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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 5px;
}

header p {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* Navigation */
.navigation {
    display: flex;
    background: #f9fafb;
    border-bottom: 2px solid #e5e7eb;
}

.nav-link {
    flex: 1;
    padding: 15px 20px;
    text-align: center;
    text-decoration: none;
    color: #6b7280;
    font-weight: 500;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
}

.nav-link:hover {
    background: #f3f4f6;
    color: #667eea;
}

.nav-link.active {
    color: #667eea;
    background: white;
    border-bottom-color: #667eea;
}

main {
    padding: 30px;
}

/* Search Bar */
.search-bar {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
}

.search-input {
    flex: 1;
    padding: 12px 20px;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.search-input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.filter-select {
    padding: 12px 20px;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-select:focus {
    outline: none;
    border-color: #667eea;
}

/* Stats */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
}

.stat-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 15px;
    color: white;
}

.stat-icon {
    font-size: 2.5rem;
}

.stat-info h3 {
    font-size: 1.5rem;
    margin-bottom: 3px;
}

.stat-info p {
    font-size: 0.85rem;
    opacity: 0.9;
}

/* Files Header */
.files-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.files-header h2 {
    color: #1f2937;
    font-size: 1.3rem;
}

.btn-clear {
    background: #ef4444;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-clear:hover {
    background: #dc2626;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(239, 68, 68, 0.4);
}

/* Files Container */
.files-container {
    display: grid;
    gap: 15px;
}

.file-card {
    background: #f9fafb;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    padding: 20px;
    transition: all 0.3s ease;
}

.file-card:hover {
    border-color: #667eea;
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.1);
    transform: translateY(-2px);
}

.file-card-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.file-type-icon {
    font-size: 2.5rem;
}

.file-card-info {
    flex: 1;
}

.file-card-info h3 {
    color: #1f2937;
    font-size: 1rem;
    margin-bottom: 5px;
    word-break: break-all;
}

.file-card-meta {
    display: flex;
    gap: 15px;
    font-size: 0.85rem;
    color: #6b7280;
}

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

.btn-action {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.btn-download {
    background: #10b981;
    color: white;
}

.btn-download:hover {
    background: #059669;
    transform: translateY(-2px);
}

.btn-delete {
    background: #ef4444;
    color: white;
}

.btn-delete:hover {
    background: #dc2626;
    transform: translateY(-2px);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    display: none;
}

.empty-state.show {
    display: block;
}

.empty-icon {
    font-size: 5rem;
    margin-bottom: 20px;
}

.empty-state h3 {
    color: #1f2937;
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.empty-state p {
    color: #6b7280;
    margin-bottom: 25px;
}

.btn-upload-link {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 12px 30px;
    border-radius: 8px;
    text-decoration: none;
    transition: all 0.3s ease;
}

.btn-upload-link:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

footer {
    background: #f9fafb;
    text-align: center;
    padding: 20px;
    color: #6b7280;
    font-size: 0.85rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        border-radius: 0;
    }
    
    header h1 {
        font-size: 1.5rem;
    }
    
    main {
        padding: 20px;
    }
    
    .search-bar {
        flex-direction: column;
    }
    
    .stats {
        grid-template-columns: 1fr;
    }
    
    .files-header {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
    }
    
    .btn-clear {
        width: 100%;
    }
    
    .file-card-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .file-card-actions {
        width: 100%;
        flex-direction: column;
    }
    
    .btn-action {
        width: 100%;
        justify-content: center;
    }
}