main.fs-l-main > .u-okayama {
    flex-basis: 20%;
}
section.fs-l-pageMain {
    flex-basis: 75%;
}

@media screen and (max-width: 767px) {

.u-okayama .site-sidenav{
 display:none  !important
}

main.fs-l-main > .u-okayama {
    flex-basis: 0%;
}

section.fs-l-pageMain {
    flex-basis: 100%;
}
}