theme: fix code font

- fixes #84

Author: casperdcl

_static/font.css

@@ -1,21 +1,22 @@
 @font-face {
-    font-family: "Pretendard";
-    src: url("https://static.premai.io/fonts/Pretendard-Regular.woff2") format("woff2");
-    font-weight: normal;
+  font-family: "Pretendard";
+  src: url("https://static.premai.io/fonts/Pretendard-Regular.woff2") format("woff2");
+  font-weight: normal;
 }
 
 @font-face {
-    font-family: "Pretendard";
-    src: url("https://static.premai.io/fonts/Pretendard-SemiBold.woff2") format("woff2");
-    font-weight: 600;
+  font-family: "Pretendard";
+  src: url("https://static.premai.io/fonts/Pretendard-SemiBold.woff2") format("woff2");
+  font-weight: 600;
 }
 
 @font-face {
-    font-family: "Pretendard";
-    src: url("https://static.premai.io/fonts/Pretendard-Bold.woff2") format("woff2");
-    font-weight: bold;
+  font-family: "Pretendard";
+  src: url("https://static.premai.io/fonts/Pretendard-Bold.woff2") format("woff2");
+  font-weight: bold;
 }
 
-* {
-    font-family: Pretendard, sans-serif;
+:root {
+  --pst-font-family-base: Pretendard, sans-serif;
+  --pst-font-family-heading: Pretendard, sans-serif;
 }