Avoid text/image/video width overrun with css

Say you have a html table or div, or in the case of mobile device browser. A long text segment, or image, or video (e.g., from youtube, using iframe), whose width is too long to fit in the parent container, this will break the layout. Since I'm working on a forum compatible with both desktop computer and mobile devices, here are my findings on the solutions.

== text ==

Use this in display:

<pre class="forum">content</pre>

Of course, it does not have to be pre tag. It can be a div too. In css [1]:

pre.forum {
    /* Wrap long text with space in the middle. */
    white-space: pre-wrap;       /* Wrap text as needed. CSS 3. */
    white-space: -moz-pre-wrap;  /* Mozilla, since 1999 */
    white-space: -pre-wrap;      /* Opera 4-6 */
    white-space: -o-pre-wrap;    /* Opera 7 */
    word-wrap: break-word;       /* Internet Explorer 5.5+, Non standard for webkit */
  
   /* Wrap long text without space in between. */
 -ms-word-break: break-all;
     word-break: break-all;

-webkit-hyphens: auto;
   -moz-hyphens: auto;
    -ms-hyphens: auto;
        hyphens: auto;
}

This css works for both desktop browser and mobile browser.

== Image ==

Use this in display:

<img src="..." class="media_img">

In css:

img.media_img {
    max-width: 100%;
    height: auto;
}

Note here use max-width instead of width, because if the image width is less than device width or parent container width (in desktop browser), we want to keep the image width and not expand it. This css works for both desktop browser and mobile browser.

This will always work in Safari. However, this may fail in firefox, if the "width" value is specified in the img tag, e.g.,

<img src="..." width="1500" class="media_img"> 

The way to fix this, is to wrap the img tag with another div tag, whose width is specified as an absolute value (the max design value):

<div class="media_img_container"> <img src="..." width="1500" class="media_img"> </div>

In css:

div.media_img_container {
    width: 1000px;
}

Then the image will be at most 1000px in width, despite the specification of width="1500" in img tag. This also means that for different design width, you need to specify different div container width.

== Video ==

For desktop browser, this usually is not a problem, since video width is often around 500px. For mobile device, this can be a problem since mobile browser width can be only 320px, so the css here can be used. This css will resize the video iframe to always match device width.

In the case the iframe width is less than device width, this will expand the iframe width. If you don't want to do it, maybe you can check the width parameter in the iframe tag and don't apply this css.

Use this in display:

<div class="aspect-ratio"><iframe ...></iframe></div>

In css [2]:

.aspect-ratio {
    position: relative;
    width: 100%;
    height: 0;
    padding-bottom: 75%; /* height/width, usually 3/4 on youtube */
}

.aspect-ratio iframe {
    position: absolute;
    width: 99%;  
    height: 99%;
    left: 0; top: 0;
}


References:

[1] http://kenneth.io/blog/2012/03/04/word-wrapping-hypernation-using-css/
[2] http://fettblog.eu/blog/2013/06/16/preserving-aspect-ratio-for-embedded-iframes/