.container {
    display: flex;
    height: 100vh;
}

.viewer {
    width: 75%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #f4f4f4;
}

.viewer img {
    max-width: 100%;
    max-height: 90vh;
    border-radius: 10px;
}

.sidebar {
    width: 25%;
    background: #333;
    color: white;
    overflow-y: auto;
    padding: 20px;
}

.folder-item {
    padding: 10px;
    cursor: pointer;
    transition: background 0.3s;
}

.folder-item:hover, .folder-item.active {
    background: #555;
}