animation-range-start
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The animation-range-start
CSS property is used to set the start of an animation's attachment range along its timeline, i.e. where along the timeline an animation will start.
The animation-range-start
and animation-range-end
properties can also be set using the animation-range
shorthand property.
Note: animation-range-start
is included in the animation
shorthand as a reset-only value. This means that including animation
resets a previously-declared animation-range-start
value to normal
, but a specific value cannot be set via animation
. When creating CSS scroll-driven animations, you need to declare animation-range-start
after declaring any animation
shorthand for it to take effect.
Syntax
css
/* Keyword or length percentage value */
animation-range-start: normal;
animation-range-start: 20%;
animation-range-start: 100px;
/* Named timeline range value */
animation-range-start: cover;
animation-range-start: contain;
animation-range-start: cover 20%;
animation-range-start: contain 100px;
Values
Allowed values for animation-range-start
are normal
, a <length-percentage>
, a <timeline-range-name>
, or a <timeline-range-name>
with a <length-percentage>
following it. See animation-range
for a detailed description of the available values.
Also check out the View Timeline Ranges Visualizer, which shows exactly what the different values mean in an easy visual format.
Formal definition
Formal syntax
Examples
Creating a named view progress timeline with range start
A view progress timeline named --subjectReveal
is defined using the view-timeline
property on a subject element with a class
of animation
.
This is then set as the timeline for the same element using animation-timeline: --subjectReveal;
. The result is that the subject element animates as it moves upwards through the document as it is scrolled.
An animation-range-start
declaration is also set to make the animation begin later than expected.
HTML
The HTML for the example is shown below.
html
<div class="content">
<h1>Content</h1>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Risus quis varius quam
quisque id. Et ligula ullamcorper malesuada proin libero nunc consequat
interdum varius. Elit ullamcorper dignissim cras tincidunt lobortis feugiat
vivamus at augue.
</p>
<p>
Dolor sed viverra ipsum nunc aliquet. Sed sed risus pretium quam vulputate
dignissim. Tortor aliquam nulla facilisi cras. A erat nam at lectus urna
duis convallis convallis. Nibh ipsum consequat nisl vel pretium lectus.
Sagittis aliquam malesuada bibendum arcu vitae elementum. Malesuada bibendum
arcu vitae elementum curabitur vitae nunc sed velit.
</p>
<div class="subject animation"></div>
<p>
Adipiscing enim eu turpis egestas pretium aenean pharetra magna ac. Arcu
cursus vitae congue mauris rhoncus aenean vel. Sit amet cursus sit amet
dictum. Augue neque gravida in fermentum et. Gravida rutrum quisque non
tellus orci ac auctor augue mauris. Risus quis varius quam quisque id diam
vel quam elementum. Nibh praesent tristique magna sit amet purus gravida
quis. Duis ultricies lacus sed turpis tincidunt id aliquet. In egestas erat
imperdiet sed euismod nisi. Eget egestas purus viverra accumsan in nisl nisi
scelerisque. Netus et malesuada fames ac.
</p>
</div>
CSS
The subject
element and its containing content
element are styled minimally, and the text content is given some basic font settings:
css
.subject {
width: 300px;
height: 200px;
margin: 0 auto;
background-color: deeppink;
}
.content {
width: 75%;
max-width: 800px;
margin: 0 auto;
}
p,
h1 {
font-family: Arial, Helvetica, sans-serif;
}
h1 {
font-size: 3rem;
}
p {
font-size: 1.5rem;
line-height: 1.5;
}
The <div>
with the class of subject
is also given a class of animation
— this is where view-timeline
is set to define a named view progress timeline. It is also given an animation-timeline
name with the same value to declare that this will be the element animated as the view progress timeline is progressed. We also give it an animation-range-start
declaration to make the animation begin later than expected.
Last, an animation is specified on the element that animates its opacity and scale, causing it to fade in and size up as it moves up the scroller.
css
.animation {
view-timeline: --subjectReveal block;
animation-timeline: --subjectReveal;
animation-name: appear;
animation-range-start: entry 25%;
animation-fill-mode: both;
animation-duration: 1ms; /* Firefox requires this to apply the animation */
}
@keyframes appear {
from {
opacity: 0;
transform: scaleX(0);
}
to {
opacity: 1,
transform: scaleX(1);
}
}
Result
Scroll to see the subject element being animated.
Specifications
Specification |
---|
Scroll-driven Animations # animation-range-start |
Browser compatibility
BCD tables only load in the browser
See also
animation-timeline
animation-range
,animation-range-end
scroll-timeline
,scroll-timeline-axis
,scroll-timeline-name
timeline-scope
view-timeline-inset
- The JavaScript equivalent: The
rangeStart
property available inElement.animate()
calls - CSS scroll-driven animations