优化 HTML 结构，调整 CSS 样式

src/@core/scss/_default-layout-w-vertical-nav.scss

@@ -48,8 +48,7 @@ $header: ".layout-navbar";
       /* ℹ️ Ensure header styles are preserved when dialog is opened,
         but only if window was scrolled before dialog opened
     */
-      html.v-overlay-scroll-blocked &.window-scrolled.layout-navbar-fixed,
-      html.dialog-scroll-locked &.window-scrolled.layout-navbar-fixed {
+      html.v-overlay-scroll-blocked &.window-scrolled.layout-navbar-fixed {
 
         #{$header} {
           padding-inline: 1rem;

src/@core/scss/_misc.scss

@@ -45,7 +45,7 @@ code {
       inset-block-start: 0;
       inset-inline: 0;
       pointer-events: none;
-      transition: all 0.3s ease-in-out;
+      transition: padding 0.3s ease-in-out;
       
       .v-theme--light & {
         background: rgba(var(--v-theme-surface), 0.6);