/* Floating Demo Navigation */
.demo-nav {
    position: fixed;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    background: #fff;
    border: 1px solid #dee2e6;
    border-left: none;
    border-radius: 0 8px 8px 0;
    box-shadow: 2px 2px 8px rgba(0,0,0,0.1);
    overflow: hidden;
}

.demo-nav a {
    display: block;
    padding: 10px 14px;
    font-size: 13px;
    color: #333;
    text-decoration: none;
    white-space: nowrap;
    border-bottom: 1px solid #eee;
    transition: background 0.15s, color 0.15s;
}

.demo-nav a:last-child {
    border-bottom: none;
}

.demo-nav a:hover {
    background: #e9ecef;
}

.demo-nav a.active {
    background: #0d6efd;
    color: #fff;
    font-weight: 600;
}

/* 导航展开/收起按钮 */
.demo-nav-toggle {
    position: fixed;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10000;
    background: #0d6efd;
    color: #fff;
    border: none;
    border-radius: 0 6px 6px 0;
    padding: 8px 4px;
    cursor: pointer;
    font-size: 14px;
    writing-mode: vertical-rl;
    letter-spacing: 2px;
    display: none;
}

.demo-nav.collapsed {
    transform: translateY(-50%) translateX(-100%);
}

.demo-nav-toggle.visible {
    display: block;
}

/* 导航为 fixed 定位，不影响页面布局 */