style.css

body {
    background-color: #263545;
    font-family: "Inconsolata", sans-serif;
    font-size: 42px;
}

.container-full {
    margin: 50px auto 0;
    width: 320px;
}

.container {
    background-color: #C4273C;
    padding: 0 20px 14px;
}

h1 {
    color: #efefef;
    font-family: "Inconsolata", sans-serif;
    margin: 20px 0;
}

.timer-display {
    background-color: #fff;
    margin: 17px 0 1px;
    padding: 20px 0;
    text-align: center;
}

.timer-display div {
    display:inline;
}

.button {
    -moz-box-shadow:inset 0px 1px 0px 0px #ffffff;
    -webkit-box-shadow:inset 0px 1px 0px 0px #ffffff;
    box-shadow:inset 0px 1px 0px 0px #ffffff;
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #ededed), color-stop(1, #dfdfdf) );
    background:-moz-linear-gradient( center top, #ededed 5%, #dfdfdf 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ededed', endColorstr='#dfdfdf');
    background-color:#ededed;
    -moz-border-radius:1px;
    -webkit-border-radius:1px;
    border-radius:1px;
    border:1px solid #dcdcdc;
    display:inline-block;
    color:#111;
    font-family:arial;
    font-size:12px;
    font-weight:bold;
    padding:8px 12px;
    text-decoration:none;
}

.button:hover {
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #dfdfdf), color-stop(1, #ededed) );
    background:-moz-linear-gradient( center top, #dfdfdf 5%, #ededed 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#dfdfdf', endColorstr='#ededed');
    background-color:#dfdfdf;
}

.button:active {
    position:relative;
    top:1px;
}

@media screen and (max-width: 550px){
    body {
        font-size: 50px;
    }

    .container-full {
        width: 90%;
    }

    #time {
        padding: 30px 0px;
    }

    .button {
        font-size: 15px;
    }
}

@media screen and (max-width: 350px) {
    body {
        font-size: 40px;
    }
}