style.css

/**********    The Real CSS    **********/

body {
    margin: 3% 5%;
    border: 5px solid #777777;
    border-radius: 10px;
    padding: 5%;
    text-align: center;
}

input#visitor-guess {
    text-align: center;
}

#buttons-container {
    width: 100%;
    max-width: 550px;
    margin: 0 auto;
}

.hints {
    display: none;
}


/**********    Column Classes    **********/


/**********    Link: http://twitter.github.io/bootstrap/assets/css/bootstrap-responsive.css    **********/

.five-sixths,
.four-sixths,
.one-fourth,
.one-half,
.one-sixth,
.one-third,
.three-fourths,
.three-sixths,
.two-fourths,
.two-sixths,
.two-thirds {
    float: left;
    margin-left: 2.564102564102564%;
}

.one-half,
.three-sixths,
.two-fourths {
    width: 48.717948717948715%;
}

.one-third,
.two-sixths {
    width: 31.623931623931625%;
}

.four-sixths,
.two-thirds {
    width: 65.81196581196582%;
}

.one-fourth {
    width: 23.076923076923077%;
}

.three-fourths {
    width: 74.35897435897436%;
}

.one-sixth {
    width: 14.52991452991453%;
}

.five-sixths {
    width: 82.90598290598291%;
}

.first {
    clear: both;
    margin-left: 0;
}