.island
{
    float: left;

    width: 50%;
}

.island__inner
{
    margin: 5% 5% 0;

    /*float: left;

    width: 44.5%;
    margin-left: 38%;*/
}

.island__container
{
    position: relative;
    z-index: 10;

    min-height: 615px;
    padding: 5%;

    background: #fff;
}

.island__shadow
{
    position: relative;
    z-index: 0;

    height: 33px;
    margin-top: -19px;

    background: -moz-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -webkit-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -o-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -ms-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
}


/*.brick
{
    float: left;

    width: 50%;
}

.brick__inner
{
    padding: 10% 10% 0;
}*/
.island
{
    display: inline-block;
    vertical-align: top;
    width: 50%;
}

.island__inner
{
    margin: 5% 5% 0;
}

.island__container
{
    position: relative;
    z-index: 10;

    min-height: 615px;
    padding: 5%;

    background: #fff;
}

.island__shadow
{
    position: relative;
    z-index: 0;

    height: 33px;
    margin-top: -19px;

    background: -moz-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -webkit-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -o-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: -ms-radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
    background: radial-gradient(center,ellipse contain,#bbbdc1 0,#f3f1ee 100%);
}
Fix index layout - change float to inline-block
Fix index layout - change float to inline-block
