Update file homepage.js

static/homepage.js

@@ -185,7 +185,7 @@ function draw(){
     let scrTop = document.documentElement.scrollTop;
     var canvas = document.getElementById("tutorial")
     canvas.width = 1300;
-    canvas.height = 8000;
+    canvas.height = 5000;
     let cvs_h = canvas.getBoundingClientRect().top + scrTop;
     let cur_h = document.documentElement.clientHeight / 1.8 + scrTop;
     top_screen = Math.floor(-canvas.getBoundingClientRect().top);