::first-line CSS pseudo-elementThe ::first-line CSS pseudo-element applies styles to the first line of a block container.
p::first-line {
font-size: 1.2rem;
font-weight: bold;
text-decoration: underline;
}<p>
In warm ocean waters around the world, you may see a strange sight: A fish
leaping from the water and soaring dozens of meters before returning to the
ocean's depths. Early Mediterranean sailors thought these flying fish returned
to the shore at night to sleep, and therefore called this family of marine
fish Exocoetidae.
</p>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.
Note: Selectors Level 3 introduced the double-colon notation (::) to distinguish pseudo-elements from the single-colon (:) pseudo-classes. Browsers accept both ::first-line and :first-line, which was introduced in CSS2.
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:
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-familybackground-color, background-clip, background-image, background-origin, background-position, background-repeat, background-size, background-attachment, and background-blend-modecolor propertyword-spacing, letter-spacing, text-decoration, text-transform, and line-heighttext-shadow, text-decoration, text-decoration-color, text-decoration-line, text-decoration-style, and vertical-align.::first-line {
/* ... */
}<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>::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.
Note: At time of writing this feature has limited support.
<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>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 {
white-space: break-spaces;
}
text::first-line {
fill: blue;
font-weight: bold;
}