:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #34495e;
    --gray-color: #95a5a6;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

header h1 {
    margin: 10px 0;
    font-size: 2.5rem;
}

header i {
    margin-right: 10px;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

@media (min-width: 768px) {
    main {
        grid-template-columns: 1fr 1fr;
    }
}

section {
    background: white;
    border-radius: 10px;
    padding: 25px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.upload-section {
    display: flex;
    flex-direction: column;
}

.files-section h2 {
    margin-bottom: 20px;
    color: var(--secondary-color);
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
}

.btn:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
}

.btn.primary {
    background-color: var(--success-color);
    margin-top: 20px;
    align-self: flex-end;
}

.btn.primary:hover {
    background-color: #27ae60;
}

.btn:disabled {
    background-color: var(--gray-color);
    cursor: not-allowed;
    transform: none;
}

.upload-box {
    border: 2px dashed var(--primary-color);
    border-radius: 10px;
    padding: 40px 20px;
    text-align: center;
    background-color: #f8f9fa;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-box:hover, .upload-box.dragover {
    background-color: #e3f2fd;
    border-color: var(--success-color);
}

.upload-box i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

#fileInput {
    display: none;
}

.file-preview {
    margin-top: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.file-preview-item {
    background-color: var(--light-color);
    padding: 10px 15px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.search-bar {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.search-bar input {
    flex: 1;
    padding: 10px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

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

.file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    border-bottom: 1px solid #eee;
    transition: background-color 0.2s;
}

.file-item:hover {
    background-color: #f8f9fa;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.file-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--light-color);
    border-radius: 5px;
    color: var(--primary-color);
}

.file-details {
    flex: 1;
}

.file-name {
    font-weight: bold;
    margin-bottom: 5px;
}

.file-meta {
    display: flex;
    gap: 15px;
    font-size: 0.9rem;
    color: var(--gray-color);
}

.file-actions {
    display: flex;
    gap: 10px;
}

.download-btn {
    background-color: var(--primary-color);
    color: white;
    padding: 8px 15px;
    border-radius: 5px;
    text-decoration: none;
    transition: background-color 0.3s;
}

.download-btn:hover {
    background-color: #2980b9;
}

.expiration-warning {
    color: var(--danger-color);
    font-weight: bold;
}

.loading {
    text-align: center;
    padding: 30px;
    color: var(--gray-color);
}

footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: var(--gray-color);
    font-size: 0.9rem;
}

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

.file-item {
    animation: fadeIn 0.3s ease-out;
}


/* 添加以下优化样式 */
.upload-box label {
    cursor: pointer;
    display: block;
    width: 100%;
    height: 100%;
}

#fileInput {
    display: none;
}

/* 修复文件预览项样式 */
.file-preview-item {
    background-color: var(--light-color);
    padding: 10px 15px;
    border-radius: 5px;
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 5px;
}