html
{
    background-color: #728284;
}

.mainLayout
{
display: grid;
 grid-template-columns: [leftOuter] 180px [leftInner] auto [rightInner]  180px [rightOuter];
 grid-template-rows: [topOuter] 300px [topInner] auto [bottomInner] 160px [bottomOuter];
 column-gap: 10;
 row-gap: 10;
 grid-template-areas: 
 "header header header"
 "leftAd content rightAd"
 "footer footer footer";
}

.header{
    grid-area: header;
    text-align: center;
}

.adLeft
{
    grid-area: leftAd;
}

.adRight
{
    grid-area: rightAd;
}

.contents{
    grid-area: content;
}

.maincontents
{
    text-align: center;
    grid-area: content;
}

.footer
{
    grid-area: footer;
    text-align: center;
}