🎨 Style: adjust the mobile header style and fix the bug that scrolling is invalid when there are too many menus on mobile (#289)

Closes #289

CHANGELOG.md

@@ -26,7 +26,8 @@ All notable changes to this project will be documented in this file.
 - :recycle: Refactor: image lazy loading ([#283](https://github.com/hugo-fixit/FixIt/pull/283))
 - :recycle: Refactor: author's avatar of post or profile ([#288](https://github.com/hugo-fixit/FixIt/pull/288))
 - :art: Style: fix `#comments` css style conflict ([#269](https://github.com/hugo-fixit/FixIt/issues/269))
-- :recycle: Refactor: theme documentation
+- :art: Style: adjust the mobile header style and fix the bug that scrolling is invalid when there are too many menus on mobile ([#289](https://github.com/hugo-fixit/FixIt/issues/289))
+- :memo: Docs: refactor the theme documentation
 - :wrench: Chore: change the theme minimum supported Hugo versions above **0.89.0**
 - :arrow_up: Chore(libs):
   - Update Update @waline/client from 2.10.0 to 2.14.7 (@Mejituu [#279](https://github.com/hugo-fixit/FixIt/pull/279))

assets/css/_core/_header.scss

@@ -351,8 +351,13 @@ header {
       background: $header-background-color;
       border-top: 2px solid $global-border-color;
       display: none;
-      padding: 0.5rem 0 0;
+      overflow-y: overlay;
+      max-height: 70vh;
       @include box-shadow(0 0.125rem 0.25rem rgba(0, 0, 0, 0.1));
+      
+      &::-webkit-scrollbar {
+        width: 0;
+      }
 
       .search-wrapper {
         display: flex;
@@ -421,6 +426,16 @@ header {
         &.theme-switch,
         &.language {
           text-align: center;
+          position: sticky;
+          background-color: $header-background-color;
+
+          [data-theme='dark'] & {
+            background-color: $header-background-color-dark;
+          }
+          bottom: 0;
+        }
+        &.theme-switch:has(+ .language) {
+          bottom: 2.5rem;
         }
 
         .language-select {