/* 右侧子导航栏样式 */
.sub-nav {
    position: fixed;
    right: 4vw;
    top: 50vh;
    transform: translateY(0);
    z-index: 999;
    background: transparent;
    backdrop-filter: none;
    border: none;
    border-radius: 0;
    padding: 50px 0 0 0;
    max-width: 400px;
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, top 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform, opacity, top;
    box-shadow: none;
}

.sub-nav.visible {
    opacity: 1;
    visibility: visible;
}

.sub-nav-header {
    margin-bottom: 2px;
    padding-bottom: 0;
    border-bottom: none;
}

.sub-nav-title {
    font-family: 'UnicaOne', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
                 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    font-size: 20px;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #ffffff;
    margin: 0;
    text-align: left;
    margin-left: -4px;
}

.sub-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sub-nav-item {
    margin-bottom: 0px;
    position: relative;
}

.sub-nav-item:last-child {
    margin-bottom: 0;
}

.sub-nav-link {
    display: block;
    color: #ffffff;
    text-decoration: none;
    font-family: 'UnicaOne', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
                 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    font-size: 16px;
    font-weight: 400;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    line-height: 1.2;
    padding: 4px 12px;
    border-left: none;
    background: transparent;
    transition: all 0.2s ease;
    position: relative;
}

.sub-nav-link::before {
    content: '|';
    font-family: 'UnicaOne', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
                 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    font-size: 1em;
    letter-spacing: 0.05em;
    display: inline-block;
    margin-right: 8px;
    color: currentColor;
}

.sub-nav-link:hover {
    color: #ffffff;
}

.sub-nav-link.active {
    color: #7FEF35;
}

.sub-nav-link.active::before {
    color: currentColor;
}

/* 电脑到平板过渡阶段 - 逐渐缩小并最终隐藏 */
@media (max-width: 1400px) and (min-width: 1201px) {
    .sub-nav {
        right: 3.5vw;
        max-width: 350px;
        min-width: 190px;
    }
    
    .sub-nav-title {
        font-size: 18px;
    }
    
    .sub-nav-link {
        font-size: 14px;
        padding: 3px 9px;
    }
}

@media (max-width: 1200px) and (min-width: 1025px) {
    .sub-nav {
        right: 2.5vw;
        max-width: 300px;
        min-width: 160px;
    }
    
    .sub-nav-title {
        font-size: 16px;
    }
    
    .sub-nav-link {
        font-size: 13px;
        padding: 2px 8px;
    }
}

@media (max-width: 1100px) and (min-width: 1025px) {
    .sub-nav {
        right: 2vw;
        max-width: 250px;
        min-width: 140px;
    }
    
    .sub-nav-title {
        font-size: 14px;
    }
    
    .sub-nav-link {
        font-size: 12px;
        padding: 1px 6px;
    }
}

/* 平板端隐藏子导航 */
@media (max-width: 1024px) and (min-width: 769px) {
    .sub-nav {
        display: none;
    }
}

/* 移动端隐藏子导航 */
@media (max-width: 768px) {
    .sub-nav {
        display: none;
    }
}

/* 当页面内容较少时隐藏子导航 */
@media (max-height: 600px) {
    .sub-nav {
        display: none;
    }
}