inline-block fix, white-space in html /

by asdf

HTML

<!doctype html>

    <body>
        <div id="col1">content</div><div id="col2">content</div>
        <div id="col3">
            content
        </div>
        <div id="col4">
            content
        </div>
    </body>

CSS

#col1, #col2, #col3, #col4 {
    display: inline-block;
    width:50%;
}
#col1{
    background-color: orange;
}

#col2 {
    background-color: yellow;
}
#col3{
    background-color: lightblue;
}
#col4{
    background-color: pink;
}