p]:inline” data-streamdown=”list-item”>GEQ15V Setup & Troubleshooting Tips for Beginners

Understanding CSS Custom Properties for Animations: –sd-animation, –sd-duration, and –sd-easing

CSS custom properties (variables) make it easy to centralize and reuse animation configuration across a site. The trio –sd-animation, –sd-duration, and –sd-easing shown as -sd-animation: sd-fadeIn; –sd-duration: 250ms; –sd-easing: ease-in; is a compact pattern for declaring animation behavior that can be consumed by component styles or JavaScript. Below is a practical guide to what each property does, how to implement them, and best practices.

What these properties represent

• –sd-animation: Stores the name of an animation or a shorthand token (e.g., sd-fadeIn) that a component’s styles will map to actual keyframe usage. Using a semantic token lets you swap animations without editing many rules.
• –sd-duration: Controls how long the animation runs (here, 250ms).
• –sd-easing: Defines the timing function (ease-in) that controls acceleration.

Example: Define keyframes and use the variables

CSS:

/Keyframes for the semantic token /@keyframes sd-fadeIn {  from { opacity: 0; transform: translateY(6px); }  to   { opacity: 1; transform: translateY(0); }}
/ Default values at root /:root {  –sd-animation: sd-fadeIn;  –sd-duration: 250ms;  –sd-easing: ease-in;}
/ Component that consumes the vars */.card {  animation-name: var(–sd-animation);  animation-duration: var(–sd-duration);  animation-timing-function: var(–sd-easing);  animation-fill-mode: both;}

Using tokens for theming and overrides

• Theme override:

.dark-theme {  –sd-duration: 350ms;  –sd-easing: cubic-bezier(.2, .8, .2, 1);}

• Per-component override:

.card.fast {  –sd-duration: 150ms;}

Accessibility and performance considerations

• Respect prefers-reduced-motion: disable or simplify animations when users request reduced motion.

@media (prefers-reduced-motion: reduce) {  .card { animation: none; transition: none; }}

• Keep animations short (150–350ms) for micro-interactions; avoid animating properties that trigger layout (use transform and opacity).
• Use will-change sparingly for complex animations to hint rendering optimizations.

JavaScript usage

You can read or set these variables at runtime:

const el = document.querySelector(’.card’);const duration = getComputedStyle(el).getPropertyValue(’–sd-duration’);el.style.setProperty(’–sd-easing’, ‘cubic-bezier(.22,.9,.32,1)’);

When to use this pattern

• Component libraries with themed motion tokens.
• Apps needing per-component or per-theme animation tuning without duplicating keyframes.
• Situations where JavaScript toggles animation behavior by changing CSS variables.

Quick checklist

• Define semantic keyframes (e.g., sd-fadeIn) once.
• Provide sensible defaults at :root.
• Honor reduced-motion preferences.
• Prefer transform/opacity for smoother performance.
• Use variables for easy overrides and theming.

This pattern keeps motion consistent, themable, and easy to maintain across a codebase while enabling runtime flexibility.