.exhibition_guide ul {display:flex;align-items:center;flex-wrap:wrap}
.exhibition_guide ul li {width:49%;margin-right:2%;text-align:center;border:1px solid #ddd;border-radius:20px;padding:20px 0;margin-bottom:20px}
.exhibition_guide ul li:nth-of-type(2n) {margin-right:0}

@media all and (max-width:500px){
.exhibition_guide ul li {width:100%;margin-right:0;margin-bottom:10px}
}