diff --git a/demo/login.html b/demo/login.html
index 42d160d..e905c07 100755
--- a/demo/login.html
+++ b/demo/login.html
@@ -4,7 +4,7 @@
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
 <title>看板娘登陆平台</title>
-<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap/dist/css/bootstrap.min.css">
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4/dist/css/bootstrap.min.css">
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/font-awesome/css/font-awesome.min.css">
 <script src="../live2d.min.js"></script>
 <style>
@@ -177,7 +177,7 @@ window.addEventListener("load", () => {
 		return;
 	}
 
-	var apiPath = "https://live2d.fghrsh.net/api", state = 0,
+	let apiPath = "https://live2d.fghrsh.net/api", state = 0,
 		modelId = localStorage.getItem("modelId"),
 		modelTexturesId = localStorage.getItem("modelTexturesId");
 	if (modelId === null) {
@@ -199,7 +199,7 @@ window.addEventListener("load", () => {
 	}
 
 	function loadRandModel() {
-		var modelId = localStorage.getItem("modelId"),
+		const modelId = localStorage.getItem("modelId"),
 			modelTexturesId = localStorage.getItem("modelTexturesId");
 		fetch(`${apiPath}/rand_textures/?id=${modelId}-${modelTexturesId}`)
 			.then(response => response.json())
@@ -214,7 +214,7 @@ window.addEventListener("load", () => {
 	}
 
 	function loadOtherModel() {
-		var modelId = localStorage.getItem("modelId");
+		const modelId = localStorage.getItem("modelId");
 		fetch(`${apiPath}/switch/?id=${modelId}`)
 			.then(response => response.json())
 			.then(result => {
@@ -232,14 +232,14 @@ window.addEventListener("load", () => {
 			.then(result => {
 				alert("「" + result.hitokoto + "」——" + result.from);
 			});
-	}
+	};
 
 	window.refresh = function() {
 		state = 0;
 		coverPosition("10%");
 		document.getElementById("refresh").setAttribute("href", "javascript:void(0)");
 		setTimeout(loadRandModel, 1000);
-	}
+	};
 
 	document.getElementById("handle").addEventListener("click", () => {
 		if (state === 1) {