Question

I’m using bootstrap 2.0 from twitter and unsure how to make it responsive.

• How can I remove elements when in mobile/small screen mode?
• How can I replace elements (i.e replace a big picture with a smaller one)?
• Change a <h2> to be <h5>? etc.

Answer 1

Hiding Elements

You can hide elements with:

display: none;
visibility: hidden;

Hopefully you’re using LESS or SASS so you can just specify:

@mixin hidden {
  display: none;
  visibility: hidden;
}

And then easily mix it in when necessary:

footer {
  @include hidden;
}

Just apply them to any selector in the relevant media query. Also, understand that media queries cascade onto smaller media queries. If you hide an element in a wide media query (tablet sized), then the element will remain hidden as the website shrinks.

Replacing Images

Bootstrap doesn’t offer image resizing as the screen shrinks, but you can manually change the dimensions of images with CSS in media queries.

But a particular solution I like is from this blog post: http://unstoppablerobotninja.com/entry/fluid-images/

/* You could instead use ".flexible" and give class="flexible" only to 
   images you want to have this property */
img { 
  max-width: 100%;
}

Now images will only appear in their full dimensions if they don’t exceed their parent container, but they’ll shrink fluidly as their parent element (like the <div> they’re in) shrinks.

Here’s a demo: http://unstoppablerobotninja.com/demos/resize/

To actually replace images, you could swap the background image with CSS. If .logo has background: url("logo.png");, then you can just specify a new background image in a media query with .logo { background: url("small-logo.png");

Change h2 to h5

If this is because you want to change the size of the heading, don’t do this. H2 has semantic value: It’s not as important as H1 and more important than H3.

Instead, just specify new sizes for your h1-h6 elements in media queries as your website gets smaller.

@media (max-width: 480px) {
  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    font-size: 80%;
  }
}