Correct way to create rounded corners in Twitter Bootstrap

I've just started with Twitter Bootstrap and here is one question.

I am creating custom <header> block, and I want it's bottom corners to be rounded.

Is there any "correct" way to do this by using predefined classes, or I have to specify it manually like:

border-radius: 10px;               // and all that cross-browser trumpery

For now, I'm using css styles. Maybe it will be better to use less for that issue?

<div class="img-rounded"> will give you rounded corners.

I guess it is what you are looking for: http://blogsh.de/tag/bootstrap-less/

@import 'bootstrap.less';
div.my-class {
    .border-radius( 5px );
}

You can use it because there is a mixin:

.border-radius(@radius: 5px) {
  -webkit-border-radius: @radius;
     -moz-border-radius: @radius;
          border-radius: @radius;
}

For Bootstrap 3, there are 4 mixins you can use...

.border-top-radius(@radius);
.border-right-radius(@radius);
.border-bottom-radius(@radius);
.border-left-radius(@radius);

or you can make your own mixin using the top 4 to do it in one shot.

.border-radius(@radius){
    .border-top-radius(@radius);
    .border-right-radius(@radius);
    .border-bottom-radius(@radius);
    .border-left-radius(@radius);
}

Bootstrap is just a big, useful, yet simple CSS file - not a framework or anything you can't override. I say this because I've noticed many developers got stick with BS classes and became lazy "I-can't-write-CSS-code-anymore" coders [this not being your case of course!].

If it features something you need, go with Bootstrap classes - if not, go write your additional code in good ol' style.css.

To have best of both worlds, you may write your own declarations in LESS and recompile the whole thing upon your needs, minimizing server request as a bonus.

As per bootstrap 3.0 documentation. there is no rounded corners class or id for div tag.

you can use circle behavior for image by using

<img class="img-circle"> 

or just use custom border-radius css3 property in css

for only bottom rounded coner use following

border-bottom-left-radius:25%; // i use percentage  u can use pix.
border-bottom-right-radius:25%;// i use percentage  u can use pix.

if you want responsive circular div then try this

referred from Responsive CSS Circles

What you want is a Bootstrap panel. Just add the panel class, and your header will look uniform. You can also add classes panel panel-info, panel panel-success, etc. It works for pretty much any block element, and should work with <header>, but I expect it would be used mostly with <div>s.

Without less, ans simply for a given div :

In a css :

.footer {
background-color: #ab0000;
padding-top: 40px;
padding-bottom: 10px;
border-radius:5px;
}

In html :

 <div class="footer">
        <p>blablabla</p>
      </div>

With bootstrap4 you can easily do it like this :-

class="rounded" 

or

class="rounded-circle"

If you're using Bootstrap Sass, here's another way that avoids having to add extra classes to your element markup:

@import "bootstrap/mixins/_border-radius";
@import "bootstrap/_variables";

.your-class {
  $r: $border-radius-base; // or $border-radius-large, $border-radius-small, ...
  @include border-top-radius($r);
  @include border-bottom-radius($r);
}

In Bootstrap 4, the correct way to border your elements is to name them as follows in the class list of your elements:

For a slight rounding effect on all corners; class="rounded"
For a slight rounding on the left; class="rounded-left"
For a slight rounding on the top; class="rounded-top"
For a slight rounding on the right; class="rounded-right"
For a slight rounding on the bottom; class="rounded-bottom" 
For a circle rounding, i.e. your element is made circular; class="rounded-circle"
And to remove rounding effects; class="rounded-0"

To use Bootstrap 4 css files, you can simply use the CDN, and use the following link in the of your HTML file:

<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>

This will provided you with the basics of Bootstrap 4. However if you would like to use the majority of Bootstrap 4 components, including tooltips, popovers, and dropdowns, then you are best to use the following code instead:

<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>

Alternatively, you can install Bootstrap using NPM, or Bower, and link to the files there.

*Note that the bottom