/* =============================================
   Mobile Bottom Navigation - Minimal B&W
   ============================================= */

/* 仅移动端生效 */
@media (max-width: 768px) {
    body {
        padding-bottom: calc(50px + env(safe-area-inset-bottom, 0px)) !important;
    }
}

.mobile-bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    z-index: 9999;
    padding-bottom: env(safe-area-inset-bottom, 0px);
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1),
                opacity 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (max-width: 768px) {
    .mobile-bottom-nav {
        display: block;
    }
}

.mobile-bottom-nav.nav-hidden {
    transform: translateY(100%);
    opacity: 0;
    pointer-events: none;
}

/* 导航列表 */
.mobile-nav-list {
    display: flex;
    width: 100%;
    margin: 0;
    padding: 0;
    list-style: none;
    height: 50px;
}

.mobile-nav-item {
    flex: 1;
}

/* 导航链接 */
.mobile-nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 50px;
    color: rgba(0, 0, 0, 0.3);
    text-decoration: none;
    font-size: 10px;
    font-weight: 400;
    letter-spacing: 0.2px;
    transition: color 0.2s ease, transform 0.2s ease;
    -webkit-tap-highlight-color: transparent;
    gap: 2px;
    background: none;
    border: none;
    border-radius: 0;
    outline: none;
    position: relative;
}

.mobile-nav-link:hover,
.mobile-nav-link:focus,
.mobile-nav-link:active {
    color: rgba(0, 0, 0, 0.7);
    text-decoration: none;
    background: none;
}

/* 选中态 */
.mobile-nav-link.active {
    color: #111;
}

/* 选中态图标背后的药丸指示器 (Material 3 风格) */
.mobile-nav-link.active::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 36px;
    height: 22px;
    background: rgba(0, 0, 0, 0.08);
    border-radius: 11px;
}

.mobile-nav-link.active .mobile-nav-label {
    font-weight: 600;
}

/* 图标 */
.mobile-nav-icon {
    font-size: 25px;
    line-height: 1;
    display: block;
}

/* 投稿按钮 - 中间图标稍大 */
.mobile-nav-item--publish .mobile-nav-icon {
    font-size: 27px;
}

/* 文字标签 */
.mobile-nav-label {
    display: block;
    line-height: 1;
    font-size: 9px;
}

/* 用户头像图标 */
.mobile-nav-avatar {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    object-fit: cover;
    border: 1.5px solid rgba(0, 0, 0, 0.08);
}

/* active 状态下头像边框高亮 */
.mobile-nav-link.active .mobile-nav-avatar {
    border-color: currentColor;
}

/* 未读消息徽标 */
.mobile-nav-badge {
    position: absolute;
    top: 2px;
    right: 42%;
    transform: translateX(14px);
    background: #ff4757;
    color: #fff;
    font-size: 10px;
    font-weight: 600;
    min-width: 16px;
    height: 16px;
    padding: 0 4px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
    pointer-events: none;
}