/* 上传区域样式 */
.upload-section {
    margin-bottom: var(--spacing-xl);
}

.upload-container {
    max-width: 800px;
    margin: 0 auto;
}

.upload-area {
    background: var(--bg-primary);
    border: 3px dashed var(--border-color);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-xl);
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(0, 136, 204, 0.05), rgba(0, 136, 204, 0.1));
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(0, 136, 204, 0.1), rgba(0, 136, 204, 0.15));
    transform: scale(1.02);
}

.upload-area.uploading {
    pointer-events: none;
    opacity: 0.8;
    background: linear-gradient(135deg, rgba(0, 136, 204, 0.1), rgba(0, 136, 204, 0.15));
    border-color: var(--primary-color);
}

.upload-area.uploading .upload-icon i {
    color: var(--primary-color) !important;
    opacity: 1 !important;
}

.upload-icon {
    margin-bottom: var(--spacing-md);
}

.upload-icon i {
    font-size: 4rem;
    color: var(--primary-color);
    opacity: 0.7;
    transition: var(--transition);
}

.upload-area:hover .upload-icon i {
    opacity: 1;
    transform: scale(1.1);
}

.upload-text h2 {
    font-size: var(--font-size-2xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.upload-text p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.upload-text small {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    display: block;
}

/* 上传进度 */
.upload-progress {
    margin-top: var(--spacing-lg);
    background: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--bg-light);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--info-color));
    border-radius: 4px;
    transition: width 0.5s ease-out;
    width: 0%;
    position: relative;
    overflow: hidden;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* 进度条脉动效果 */
.progress-fill.uploading {
    animation: progressPulse 1.5s ease-in-out infinite;
}

@keyframes progressPulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.8;
    }
}

.progress-text {
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s ease;
}

.progress-text.uploading {
    color: var(--primary-color);
    font-weight: 600;
}

/* 文件预览 */
.file-preview {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: var(--bg-light);
    border-radius: var(--border-radius-lg);
}

.file-preview-item {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
}

.file-preview-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.file-preview-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
    color: var(--primary-color);
}

.file-preview-name {
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    word-break: break-all;
    margin-bottom: var(--spacing-xs);
}

.file-preview-size {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.file-preview-remove {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 20px;
    height: 20px;
    background: var(--danger-color);
    color: var(--text-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    transition: var(--transition);
}

.file-preview-remove:hover {
    background: #c82333;
    transform: scale(1.1);
}

/* 上传状态 */
.upload-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    font-size: var(--font-size-sm);
}

.upload-status.success {
    background: rgba(40, 167, 69, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(40, 167, 69, 0.2);
}

.upload-status.error {
    background: rgba(220, 53, 69, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(220, 53, 69, 0.2);
}

.upload-status.warning {
    background: rgba(255, 193, 7, 0.1);
    color: var(--warning-color);
    border: 1px solid rgba(255, 193, 7, 0.2);
}

.upload-status i {
    font-size: 1rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .upload-area {
        padding: var(--spacing-lg);
    }
    
    .upload-icon i {
        font-size: 3rem;
    }
    
    .upload-text h2 {
        font-size: var(--font-size-xl);
    }
    
    .upload-text p {
        font-size: var(--font-size-base);
    }
    
    .file-preview {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .upload-area {
        padding: var(--spacing-md);
    }
    
    .upload-icon i {
        font-size: 2.5rem;
    }
    
    .upload-text h2 {
        font-size: var(--font-size-lg);
    }
    
    .upload-text p {
        font-size: var(--font-size-sm);
    }
    
    .file-preview {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    }
    
    .file-preview-item {
        padding: var(--spacing-xs);
    }
    
    .file-preview-icon {
        font-size: 1.5rem;
    }
    
    .file-preview-name {
        font-size: 0.75rem;
    }
}

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

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* 旋转动画 - 修复转圈圈不动的问题 */
@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

.fa-spin {
    animation: spin 1s linear infinite;
}

.upload-area.pulse {
    animation: pulse 2s infinite;
}

.fade-in-up {
    animation: fadeInUp 0.5s ease-out;
}

/* 拖拽提示 */
.drag-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 136, 204, 0.1);
    backdrop-filter: blur(5px);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.drag-overlay.show {
    opacity: 1;
    visibility: visible;
}

.drag-overlay-content {
    background: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius-xl);
    text-align: center;
    box-shadow: var(--shadow-lg);
    border: 3px dashed var(--primary-color);
}

.drag-overlay-content i {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.drag-overlay-content h3 {
    font-size: var(--font-size-2xl);
    color: var(--text-primary);
    margin: 0;
}