Bootstrap v3 において特によく使いそうなコード
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
<div class="container">
<div class="row">
<div class="col-xs-12 col-sm-6 col-md-8 col-lg-8">
<p>ココに内容</p>
</div>
</div>
</div>
<p class="text-left">Left aligned text.</p>
<p class="text-center">Center aligned text.</p>
<p class="text-right">Right aligned text.</p>
<p class="text-justify">Justified text.</p>
<p class="text-nowrap">No wrap text.</p>
<a class="btn btn-default" href="#" role="button">Link</a>
<button class="btn btn-default" type="submit">Button</button>
<!-- Standard button -->
<button type="button" class="btn btn-default">Default</button>
<!-- Provides extra visual weight and identifies the primary action in a set of buttons -->
<button type="button" class="btn btn-primary">Primary</button>
<!-- Indicates a successful or positive action -->
<button type="button" class="btn btn-success">Success</button>
<!-- Contextual button for informational alert messages -->
<button type="button" class="btn btn-info">Info</button>
<!-- Indicates caution should be taken with this action -->
<button type="button" class="btn btn-warning">Warning</button>
<!-- Indicates a dangerous or potentially negative action -->
<button type="button" class="btn btn-danger">Danger</button>
<!-- Deemphasize a button by making it look like a link while maintaining button behavior -->
<button type="button" class="btn btn-link">Link</button>
<p>
<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-default btn-lg">Large button</button>
</p>
<p>
<button type="button" class="btn btn-primary">Default button</button>
<button type="button" class="btn btn-default">Default button</button>
</p>
<p>
<button type="button" class="btn btn-primary btn-sm">Small button</button>
<button type="button" class="btn btn-default btn-sm">Small button</button>
</p>
<p>
<button type="button" class="btn btn-primary btn-xs">Extra small button</button>
<button type="button" class="btn btn-default btn-xs">Extra small button</button>
</p>
<button type="button" class="btn btn-primary btn-lg btn-block">Block level button</button>
<button type="button" class="btn btn-default btn-lg btn-block">Block level button</button>
.visible-xs-*
.visible-sm-*
.visible-md-*
.visible-lg-*
.hidden-xs
.hidden-sm
.hidden-md
.hidden-lg
<img src="..." alt="..." class="img-rounded">
<img src="..." alt="..." class="img-circle">
<img src="..." alt="..." class="img-thumbnail">