    }
    
    .fls-flashcard-front h2,
    .fls-flashcard-back h2 {
        font-size: 2.2em;
    }
    
    .fls-quality-buttons {
        grid-template-columns: 1fr;
    }
    
    .fls-btn {
        width: 100%;
        margin: 5px 0;
    }
    
    .fls-learning-area {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .fls-flashcard-front h2,
    .fls-flashcard-back h2 {
        font-size: 1.8em;
    }
    
    .fls-translation p {
        font-size: 1.2em;
    }
    
    .fls-example p {
        font-size: 1em;
    }
}