/* 基础样式 */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    --light-color: #f8fafc;
    --dark-color: #1e293b;
    --gray-color: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--dark-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* 导航栏 */
.navbar {
    background: white;
    border-radius: var(--radius-xl);
    padding: 1.5rem 2rem;
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 2rem;
}

.nav-stats {
    display: flex;
    gap: 2rem;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--gray-color);
    font-size: 0.9rem;
}

.stat-item i {
    color: var(--primary-color);
}

/* 主内容区 */
.main-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

/* 上传区域 */
.upload-section {
    background: white;
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-md);
}

.section-header {
    margin-bottom: 1.5rem;
}

.section-header h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-header p {
    color: var(--gray-color);
    font-size: 0.9rem;
}

.upload-area {
    border: 3px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--light-color);
    margin-bottom: 1.5rem;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: #f0f9ff;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #e0f2fe;
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.upload-area h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.upload-area p {
    color: var(--gray-color);
    margin-bottom: 0.5rem;
}

.upload-hint {
    font-size: 0.85rem;
    color: var(--gray-color);
    margin-bottom: 1.5rem !important;
}

/* 按钮样式 */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-outline {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: #059669;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

/* 文件类型标签 */
.file-types {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.file-type-tag {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.file-type-tag.image {
    background: #dbeafe;
    color: #1d4ed8;
}

.file-type-tag.document {
    background: #dcfce7;
    color: #047857;
}

.file-type-tag.video {
    background: #fef3c7;
    color: #92400e;
}

.file-type-tag.audio {
    background: #f3e8ff;
    color: #7c3aed;
}

.file-type-tag.archive {
    background: #ffe4e6;
    color: #be123c;
}

/* 文件列表区域 */
.files-section {
    background: white;
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-md);
}

.section-actions {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.search-box {
    display: flex;
    align-items: center;
    background: var(--light-color);
    border-radius: var(--radius-md);
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
}

.search-box i {
    color: var(--gray-color);
    margin-right: 0.5rem;
}

.search-box input {
    border: none;
    background: transparent;
    outline: none;
    width: 200px;
    font-size: 0.9rem;
}

.files-container {
    margin-top: 1.5rem;
}

.files-header {
    display: grid;
    grid-template-columns: 3fr 1fr 1.5fr 1fr;
    padding: 1rem;
    background: var(--light-color);
    border-radius: var(--radius-md);
    font-weight: 600;
    color: var(--gray-color);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.files-list {
    max-height: 500px;
    overflow-y: auto;
}

.file-item {
    display: grid;
    grid-template-columns: 3fr 1fr 1.5fr 1fr;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    align-items: center;
    transition: background 0.2s ease;
}

.file-item:hover {
    background: #f8fafc;
}

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

.file-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.file-icon.image { background: #dbeafe; color: #1d4ed8; }
.file-icon.pdf { background: #fee2e2; color: #dc2626; }
.file-icon.doc { background: #dcfce7; color: #059669; }
.file-icon.xls { background: #fef3c7; color: #d97706; }
.file-icon.ppt { background: #f3e8ff; color: #7c3aed; }
.file-icon.zip { background: #fce7f3; color: #be185d; }
.file-icon.video { background: #fef3c7; color: #92400e; }
.file-icon.audio { background: #f0f9ff; color: #0369a1; }
.file-icon.other { background: #f1f5f9; color: #475569; }

.file-name {
    font-weight: 500;
    color: var(--dark-color);
}

.file-size {
    color: var(--gray-color);
    font-size: 0.9rem;
}

.file-date {
    color: var(--gray-color);
    font-size: 0.85rem;
}

.file-actions {
    display: flex;
    gap: 0.5rem;
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--gray-color);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: #cbd5e1;
}

/* 上传进度 */
.upload-progress {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-top: 1.5rem;
    display: none;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.75rem;
    font-weight: 500;
}

.progress-bar {
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--gray-color);
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

/* 模态框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background: white;
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-color);
    cursor: pointer;
    padding: 0.5rem;
}

.modal-body {
    padding: 1.5rem;
    max-height: calc(90vh - 80px);
    overflow-y: auto;
}

/* 加载动画 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 5px solid #f3f3f3;
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* 底部 */
.footer {
    text-align: center;
    padding: 2rem;
    color: white;
    font-size: 0.9rem;
}

.footer-links {
    margin-top: 0.5rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    margin: 0 0.5rem;
}

.footer-links a:hover {
    color: white;
    text-decoration: underline;
}