style.css

html, body {
    margin: 0;
    padding: 0;
    font-family: Arial;
}

canvas {
    display: block;
    margin: auto;
}

/* Style the tab */
.tab {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
}

/* Style the buttons inside the tab */
.tab button,
.tab a {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-size: 17px;
}

/* Change background color of buttons on hover */
.tab button:hover, a:hover {
  background-color: #ddd;
}

/* Create an active/current tablink class */
.tab button.active,
.tab a.active {
  background-color: #ccc;
}
.tab .tablink a:active {
  background-color: #ccc;
}

/* Style the tab content */
.tabcontent {
  display: none;
  width: 15rem;
  position: absolute;

}

.tabcontent .tab button,
.tabcontent .tab a {
    width: 100%;
}

a {
  text-decoration: none;

}