/**
 * Ethantheme Child - Footer Styles
 * 支持 4 套预设：classic_4col / centered / split / minimal
 * 含社媒按钮、菜单列、版权栏、回到顶部、进入动画、响应式
 */

/* ==========================================================================
   1. Footer 通用容器
   ========================================================================== */
.eth-footer {
    background: var(--eth-dark);
    color: var(--eth-light);
    padding-block: var(--eth-space-2xl);
    position: relative;
    overflow: hidden;
}

/* 暗色反转：Footer 内部强制暗色语义 */
.eth-footer {
    --eth-bg-body: hsl(0, 0%, 8%);
    --eth-bg-surface: hsl(0, 0%, 12%);
    --eth-bg-muted: hsl(0, 0%, 16%);
    --eth-text-body: hsla(0, 0%, 100%, 0.7);
    --eth-text-title: hsl(0, 0%, 100%);
    --eth-text-muted: hsla(0, 0%, 100%, 0.5);
    --eth-border: hsla(0, 0%, 100%, 0.1);
    --eth-border-strong: hsla(0, 0%, 100%, 0.2);
}

.eth-footer__inner {
    max-width: var(--eth-container);
    margin-inline: auto;
    padding-inline: var(--eth-space-m);
}

.eth-footer a {
    color: var(--eth-text-body);
    text-decoration: none;
    transition: color var(--eth-transition-s);
}
.eth-footer a:hover {
    color: var(--eth-primary-l-1);
}

/* ==========================================================================
   2. Logo + 描述
   ========================================================================== */
.eth-footer__brand {
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-s);
}
.eth-footer__logo img {
    max-height: 40px;
    width: auto;
    filter: brightness(0) invert(1); /* 白色logo */
}
.eth-footer__logo-text {
    font-size: var(--eth-fs-l);
    font-weight: var(--eth-fw-bold);
    color: var(--eth-text-title);
}
.eth-footer__description {
    font-size: var(--eth-fs-small);
    line-height: var(--eth-lh-body);
    color: var(--eth-text-body);
    max-width: 300px;
}
.eth-footer__description p { margin: 0; }
.eth-footer__description p + p { margin-top: var(--eth-space-2xs); }

/* ==========================================================================
   3. 社媒按钮
   ========================================================================== */
.eth-social-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--eth-space-2xs);
}
.eth-social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--eth-radius-full);
    background: hsla(0, 0%, 100%, 0.08);
    color: var(--eth-text-body);
    font-size: var(--eth-fs-xs);
    text-decoration: none;
    transition: all var(--eth-transition-s);
    border: 1px solid transparent;
    overflow: hidden;
    position: relative;
}
.eth-social-link:hover {
    background: var(--eth-primary);
    color: var(--eth-light);
    transform: translateY(-2px);
    box-shadow: var(--eth-shadow-m);
}
/* 社媒图标用文字首字母替代（简化，无 SVG） */
.eth-social-link--x::before { content: 'X'; }
.eth-social-link--youtube::before { content: 'YT'; }
.eth-social-link--instagram::before { content: 'IG'; }
.eth-social-link--linkedin::before { content: 'in'; }
.eth-social-link--tiktok::before { content: 'TT'; }
.eth-social-link--facebook::before { content: 'f'; }
/* 隐藏原始文字（aria-label 保留可访问性） */
.eth-social-link { font-size: 0; }
.eth-social-link::before {
    font-size: var(--eth-fs-xs);
    font-weight: var(--eth-fw-semibold);
}

/* ==========================================================================
   4. 菜单列
   ========================================================================== */
.eth-footer__menu-col {
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-s);
}
.eth-footer__menu-title {
    font-size: var(--eth-fs-small);
    font-weight: var(--eth-fw-semibold);
    color: var(--eth-text-title);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin: 0 0 var(--eth-space-xs);
}
.eth-footer__menu {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-2xs);
}
.eth-footer__menu a {
    font-size: var(--eth-fs-small);
    color: var(--eth-text-body);
    transition: color var(--eth-transition-s), padding-left var(--eth-transition-s);
}
.eth-footer__menu a:hover {
    color: var(--eth-primary-l-1);
    padding-left: 4px;
}

/* ==========================================================================
   5. 底部版权栏
   ========================================================================== */
.eth-footer__bottom {
    margin-top: var(--eth-space-xl);
    padding-top: var(--eth-space-m);
    border-top: 1px solid var(--eth-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--eth-space-m);
    flex-wrap: wrap;
}
.eth-footer__copyright {
    font-size: var(--eth-fs-xs);
    color: var(--eth-text-muted);
    margin: 0;
}
.eth-footer__top {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--eth-radius-full);
    background: hsla(0, 0%, 100%, 0.08);
    color: var(--eth-text-body);
    border: none;
    cursor: pointer;
    transition: all var(--eth-transition-s);
}
.eth-footer__top:hover {
    background: var(--eth-primary);
    color: var(--eth-light);
    transform: translateY(-2px);
}

/* ==========================================================================
   6. 预设1：classic_4col（4 列网格）
   ========================================================================== */
/* 整体 2 列：品牌列（竖向） + 菜单区（内部再分 3 列） */
.eth-footer--classic_4col .eth-footer__main {
    display: grid;
    grid-template-columns: 1.5fr 3fr;
    gap: var(--eth-space-xl);
    align-items: start;
}
/* 第 1 列：品牌信息竖向排列 */
.eth-footer--classic_4col .eth-footer__brand-col,
.eth-footer--classic_4col .eth-footer__brand {
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-m);
}
/* 菜单区：3 列网格，对应 3 个菜单 */
.eth-footer--classic_4col .eth-footer__menus--col {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--eth-space-l);
    align-items: start;
}
/* 每个菜单列：标题在上，菜单项横向排列 */
.eth-footer--classic_4col .eth-footer__menu-col {
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-s);
}
.eth-footer--classic_4col .eth-footer__menu {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--eth-space-2xs) var(--eth-space-m);
}
.eth-footer--classic_4col .eth-footer__menu a:hover {
    padding-left: 0;
    color: var(--eth-primary-l-1);
}
@media (max-width: 992px) {
    .eth-footer--classic_4col .eth-footer__main {
        grid-template-columns: 1fr;
        gap: var(--eth-space-l);
    }
    .eth-footer--classic_4col .eth-footer__menus--col {
        grid-template-columns: 1fr 1fr;
    }
}
@media (max-width: 600px) {
    .eth-footer--classic_4col .eth-footer__menus--col {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   7. 预设2：centered（居中布局）
   ========================================================================== */
.eth-footer--centered .eth-footer__main {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--eth-space-l);
}
.eth-footer--centered .eth-footer__brand-col {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--eth-space-s);
}
.eth-footer--centered .eth-footer__description { max-width: 480px; }
.eth-footer--centered .eth-footer__menus {
    display: flex;
    justify-content: center;
    gap: var(--eth-space-2xl);
    flex-wrap: wrap;
}
.eth-footer--centered .eth-footer__menu-col { align-items: center; }
.eth-footer--centered .eth-footer__menu { align-items: center; }
.eth-footer--centered .eth-footer__bottom { justify-content: center; }
@media (max-width: 768px) {
    .eth-footer--centered .eth-footer__menus {
        flex-direction: column;
        gap: var(--eth-space-m);
    }
}

/* ==========================================================================
   8. 预设3：split（左右分栏）
   ========================================================================== */
.eth-footer--split .eth-footer__main {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--eth-space-2xl);
}
.eth-footer--split .eth-footer__brand-col {
    display: flex;
    flex-direction: column;
    gap: var(--eth-space-m);
}
.eth-footer--split .eth-footer__menus {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--eth-space-l);
}
@media (max-width: 768px) {
    .eth-footer--split .eth-footer__main {
        grid-template-columns: 1fr;
    }
    .eth-footer--split .eth-footer__menus {
        grid-template-columns: 1fr 1fr;
    }
}
@media (max-width: 480px) {
    .eth-footer--split .eth-footer__menus {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   9. 预设4：minimal（极简单行）
   ========================================================================== */
.eth-footer--minimal {
    padding-block: var(--eth-space-m);
}
.eth-footer--minimal .eth-footer__main {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--eth-space-m);
    flex-wrap: wrap;
}
.eth-footer--minimal .eth-footer__bottom {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
    flex: 1;
    justify-content: space-between;
}
.eth-footer--minimal .eth-footer__brand-col,
.eth-footer--minimal .eth-footer__menus {
    display: none;
}

/* ==========================================================================
   10. 进入动画
   ========================================================================== */
/* Footer 进入动画：fade-in-up */
.eth-footer {
    animation: eth-footer-enter 0.6s ease-out;
}
@keyframes eth-footer-enter {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 子元素错峰动画（stagger） */
.eth-footer--classic_4col .eth-footer__brand-col,
.eth-footer--classic_4col .eth-footer__menu-col {
    animation: eth-footer-item-enter 0.5s ease-out backwards;
}
.eth-footer--classic_4col .eth-footer__menu-col:nth-child(2) { animation-delay: 0.1s; }
.eth-footer--classic_4col .eth-footer__menu-col:nth-child(3) { animation-delay: 0.2s; }
.eth-footer--classic_4col .eth-footer__menu-col:nth-child(4) { animation-delay: 0.3s; }

@keyframes eth-footer-item-enter {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 尊重 prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
    .eth-footer,
    .eth-footer * {
        animation: none !important;
        transition: none !important;
    }
}

/* ==========================================================================
   11. 可访问性
   ========================================================================== */
.eth-social-link:focus-visible {
    outline: 2px solid var(--eth-primary);
    outline-offset: 2px;
}
.eth-footer__top:focus-visible {
    outline: 2px solid var(--eth-primary);
    outline-offset: 2px;
}