@charset "UTF-8";

.partner_cont ul::after {content: ""; display: block; clear:both;}
.partner_cont ul li {float: left; width: calc(20% - 6px); margin: 0 6px 6px 0; box-sizing: border-box; border: 1px solid #dddddd;}
.partner_cont ul li:hover {border: 1px solid #333; box-sizing: border-box;}

@media screen and (max-width:640px) {
    .partner_cont ul li {width: calc(33% - 6px);}
    .partner_cont ul li:nth-child(3n) {margin-right: 0;}
    .partner_cont ul li:nth-child(5n) {margin-right: 6px;}
}