.youtubesm{
background:#fff
}
.youtubesm a{
border:2px
solid #fff;
display:block;
position:relative
}
.youtubesm a:hover{
opacity:.6
}
.youtubesm a::before{
background:url(http://e-okomeshop.com/wp-content/uploads/YOUTUBE/yt_icon_mono_light.png) center center / 100px 64px no-repeat;content:"";
display:block;
width:100%; /*アイコンの幅調整*/
height:60px; /*アイコンの高さ調整*/
margin:-32px auto 0;
position:absolute;
top:50%;
left:0;
right:0;
z-index:1;
opacity:.8;
}
.youtubesm a img{
width:100%
}