added breakpoint for mobile height responsiveness

Author: Ajsalemo

static/index/scss/style.scss

@@ -258,6 +258,7 @@ $users-background-color: #000;
   // Main background
   &-background {
     background-color: $todo-page-background-color;
+    height: initial;
     @media (min-width: 992px) { 
       height: -webkit-fill-available;
       height: -moz-available;