style.css

body {
    margin: 0;
    font: normal 16px/1.3em 'Helvetica',arial,sans-serif;
}
.main {
    margin: 50px auto;
    max-width: 400px;
    display: block;
    padding: 16px;
    background: #eee;
}
.main:after {content: '';display: block;clear: both;}
section {
    float: left;
    width: calc(100% - 40%);
    border-right: 1px solid #999;
}

aside.sidebar {
    float: right;
    width: 38%;
}

.soal {
    padding: 15px;
    background: #E9F2F9;
    text-align: center;
    font-size: 40px;
    font-weight: 700;
    display: block;
    margin-bottom: 16px;
}
.pause {
    display: none;
    text-align: center;
    min-height: 100px;
    font-size: 1.2em;
    font-weight: 700;
}
.hasil {
    padding: 25px 0;
}
.hasil strong {
    padding: 20px 0;
    display: block;
    font-size: 1.5em;
}
.score, .level {
    padding: 7px;
}

select.opsi {
    background: #FFF;
    border: 0;
    width: 100%;
    height: 25px;
    text-transform: uppercase;
    font-size: 14px;
    outline: none;
    outline-offset: 0;
}

button, input {
    background: #fff;
    border: 0;
    width: 65px;
    height: 27px;
    font-weight: 700;
    font-size: 15px;
    outline: none;
}

input {
    width: 150px;
    padding: 7px;
    height: 13px;
}