feat: 更新样式以支持导航面板内部滚动并调整页面布局

public/themes/dist_static/static/css/common.css

@@ -1297,6 +1297,7 @@ body {
   z-index: 2;
   display: grid;
   grid-template-rows: 0fr;
+  max-height: calc(100dvh - var(--header-h));
   visibility: hidden;
   background: var(--color-white);
   border-top: 1px solid rgb(223, 224, 226);
@@ -1305,6 +1306,10 @@ body {
 }.nav-mega__inner {
   overflow: hidden;
   min-height: 0;
+}.site-header__nav-item:hover .nav-mega__inner {
+  overflow-y: auto;
+  overscroll-behavior: contain;
+  -webkit-overflow-scrolling: touch;
 }.nav-mega__dropdown-content.product {
   display: grid;
   min-height: 45rem;

public/themes/dist_static/static/js/common.js

@@ -147,6 +147,9 @@ $(function() {
 		$(this).attr("aria-expanded", !isExpanded);
 	});
 
+	// Lenis.stop() 会 preventDefault 所有滚轮；面板需 data-lenis-prevent 才能内部滚动
+	$(".nav-mega").attr("data-lenis-prevent", "");
+
 	// hover 展开 mega 面板时禁止/恢复页面滚动
 	$(".site-header__nav-item--mega").on("mouseenter", function() {
 		if ($("body").hasClass("is-mask-open")) return;