.sub-img {
    opacity:0.8;
    width:100%;
}
.sub-txt {
    margin-left:245px;  
}
.sub-txt > p {
    margin-bottom:1.3em;
}

/* PC */
@media screen and (min-width:992px) { 
    .sub-img { width:230px;float:left; }
}
/* Tablet (iPad) */
@media screen and (min-width:768px) and (max-width:991px) {
    .sub-img { width:230px;float:left; }
}
/* Smart Phone */
@media screen and (max-width:767px) { 
    /* .sub-img { width:35%;float:left; }
    .sub-txt { margin-left:37%; } */
    .sub-img { width: 100%; float:none; }
    .sub-txt { margin-left: auto; }
}