html {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
*, *:before, *:after {
    -webkit-box-sizing: inherit;
    -moz-box-sizing: inherit;
    box-sizing: inherit;
}

.wrapper {
    max-width:900px;
    width:100%;
    margin:0 auto;
    padding:0 20px 0 20px;
}
.wrapper img {
    width:100%;
}
.bbv1, .bbv2 {
    margin-top:50px;
    float:left;
    width:50%;
}
.bbv1 {
    padding-right:50px;
}
.bbv2 {
    padding-left:50px;
}

@media screen and (max-width: 700px) {
    .bbv1, .bbv2 {
        float:none;
        padding:20px;
        width:100%;
    }
}