<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Chart.js demo</title>
    <style>
        html, body {
            margin:0;
        }
        .w{
            overflow:hidden;
        }
        section div {
            float: left;
            height: 24vw;
            margin: 1%;
            margin-bottom: 50px;
            width: 46%;
            border-style: solid;
            border-width: 1px;
        }

        section div button {
            margin-left: -1px;
            margi