Those are CSS custom properties (CSS variables) used by a component or library to control an animation. Breakdown:
- -sd-animation: sd-fadeIn;
- Purpose: selects the animation name or preset (here, “sd-fadeIn”). The component likely maps that name to keyframes or a predefined animation behavior.
- –sd-duration: 250ms;
- Purpose: animation duration — how long the animation runs (250 milliseconds).
- –sd-easing: ease-in;
- Purpose: timing function — controls acceleration of the animation (starts slowly and speeds up).
How they’re typically used in CSS:
- Defined on an element or container:
.my-element {–sd-animation: sd-fadeIn; –sd-duration: 250ms; –sd-easing: ease-in;} - Consumed in a rule that applies animation:
.my-element { animation-name: var(–sd-animation); animation-duration: var(–sd-duration); animation-timing-function: var(–sd-easing); animation-fill-mode: both;}
Notes:
- The variable name spelling must match exactly (leading hyphen vs. double hyphen — use double hyphen for custom properties: –sd-animation).
- If the library expects specific names (like “sd-fadeIn”), those preset keyframes must exist (e.g., @keyframes sd-fadeIn).
- Fallbacks: provide defaults or fallback values: animation-duration: var(–sd-duration, 300ms);
- For smoother motion, pair with will-change or transform/opacity-only animations (fade typically animates opacity and/or translateY).
Leave a Reply