index.html

<html>
<head>
<title>簡單抽獎小工具</title>
</head>
<body>
<script>
function rand(a, b) {  
  return 0.5-Math.random();
}  

function shuffle(array) {
  array.sort(rand);

  return array;
}

function start() {
	var candidates = document.getElementById("candidates").value;
	candidates = candidates.split('\n');
	shuffle(candidates);
	alert(candidates.join("\n"));
}

function random_bg_color() {
    var x = Math.floor(Math.random() * 256);
    var y = Math.floor(Math.random() * 256);
    var z = Math.floor(Math.random() * 256);
    var bgColor = "rgb(" + x + "," + y + "," + z + ")";
  
    document.body.style.background = bgColor;
}

random_bg_color();
window.setInterval(( () => random_bg_color() ), 500);
</script>
<textarea id="candidates" style="font-size: 24px; width: 100%; height: 70%;">
</textarea>
<hr>
<button onclick="start()" style="font-size: 60px; width: 100%; height: 20%;">抽抽抽！ヾ(•ω•`)o</button>
</body>
</html>