index.css

/* Turn on a 13x13 scrollbar */
::-webkit-scrollbar {
  width: 5px;
}

::-webkit-scrollbar-button:start:decrement,
::-webkit-scrollbar-button:end:increment { 
  display: block; 
}

 /* Turn off the down area up on top, and up area on bottom */
::-webkit-scrollbar-button:vertical:start:increment,
::-webkit-scrollbar-button:vertical:end:decrement {
  display: none;
}

/* Track below and above */
::-webkit-scrollbar-track-piece:vertical:decrement {
  background: #29d;
  box-shadow: 0 0 10px #29d, 0 0 5px #29d;
}

/* The thumb itself */
::-webkit-scrollbar-thumb:vertical {
  background: #29d;
}

/* Corner */
::-webkit-scrollbar-corner:vertical {
  background-color: red;
}