#leftImage
{
    background-image: url('../images/logo.gif');
}
#centreImage
{
    background-image: url('../images/ms9.jpg');
}
#rightImage
{
    background-image: url('../images/docks1.jpg');
}

.section1
{
	display:flex;
	justify-content:center;
}

.subSection
{
	margin-left:0px; //let flex justification do its job
}

@media(min-width:800px)
{
	.subSection
	{
		width: calc(100% - 160px);
	}
}