remove variable-font-size mixin

apps/app/src/components/Layout/Admin.module.scss

@@ -5,16 +5,6 @@ $slack-work-space-name-card-background: #fff5ff;
 $slack-work-space-name-card-border: #efc1f6;
 
 .admin-page :global {
-  .title {
-    padding-top: 1rem;
-    padding-bottom: 1rem;
-
-    line-height: 1em;
-
-    @include mixins.variable-font-size(28px);
-    line-height: 1.1em;
-  }
-
   .admin-user-menu {
     .dropdown-menu {
       right: 0;

apps/app/src/components/Layout/AdminLayout.tsx

@@ -29,7 +29,7 @@ const AdminLayout = ({
       <div className={`admin-page ${styles['admin-page']}`}>
 
         <header className="py-0 container-fluid">
-          <h1 className="title px-3">{componentTitle}</h1>
+          <h1 className="p-3 fs-2">{componentTitle}</h1>
         </header>
         <div id="main" className="main">
           <div className="container-fluid">

apps/app/src/styles/_mixins.scss

@@ -1,22 +1,6 @@
 @use '@growi/core/scss/bootstrap/init' as bs;
 @use './variables' as var;
 
-@mixin variable-font-size($basesize) {
-  font-size: $basesize * 0.6;
-
-  @include bs.media-breakpoint-only(sm) {
-    font-size: #{$basesize * 0.7};
-  }
-  @include bs.media-breakpoint-only(md) {
-    font-size: #{$basesize * 0.8};
-  }
-  @include bs.media-breakpoint-only(lg) {
-    font-size: #{$basesize * 0.9};
-  }
-  @include bs.media-breakpoint-up(xl) {
-    font-size: $basesize;
-  }
-}
 
 @mixin apply-navigation-transition() {
   transition-timing-function: cubic-bezier(0.25, 1, 0.5, 1);