* {
    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 {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid #e0e0e0;
    flex-wrap: wrap;
    gap: 15px;
}

h1 {
    color: #333;
    font-size: 28px;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

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

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #e0e0e0;
    color: #333;
}

.btn-secondary:hover {
    background: #d0d0d0;
}

.catalog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.catalog-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.catalog-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

.catalog-card a {
    text-decoration: none;
    color: inherit;
}

.thumbnail {
    width: 100%;
    height: 250px;
    overflow: hidden;
    background: #f5f5f5;
}

.thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.card-content {
    padding: 15px;
}

.card-content h3 {
    color: #333;
    margin-bottom: 8px;
    font-size: 16px;
}

.date {
    color: #999;
    font-size: 13px;
}

.upload-form {
    max-width: 600px;
    margin: 30px auto;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 600;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
}

.alert-error {
    background: #fee;
    color: #c33;
    border-left: 4px solid #c33;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #999;
    grid-column: 1 / -1;
}

.empty-state p {
    font-size: 20px;
    margin-bottom: 20px;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .container {
        padding: 20px;
    }

    h1 {
        font-size: 22px;
    }

    .catalog-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 15px;
    }

    .thumbnail {
        height: 200px;
    }

    .card-content h3 {
        font-size: 14px;
    }

    .btn {
        padding: 10px 16px;
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .catalog-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .thumbnail {
        height: 180px;
    }
    .btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

.card-actions {
    padding: 10px 15px;
    border-top: 1px solid #e0e0e0;
    text-align: center;
}

.btn-delete {
    display: inline-block;
    padding: 8px 12px;
    background: #dc3545;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-size: 13px;
    transition: all 0.3s;
}

.btn-delete:hover {
    background: #c82333;
}
}