Remove some unnecessary css rules

default_app/index.html

@@ -4,11 +4,7 @@
   <style>
     body {
       color: #205161;
-      background-color: #fff;
       font-family: Roboto, -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Segoe UI", "Oxygen", "Ubuntu", "Cantarell", "Open Sans", sans-serif;
-      font-style: normal;
-      font-variant: normal;
-      padding: 0;
       margin: 0;
       display: flex;
       flex-direction: column;
@@ -26,7 +22,6 @@
       border-bottom: 1px solid #1a1b23;
       color: #9feaf9;
       padding: 15px 30px;
-      margin: 0;
     }
 
     .header a,
@@ -104,7 +99,6 @@
       border-radius: 3px;
       font-size: 30px;
       font-weight: 300;
-      text-align: center;
       cursor: default;
       -webkit-user-select: none;
     }