CSS: containing five floated 20% elements with borders

Question

I'm trying to align five horizontal menu elements with 'float:left' next to each other inside a container that spans 80% of the screen and a minimum of 960px. For this, I had initially set their min-width to 192px (960/5) and their width to 20%, but quickly realized this does not play well with adding 1px borders, causing one of the buttons to be 'thrown overboard'.

Changing the widths to 19.895333% and 191px, respectively, solved the issue, however this is clearly a hacky solution which also leaves an ugly space of 2-3 pixels at the right side of the menu.

Is there a more elegant way to align these elements and account for the bonus width added by borders, padding etc? I have tried 'overflow:hidden' to simply hide whatever may poke outside the container, but this just hides the entire 5th button.

A picture to illustrate the result: enter image description here

The html code:

    <div class="menucontainer">
        <div class="menutab" id="menutab_first">News</div>
        <div class="menutab">Game Guide</div>
        <div class="menutab">Articles</div>
        <div class="menutab">Media</div>
        <div class="menutab" id="menutab_last">Community</div>
    </div>

The css code:

.menucontainer {
    height: 26px;
    margin-left: auto;
    margin-right: auto;
    border-width: 1px;
    border-style: solid;
    border-color: #303030 #101010 #000 #101010;
    border-radius: 0px 0px 8px 8px;
}

.menutab {               
    line-height: 26px;
    float: left;
    width: 19.895333%;
    text-align: center;
    min-width: 191px;
    border-right: 1px solid #202020;
    background-image: url('../img/menubutton2.png');
    background-size: 100% 100%;
    font-family: 'Cabin', sans-serif;
}

#menutab_first {
    border-radius: 0px 0px 0px 8px;
}

#menutab_last {
    border-right: 0px;  
    width: 20%;
    min-width: 192px;  
    border-radius: 0px 0px 8px 0px;
}

Thank you in advance!

score 1 · Answer 1 · answered Nov 01 '13 at 11:38

What you need is box-sizing:border-box;

This CSS property will change the box model for the element such that the border is included inside the width, rather than outside of it as with the standard box model.

This means that your boxes will then be 20% of the width of the page, rather than 20% + the width of the borders.

Problem solved.

score 1 · Accepted Answer · answered Nov 01 '13 at 11:38

For this you can make use of the box-sizing property to set your borders to appear within your elements rather than outside of them:

elem {
    -webkit-box-sizing: border-box; /* Some mobile browsers. */
    -moz-box-sizing: border-box; /* Firefox. */
    box-sizing: border-box; /* All other browsers IE8+. */
}

border-box
The specified width and height (and respective min/max properties) on this element determine the border box of the element. That is, any padding or border specified on the element is laid out and drawn inside this specified width and height. The content width and height are calculated by subtracting the border and padding widths of the respective sides from the specified ‘width’ and ‘height’ properties.

So in the case of your CSS:

.menutab {               
    ...
    width: 20%;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    ...
}

score 1 · Answer 3 · answered Nov 01 '13 at 11:41

box-sizing: border-box causes the width of the borders to be counted as part of the 20%. That's the best solution but if that will interfere with your layout in some way, an alternative is use calc to subtract the borders from the 20%, e.g. width: calc(20% - 2px);

CSS: containing five floated 20% elements with borders

3 Answers3