.container {
    width: 90%;
    margin: 0 auto;
    text-align: center;
    padding: 10px; /* 添加内边距 */
}

.content-area {
    display: flex;
    justify-content: space-between;
    margin: 10px 0; /* 减少外边距 */
    gap: 15px; /* 调整间距 */
}

.osi-area, .functions-area {
    flex: 0 0 48%;
    padding: 5px; /* 添加内边距 */
}

.sortable-list {
    list-style-type: none;
    padding: 0;
    min-height: 350px; /* 减少最小高度 */
    border: 1px dashed #ccc;
    padding: 8px; /* 减少内边距 */
    margin: 5px 0; /* 调整外边距 */
}

.layer-item, .function-item {
    margin: 8px; /* 减少外边距 */
    padding: 12px; /* 减少内边距 */
    background: #f0f0f0;
    border-radius: 5px;
}

.control-area {
    margin: 15px 0; /* 减少外边距 */
    padding: 5px;
}

.jtk-connector {
    stroke: #666;
    stroke-width: 2px;
}

.correct-connection {
    stroke: green;
}

.wrong-connection {
    stroke: red;
}