/*
 * NexoFlow Language Switcher - self-contained design tokens (brand-aligned)
 * 颜色/圆角/字体与 SaaS 官方设计系统对齐（主色 #2563EB / Inter / 8-12px 圆角）
 * 作用域限定在 .nexoflow-lang 内。
 *
 * 修复项（见审查报告 P0/P1）：
 *  - 原先 lang.css 为 0 字节 → 切换器 <ul> 以裸项目符号列表常驻页面、破版。
 *  - emoji 国旗改为内联 SVG 国旗（.nexoflow-lang-flag > svg），跨平台一致，不再依赖系统 emoji 字体。
 *  - Position on Page 联动：left→左对齐、right→右对齐、footer center→水平居中；dropdown 模式 top→向下展开、bottom→向上展开。
 */

.nexoflow-lang {
    --nf-primary: var(--nfx-brand-color, #2563EB);
    --nf-primary-700: #1D4ED8;
    --nf-primary-50: #EFF4FD;
    --nf-text: #0F172A;
    --nf-muted: #64748B;
    --nf-border: rgba(14,35,80,.10);
    --nf-surface: #F8FAFC;
    --nf-surface-2: #F1F5F9;
    --nfx-radius-lg: 12px;
    --nfx-radius-sm: 6px;
    --nf-font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    --nf-shadow: 0 4px 12px rgba(15, 23, 42, 0.10), 0 2px 4px rgba(15, 23, 42, 0.06);
    --nf-space-2: 8px;
    --nf-space-3: 12px;

    font-family: var(--nf-font);
    color: var(--nf-text);
    -webkit-font-smoothing: antialiased;
    display: inline-block;
    position: relative;
    box-sizing: border-box;
}

.nexoflow-lang *,
.nexoflow-lang *::before,
.nexoflow-lang *::after {
    box-sizing: border-box;
}

/* === Shared bits === */
.nexoflow-lang-flag {
    display: inline-block;
    width: 20px;
    height: 15px;
    font-size: 15px;
    line-height: 1;
    flex-shrink: 0;
    vertical-align: middle;
}

.nexoflow-lang-flag svg {
    display: block;
    width: 100%;
    height: 100%;
    border-radius: 2px;
    overflow: hidden;
}

.nexoflow-lang-name {
    font-size: 0.875rem;
    line-height: 1;
}

.nexoflow-lang-arrow {
    margin-left: auto;
    font-size: 0.625rem;
    color: var(--nf-muted);
    transition: transform 0.2s ease;
}

/* === Dropdown mode === */
.nexoflow-lang-dropdown .nexoflow-lang-toggle {
    display: inline-flex;
    align-items: center;
    gap: var(--nf-space-2);
    padding: 6px 10px;
    background: #fff;
    border: 1px solid var(--nf-border);
    border-radius: var(--nfx-radius-sm);
    cursor: pointer;
    font-family: var(--nf-font);
    font-size: 0.875rem;
    color: var(--nf-text);
    transition: all 0.15s ease;
}

.nexoflow-lang-dropdown .nexoflow-lang-toggle:hover {
    border-color: var(--nf-primary);
}

.nexoflow-lang-dropdown .nexoflow-lang-toggle:focus-visible {
    outline: 3px solid var(--nf-primary);
    outline-offset: 2px;
}

.nexoflow-lang-dropdown.open .nexoflow-lang-arrow {
    transform: rotate(180deg);
}

/* 关键修复：默认隐藏菜单，仅在 .open 时显示 */
.nexoflow-lang-menu {
    list-style: none;
    margin: 6px 0 0;
    padding: var(--nf-space-2);
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 180px;
    background: #fff;
    border: 1px solid var(--nf-border);
    border-radius: var(--nfx-radius-lg);
    box-shadow: var(--nf-shadow);
    z-index: 100;
    display: none;
}

.nexoflow-lang-dropdown.open .nexoflow-lang-menu {
    display: block;
    animation: nf-lang-pop 0.15s ease;
}

@keyframes nf-lang-pop {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* === Position on Page 联动（auto-inject 的固定角标 #nexoflow-lang-auto）===
 * 菜单对齐：left → 左对齐；right → 右对齐；footer center → 水平居中
 * 展开方向：top 位置 → 向下展开；bottom 位置 → 向上展开 */
#nexoflow-lang-auto .nexoflow-lang-menu {
    left: auto;
    right: 0;
}

#nexoflow-lang-auto.nexoflow-lang-pos-left .nexoflow-lang-menu {
    left: 0;
    right: auto;
}

#nexoflow-lang-auto.nexoflow-lang-pos-center .nexoflow-lang-menu {
    left: 50%;
    right: auto;
    transform: translateX(-50%);
}

#nexoflow-lang-auto.nexoflow-lang-pos-bottom .nexoflow-lang-menu {
    top: auto;
    bottom: 100%;
    margin: 0 0 6px;
}

#nexoflow-lang-auto.nexoflow-lang-pos-bottom .nexoflow-lang-dropdown.open .nexoflow-lang-menu {
    animation: nf-lang-pop-up 0.15s ease;
}

#nexoflow-lang-auto.nexoflow-lang-pos-center .nexoflow-lang-dropdown.open .nexoflow-lang-menu {
    animation: nf-lang-pop-center 0.15s ease;
}

#nexoflow-lang-auto.nexoflow-lang-pos-center.nexoflow-lang-pos-bottom .nexoflow-lang-dropdown.open .nexoflow-lang-menu {
    animation: nf-lang-pop-center-up 0.15s ease;
}

@keyframes nf-lang-pop-up {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes nf-lang-pop-center {
    from { opacity: 0; transform: translateX(-50%) translateY(-4px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

@keyframes nf-lang-pop-center-up {
    from { opacity: 0; transform: translateX(-50%) translateY(4px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.nexoflow-lang-menu li {
    margin: 0;
}

.nexoflow-lang-menu li + li {
    margin-top: 2px;
}

.nexoflow-lang-link {
    display: flex;
    align-items: center;
    gap: var(--nf-space-2);
    padding: 8px 10px;
    border-radius: var(--nfx-radius-sm);
    text-decoration: none;
    color: var(--nf-text);
    font-size: 0.875rem;
    transition: background 0.15s ease;
}

.nexoflow-lang-link:hover {
    background: var(--nf-surface-2);
    color: var(--nf-primary);
}

.nexoflow-lang-menu li.active .nexoflow-lang-link {
    background: var(--nf-primary-50);
    color: var(--nf-primary);
    font-weight: 600;
}

/* === Buttons mode === */
.nexoflow-lang-buttons {
    display: inline-flex;
    flex-wrap: wrap;
    gap: var(--nf-space-2);
}

.nexoflow-lang-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: #fff;
    border: 1px solid var(--nf-border);
    border-radius: 6px;
    text-decoration: none;
    color: var(--nf-text);
    font-size: 0.875rem;
    font-family: var(--nf-font);
    transition: all 0.15s ease;
}

.nexoflow-lang-btn:hover {
    border-color: var(--nf-primary);
    color: var(--nf-primary);
}

.nexoflow-lang-btn.active {
    background: var(--nf-primary);
    border-color: var(--nf-primary);
    color: #fff;
}

/* === Inline mode === */
.nexoflow-lang-inline {
    display: inline-flex;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--nf-space-2);
}

.nexoflow-lang-inline .nexoflow-lang-link {
    padding: 4px 8px;
}

.nexoflow-lang-sep {
    color: var(--nf-muted);
}

@media (prefers-reduced-motion: reduce) {
    .nexoflow-lang * {
        transition: none !important;
        animation: none !important;
    }
}

@media (max-width: 640px) {
    #nexoflow-lang-auto.nexoflow-lang-pos-right .nexoflow-lang-menu {
        right: -8px;
    }
    #nexoflow-lang-auto.nexoflow-lang-pos-left .nexoflow-lang-menu {
        left: -8px;
    }
    .nexoflow-lang-menu {
        min-width: 160px;
    }
    .nexoflow-lang-dropdown .nexoflow-lang-toggle {
        padding: 8px 12px;
        font-size: 1rem;
    }
    .nexoflow-lang-btn {
        padding: 8px 14px;
        font-size: 1rem;
    }
    .nexoflow-lang-link {
        padding: 10px 12px;
        font-size: 1rem;
    }
}