Initial state

import/html_scroll.php

@@ -0,0 +1,42 @@
+<?php
+include_once "include/constantes.php";
+?>
+
+<a href="#top" id="scroll-up" class="btn btn-primary btn-sm" role="button" aria-pressed="true" style="display: none; position: fixed; bottom: 3rem; right: 1rem;">
+    <?= $ICO['arriba'] ?>
+</a>
+<!-- Scroll down -->
+<a href="#bottom" id="scroll-down" class="btn btn-primary btn-sm" role="button" aria-pressed="true" style="display: none; position: fixed; bottom: 1rem; right: 1rem;">
+    <?= $ICO['abajo'] ?>
+</a>
+
+<script>
+    $(document).ready(function() {
+        $(window).scroll(function() {
+            if ($(this).scrollTop() > 100) {
+                $('#scroll-up').fadeIn();
+            } else {
+                $('#scroll-up').fadeOut();
+            }
+
+            if ($(this).scrollTop() < $(document).height() - $(window).height() - 100) {
+                $('#scroll-down').fadeIn();
+            } else {
+                $('#scroll-down').fadeOut();
+            }
+        });
+        $('#scroll-up').click(function() {
+            $("html, body").animate({
+                scrollTop: 0
+            }, 600);
+            return false;
+        });
+
+        $('#scroll-down').click(function() {
+            $("html, body").animate({
+                scrollTop: $(document).height()
+            }, 600);
+            return false;
+        });
+    });
+</script>