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

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-bg: #0f172a;
    --dark-surface: #1e293b;
    --dark-border: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--dark-bg);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

/* 登录/注册页面 */
.login-page, .register-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: var(--gradient-1);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.login-container, .register-container {
    width: 100%;
    max-width: 420px;
    padding: 20px;
}

.login-box, .register-box {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.login-box h1, .register-box h1 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: var(--gradient-2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    text-align: center;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 30px;
    font-size: 1.1rem;
}

/* 表单样式 */
.auth-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.95rem;
}

.form-group input,
.form-group select {
    padding: 12px 16px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    font-size: 1rem;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.15);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

/* 下拉菜单样式 */
.form-group select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23ffffff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
    cursor: pointer;
}

.form-group select option {
    background: var(--dark-surface);
    color: var(--text-primary);
    padding: 12px;
}

.form-group select option:hover {
    background: var(--primary-color);
}

.form-group small {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.85rem;
}

/* 按钮样式 */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    justify-content: center;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
}

.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-block {
    width: 100%;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

/* 认证页面底部 */
.auth-footer {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.auth-footer p {
    color: rgba(255, 255, 255, 0.8);
}

.auth-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.auth-footer a:hover {
    text-decoration: underline;
}

/* 消息提示 */
.message {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 16px 24px;
    border-radius: 12px;
    font-size: 1rem;
    display: none;
    z-index: 1000;
    max-width: 400px;
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.message.success {
    background: rgba(16, 185, 129, 0.9);
    border: 1px solid var(--success-color);
    color: white;
    display: block;
}

.message.error {
    background: rgba(239, 68, 68, 0.9);
    border: 1px solid var(--danger-color);
    color: white;
    display: block;
}

/* 仪表板页面 */
.dashboard-page {
    background: var(--dark-bg);
}

.dashboard-container {
    display: flex;
    min-height: 100vh;
}

/* 侧边栏 */
.sidebar {
    width: 280px;
    background: var(--dark-surface);
    border-right: 1px solid var(--dark-border);
    display: flex;
    flex-direction: column;
    padding: 20px;
}

.logo {
    padding: 20px 0;
    border-bottom: 1px solid var(--dark-border);
    margin-bottom: 20px;
}

.logo h2 {
    font-size: 1.8rem;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    border-radius: 10px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
}

.nav-item:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--text-primary);
}

.nav-item.active {
    background: var(--gradient-1);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.nav-item .icon {
    font-size: 1.3rem;
}

/* 用户面板 */
.user-panel {
    padding: 16px;
    border-top: 1px solid var(--dark-border);
    background: rgba(255, 255, 255, 0.02);
}

.user-card {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding: 12px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
}

.user-avatar-wrapper {
    position: relative;
}

.user-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: bold;
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.user-avatar:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

.user-status {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #10b981;
    border: 2px solid var(--dark-surface);
}

.user-info {
    flex: 1;
}

.username {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
    font-size: 1rem;
}

.user-role {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.user-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 14px;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.action-btn.primary {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.2) 0%, rgba(118, 75, 162, 0.2) 100%);
    color: var(--primary-color);
    border: 1px solid rgba(102, 126, 234, 0.3);
}

.action-btn.primary:hover {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.action-btn.danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.action-btn.danger:hover {
    background: var(--danger-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.4);
}

.btn-icon {
    font-size: 1rem;
}

.btn-text {
    font-weight: 500;
}

/* 主内容区 */
.main-content {
    flex: 1;
    padding: 30px;
    overflow-y: auto;
}

/* 存储信息 */
.storage-info {
    margin-bottom: 30px;
}

.storage-card {
    background: var(--dark-surface);
    border-radius: 15px;
    padding: 25px;
    border: 1px solid var(--dark-border);
}

.storage-card h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.storage-bar {
    height: 12px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 10px;
}

.storage-progress {
    height: 100%;
    background: var(--gradient-3);
    border-radius: 6px;
    transition: width 0.5s ease;
}

.storage-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* 内容区域 */
.content-section {
    display: none;
}

.content-section.active {
    display: block;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
}

.section-header h2 {
    font-size: 1.8rem;
    color: var(--text-primary);
}

/* 上传区域 */
.file-actions {
    margin-bottom: 25px;
}

.upload-area {
    background: var(--dark-surface);
    border: 2px dashed var(--dark-border);
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.upload-area p {
    font-size: 1.1rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.upload-area small {
    color: var(--text-secondary);
}

/* 上传进度 */
.upload-progress {
    background: var(--dark-surface);
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 25px;
    border: 1px solid var(--dark-border);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
}

.progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-1);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.progress-meta {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

#uploadSpeed {
    color: var(--success-color);
}

#uploadTimeRemaining {
    color: var(--warning-color);
}

/* 文件列表 */
.file-list, .shares-list, .users-list, .all-files-list {
    display: grid;
    gap: 15px;
}

.file-item, .share-item, .user-item {
    background: var(--dark-surface);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--dark-border);
    display: flex;
    align-items: center;
    gap: 15px;
    transition: all 0.3s ease;
}

.file-item:hover, .share-item:hover, .user-item:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.file-icon, .share-icon, .user-icon {
    width: 50px;
    height: 50px;
    border-radius: 10px;
    background: var(--gradient-2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.file-info, .share-info, .user-info-content {
    flex: 1;
    min-width: 0;
}

.file-name, .share-name, .user-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 5px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-meta, .share-meta, .user-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.file-actions-buttons, .share-actions, .user-actions {
    display: flex;
    gap: 8px;
}

.action-btn {
    padding: 8px 12px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.action-btn.download {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

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

.action-btn.share {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

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

.action-btn.delete {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

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

.action-btn.view {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.action-btn.view:hover {
    background: var(--warning-color);
    color: white;
}

/* 管理员面板 */
.admin-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
    border-bottom: 2px solid var(--dark-border);
    padding-bottom: 15px;
}

.tab-btn {
    padding: 10px 20px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--text-primary);
}

.tab-btn.active {
    background: var(--gradient-1);
    color: white;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* 统计信息 */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.stat-card {
    background: var(--dark-surface);
    border-radius: 15px;
    padding: 25px;
    border: 1px solid var(--dark-border);
    text-align: center;
}

.stat-card h3 {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 10px;
}

.stat-card .stat-value {
    font-size: 2.5rem;
    font-weight: bold;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--dark-surface);
    border-radius: 20px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    border: 1px solid var(--dark-border);
}

.modal-content.large-modal {
    max-width: 800px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 25px;
    border-bottom: 1px solid var(--dark-border);
}

.modal-header h3 {
    color: var(--text-primary);
    font-size: 1.3rem;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.close-btn:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 25px;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    padding: 25px;
    border-top: 1px solid var(--dark-border);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .dashboard-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        padding: 15px;
    }
    
    .main-content {
        padding: 20px;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }
    
    .file-item, .share-item, .user-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .file-actions-buttons, .share-actions, .user-actions {
        width: 100%;
        justify-content: flex-start;
    }
    
    .stats-container {
        grid-template-columns: 1fr;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.file-item, .share-item, .user-item {
    animation: fadeIn 0.3s ease;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--dark-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--dark-border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* 搜索框样式 */
.search-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.search-bar input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--dark-border);
    border-radius: 10px;
    font-size: 1rem;
    background: var(--dark-surface);
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.search-bar input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.search-bar input::placeholder {
    color: var(--text-secondary);
}

.search-bar button {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    background: var(--gradient-1);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.search-bar button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.6);
}

/* 分页样式 */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    margin-top: 25px;
    padding: 20px 0;
}

.pagination button {
    padding: 8px 16px;
    border: 2px solid var(--dark-border);
    border-radius: 8px;
    background: var(--dark-surface);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.95rem;
    font-weight: 500;
}

.pagination button:hover:not(:disabled) {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.pagination button.active {
    background: var(--gradient-1);
    border-color: transparent;
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.pagination button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.pagination .page-info {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0 10px;
}