p]:inline” data-streamdown=”list-item”>X-Celtx: A Complete Guide to Features and Workflow

These look like custom CSS properties (CSS variables) used to control a simple animation named “sd-fadeIn.” Explanation:

• –sd-animation: sd-fadeIn;
  • Selects the animation to apply. The value likely corresponds to a keyframes animation named @keyframes sd-fadeIn.
• –sd-duration: 250ms;
  • Sets how long the animation runs (250 milliseconds).
• –sd-easing: ease-in;
  • Sets the timing function controlling acceleration (starts slowly then speeds up).

Typical usage pattern in CSS:

• Define keyframes:

@keyframes sd-fadeIn {from { opacity: 0; transform: translateY(4px); }  to   { opacity: 1; transform: translateY(0); }}

• Use the variables on an element (fallbacks optional):

.element {  animation-name: var(–sd-animation, sd-fadeIn);  animation-duration: var(–sd-duration, 250ms);  animation-timing-function: var(–sd-easing, ease-in);  animation-fill-mode: both;}

Notes:

• Ensure the @keyframes name matches –sd-animation.
• You can add other variables for delay, iteration-count, or fill-mode.
• Browser support: CSS variables and animations are widely supported in modern browsers.