09Letters Whose Depth Value Lifts When the Cursor Arrives

<main class="stage">
<div class="hv is-demo" id="hv">
  <p class="hv__badge"><span class="hv__badgeLabel">Lift value</span> <span class="hv__badgeValue" id="hvValue">0.0px</span></p>
  <div class="hv__scene" id="hvScene">
    <h1 class="hv__word" id="hvWord" tabindex="0">Lift</h1>
  </div>
</div>
</main>

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

// 핵심: 근접도 값(p 0~1) 하나로 그림자 오프셋·번짐 값을 함께 밀어 올린다.
// 포인터가 글자 위에 오르면 p 가 커지며 그림자 깊이가 늘고 글자가 살짝 떠오른다.

$duration: $dur-quick;
$easing: $ease-out;
$color: $subject-cream;

@include stage($stage-ink);

.hv {
  display: grid;
  gap: $sp-4;
  justify-items: center;
  text-align: center;
}

.hv__badge {
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .1);
  color: $subject-cream;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.hv__scene {
  padding: $sp-10;
}

.hv__word {
  margin: 0;
  font-weight: 800;
  font-size: clamp(72px, 24vw, 140px);
  line-height: 1;
  white-space: nowrap;
  color: $color;
  cursor: pointer;
  will-change: text-shadow, transform;
}

.hv__word:focus-visible {
  outline: 2px solid $subject-cream;
  outline-offset: 8px;
}

@media (max-width: 340px) {
  .hv__scene { padding: $sp-6; }
  .hv__word { font-size: clamp(52px, 26vw, 92px); }
}

@media (prefers-reduced-motion: reduce) {
  .hv__word { transition: none; }
}

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);
}

.hv {
  display: grid;
  gap: 16px;
  justify-items: center;
  text-align: center;
}

.hv__badge {
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.1);
  color: #fff7e6;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.hv__scene {
  padding: 40px;
}

.hv__word {
  margin: 0;
  font-weight: 800;
  font-size: clamp(72px, 24vw, 140px);
  line-height: 1;
  white-space: nowrap;
  color: #fff7e6;
  cursor: pointer;
  will-change: text-shadow, transform;
}

.hv__word:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 8px;
}

@media (max-width: 340px) {
  .hv__scene {
    padding: 24px;
  }
  .hv__word {
    font-size: clamp(52px, 26vw, 92px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .hv__word {
    transition: none;
  }
}

(function () {
  var HOVER_LIFT_PX = 4;
  var LIFT_MULTIPLIER = 5;
  var LERP = 0.18;
  var PERIOD_MS = 1000;

  var scene = document.getElementById('hvScene');
  var word = document.getElementById('hvWord');
  var value = document.getElementById('hvValue');
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var targetP = 0;
  var curP = 0;
  var hasPointer = false;

  // 근접도 값(p 0~1) 하나로 그림자 오프셋·번짐 값을 함께 밀어 올려, 글자가 배경에서
  // 떠오르는 것처럼 보인다. Depth 기본 단위는 HOVER_LIFT_PX
  function buildLiftShadow(p) {
    var y = (p * HOVER_LIFT_PX * 1.6).toFixed(2);
    var y2 = (p * HOVER_LIFT_PX * LIFT_MULTIPLIER).toFixed(2);
    var blur = (4 + p * HOVER_LIFT_PX * 6.5).toFixed(1);
    return [
      '0px ' + y + 'px 0 rgba(10,79,232,' + (0.55 + p * 0.3).toFixed(2) + ')',
      '0px ' + y2 + 'px ' + blur + 'px rgba(10,79,232,' + (0.22 + p * 0.36).toFixed(2) + ')'
    ].join(', ');
  }

  function renderLift(p) {
    word.style.textShadow = buildLiftShadow(p);
    word.style.transform = 'translateY(' + (-(p * HOVER_LIFT_PX * 1.2)).toFixed(2) + 'px)';
    value.textContent = (p * HOVER_LIFT_PX).toFixed(1) + 'px';
  }

  function clamp(v, lo, hi) { return Math.max(lo, Math.min(hi, v)); }

  var startTime = null;
  function loop(now) {
    if (startTime === null) startTime = now;
    if (!hasPointer && !reduce) {
      var t = (now - startTime) % PERIOD_MS;
      var phase = (Math.sin((t / PERIOD_MS) * Math.PI * 2 - Math.PI / 2) + 1) / 2;
      targetP = phase;
    }
    curP += (targetP - curP) * LERP;
    renderLift(curP);
    requestAnimationFrame(loop);
  }

  scene.addEventListener('pointerenter', function () {
    hasPointer = true;
    targetP = 1;
    if (reduce) { curP = 1; renderLift(1); }
  });
  scene.addEventListener('pointerleave', function () {
    hasPointer = false;
    targetP = 0;
    if (reduce) { curP = 0; renderLift(0); }
  });
  word.addEventListener('focus', function () {
    hasPointer = true;
    targetP = 1;
    if (reduce) { curP = 1; renderLift(1); }
  });
  word.addEventListener('blur', function () {
    hasPointer = false;
    targetP = 0;
    if (reduce) { curP = 0; renderLift(0); }
  });

  if (reduce) {
    renderLift(0);
  } else {
    requestAnimationFrame(loop);
  }
})();

// TextShadowHoverDepthLift — vanilla 판(run/412/demo/09-text-shadow-hover-depth-lift/index.html) 의 React 포트.
// 근접도 값(p 0~1) 하나로 그림자 오프셋·번짐 값을 함께 밀어 올린다. 포인터가 글자 위에
// 오르면 p 가 커지며 그림자 깊이가 늘고 글자가 살짝 떠오른다.
import { useEffect, useRef, useState } from "react";
import styles from "./TextShadowHoverDepthLift.module.scss";

type Box<T> = { current: T };

const HOVER_LIFT_PX = 4;
const LIFT_MULTIPLIER = 5;
const LERP = 0.18;
const PERIOD_MS = 1000;

function buildLiftShadow(p: number): string {
  const y = (p * HOVER_LIFT_PX * 1.6).toFixed(2);
  const y2 = (p * HOVER_LIFT_PX * LIFT_MULTIPLIER).toFixed(2);
  const blur = (4 + p * HOVER_LIFT_PX * 6.5).toFixed(1);
  return [
    "0px " + y + "px 0 rgba(10,79,232," + (0.55 + p * 0.3).toFixed(2) + ")",
    "0px " + y2 + "px " + blur + "px rgba(10,79,232," + (0.22 + p * 0.36).toFixed(2) + ")"
  ].join(", ");
}

export default function TextShadowHoverDepthLift() {
  const sceneRef = useRef<HTMLDivElement | null>(null);
  const wordRef = useRef<HTMLHeadingElement | null>(null);
  const valueRef = useRef<HTMLSpanElement | null>(null);
  const targetPRef = useRef<number>(0) as Box<number>;
  const curPRef = useRef<number>(0) as Box<number>;
  const hasPointerRef = useRef<boolean>(false) as Box<boolean>;
  const t0Ref = useRef<number>(0) as Box<number>;
  const frameRef = useRef<number>(0) as Box<number>;
  const [demo] = useState(true);
  const [reduce, setReduce] = useState(false);

  function render(p: number): void {
    const word = wordRef.current;
    const value = valueRef.current;
    if (!word || !value) return;
    word.style.textShadow = buildLiftShadow(p);
    word.style.transform = "translateY(" + (-(p * HOVER_LIFT_PX * 1.2)).toFixed(2) + "px)";
    value.textContent = (p * HOVER_LIFT_PX).toFixed(1) + "px";
  }

  useEffect(() => {
    setReduce(window.matchMedia("(prefers-reduced-motion: reduce)").matches);
  }, []);

  useEffect(() => {
    if (reduce) {
      render(0);
      return;
    }
    function loop(now: number): void {
      if (t0Ref.current === 0) t0Ref.current = now;
      if (!hasPointerRef.current) {
        const t = (now - t0Ref.current) % PERIOD_MS;
        const phase = (Math.sin((t / PERIOD_MS) * Math.PI * 2 - Math.PI / 2) + 1) / 2;
        targetPRef.current = phase;
      }
      curPRef.current += (targetPRef.current - curPRef.current) * LERP;
      render(curPRef.current);
      frameRef.current = requestAnimationFrame(loop);
    }
    frameRef.current = requestAnimationFrame(loop);
    return () => cancelAnimationFrame(frameRef.current);
  }, [reduce]);

  function onPointerEnter(): void {
    hasPointerRef.current = true;
    targetPRef.current = 1;
    if (reduce) { curPRef.current = 1; render(1); }
  }
  function onPointerLeave(): void {
    hasPointerRef.current = false;
    targetPRef.current = 0;
    if (reduce) { curPRef.current = 0; render(0); }
  }
  function onFocus(): void {
    hasPointerRef.current = true;
    targetPRef.current = 1;
    if (reduce) { curPRef.current = 1; render(1); }
  }
  function onBlur(): void {
    hasPointerRef.current = false;
    targetPRef.current = 0;
    if (reduce) { curPRef.current = 0; render(0); }
  }

  const cls = [styles.hv, demo ? styles.isDemo : ""].filter(Boolean).join(" ");
  return (
    <main className={styles.stage}>
      <div className={cls}>
        <p className={styles.badge}><span>떠오름 값</span> <span ref={valueRef}>0.0px</span></p>
        <div className={styles.scene} ref={sceneRef} onPointerEnter={onPointerEnter} onPointerLeave={onPointerLeave}>
          <h1 className={styles.word} ref={wordRef} tabIndex={0} onFocus={onFocus} onBlur={onBlur}>부상</h1>
        </div>
      </div>
    </main>
  );
}