main.css

body{
    width: 80%;
    margin: 0 auto !important;
}
.form-control{
    width: 20% !important;
    display: block;
    margin-bottom: 10px;
    margin: 0 auto;
}
.chkbox {
    display: block;
    margin: 20px auto;
}
.btn12{
    background-color: #4CAF50; /* Green */
    border: none;
    color: white;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: block;
    font-size: 16px;
    margin: 20px auto;
    cursor: pointer;
    -webkit-transition-duration: 0.4s; /* Safari */
    transition-duration: 0.4s;
}

h3,h1{
    text-align: center;
}
h2,p{
    font-size:100%;
    font-weight:normal;
}
li{
    list-style:none;
    background: #ffc;
    width: 20%;
}
ul{
    overflow:hidden;
    padding:3em;
}
ul li a{
    text-decoration:none;
    color:#000;
    background:#ffc;
    display:block;
    height:10em;
    width:10em;
    padding:1em;
}
ul li{
    margin:1em;
    float:left;
}
ol{text-align:center;}
ol li{display:inline;padding-right:1em;}
ol li a{color:#fff;}