Simple HTML Platformer Game: Build Your Own Jump & Run

<style type="text/css">
    body {
        margin: 0;
        padding: 0;
    }

    #container {
        width: 600px;
        height: 400px;
        margin: 0 auto;
        position: relative;
        border: 1px solid black;
    }

    #player {
        position: absolute;
        left: 50px;
        top: 50px;
        width: 50px;
        height: 50px;
        background-color: blue;
    }

    .platform {
        position: absolute;
        width: 200px;
        height: 30px;
        background-color: green;
    }

    #platform1 {
        top: 100px;
        left: 200px;
    }

    #platform2 {
        top: 250px;
        left: 0px;
    }

</style>