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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

main {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.upload-section {
    margin-bottom: 40px;
}

.upload-area {
    border: 3px dashed #ddd;
    border-radius: 15px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.upload-area:hover {
    border-color: #667eea;
    background: #f0f4ff;
    transform: translateY(-2px);
}

.upload-area.dragover {
    border-color: #667eea;
    background: #e8f2ff;
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.upload-content h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #333;
}

.upload-content p {
    color: #666;
    font-size: 1rem;
}

.files-section h2 {
    margin-bottom: 20px;
    color: #333;
    font-size: 1.8rem;
}

.files-list {
    min-height: 100px;
}

.no-files {
    text-align: center;
    color: #999;
    padding: 40px;
    font-style: italic;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 15px;
    border: 1px solid #eee;
    border-radius: 10px;
    margin-bottom: 10px;
    background: #fafafa;
    transition: all 0.3s ease;
}

.file-item:hover {
    background: #f0f4ff;
    border-color: #667eea;
    transform: translateX(5px);
}

.file-icon {
    font-size: 2rem;
    margin-right: 15px;
    min-width: 40px;
}

.file-info {
    flex: 1;
}

.file-name {
    font-weight: 600;
    margin-bottom: 5px;
    color: #333;
}

.file-size {
    font-size: 0.9rem;
    color: #666;
}

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

.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-download {
    background: #667eea;
    color: white;
}

.btn-download:hover {
    background: #5a6fd8;
    transform: translateY(-1px);
}

.btn-delete {
    background: #ff4757;
    color: white;
}

.btn-delete:hover {
    background: #e63946;
    transform: translateY(-1px);
}

.btn-copy {
    background: #2ed573;
    color: white;
}

.btn-copy:hover {
    background: #26d0ce;
    transform: translateY(-1px);
}

footer {
    text-align: center;
    color: white;
    opacity: 0.8;
    font-size: 0.9rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    main {
        padding: 20px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .file-item {
        flex-direction: column;
        text-align: center;
    }
    
    .file-icon {
        margin-right: 0;
        margin-bottom: 10px;
    }
    
    .file-actions {
        margin-top: 10px;
    }
}

/* Animation for new files */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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