排版(Typography)

<h1>h1. Bootstrap heading</h1>
<h2>h2. Bootstrap heading</h2>
<h3>h3. Bootstrap heading</h3>
<h4>h4. Bootstrap heading</h4>
<h5>h5. Bootstrap heading</h5>
<h6>h6. Bootstrap heading</h6>

<p class="h1">h1. Bootstrap heading</p>
<p class="h2">h2. Bootstrap heading</p>
<p class="h3">h3. Bootstrap heading</p>
<p class="h4">h4. Bootstrap heading</p>
<p class="h5">h5. Bootstrap heading</p>
<p class="h6">h6. Bootstrap heading</p>

<h3>
  Fancy display heading
  <small class="text-muted">With faded secondary text</small>
</h3>

<h1 class="display-1">Display 1</h1>
<h1 class="display-2">Display 2</h1>
<h1 class="display-3">Display 3</h1>
<h1 class="display-4">Display 4</h1>
<h1 class="display-5">Display 5</h1>
<h1 class="display-6">Display 6</h1>

$display-font-sizes: (
  1: 5rem,
  2: 4.5rem,
  3: 4rem,
  4: 3.5rem,
  5: 3rem,
  6: 2.5rem
);

$display-font-weight: 300;
$display-line-height: $headings-line-height;

<p class="lead">
  This is a lead paragraph. It stands out from regular paragraphs.
</p>

<p>You can use the mark tag to <mark>highlight</mark> text.</p>
<p><del>This line of text is meant to be treated as deleted text.</del></p>
<p><s>This line of text is meant to be treated as no longer accurate.</s></p>
<p><ins>This line of text is meant to be treated as an addition to the document.</ins></p>
<p><u>This line of text will render as underlined.</u></p>
<p><small>This line of text is meant to be treated as fine print.</small></p>
<p><strong>This line rendered as bold text.</strong></p>
<p><em>This line rendered as italicized text.</em></p>

<p><abbr title="attribute">attr</abbr></p>
<p><abbr title="HyperText Markup Language" class="initialism">HTML</abbr></p>

<blockquote class="blockquote">
  <p>A well-known quote, contained in a blockquote element.</p>
</blockquote>

<figure>
  <blockquote class="blockquote">
    <p>A well-known quote, contained in a blockquote element.</p>
  </blockquote>
  <figcaption class="blockquote-footer">
    Someone famous in <cite title="Source Title">Source Title</cite>
  </figcaption>
</figure>

<figure class="text-center">
  <blockquote class="blockquote">
    <p>A well-known quote, contained in a blockquote element.</p>
  </blockquote>
  <figcaption class="blockquote-footer">
    Someone famous in <cite title="Source Title">Source Title</cite>
  </figcaption>
</figure>

<figure class="text-end">
  <blockquote class="blockquote">
    <p>A well-known quote, contained in a blockquote element.</p>
  </blockquote>
  <figcaption class="blockquote-footer">
    Someone famous in <cite title="Source Title">Source Title</cite>
  </figcaption>
</figure>

<ul class="list-unstyled">
  <li>This is a list.</li>
  <li>It appears completely unstyled.</li>
  <li>Structurally, it's still a list.</li>
  <li>However, this style only applies to immediate child elements.</li>
  <li>Nested lists:
    <ul>
      <li>are unaffected by this style</li>
      <li>will still show a bullet</li>
      <li>and have appropriate left margin</li>
    </ul>
  </li>
  <li>This may still come in handy in some situations.</li>
</ul>

<ul class="list-inline">
  <li class="list-inline-item">This is a list item.</li>
  <li class="list-inline-item">And another one.</li>
  <li class="list-inline-item">But they're displayed inline.</li>
</ul>

<dl class="row">
  <dt class="col-sm-3">Description lists</dt>
  <dd class="col-sm-9">A description list is perfect for defining terms.</dd>

  <dt class="col-sm-3">Term</dt>
  <dd class="col-sm-9">
    <p>Definition for the term.</p>
    <p>And some more placeholder definition text.</p>
  </dd>

  <dt class="col-sm-3">Another term</dt>
  <dd class="col-sm-9">This definition is short, so no extra paragraphs or anything.</dd>

  <dt class="col-sm-3 text-truncate">Truncated term is truncated</dt>
  <dd class="col-sm-9">This can be useful when space is tight. Adds an ellipsis at the end.</dd>

  <dt class="col-sm-3">Nesting</dt>
  <dd class="col-sm-9">
    <dl class="row">
      <dt class="col-sm-4">Nested definition list</dt>
      <dd class="col-sm-8">I heard you like definition lists. Let me put a definition list inside your definition list.</dd>
    </dl>
  </dd>
</dl>

$headings-margin-bottom:      $spacer * .5;
$headings-font-family:        null;
$headings-font-style:         null;
$headings-font-weight:        500;
$headings-line-height:        1.2;
$headings-color:              null;

$lead-font-size:              $font-size-base * 1.25;
$lead-font-weight:            300;

$small-font-size:             .875em;

$sub-sup-font-size:           .75em;

$text-muted:                  $gray-600;

$initialism-font-size:        $small-font-size;

$blockquote-margin-y:         $spacer;
$blockquote-font-size:        $font-size-base * 1.25;
$blockquote-footer-color:     $gray-600;
$blockquote-footer-font-size: $small-font-size;

$hr-margin-y:                 $spacer;
$hr-color:                    inherit;
$hr-height:                   $border-width;
$hr-opacity:                  .25;

$legend-margin-bottom:        .5rem;
$legend-font-size:            1.5rem;
$legend-font-weight:          null;

$mark-padding:                .2em;

$dt-font-weight:              $font-weight-bold;

$nested-kbd-font-weight:      $font-weight-bold;

$list-inline-padding:         .5rem;

$mark-bg:                     #fcf8e3;