#portfoliolist li{
 float: left;
 width: 44%;
 margin: 0 20px 0 0;
 padding: 2px 0 40px;
 background: none;
 list-style: none;
}

#portfoliolist img {
	width: 100%;
}

/* 幅360px以下
------------------------------------------------------------*/
@media only screen and (max-width: 380px){

#portfoliolist li{
 float: none;
 width: 100%;
 margin: 0 0 0.5em;
 padding: 0;
}

}