body {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    min-height: 100vh;
    padding: 2rem 0;
}

.video-merger-tool {
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    padding: 2rem;
    margin-bottom: 2rem;
}

.video-merger-tool h2 {
    font-size: 1.75rem;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.75rem;
}

/* 上传区域样式 */
.upload-area {
    border: 2px dashed #e0e0e0;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    background: #f8f9fa;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 2rem;
}

.upload-area:hover {
    border-color: #4a90e2;
    background: #f0f7ff;
}

.upload-area.drag-over {
    border-color: #4a90e2;
    background: #f0f7ff;
}

.upload-hint {
    color: #6c757d;
}

.upload-hint i {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #adb5bd;
}

.upload-hint p {
    margin-bottom: 0.5rem;
}

.upload-hint .sub-hint {
    font-size: 0.875rem;
    color: #adb5bd;
}

/* 视频列表样式 */
.video-list-section {
    margin-bottom: 2rem;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.section-header h3 {
    font-size: 1.25rem;
    font-weight: 500;
    margin: 0;
    color: #2c3e50;
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.video-list {
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    overflow: hidden;
}

.video-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid #e0e0e0;
}

.video-item:last-child {
    border-bottom: none;
}

.thumbnail-container {
    width: 160px;
    height: 90px;
    background: #f0f0f0;
    border-radius: 4px;
    overflow: hidden;
    margin-right: 1rem;
    flex-shrink: 0;
}

.video-thumbnail {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-info {
    flex: 1;
    min-width: 0;
}

.video-name {
    font-weight: 500;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.video-duration, .video-resolution {
    font-size: 0.875rem;
    color: #6c757d;
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.empty-list-hint {
    text-align: center;
    padding: 2rem;
    color: #6c757d;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
}

.empty-list-hint i {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #adb5bd;
}

/* 预览区域样式 */
.preview-section {
    margin-top: 2rem;
}

.preview-section h3 {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.preview-container {
    margin-bottom: 1rem;
}

.preview-container video {
    width: 100%;
    border-radius: 8px;
}

.preview-hint {
    text-align: center;
    color: #6c757d;
    font-size: 0.875rem;
}

/* 处理遮罩层样式 */
.processing-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    z-index: 9999;
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
}

/* 圆形进度条容器 */
.circular-progress-container {
    position: relative;
    width: 150px;
    height: 150px;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 圆形进度条 */
.circular-progress {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: conic-gradient(#4a90e2 0%, transparent 0%);
    position: absolute;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.circular-progress::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    background-color: rgba(0, 0, 0, 0.8);
    border-radius: 50%;
}

/* 进度文本 */
.progress-text {
    position: relative;
    font-size: 2rem;
    font-weight: bold;
    color: white;
    z-index: 1;
}

/* 状态文本 */
.status-text {
    color: white;
    font-size: 1.2rem;
    text-align: center;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .action-buttons {
        width: 100%;
    }
    
    .action-buttons button {
        flex: 1;
    }
    
    .video-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .thumbnail-container {
        width: 100%;
        height: auto;
        aspect-ratio: 16/9;
        margin-right: 0;
        margin-bottom: 1rem;
    }
    
    .video-info {
        width: 100%;
        margin-bottom: 1rem;
    }
}

/* FFmpeg状态消息 */
.ffmpeg-status {
    background-color: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 1000;
    font-size: 14px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}