p]:inline” data-streamdown=”list-item”>Freestyle Techniques for Creative Expression

Those are CSS custom properties (CSS variables) likely used by a design system or component library to control a small animation. Breakdown:

• -sd-animation: sd-fadeIn;
  • Specifies which animation to apply (here a named animation “sd-fadeIn”).
• –sd-duration: 250ms;
  • Controls the animation duration: 250 milliseconds.
• –sd-easing: ease-in;
  • Sets the timing function/transition curve: “ease-in” (slow start, faster end).

How they’re typically used in CSS:

• Defined on an element (or :root) as variables, then consumed in animation rules:
  .component {–sd-animation: sd-fadeIn;  –sd-duration: 250ms;  –sd-easing: ease-in;  animation-name: var(–sd-animation);  animation-duration: var(–sd-duration);  animation-timing-function: var(–sd-easing);  animation-fill-mode: both;}
  @keyframes sd-fadeIn {  from { opacity: 0; transform: translateY(6px); }  to   { opacity: 1; transform: translateY(0); }}

Notes and tips:

• Prefix style: one property uses single dash (-sd-) and others use double (–sd-). Standard custom properties must start with –; a single-dash name is not a valid CSS custom property and might be a regular property or a typo. If intended as a variable, change to –sd-animation.
• animation-fill-mode: both or forwards keeps end state visible.
• Consider prefers-reduced-motion: set duration to 0 or remove animation for accessibility.