重新设计用户/作者卡片小工具：消除多层卡片堆叠

- WidgetUserCard/WidgetAuthorCard 内层根节点去掉重复的 zib-widget widget 类
- 用户卡片补 classname=widget_aksrt_user_card 钩子
- widget-batch5.css 新增外层 .zib-widget 包裹层透明化规则（含首页侧栏覆盖）
- 内层 .aksrt-user-card/.aksrt-author-card margin-bottom 归零，间距由外层统一
- 删除 custom-amount.css 重复的 .aksrt-user-card* 段
- 删除 sidebar.css 失效的 .widget-user-card* 死代码
- author-actions.css .user-card.author.zib-widget → .user-card.author

assets/css/frontend/enhancements/components/custom-amount.css

@@ -110,116 +110,6 @@
     animation-play-state: paused;
 }
 
-/* ============================================================
- * 10. 用户卡片 Widget
- * ============================================================ */
-.aksrt-user-card {
-    text-align: center;
-    padding: 20px;
-}
-
-.aksrt-user-card__avatar {
-    width: 72px;
-    height: 72px;
-    border-radius: 50%;
-    margin: 0 auto 12px;
-    overflow: hidden;
-    border: 3px solid var(--color-primary-soft, rgba(136,171,218,0.1));
-}
-
-.aksrt-user-card__avatar img {
-    width: 100%;
-    height: 100%;
-    object-fit: cover;
-}
-
-.aksrt-user-card__name {
-    margin: 0 0 4px;
-    font-size: 16px;
-    font-weight: 600;
-    color: var(--color-ink);
-}
-
-.aksrt-user-card__name a {
-    color: inherit;
-    text-decoration: none;
-}
-
-.aksrt-user-card__name a:hover {
-    color: var(--color-primary, var(--color-primary));
-}
-
-.aksrt-user-card__bio {
-    margin: 0 0 12px;
-    font-size: 13px;
-    color: var(--color-ink-3);
-    line-height: 1.5;
-    display: -webkit-box;
-    -webkit-line-clamp: 2;
-    -webkit-box-orient: vertical;
-    overflow: hidden;
-}
-
-.aksrt-user-card__stats {
-    display: flex;
-    justify-content: center;
-    gap: 20px;
-    margin-bottom: 16px;
-}
-
-.aksrt-user-card__stat {
-    text-align: center;
-}
-
-.aksrt-user-card__stat-value {
-    display: block;
-    font-size: 18px;
-    font-weight: 600;
-    color: var(--color-ink);
-}
-
-.aksrt-user-card__stat-label {
-    font-size: 12px;
-    color: var(--color-ink-4, #8A8F98);
-}
-
-.aksrt-user-card__actions {
-    display: flex;
-    gap: 8px;
-    justify-content: center;
-}
-
-.aksrt-user-card__btn {
-    display: inline-flex;
-    align-items: center;
-    gap: 4px;
-    padding: 6px 16px;
-    border-radius: var(--radius, 10px);
-    font-size: 13px;
-    text-decoration: none;
-    transition: all 0.15s;
-}
-
-.aksrt-user-card__btn--primary {
-    background: var(--color-primary, var(--color-primary));
-    color: #fff;
-}
-
-.aksrt-user-card__btn--primary:hover {
-    opacity: 0.85;
-    color: #fff;
-}
-
-.aksrt-user-card__btn--ghost {
-    border: 1px solid var(--color-line);
-    color: var(--color-ink-2);
-}
-
-.aksrt-user-card__btn--ghost:hover {
-    border-color: var(--color-primary, var(--color-primary));
-    color: var(--color-primary, var(--color-primary));
-}
-
 /* ============================================================
  * 11. 滚动触发动画初始状态
  * ============================================================ */