some changes

frontend/src/assets/base.css

@@ -48,6 +48,7 @@
 
   --border-radius: 6px;
   --section-gap: 160px;
+  --header-height: 4em;
 }
 
 /* Z-Index hierarchy */

frontend/src/assets/main.css

@@ -23,7 +23,7 @@ main {
 }
 
 .main-header {
-  height: 3em;
+  height: var(--header-height);
   border-bottom: 1px solid var(--color-border);
   display: flex;
   flex-direction: row;