Revert "fix: set fixed banner height for all screen sizes"

This reverts commit c8cd1996730a6396b425846f7c2f5a07f405907a.

src/view/HomePage.vue

@@ -325,7 +325,7 @@ export default {
 /* 媒体查询（手机） */
 @media screen and (max-width: 768px) {
   #swiper {
-    height: 300px;
+    height: auto;
   }
 
   #swiper .banner-swiper .swiper-slide-title > h1 {
@@ -431,7 +431,7 @@ export default {
 /* 媒体查询（平板） */
 @media screen and (min-width: 768px) and (max-width: 996px) {
   #swiper {
-    height: 400px;
+    height: auto;
   }
 
   #swiper .banner-swiper .swiper-slide-title > h1 {