Remove setting font-size for h1 and h2

src/styles/index.scss

@@ -22,16 +22,8 @@ label {
 html {
   height: 100%;
   box-sizing: border-box;
-  font-size: 62.5%;
 }
 
-h1 {
-  font-size: 3.2em;
-}
-
-h2 {
-  font-size: 2.4em;
-}
 #app {
   height: 100%;
 }