/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #4a90e2;
    --secondary-color: #7b68ee;
    --success-color: #52c41a;
    --error-color: #f5222d;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --border-color: #e8e8e8;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部样式 */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
    padding: 0.5rem 1rem;
    border-radius: 8px;
}

.nav-link:hover {
    color: var(--primary-color);
    background: var(--bg-color);
}

.upload-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white !important;
    padding: 0.6rem 1.5rem;
    border-radius: 25px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    transition: transform 0.3s, box-shadow 0.3s;
}

.upload-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

/* 主内容区 */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 200px);
}

/* 页面头部 */
.page-header {
    text-align: center;
    margin-bottom: 2rem;
    color: white;
}

.page-header h2 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* 文件网格 */
.files-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

/* 文件卡片 */
.file-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    animation: fadeInUp 0.5s ease-out;
}

.file-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 文件预览 */
.file-preview {
    width: 100%;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    position: relative;
    overflow: hidden;
}

.image-preview {
    background: #000;
}

.preview-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    cursor: pointer;
    transition: transform 0.3s;
}

.preview-img:hover {
    transform: scale(1.05);
}

.audio-preview {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.audio-icon {
    font-size: 3rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.audio-player {
    width: 100%;
    max-width: 250px;
}

.other-preview {
    background: linear-gradient(135deg, #89f7fe 0%, #66a6ff 100%);
}

.file-icon {
    font-size: 4rem;
}

/* 文件信息 */
.file-info {
    padding: 1rem;
}

.file-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-color);
}

.file-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.file-stats {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.download-link {
    display: block;
    text-decoration: none;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.6rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    text-align: center;
}

.btn-download {
    width: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--bg-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

/* 上传页面 */
.upload-container {
    max-width: 600px;
    margin: 0 auto;
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.upload-form {
    margin-top: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

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

.file-input-wrapper {
    position: relative;
}

.file-input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.file-input-label {
    display: block;
    padding: 3rem 2rem;
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--bg-color);
}

.file-input-label:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
}

.file-input-text {
    font-size: 1.1rem;
    color: var(--text-light);
}

.file-list {
    margin-top: 1rem;
}

.selected-files {
    list-style: none;
}

.selected-files li {
    padding: 0.5rem;
    background: var(--bg-color);
    border-radius: 6px;
    margin-bottom: 0.5rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.form-actions .btn {
    flex: 1;
}

/* 上传结果 */
.upload-result {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
}

.upload-result.success {
    background: #f6ffed;
    border: 1px solid #b7eb8f;
    color: var(--success-color);
}

.upload-result.error {
    background: #fff2f0;
    border: 1px solid #ffccc7;
    color: var(--error-color);
}

/* 上传进度 */
.upload-progress {
    margin-top: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-color);
    border-radius: 12px;
    border: 2px solid var(--border-color);
}

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

.progress-title {
    font-weight: 600;
    color: var(--text-color);
    font-size: 1rem;
}

.progress-percent {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--primary-color);
}

.progress-bar-container {
    width: 100%;
    height: 24px;
    background: #e8e8e8;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    transition: width 0.3s ease;
    box-shadow: 0 2px 4px rgba(102, 126, 234, 0.3);
    position: relative;
    overflow: hidden;
}

.progress-bar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: shimmer 2s infinite;
}

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

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--text-light);
}

.progress-info span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.progress-info span::before {
    content: '📊';
    font-size: 1rem;
}

.progress-info span:last-child::before {
    content: '⏱️';
}

/* 上传进度动画 */
.upload-progress {
    animation: fadeInUp 0.4s ease-out;
}

/* 图片模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    padding-top: 50px;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.9);
}

.modal-content {
    margin: auto;
    display: block;
    max-width: 90%;
    max-height: 80vh;
    animation: zoom 0.3s;
}

@keyframes zoom {
    from { transform: scale(0); }
    to { transform: scale(1); }
}

.close {
    position: absolute;
    top: 15px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    transition: 0.3s;
    cursor: pointer;
}

.close:hover,
.close:focus {
    color: #bbb;
}

#caption {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
    text-align: center;
    color: #ccc;
    padding: 10px 0;
    height: 150px;
}

/* 空状态 */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 3rem;
    color: white;
    font-size: 1.2rem;
}

.empty-state a {
    color: white;
    text-decoration: underline;
}

/* 底部 */
.footer {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1.5rem 0;
    text-align: center;
    color: var(--text-light);
    margin-top: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .files-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 1rem;
    }
    
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .page-header h2 {
        font-size: 2rem;
    }
    
    .upload-container {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .files-grid {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
}