/* ==========================================================================
   i18n — 导航栏语言切换器（.jx-lang）
   独立文件，避免修改 app.css；全部使用既有设计令牌，自动适配明暗主题。
   ========================================================================== */

.jx-lang {
    position: relative;
    display: inline-flex;
    align-items: center;
}

.jx-lang__toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    height: 2rem;
    padding: 0 0.5rem;
    border: none;
    border-radius: var(--radius);
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.8125rem;
    font-weight: 500;
    line-height: 1;
    cursor: pointer;
    list-style: none;
    white-space: nowrap;
    user-select: none;
    transition: background var(--transition), color var(--transition);
}

.jx-lang__toggle::-webkit-details-marker {
    display: none;
}

.jx-lang__toggle::marker {
    content: '';
}

.jx-lang__toggle:hover,
.jx-lang[open] > .jx-lang__toggle {
    color: var(--text);
    background: var(--fill-secondary);
}

.jx-lang__toggle:active {
    background: var(--surface-tertiary);
}

.jx-lang__toggle:focus-visible {
    outline: 2px solid var(--fill-primary);
    outline-offset: 2px;
}

.jx-lang__globe {
    flex: none;
}

.jx-lang__current {
    display: inline-block;
    max-width: 6rem;
    overflow: hidden;
    text-overflow: ellipsis;
}

.jx-lang__menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    z-index: 120;
    min-width: 9.5rem;
    margin: 0;
    padding: 0.25rem;
    list-style: none;
    background: var(--surface-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    animation: jx-lang-menu-in 0.16s ease both;
}

@keyframes jx-lang-menu-in {
    from {
        opacity: 0;
        transform: translateY(-4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.jx-lang__item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    padding: 0.4rem 0.6rem;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    line-height: 1.4;
    text-decoration: none;
    white-space: nowrap;
    transition: background var(--transition), color var(--transition);
}

.jx-lang__item:hover {
    background: var(--fill-secondary);
    color: var(--text);
}

.jx-lang__item.is-active {
    color: var(--text);
    font-weight: 600;
}

.jx-lang__item.is-active::after {
    content: '✓';
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* 移动端导航内的语言入口 */
.jx-nav__mobile-link--lang {
    font-size: 0.8125rem;
}

.jx-nav__mobile-link--lang.is-current {
    font-weight: 600;
}

@media (max-width: 640px) {
    .jx-lang__toggle {
        padding: 0 0.4rem;
    }

    .jx-lang__current {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    .jx-lang__menu {
        animation: none;
    }
}