Use icons for all buttons

app/styles/_buttons.scss

@@ -9,17 +9,31 @@ div.button-group + div.button-group {
 
 header {
   button {
-    padding: 0.4rem 0.8rem 0.3rem;
+    padding: 0.4rem 0 0.3rem;
     border: 1px solid $dark-grey-2;
     border-radius: 0.2em;
     background-color: #fff;
     color: $dark-grey-2;
     font-size: 0.8rem;
     text-transform: uppercase;
+    width: 3rem;
+
+    svg {
+      height: 1rem;
+      path {
+        fill: $dark-grey-2;
+      }
+    }
 
     &:hover {
       background-color: $dark-grey-2;
       color: #fff;
+
+      svg {
+        path {
+          fill: #fff;
+        }
+      }
     }
 
     &:disabled,
@@ -27,6 +41,12 @@ header {
       border-color: $dark-grey-3;
       background-color: #fff;
       color: $dark-grey-3;
+
+      svg {
+        path {
+          fill: $dark-grey-3;
+        }
+      }
     }
   }
 }

app/styles/_layout.scss

@@ -77,6 +77,7 @@
       nav.actions {
         grid-column-start: 3;
         text-align: right;
+        margin-top: -0.4rem;
       }
     }
   }

app/styles/app.scss

@@ -5,7 +5,7 @@
 
 body {
   background-color: white;
-  font-size: 16px;
+  font-size: 15px;
   font-family: Open Sans, sans-serif;
   color: $dark-grey-1;
   margin: 0;

app/styles/vendor/_json-tree-view.scss

@@ -1,8 +1,8 @@
 .jsonView{
     margin-left: 20px;
     font-family: Consolas, "Lucida Console", Menlo, "dejavu sans mono", monospace;
-    font-size: 16px;
-    line-height: 16px;
+    font-size: 15px;
+    line-height: 15px;
     padding: 2px;
     cursor: default;
     color: rgb(66, 66, 66);
@@ -146,4 +146,4 @@
 .jsonView>.insert:hover{
     color: rgb(0, 0, 0);
     background: rgb(220, 220, 220);
-}
+}