::first-line

The effects of ::first-line are limited by the length and content of the first line of text in the element. The length of the first line depends on many factors, including the width of the element, the width of the document, and the font size of the text. ::first-line has no effect when the first child of the element, which would be the first part of the first line, is an inline block-level element, such as an inline table.

For the purposes of CSS background, the ::first-line pseudo-element is like an inline-level element meaning that in a left-justified first line, the background may not extend all the way to the right margin.

Only a small subset of CSS properties can be used with the ::first-line pseudo-element:

• All font-related properties: font, font-kerning, font-style, font-variant, font-variant-numeric, font-variant-position, font-variant-east-asian, font-variant-caps, font-variant-alternates, font-variant-ligatures, font-synthesis, font-feature-settings, font-language-override, font-weight, font-size, font-size-adjust, font-stretch, and font-family
• All background-related properties: background-color, background-clip, background-image, background-origin, background-position, background-repeat, background-size, background-attachment, and background-blend-mode
• The color property
• word-spacing, letter-spacing, text-decoration, text-transform, and line-height
• text-shadow, text-decoration, text-decoration-color, text-decoration-line, text-decoration-style, and vertical-align.

HTML

<p>
  Styles will only be applied to the first line of this paragraph. After that,
  all text will be styled like normal. See what I mean?
</p>

<span>
  The first line of this text will not receive special styling because it is not
  a block-level element.
</span>

CSS

* {
  font-size: 20px;
  font-family: sans-serif;
}

::first-line {
  color: blue;
  font-weight: bold;

  /* WARNING: DO NOT USE THESE */
  /* Many properties are invalid in ::first-line pseudo-elements */
  margin-left: 20px;
  text-indent: 20px;
}

In this example, we style the first line of an SVG <text> element using the ::first-line pseudo-element.

HTML

<svg viewBox="0 0 320 150">
  <text y="20">Here is an English paragraph
that is broken into multiple lines
in the source code so that it can
be more easily read and edited
in a text editor.
  </text>
</svg>

CSS

In order to make the SVG <text> element wrap to multiple lines, we use the white-space CSS property. We then select the first line using the ::first-line pseudo-element.

text {
  font-size: 20px;
  font-family: sans-serif;
}

text {
  white-space: break-spaces;
}

text::first-line {
  fill: blue;
  font-weight: bold;
}

Result

• ::first-letter
• white-space