unify border radius, use var instead hardcoded value

Author: Simek

website/src/css/customTheme.scss

@@ -466,10 +466,10 @@ hr {
 
   div[class*="codeBlockContainer"] {
     box-shadow: none;
-    border-radius: 8px;
+    border-radius: var(--ifm-global-radius);
 
     pre {
-      border-radius: 8px;
+      border-radius: var(--ifm-global-radius);
     }
 
     button {
@@ -1129,7 +1129,7 @@ aside[class^="theme-doc-sidebar-container"] {
   }
 
   .menu__link {
-    border-radius: 8px;
+    border-radius: var(--ifm-global-radius);
     padding: 6px 12px;
   }
 
@@ -1311,7 +1311,6 @@ div[class^="tableOfContents"] {
   .table-of-contents__link--active {
     font-weight: 500;
     color: var(--home-button-primary) !important;
-    border-radius: 8px;
 
     code {
       font-weight: 700;
@@ -1632,7 +1631,7 @@ div[class*="announcementBarContent"] {
       float: left;
       width: 36px;
       height: 36px;
-      border-radius: 8px;
+      border-radius: var(--ifm-global-radius);
       background-color: #6170af;
       background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 23 21' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath fill-rule='evenodd' clip-rule='evenodd' d='M0 18.036c.042.507.221 1.016.692 1.699.558.81 1.518 1.254 2.218.54.473-.481 5.582-9.335 8.045-12.69a.737.737 0 011.202 0c2.463 3.355 7.572 12.209 8.045 12.69.7.714 1.66.27 2.218-.54.55-.798.702-1.358.702-1.955 0-.407-7.958-15.086-8.76-16.308C13.593.297 13.357.042 12.053 0h-.994c-1.304.041-1.54.297-2.31 1.472C7.964 2.67.317 16.77 0 17.737v.299z' fill='%23fff'/%3E%3C/svg%3E%0A");
       background-repeat: no-repeat;
@@ -2034,7 +2033,7 @@ html[data-theme="dark"] .docsRating {
   a[class*="sidebarItemLink"] {
     border-left: 0 !important;
     padding: 4px 12px !important;
-    border-radius: 8px;
+    border-radius: var(--ifm-global-radius);
     transition:
       color 0.15s,
       background-color 0.15s;