/* 文件上传组件样式系统 - File Upload Component System */
/* 基于 design-tokens.css 的变量系统构建 */

/* ===== 文件上传区域基础样式 - Base Upload Section ===== */
.file-upload-section {
    background: var(--upload-bg);
    border: var(--border-width-dashed) var(--border-style-dashed) var(--upload-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-4xl);
    text-align: center;
    margin-bottom: var(--section-margin);
    transition: all var(--transition-normal);
    position: relative;
    cursor: pointer;
    min-height: 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* ===== 悬停状态 - Hover States ===== */
.file-upload-section:hover {
    border-color: var(--upload-border-hover);
    background: var(--color-primary-lighter);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===== 拖拽状态 - Drag States ===== */
.file-upload-section.dragover {
    border-color: var(--color-primary-dark);
    background: var(--color-primary-light);
    transform: scale(1.02);
    box-shadow: var(--shadow-lg);
    animation: upload-pulse 1.5s infinite;
}

/* ===== 上传图标 - Upload Icon ===== */
.upload-icon {
    font-size: 4em;
    color: var(--upload-text-muted);
    margin-bottom: var(--spacing-xl);
    transition: all var(--transition-normal);
}

.file-upload-section:hover .upload-icon {
    color: var(--color-primary);
    transform: scale(1.1);
}

.file-upload-section.dragover .upload-icon {
    color: var(--color-primary-dark);
    transform: scale(1.2);
}

/* ===== 上传区域标题 - Upload Section Title ===== */
.file-upload-section h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-lg);
    color: var(--upload-text);
    font-weight: var(--font-weight-semibold);
}

/* ===== 上传区域描述 - Upload Section Description ===== */
.file-upload-section p {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
    line-height: var(--line-height-relaxed);
    font-size: var(--font-size-base);
}

.file-upload-section p.description-text {
    margin-bottom: var(--spacing-lg);
}

/* ===== 文件选择状态 - File Selected State ===== */
.file-upload-section.file-selected {
    border-color: var(--color-success);
    background: var(--color-success-lighter);
}

.file-upload-section.file-selected .upload-icon {
    color: var(--color-success);
}

.file-upload-section.file-selected h3,
.file-upload-section.file-selected p {
    color: var(--color-success-darker);
}

/* ===== 错误状态 - Error State ===== */
.file-upload-section.error {
    border-color: var(--color-error);
    background: var(--color-error-lighter);
}

.file-upload-section.error .upload-icon {
    color: var(--color-error);
}

.file-upload-section.error h3,
.file-upload-section.error p {
    color: var(--color-error);
}

/* ===== 文件信息显示 - File Info Display ===== */
.file-info {
    background: var(--card-bg);
    border: var(--border-width-thin) var(--border-style-solid) var(--card-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-lg);
    display: none;
    text-align: left;
}

.file-info.show {
    display: block;
    animation: fade-in 0.3s ease;
}

.file-info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    border-bottom: var(--border-width-thin) var(--border-style-solid) var(--color-gray-100);
}

.file-info-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.file-info-label {
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.file-info-value {
    color: var(--color-text-primary);
    font-size: var(--font-size-sm);
}

/* ===== 进度指示器 - Progress Indicator ===== */
.upload-progress {
    width: 100%;
    height: 8px;
    background: var(--color-gray-200);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-lg);
    overflow: hidden;
    display: none;
}

.upload-progress.show {
    display: block;
    animation: fade-in 0.3s ease;
}

.upload-progress-bar {
    height: 100%;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    width: 0%;
    transition: width var(--transition-normal);
    border-radius: var(--radius-sm);
}

.upload-progress-text {
    text-align: center;
    margin-top: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    display: none;
}

.upload-progress.show .upload-progress-text {
    display: block;
}

/* ===== 多文件上传支持 - Multiple File Upload Support ===== */
.file-upload-section.multiple {
    min-height: 250px;
}

.file-list {
    width: 100%;
    margin-top: var(--spacing-lg);
    text-align: left;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    background: var(--color-bg-white);
    border: var(--border-width-thin) var(--border-style-solid) var(--border-color-light);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-normal);
}

.file-item:hover {
    background: var(--color-gray-50);
    box-shadow: var(--shadow-sm);
}

.file-item:last-child {
    margin-bottom: 0;
}

.file-item-info {
    display: flex;
    align-items: center;
    flex: 1;
}

.file-item-icon {
    margin-right: var(--spacing-md);
    font-size: var(--font-size-lg);
    color: var(--color-primary);
}

.file-item-details {
    flex: 1;
}

.file-item-name {
    font-weight: var(--font-weight-medium);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-sm);
}

.file-item-size {
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
}

.file-item-remove {
    background: var(--color-error);
    color: var(--color-text-white);
    border: none;
    border-radius: var(--radius-round);
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-size: var(--font-size-xs);
}

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

/* ===== 拖拽区域高亮 - Drag Zone Highlight ===== */
.drag-zone-highlight {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border: var(--border-width-thick) var(--border-style-dashed) var(--color-primary);
    border-radius: var(--radius-lg);
    background: rgba(66, 133, 244, 0.05);
    display: none;
    pointer-events: none;
}

.file-upload-section.dragover .drag-zone-highlight {
    display: block;
    animation: dash-move 1s linear infinite;
}

/* ===== 文件类型验证提示 - File Type Validation Hints ===== */
.file-type-hint {
    background: var(--color-gray-100);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-md);
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.file-type-hint-icon {
    font-size: var(--font-size-sm);
}

/* ===== 上传状态指示 - Upload Status Indicators ===== */
.upload-status {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-xl);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
    display: none;
}

.upload-status.success {
    background: var(--color-success-light);
    color: var(--color-success);
    display: block;
}

.upload-status.error {
    background: var(--color-error-light);
    color: var(--color-error);
    display: block;
}

.upload-status.uploading {
    background: var(--color-warning-light);
    color: var(--color-warning);
    display: block;
    animation: upload-pulse 1.5s infinite;
}

/* ===== 动画效果 - Animations ===== */
@keyframes upload-pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

@keyframes fade-in {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes dash-move {
    0% {
        stroke-dashoffset: 0;
    }
    100% {
        stroke-dashoffset: 20px;
    }
}

@keyframes file-added {
    0% {
        opacity: 0;
        transform: translateX(-20px);
    }
    100% {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ===== 响应式调整 - Responsive Adjustments ===== */
@media (max-width: 768px) {
    .file-upload-section {
        padding: var(--spacing-3xl) var(--spacing-lg);
        min-height: 180px;
    }
    
    .upload-icon {
        font-size: 3em;
        margin-bottom: var(--spacing-lg);
    }
    
    .file-upload-section h3 {
        font-size: var(--font-size-xl);
        margin-bottom: var(--spacing-md);
    }
    
    .file-upload-section p {
        font-size: var(--font-size-sm);
        margin-bottom: var(--spacing-lg);
    }
    
    .file-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .file-item-info {
        width: 100%;
    }
    
    .file-item-remove {
        align-self: flex-end;
    }
    
    .file-info {
        padding: var(--spacing-md);
    }
    
    .file-info-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
}

/* ===== 小屏设备优化 - Small Screen Optimizations ===== */
@media (max-width: 480px) {
    .file-upload-section {
        padding: var(--spacing-xl);
        min-height: 150px;
    }
    
    .upload-icon {
        font-size: 2.5em;
    }
    
    .file-upload-section h3 {
        font-size: var(--font-size-lg);
    }
    
    .file-upload-section p {
        font-size: var(--font-size-xs);
        line-height: var(--line-height-normal);
    }
}

/* ===== 高对比度支持 - High Contrast Support ===== */
@media (prefers-contrast: high) {
    .file-upload-section {
        border-width: var(--border-width-thick);
        border-color: var(--color-gray-800);
    }
    
    .file-upload-section:hover {
        border-color: var(--color-primary-dark);
    }
    
    .file-upload-section.dragover {
        border-color: var(--color-primary-darker);
        background: var(--color-primary-lighter);
    }
}

/* ===== 减少动画设置 - Reduced Motion Support ===== */
@media (prefers-reduced-motion: reduce) {
    .file-upload-section,
    .upload-icon,
    .file-item,
    .upload-progress-bar {
        transition: none;
    }
    
    .upload-pulse,
    .dash-move,
    .fade-in,
    .file-added {
        animation: none;
    }
    
    .file-upload-section:hover,
    .file-upload-section.dragover {
        transform: none;
    }
}

/* ===== 文件大小信息样式 - File Size Info ===== */
.file-size-info {
    display: block;
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
    font-weight: normal;
    opacity: 0.8;
}