restruct: updated scss @import rules to @use; package upgrade

src/styles/_global.scss

@@ -2,6 +2,7 @@ $breakpointMd: 960px;
 $breakpointSm: 550px;
 
 $bgColor: #2b3552;
+$bgColorDarker: #1f263b;
 $textColor: #fff;
 $secondaryColor: #1b1b1b;
 $accentColor: #e4c428;

src/styles/_tab.scss

@@ -1,4 +1,4 @@
-@import './global.scss';
+@use 'global';
 
 .tab {
   height: 100%;
@@ -7,7 +7,7 @@
   &_header {
     padding: 0.5em 1em;
 
-    background-color: $secondaryColor;
+    background-color: global.$secondaryColor;
     text-align: center;
 
     h2 {