Fixed overlapping of the back to top button

- Fix moodle-an-hochschulen#378 (UN-245)

scss/boost_union/post.scss

@@ -345,6 +345,7 @@
         /* On larger screens. */
         @include media-breakpoint-up(sm) {
             bottom: calc(60px + 4rem);
+            right: 3rem;
         }
     }
 }
@@ -2048,10 +2049,35 @@ so the dropdown menu won't hide behind the screen on responsive */
 @include media-breakpoint-down(sm) {
     /* Move the learning tools floating button up as soon as the bottom menu is shown. */
     #page.footer-bottom-menu .learningtools-action-info .floating-button {
+        right: 25px;
         bottom: 4rem;
     }
 }
 
+/* Back to top button position */
+@include media-breakpoint-down(sm) {
+    /* Move the back to top button when learning tools floating button and as soon as the bottom menu is shown. */
+    #page-wrapper #page.footer-bottom-menu .learningtools-action-info ~ #back-to-top {
+        right: 3rem;
+    }
+    .theme-boost-union-smartmenu #page-wrapper #page.footer-bottom-menu .learningtools-action-info ~ .btn-footer-popover {
+        right: 5rem;
+    }
+}
+
+/* Move the back to top button when learning tools floating button and as soon as the bottom menu is shown. */
+@include media-breakpoint-down(xs) {
+    #page-wrapper #page {
+        .learningtools-action-info ~ #back-to-top {
+            bottom: 5rem;
+        }
+        &.footer-bottom-menu .learningtools-action-info ~ #back-to-top {
+            bottom: 8rem;
+        }
+    }
+}
+
+
 
 /*---------------------------------------
  * Dash Pro