.clearfix:after {
    content: "";
    display: block;
    clear: both;
}

body {
    width: 100%;
    -webkit-text-size-adjust: 100%;
    /*max-width: 1400px;*/
}

/* TODO consider about fluid */
main {
    width: 100%;
    margin: 0 auto;
}

article {
    width: 100%;
    margin: 0 auto;
}

.sections {
    width: 85%;
    margin: 0 auto;
}

.none-display {
    display: none;
}

/* margin */
.mt-40 {
    margin-top: 40px;
}

.mt-60 {
    margin-top: 60px;
}

.mt-80 {
    margin-top: 80px;
}

.mt-100 {
    margin-top: 100px;
}

.mt-120 {
    margin-top: 120px;
}

.mt-140 {
    margin-top: 140px;
}

.my-100 {
    margin: 100px 0;
}

.pt-100 {
    padding-top: 100px;
}

.pt-120 {
    padding-top: 120px;
}

.pt-140 {
    padding-top: 140px;
}