/* 📚 内容导航按钮样式
 *
 * ContentNavManager.js 点击 .content-nav-btn 时会 toggle .active 到
 * .content-nav-toggle 上。此前缺 CSS 导致 dropdown 永远可见，2026-04-25 补齐。
 * 设计语言参考 history-toggle（chat.css）+ card-skin-toggle（JS 内嵌）。
 */

/* 按钮容器 — 与 history-toggle 同排放在左上，紧挨其右 */
.content-nav-toggle {
    position: fixed;
    top: 20px;
    left: 74px; /* history-toggle 20 + 44 + 10 gap */
    z-index: 4999;
}

/* 按钮本体 44x44 dark rounded，和 history-toggle / card-skin-btn 完全一致 */
.content-nav-btn {
    background: rgba(15, 15, 15, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    width: 44px;
    height: 44px;
    min-width: 44px;
    max-width: 44px;
    min-height: 44px;
    max-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: rgba(255, 255, 255, 0.8);
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    font-size: 16px;
    padding: 0;
    margin: 0;
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

.content-nav-btn:hover {
    background: rgba(25, 25, 25, 0.9);
    border-color: rgba(255, 255, 255, 0.2);
    color: rgba(255, 255, 255, 1);
    transform: scale(1.05);
}

/* 下拉菜单 — 默认隐藏，.active 时显示 */
.content-nav-dropdown {
    position: absolute;
    top: 52px;
    left: 0;
    min-width: 200px;
    background: rgba(15, 15, 15, 0.95);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    overflow: hidden;
    z-index: 5000;
    pointer-events: none;
}

.content-nav-toggle.active .content-nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}

/* 下拉头部 */
.content-nav-header {
    padding: 12px 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.9);
    font-size: 14px;
    font-weight: 500;
}

.content-nav-header i {
    color: rgba(255, 255, 255, 0.6);
}

/* 菜单列表 */
.content-nav-menu {
    padding: 8px;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

/* 菜单项 — 去除 <a> 默认 underline 和颜色 */
.content-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 8px;
    color: rgba(255, 255, 255, 0.75);
    text-decoration: none;
    transition: all 0.2s ease;
    -webkit-tap-highlight-color: transparent;
}

.content-nav-item:hover {
    background: rgba(255, 255, 255, 0.08);
    color: rgba(255, 255, 255, 1);
}

.content-nav-item i {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    width: 16px;
    text-align: center;
    flex-shrink: 0;
}

.content-nav-item span {
    font-size: 13px;
    white-space: nowrap;
}

/* 移动端：按钮缩小 + dropdown 宽度自适应 */
@media (max-width: 768px) {
    .content-nav-toggle {
        left: 72px; /* 与移动端 history-toggle 对齐 */
    }
    .content-nav-btn {
        width: 40px;
        height: 40px;
        min-width: 40px;
        max-width: 40px;
        min-height: 40px;
        max-height: 40px;
        font-size: 15px;
    }
    .content-nav-dropdown {
        top: 48px;
        min-width: 180px;
    }
}