#structures { display: flex; justify-content: center; gap: 20px; flex-wrap: wrap; margin-bottom: 1rem; }

.viewer-canvas, .viewer-container {
    width: 300px;
    height: 300px;
    position: relative;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: white;
    display: flex;
    justify-content: center;
    align-items: center; 
}