fix(listings): 手机轮播改为居中裁切，左右滑只切换图片

超宽海报在图内横滑不好看。轮播和预览都只保留中间一段，左右滑动回到切换下一张。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/features/listings/views/MobileHomeView.css

@@ -330,59 +330,23 @@
 
 .banner-swipe.is-poster {
   height: 168px;
-  background: #eef3f8;
 }
 
 .mobile-banner.is-poster {
   height: 168px;
   min-height: 0;
   padding: 0;
-  background: #eef3f8;
-}
-
-.poster-scroller {
-  height: 100%;
-  overflow-x: auto;
-  overflow-y: hidden;
-  -webkit-overflow-scrolling: touch;
-  scrollbar-width: none;
-}
-
-.poster-scroller::-webkit-scrollbar {
-  display: none;
 }
 
 .mobile-banner.is-poster .banner-image {
-  position: static;
-  display: block;
-  width: auto;
-  max-width: none;
-  height: 168px;
-  object-fit: unset;
-  background: transparent;
+  object-fit: cover;
+  object-position: center;
 }
 
 .mobile-banner.is-poster .banner-badge {
   display: none;
 }
 
-.banner-step-row {
-  display: flex;
-  justify-content: flex-end;
-  gap: 8px;
-  margin: -4px 0 12px;
-}
-
-.banner-step-row button {
-  border: 0;
-  padding: 4px 10px;
-  border-radius: 999px;
-  background: #e8eef5;
-  color: #334155;
-  font-size: 12px;
-  font-weight: 700;
-}
-
 .banner-lightbox {
   position: fixed;
   inset: 0;
@@ -412,39 +376,29 @@
   border-radius: 999px;
 }
 
-.banner-lightbox-count,
-.banner-lightbox-hint {
-  margin: 0;
-  text-align: center;
-}
-
 .banner-lightbox-count {
   position: absolute;
   top: calc(18px + env(safe-area-inset-top));
   left: 0;
   right: 0;
+  margin: 0;
+  text-align: center;
   font-size: 14px;
   font-weight: 700;
 }
 
-.banner-lightbox-scroller {
-  overflow-x: auto;
-  overflow-y: hidden;
-  -webkit-overflow-scrolling: touch;
+.banner-lightbox-frame {
+  width: 100%;
+  aspect-ratio: 2.15 / 1;
+  overflow: hidden;
 }
 
-.banner-lightbox-scroller img {
+.banner-lightbox-frame img {
   display: block;
-  width: auto;
-  max-width: none;
-  height: 58vh;
-  margin: 0 auto;
-}
-
-.banner-lightbox-hint {
-  margin-top: 14px;
-  color: rgba(255, 255, 255, 0.72);
-  font-size: 12px;
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  object-position: center;
 }
 
 .banner-lightbox-nav {

frontend/src/features/listings/views/MobileHomeView.vue

@@ -103,10 +103,8 @@ const displayBanners = computed<HomeBannerSlide[]>(() => {
   }
   return bannerSlides.value
 })
-const bannerSwipeRef = ref<{ prev: () => void; next: () => void } | null>(null)
 const bannerPreviewVisible = ref(false)
 const bannerPreviewIndex = ref(0)
-const bannerPreviewScroller = ref<HTMLElement | null>(null)
 const bannerPreviewImages = computed(() =>
   displayBanners.value
     .map(slide => slide.image_url?.trim() || '')
@@ -520,42 +518,6 @@ function openCooperationFeedback() {
   cooperationFeedbackPreviewVisible.value = true
 }
 
-let posterDragged = false
-
-function centerWideImage(event: Event) {
-  const img = event.target as HTMLImageElement
-  const scroller = img.parentElement
-  if (!scroller) return
-  scroller.scrollLeft = Math.max(0, (scroller.scrollWidth - scroller.clientWidth) / 2)
-}
-
-function onPosterTouchStart() {
-  posterDragged = false
-}
-
-function onPosterTouchMove() {
-  posterDragged = true
-}
-
-function onPosterClick(slide: HomeBannerSlide) {
-  if (posterDragged) {
-    posterDragged = false
-    return
-  }
-  openBannerPreview(slide)
-}
-
-function stepBanner(step: number) {
-  if (step < 0) bannerSwipeRef.value?.prev()
-  else bannerSwipeRef.value?.next()
-}
-
-function centerBannerPreview() {
-  const scroller = bannerPreviewScroller.value
-  if (!scroller) return
-  scroller.scrollLeft = Math.max(0, (scroller.scrollWidth - scroller.clientWidth) / 2)
-}
-
 function openBannerPreview(slide: HomeBannerSlide) {
   const url = slide.image_url?.trim()
   if (!url) return
@@ -575,11 +537,8 @@ function shiftBannerPreview(step: number) {
   bannerPreviewIndex.value = (bannerPreviewIndex.value + step + total) % total
 }
 
-watch([bannerPreviewVisible, bannerPreviewIndex], async ([open]) => {
+watch(bannerPreviewVisible, open => {
   document.body.style.overflow = open ? 'hidden' : ''
-  if (!open) return
-  await nextTick()
-  centerBannerPreview()
 })
 
 function hasBannerCopy(slide: HomeBannerSlide) {
@@ -973,7 +932,6 @@ if (!restoreHomeConfigFromCache()) {
 
           <!-- Banner 轮播 -->
           <van-swipe
-            ref="bannerSwipeRef"
             class="banner-swipe"
             :class="{
               'is-poster': displayBanners.some(slide => slide.image_url && !hasBannerCopy(slide)),
@@ -995,22 +953,8 @@ if (!restoreHomeConfigFromCache()) {
                 ]"
                 @click="openBannerPreview(slide)"
               >
-                <div
-                  v-if="slide.image_url && !hasBannerCopy(slide)"
-                  class="poster-scroller"
-                  @touchstart.stop="onPosterTouchStart"
-                  @touchmove.stop="onPosterTouchMove"
-                  @click.stop="onPosterClick(slide)"
-                >
-                  <img
-                    class="banner-image"
-                    :src="slide.image_url"
-                    :alt="slide.title || '首页轮播图'"
-                    @load="centerWideImage"
-                  />
-                </div>
                 <img
-                  v-else-if="slide.image_url"
+                  v-if="slide.image_url"
                   class="banner-image"
                   :src="slide.image_url"
                   :alt="slide.title || slide.eyebrow || '首页轮播图'"
@@ -1024,16 +968,6 @@ if (!restoreHomeConfigFromCache()) {
               </div>
             </van-swipe-item>
           </van-swipe>
-          <div
-            v-if="
-              displayBanners.length > 1 &&
-              displayBanners.some(slide => slide.image_url && !hasBannerCopy(slide))
-            "
-            class="banner-step-row"
-          >
-            <button type="button" @click="stepBanner(-1)">上一张</button>
-            <button type="button" @click="stepBanner(1)">下一张</button>
-          </div>
 
           <div class="biz-entry-grid" aria-label="业务入口">
             <RouterLink class="biz-entry" to="/">
@@ -1388,14 +1322,9 @@ if (!restoreHomeConfigFromCache()) {
         <p class="banner-lightbox-count">
           {{ bannerPreviewIndex + 1 }}/{{ bannerPreviewImages.length }}
         </p>
-        <div ref="bannerPreviewScroller" class="banner-lightbox-scroller">
-          <img
-            :src="bannerPreviewImages[bannerPreviewIndex]"
-            alt="轮播图预览"
-            @load="centerBannerPreview"
-          />
+        <div class="banner-lightbox-frame">
+          <img :src="bannerPreviewImages[bannerPreviewIndex]" alt="轮播图预览" />
         </div>
-        <p class="banner-lightbox-hint">左右滑动查看完整海报</p>
         <div v-if="bannerPreviewImages.length > 1" class="banner-lightbox-nav">
           <button type="button" @click="shiftBannerPreview(-1)">上一张</button>
           <button type="button" @click="shiftBannerPreview(1)">下一张</button>