/* ============================================
 * 模块: 页脚
 * 文件: assets/css/footer.css
 * 依赖: main.css
 * @since 3.0.0
 * ============================================ */

/* ---------- 页脚容器 ---------- */
.site-footer {
    background: #1D2129;
    color: rgba(255, 255, 255, 0.7);
    padding: var(--spacing-xxxl) 0 var(--spacing-xl);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-loose);
}

/* ---------- 三列网格 ---------- */
.site-footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.site-footer__col { }
.site-footer__title {
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: #fff;
    margin-bottom: var(--spacing-md);
}
.site-footer__desc {
    color: rgba(255, 255, 255, 0.5);
    line-height: var(--line-height-loose);
}

/* ---------- 链接列表 ---------- */
.site-footer__links {
    list-style: none;
}
.site-footer__links li {
    margin-bottom: var(--spacing-xs);
}
.site-footer__links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}
.site-footer__links a:hover {
    color: #fff;
}

/* ---------- 社交联系项 ---------- */
.site-footer__contact {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}
.site-footer__social-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}
.site-footer__social-link:hover {
    color: #fff;
}
.site-footer__social-link svg {
    flex-shrink: 0;
    fill: currentColor;
}

/* ---------- 二维码 ---------- */
.site-footer__qrcode {
    margin-top: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
}
.site-footer__qrcode-img {
    width: 120px;
    height: 120px;
    object-fit: contain;
    background: #fff;
    border-radius: var(--radius-small);
    padding: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}
.site-footer__qrcode-text {
    font-size: var(--font-size-xs);
    color: rgba(255, 255, 255, 0.5);
    text-align: center;
    max-width: 120px;
}

/* ---------- 底部版权 ---------- */
.site-footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    margin-top: var(--spacing-lg);
}
.site-footer__copyright {
    color: rgba(255, 255, 255, 0.4);
    font-size: var(--font-size-xs);
}
.site-footer__icp {
    color: rgba(255, 255, 255, 0.4);
    font-size: var(--font-size-xs);
}
.site-footer__icp a {
    color: rgba(255, 255, 255, 0.4);
    text-decoration: none;
}
.site-footer__icp a:hover {
    color: rgba(255, 255, 255, 0.7);
}
.site-footer__sep {
    margin: 0 var(--spacing-xs);
    color: rgba(255, 255, 255, 0.2);
}

/* ---------- 友情链接 ---------- */
.site-footer__friends {
    padding-top: var(--spacing-lg);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-xs) var(--spacing-md);
}
.site-footer__friends-title {
    color: rgba(255, 255, 255, 0.4);
    font-size: var(--font-size-xs);
}
.site-footer__friends a {
    color: rgba(255, 255, 255, 0.4);
    font-size: var(--font-size-xs);
    text-decoration: none;
    transition: color var(--transition-base);
}
.site-footer__friends a:hover {
    color: rgba(255, 255, 255, 0.7);
}

/* ---------- 浮动工具栏 ---------- */
.floating-toolbar {
    position: fixed;
    right: var(--spacing-xl);
    bottom: var(--spacing-xxl);
    z-index: 900;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

/* ---- 主题切换按钮 ---- */
.floating-toolbar__theme {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-circle);
    background: var(--color-bg-container);
    box-shadow: var(--shadow-2);
    cursor: pointer;
    color: var(--color-text-primary);
    transition: background var(--transition-base), color var(--transition-base), transform 0.15s ease;
    -webkit-tap-highlight-color: transparent;
    outline: none;
}
.floating-toolbar__theme:hover {
    background: var(--color-bg-hover);
    color: var(--color-primary);
}
.floating-toolbar__theme:active {
    transform: scale(0.88);
}
.floating-toolbar__theme:focus-visible {
    box-shadow: var(--shadow-2), 0 0 0 2px var(--color-primary);
}

/* 暗黑模式下提亮悬浮按钮 */
[data-theme="dark"] .floating-toolbar__theme {
    background: #383838;
    border-color: #4A4A4A;
    color: rgba(255, 255, 255, 0.9);
}
[data-theme="dark"] .floating-toolbar__theme:hover {
    background: #4A4A4A;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .floating-toolbar__theme {
        background: #383838;
        border-color: #4A4A4A;
        color: rgba(255, 255, 255, 0.9);
    }
    :root:not([data-theme="light"]) .floating-toolbar__theme:hover {
        background: #4A4A4A;
    }
}

/* 主题图标切换 */
.floating-toolbar__theme-icon {
    display: flex;
    align-items: center;
    justify-content: center;
}
.floating-toolbar__theme-icon--dark {
    display: none;
}
[data-theme="dark"] .floating-toolbar__theme-icon--light {
    display: none;
}
[data-theme="dark"] .floating-toolbar__theme-icon--dark {
    display: flex;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .floating-toolbar__theme-icon--light {
        display: none;
    }
    :root:not([data-theme="light"]) .floating-toolbar__theme-icon--dark {
        display: flex;
    }
}

/* ---- 返回顶部按钮 ---- */
.back-to-top {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-circle);
    background: var(--color-bg-container);
    box-shadow: var(--shadow-2);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease, background var(--transition-base);
    -webkit-tap-highlight-color: transparent;
    outline: none;
}
.back-to-top--visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    background: var(--color-primary);
    color: #fff;
}
.back-to-top:active {
    transform: translateY(0) scale(0.88);
}
.back-to-top:focus-visible {
    box-shadow: var(--shadow-2), 0 0 0 2px var(--color-primary);
}
/* 暗黑模式下提亮 */
[data-theme="dark"] .back-to-top {
    background: #383838;
    border: 1px solid #4A4A4A;
    color: rgba(255, 255, 255, 0.9);
}
[data-theme="dark"] .back-to-top:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #fff;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .back-to-top {
        background: #383838;
        border: 1px solid #4A4A4A;
        color: rgba(255, 255, 255, 0.9);
    }
    :root:not([data-theme="light"]) .back-to-top:hover {
        background: var(--color-primary);
        border-color: var(--color-primary);
        color: #fff;
    }
}
.back-to-top svg {
    fill: currentColor;
}

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
    .site-footer__grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-lg);
    }
    .site-footer {
        padding: var(--spacing-xxl) 0 var(--spacing-lg);
    }
}
@media (max-width: 640px) {
    .site-footer {
        padding: var(--spacing-xl) 0 var(--spacing-lg);
    }
    .site-footer__grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    .site-footer__bottom {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    .floating-toolbar {
        right: var(--spacing-md);
        bottom: var(--spacing-md);
    }
}