Add theme-based text color and fix spin (#148)

Disclaimer: This is bad practice!

HOWEVER! I noticed that the spinning animation was sorta off. It took me a while to figure it out, but eventually I noticed that the spinning icon provided by FontAwesome had the dimensions 28x29.

Since width and height wasn't the same it create a sort of jumping (?) and made the animation less smooth.

To fix it I checked what font-size it currently had and literally tried some numbers above and below it.

My first attempt was `2.072`, which made the icon 29x29 - which didn't solve the issue, since the animation wasn't perfectly centered anymore.

`1.99999999`, as unfortunate it is, turned the icon into 28x28 and fixed the animation.

src/pages/Authorizing.vue

@@ -11,6 +11,7 @@
 
 .authorizing {
   background: var(--body-background);
+  color: var(--primary-text-color);
   height: 100vh;
   position: fixed;
   top: 0;
@@ -25,6 +26,7 @@
   }
 
   i {
+    font-size: 1.99999999em;
     margin: $gp;
   }
 }