style improvements

Author: francescospissu

arduino-ide-extension/src/browser/style/fonts.css

@@ -1,8 +1,6 @@
 @font-face {
   font-family: 'Open Sans';
-  font-style: normal;
-  font-weight: 300;
-  src: url('fonts/OpenSans-Regular-webfont.woff') format('woff');
+  src: url('fonts/OpenSans-Bold-webfont.woff') format('woff');
 }
 
 @font-face {

arduino-ide-extension/src/browser/style/fonts/OpenSans-Bold-webfont.woff

@@ -69,7 +69,7 @@ button.theia-button,
   justify-content: center;
   cursor: pointer;
   letter-spacing: .01em;
-  line-height: 23.8px;
+  line-height: 24px;
   outline: none;
   padding: 0 16px;
   position: relative;
@@ -93,7 +93,7 @@ button.theia-button {
 }
 
 button.theia-button.secondary {
-  border: 1.5px solid var(--theia-secondaryButton-foreground);
+  border: 2px solid var(--theia-secondaryButton-foreground);
 }
 
 button.theia-button[disabled], .theia-button[disabled] {