feat: animated slider

src/components/slider/index.tsx

@@ -22,6 +22,11 @@ type SliderProps = Omit<ComponentPropsWithoutRef<typeof RSlider.Root>, 'classNam
   notches?: NotchPlacement;
   /** Thumb shape. `'square'` (default) has a small border-radius; `'round'` is a full circle. */
   knobStyle?: KnobStyle;
+  /**
+   * Enable step-glide animation. Defaults to `true` when `marks` is set, `false` otherwise.
+   * Explicitly setting this always overrides the default.
+   */
+  animated?: boolean;
   className?: string;
 };
 
@@ -73,6 +78,7 @@ export const Slider = ({
   marks,
   notches = 'bottom',
   knobStyle = 'square',
+  animated,
   min = 0,
   max = 100,
   step = 1,
@@ -84,10 +90,12 @@ export const Slider = ({
   const hasLabels = resolved.some((m) => m.label != null);
   const showTop = hasMarks && (notches === 'top' || notches === 'both');
   const showBottom = hasMarks && (notches === 'bottom' || notches === 'both');
+  const isAnimated = animated !== undefined ? animated : hasMarks;
 
   const cls = [
     'modern-sk-slider',
     `modern-sk-slider--knob-${knobStyle}`,
+    isAnimated && 'modern-sk-slider--animated',
     hasMarks && 'modern-sk-slider--has-marks',
     hasLabels && 'modern-sk-slider--has-labels',
     showTop && 'modern-sk-slider--notch-top',

src/styles/components.css

@@ -626,8 +626,10 @@ textarea.modern-sk-field {
   border-radius: 3px;
   background: linear-gradient(90deg, var(--lime-deep), var(--lime));
   box-shadow: 0 0 10px rgba(190, 242, 100, 0.4);
-  /* Radix positions the range via left/right offsets (not width); ease those
-     so the fill glides between discrete steps while dragging. */
+}
+/* Radix positions the range via left/right offsets (not width); ease those
+   so the fill glides between discrete steps while dragging. */
+.modern-sk-slider--animated .modern-sk-slider__range {
   transition:
     left 0.12s ease-out,
     right 0.12s ease-out;
@@ -647,12 +649,12 @@ textarea.modern-sk-field {
 /* Radix sets the step position (left) on a WRAPPER span around the thumb, not on
    the thumb element itself — so the transition must live on that wrapper. The
    wrapper is the slider's direct child span that isn't the track. */
-.modern-sk-slider > span:not(.modern-sk-slider__track) {
+.modern-sk-slider--animated > span:not(.modern-sk-slider__track) {
   transition: left 0.12s ease-out;
 }
 @media (prefers-reduced-motion: reduce) {
-  .modern-sk-slider > span:not(.modern-sk-slider__track),
-  .modern-sk-slider__range {
+  .modern-sk-slider--animated > span:not(.modern-sk-slider__track),
+  .modern-sk-slider--animated .modern-sk-slider__range {
     transition: none;
   }
 }