01Cursor shape morph

<main class="stage">
  <div class="cm-area is-demo">
    <a class="cm-link" href="#" data-cursor="link" tabindex="-1">Learn more</a>
    <div class="cm-cursor" aria-hidden="true">
      <span class="cm-cursor__shape">
        <svg viewBox="0 0 256 256"><g fill="currentColor"><path d="m216 128l-72 72V56Z" opacity=".2"/><path d="m221.66 122.34l-72-72A8 8 0 0 0 136 56v64H40a8 8 0 0 0 0 16h96v64a8 8 0 0 0 13.66 5.66l72-72a8 8 0 0 0 0-11.32M152 180.69V75.31L204.69 128Z"/></g></svg>
      </span>
    </div>
  </div>
</main>

@use "../../../../site/static/demo-tokens" as *;

$duration: $dur-quick;                                 // 커서 모양 전환 시간
$easing: $ease-spring;
$color: $stage-paper;

@include stage($stage-ink);

.cm-area {
  position: relative;
  width: min(220px, 74vw);
  height: 110px;
}

.cm-link {
  position: absolute;
  left: 44px;
  top: 30px;
  width: 128px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: $r-control;
  border: 1px dashed rgba(255, 255, 255, .4);
  color: $color;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

// pointer(마우스)가 있는 기기만 커스텀 커서를 그린다 — 손가락엔 커서가 없다
.cm-cursor {
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 0;
  pointer-events: none;
  transform: translate(6px, 90px);
  transition: transform $duration $easing;
}

.cm-cursor__shape {
  position: absolute;
  left: -11px;
  top: -11px;
  width: 22px;
  height: 22px;
  display: grid;
  place-items: center;
  border-radius: $r-pill;
  background: $color;
  transition: transform $duration $easing, background $duration $easing;
}
.cm-cursor__shape svg {
  width: 13px;
  height: 13px;
  color: $stage-ink;
  opacity: 0;
  transform: scale(.4);
  transition: opacity $duration $easing, transform $duration $easing;
}

.cm-cursor.is-link .cm-cursor__shape {
  transform: scale(1.9);
  background: $subject-blue;
}
.cm-cursor.is-link .cm-cursor__shape svg {
  opacity: 1;
  transform: scale(1);
  color: $stage-paper;
}

@media (hover: none), (pointer: coarse) {
  .cm-cursor { display: none; }               // 터치 기기: 커스텀 커서 자체가 의미 없다 (함정 참고)
}

// 데모 강제 루프 — 실제 pointermove 없이도 같은 두 상태를 오간다
.cm-area.is-demo .cm-cursor      { animation: cm-move $dur-loop $easing infinite; }
.cm-area.is-demo .cm-cursor__shape     { animation: cm-shape $dur-loop $easing infinite; }
.cm-area.is-demo .cm-cursor__shape svg { animation: cm-icon $dur-loop $easing infinite; }

@keyframes cm-move {
  0%, 12%   { transform: translate(6px, 90px); }
  40%, 62%  { transform: translate(108px, 50px); }
  90%, 100% { transform: translate(6px, 90px); }
}
@keyframes cm-shape {
  0%, 12%   { transform: scale(1); background: $color; }
  40%, 62%  { transform: scale(1.9); background: $subject-blue; }
  90%, 100% { transform: scale(1); background: $color; }
}
@keyframes cm-icon {
  0%, 12%   { opacity: 0; transform: scale(.4); color: $stage-ink; }
  40%, 62%  { opacity: 1; transform: scale(1); color: $stage-paper; }
  90%, 100% { opacity: 0; transform: scale(.4); color: $stage-ink; }
}

@media (prefers-reduced-motion: reduce) {
  .cm-cursor, .cm-cursor__shape, .cm-cursor__shape svg { animation: none !important; transition: none !important; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cm-area {
  position: relative;
  width: min(220px, 74vw);
  height: 110px;
}

.cm-link {
  position: absolute;
  left: 44px;
  top: 30px;
  width: 128px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  border: 1px dashed rgba(255, 255, 255, 0.4);
  color: #ffffff;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}

.cm-cursor {
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 0;
  pointer-events: none;
  transform: translate(6px, 90px);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.cm-cursor__shape {
  position: absolute;
  left: -11px;
  top: -11px;
  width: 22px;
  height: 22px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: #ffffff;
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), background 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.cm-cursor__shape svg {
  width: 13px;
  height: 13px;
  color: #17141a;
  opacity: 0;
  transform: scale(0.4);
  transition: opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1), transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.cm-cursor.is-link .cm-cursor__shape {
  transform: scale(1.9);
  background: #2f6df6;
}

.cm-cursor.is-link .cm-cursor__shape svg {
  opacity: 1;
  transform: scale(1);
  color: #ffffff;
}

@media (hover: none), (pointer: coarse) {
  .cm-cursor {
    display: none;
  }
}
.cm-area.is-demo .cm-cursor {
  animation: cm-move 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.cm-area.is-demo .cm-cursor__shape {
  animation: cm-shape 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.cm-area.is-demo .cm-cursor__shape svg {
  animation: cm-icon 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes cm-move {
  0%, 12% {
    transform: translate(6px, 90px);
  }
  40%, 62% {
    transform: translate(108px, 50px);
  }
  90%, 100% {
    transform: translate(6px, 90px);
  }
}
@keyframes cm-shape {
  0%, 12% {
    transform: scale(1);
    background: #ffffff;
  }
  40%, 62% {
    transform: scale(1.9);
    background: #2f6df6;
  }
  90%, 100% {
    transform: scale(1);
    background: #ffffff;
  }
}
@keyframes cm-icon {
  0%, 12% {
    opacity: 0;
    transform: scale(0.4);
    color: #17141a;
  }
  40%, 62% {
    opacity: 1;
    transform: scale(1);
    color: #ffffff;
  }
  90%, 100% {
    opacity: 0;
    transform: scale(0.4);
    color: #17141a;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cm-cursor, .cm-cursor__shape, .cm-cursor__shape svg {
    animation: none !important;
    transition: none !important;
  }
}

(function () {
  var area = document.querySelector('.cm-area');
  var cursor = area.querySelector('.cm-cursor');
  var link = area.querySelector('.cm-link');
  // 실제 사용자: pointermove 로 커서 점이 실제 포인터를 따라가고, data-cursor 요소 위에서 링+화살표로 커진다
  area.addEventListener('pointermove', function (e) {
    if (area.classList.contains('is-demo')) return;
    var r = area.getBoundingClientRect();
    cursor.style.transform = 'translate(' + (e.clientX - r.left) + 'px,' + (e.clientY - r.top) + 'px)';
  });
  link.addEventListener('pointerenter', function () { cursor.classList.add('is-link'); });
  link.addEventListener('pointerleave', function () { cursor.classList.remove('is-link'); });
  // 터치 기기엔 pointermove 오버가 없다 — 첫 터치를 감지하면 데모 루프로 되돌려 커서가 화면에 박혀 남지 않게 한다
  area.addEventListener('pointerdown', function (e) {
    if (e.pointerType === 'touch') { area.classList.add('is-demo'); cursor.style.transform = ''; }
  });
})();

import { useRef, type CSSProperties, type PointerEvent } from "react";
import styles from "./CursorShapeMorphLink.module.scss";

export type CursorShapeMorphLinkProps = {
  href?: string;
  label?: string;
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

/** pointermove 로 커서 점이 따라가고, 링크 위에서 화살표 든 원으로 커진다. 터치 기기는 CSS 로 커서를 숨긴다 */
export default function CursorShapeMorphLink({
  href = "#",
  label = "자세히 보기",
  duration = 220,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#ffffff",
}: CursorShapeMorphLinkProps) {
  const areaRef = useRef<HTMLDivElement>(null);
  const cursorRef = useRef<HTMLDivElement>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  const move = (e: PointerEvent<HTMLDivElement>) => {
    const area = areaRef.current, cursor = cursorRef.current;
    if (!area || !cursor) return;
    const r = area.getBoundingClientRect();
    cursor.style.transform = `translate(${e.clientX - r.left}px,${e.clientY - r.top}px)`;
  };

  return (
    <div ref={areaRef} className={styles.area} style={vars} onPointerMove={move}>
      <a
        className={styles.link}
        href={href}
        onPointerEnter={() => cursorRef.current?.classList.add(styles.isLink)}
        onPointerLeave={() => cursorRef.current?.classList.remove(styles.isLink)}
      >
        {label}
      </a>
      <div ref={cursorRef} className={styles.cursor} aria-hidden="true">
        <span className={styles.shape}>
          <svg viewBox="0 0 256 256"><g fill="currentColor"><path d="m216 128l-72 72V56Z" opacity=".2" /><path d="m221.66 122.34l-72-72A8 8 0 0 0 136 56v64H40a8 8 0 0 0 0 16h96v64a8 8 0 0 0 13.66 5.66l72-72a8 8 0 0 0 0-11.32M152 180.69V75.31L204.69 128Z" /></g></svg>
        </span>
      </div>
    </div>
  );
}