.container {
    max-width: 1200px;
    margin: 40px auto;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    padding: 30px 20px;
    text-align: center;
}
.transition-controls {
    margin: 20px 0 30px 0;
}
.transition-demo-area {
    min-height: 220px;
    margin: 20px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: row; /* 保证横向排列 */
    max-width: 1200px;   /* 加宽页面区域 */
    margin-left: auto;
    margin-right: auto;
}
.transition-explanation {
    background: #f8f8f8;
    border-radius: 6px;
    padding: 18px;
    text-align: left;
    font-size: 1em;
    margin-top: 20px;
}
.node {
    display: inline-block;
    padding: 12px 18px;
    border-radius: 6px;
    background: #e3f2fd;
    border: 2px solid #2196f3;
    margin: 0 10px;
    font-weight: bold;
    font-size: 1.1em;
    position: relative;
}
.node.ipv6 {
    background: #e8f5e9;
    border-color: #43a047;
}
.node.dual {
    background: #fffde7;
    border-color: #fbc02d;
}
.arrow {
    display: inline-block;
    font-size: 2em;
    margin: 0 10px;
    vertical-align: middle;
}
.tunnel {
    display: inline-block;
    padding: 6px 18px;
    background: #b3e5fc;
    border: 2px dashed #0288d1;
    border-radius: 20px;
    margin: 0 10px;
    font-size: 1em;
}
.translator {
    display: inline-block;
    padding: 6px 18px;
    background: #ffe0b2;
    border: 2px dashed #fb8c00;
    border-radius: 20px;
    margin: 0 10px;
    font-size: 1em;
}