Update button styles with !important flags

Added !important to margin-bottom and background color.

Author: roniui

_sass/components/_buttons.scss

@@ -9,7 +9,7 @@
   position: fixed;
   right: 1rem;
   bottom: calc(v.$footer-height-large - v.$back2top-size / 2);
-  margin-bottom: 2rem;
+  margin-bottom: 2rem !important;
   background: #28a745 !important;
   color: #b32c22 !important;
   padding: 0;