03Nghiêng 3D thị sai

<main class="stage">
  <div class="frame">
    <article class="card is-demo" tabindex="0">
      <span class="card__layer card__layer--back" aria-hidden="true"></span>
      <div class="card__layer card__layer--front">
        <h3 class="card__title">Dự án portfolio</h3>
        <p class="card__meta">Xem chi tiết</p>
      </div>
    </article>
  </div>
</main>

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

$duration: $dur-base;                                 // 기울기가 붙는 시간
$easing: $ease-spring;                                 // 탄력 있게
$color: $subject-cream;                                // 카드 배경

@include stage($stage-orange);
.stage { padding: clamp(6px, 2.4vw, 16px); }

// 스포트라이트(커서 하이라이트) — 기존 틸트 효과는 그대로, 이 층만 얹는다
@property --mx { syntax: "<percentage>"; inherits: true; initial-value: 50%; }
@property --my { syntax: "<percentage>"; inherits: true; initial-value: 50%; }
@property --sp { syntax: "<number>"; inherits: true; initial-value: 0; }

.frame { perspective: 700px; }                          // 자식 카드가 이 값 기준으로 기운다

.card {
  position: relative;
  width: min(190px, 58vw);
  border-radius: $r-card;
  background: $color;
  box-shadow: $shadow-raised;
  outline: none;
  cursor: pointer;
  overflow: hidden;
  transform-style: preserve-3d;
  transform: rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
  transition: transform $duration $easing;
}
.card__layer--back {
  position: absolute;
  inset: -12%;
  background: linear-gradient(155deg, $subject-blue-deep 0%, $stage-ink 100%);
  transform: translateZ(-20px) translateX(var(--pz, 0px));
  transition: transform $duration $easing;
}
.card__layer--front {
  position: relative;
  padding: 36px 14px 14px;
  transform: translateZ(20px);
}
.card__layer--front::after {
  content: '';
  position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(120px circle at var(--mx) var(--my), rgba(255, 255, 255, .32), transparent 70%);
  opacity: var(--sp);
}
.card__title { position: relative; z-index: 1; margin: 0 0 4px; font-weight: 700; font-size: clamp(12px, 3.4vw, 14px); line-height: 1.3; font-family: inherit; color: $subject-cream; }
.card__meta { position: relative; z-index: 1; margin: 0; font-weight: 500; font-size: clamp(11px, 3vw, 12px); line-height: 1.3; font-family: inherit; color: rgba($subject-cream, .72); }

.card:focus-visible,
.card:active {
  transform: rotateX(-8deg) rotateY(12deg);
}
.card:focus-visible .card__layer--back,
.card:active .card__layer--back {
  transform: translateZ(-20px) translateX(10px);
}

.card.is-demo { animation: tilt-loop $dur-loop $easing infinite, spot-loop $dur-loop $easing infinite; }
.card.is-demo .card__layer--back { animation: tilt-loop-bg $dur-loop $easing infinite; }

@keyframes tilt-loop {
  0%, 15%  { transform: rotateX(0) rotateY(0); }
  40%      { transform: rotateX(-8deg) rotateY(12deg); }
  65%      { transform: rotateX(6deg) rotateY(-10deg); }
  100%     { transform: rotateX(0) rotateY(0); }
}
@keyframes tilt-loop-bg {
  0%, 15%  { transform: translateZ(-20px) translateX(0); }
  40%      { transform: translateZ(-20px) translateX(10px); }
  65%      { transform: translateZ(-20px) translateX(-8px); }
  100%     { transform: translateZ(-20px) translateX(0); }
}
@keyframes spot-loop {
  0%, 15%   { --sp: 0; --mx: 15%; --my: 20%; }
  30%       { --sp: 1; }
  50%       { --mx: 85%; --my: 30%; }
  70%       { --mx: 50%; --my: 80%; }
  85%, 100% { --sp: 0; }
}

@media (hover: none) {
  .card:active { transform: rotateX(-8deg) rotateY(12deg); }
  .card:active .card__layer--back { transform: translateZ(-20px) translateX(10px); }
}
@media (prefers-reduced-motion: reduce) {
  .card, .card__layer--back { transition: none; }
  .card.is-demo, .card.is-demo .card__layer--back { animation: none; }
  .card.is-demo { --sp: 0; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.stage {
  padding: clamp(6px, 2.4vw, 16px);
}

@property --mx {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}
@property --my {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}
@property --sp {
  syntax: "<number>";
  inherits: true;
  initial-value: 0;
}
.frame {
  perspective: 700px;
}

.card {
  position: relative;
  width: min(190px, 58vw);
  border-radius: 16px;
  background: #fff7e6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  outline: none;
  cursor: pointer;
  overflow: hidden;
  transform-style: preserve-3d;
  transform: rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.card__layer--back {
  position: absolute;
  inset: -12%;
  background: linear-gradient(155deg, #0a4fe8 0%, #17141a 100%);
  transform: translateZ(-20px) translateX(var(--pz, 0px));
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.card__layer--front {
  position: relative;
  padding: 36px 14px 14px;
  transform: translateZ(20px);
}

.card__layer--front::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(120px circle at var(--mx) var(--my), rgba(255, 255, 255, 0.32), transparent 70%);
  opacity: var(--sp);
}

.card__title {
  position: relative;
  z-index: 1;
  margin: 0 0 4px;
  font-weight: 700;
  font-size: clamp(12px, 3.4vw, 14px);
  line-height: 1.3;
  font-family: inherit;
  color: #fff7e6;
}

.card__meta {
  position: relative;
  z-index: 1;
  margin: 0;
  font-weight: 500;
  font-size: clamp(11px, 3vw, 12px);
  line-height: 1.3;
  font-family: inherit;
  color: rgba(255, 247, 230, 0.72);
}

.card:focus-visible,
.card:active {
  transform: rotateX(-8deg) rotateY(12deg);
}

.card:focus-visible .card__layer--back,
.card:active .card__layer--back {
  transform: translateZ(-20px) translateX(10px);
}

.card.is-demo {
  animation: tilt-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite, spot-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.card.is-demo .card__layer--back {
  animation: tilt-loop-bg 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes tilt-loop {
  0%, 15% {
    transform: rotateX(0) rotateY(0);
  }
  40% {
    transform: rotateX(-8deg) rotateY(12deg);
  }
  65% {
    transform: rotateX(6deg) rotateY(-10deg);
  }
  100% {
    transform: rotateX(0) rotateY(0);
  }
}
@keyframes tilt-loop-bg {
  0%, 15% {
    transform: translateZ(-20px) translateX(0);
  }
  40% {
    transform: translateZ(-20px) translateX(10px);
  }
  65% {
    transform: translateZ(-20px) translateX(-8px);
  }
  100% {
    transform: translateZ(-20px) translateX(0);
  }
}
@keyframes spot-loop {
  0%, 15% {
    --sp: 0;
    --mx: 15%;
    --my: 20%;
  }
  30% {
    --sp: 1;
  }
  50% {
    --mx: 85%;
    --my: 30%;
  }
  70% {
    --mx: 50%;
    --my: 80%;
  }
  85%, 100% {
    --sp: 0;
  }
}
@media (hover: none) {
  .card:active {
    transform: rotateX(-8deg) rotateY(12deg);
  }
  .card:active .card__layer--back {
    transform: translateZ(-20px) translateX(10px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .card, .card__layer--back {
    transition: none;
  }
  .card.is-demo, .card.is-demo .card__layer--back {
    animation: none;
  }
  .card.is-demo {
    --sp: 0;
  }
}

// 카드 위 커서 위치로 기울기를 만든다. 배경 레이어가 반대로 움직여 층이 갈린다(시차).
var card = document.querySelector('.card');
card.addEventListener('pointermove', function (e) {
  card.classList.remove('is-demo');
  var r = card.getBoundingClientRect(), px = (e.clientX - r.left) / r.width - .5, py = (e.clientY - r.top) / r.height - .5;
  card.style.setProperty('--rx', (-py * 14) + 'deg');
  card.style.setProperty('--ry', (px * 16) + 'deg');
  card.style.setProperty('--pz', (px * -12) + 'px');
  // 스포트라이트(커서 하이라이트) — 틸트는 그대로, 이 층만 얹는다
  card.style.setProperty('--mx', ((e.clientX - r.left) / r.width * 100) + '%');
  card.style.setProperty('--my', ((e.clientY - r.top) / r.height * 100) + '%');
  card.style.setProperty('--sp', 1);
});
card.addEventListener('pointerleave', function () { card.style.cssText = ''; });

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

export type TiltParallaxCardProps = {
  title: string;
  meta: string;
  /** 기울기가 붙는 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function TiltParallaxCard({
  title,
  meta,
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#fff7e6",
}: TiltParallaxCardProps) {
  const ref = useRef<HTMLElement>(null);

  const move = useCallback((e: PointerEvent<HTMLElement>) => {
    const el = ref.current;
    if (!el) return;
    const r = el.getBoundingClientRect();
    const px = (e.clientX - r.left) / r.width - 0.5;
    const py = (e.clientY - r.top) / r.height - 0.5;
    el.style.setProperty("--rx", `${-py * 14}deg`);
    el.style.setProperty("--ry", `${px * 16}deg`);
    el.style.setProperty("--pz", `${px * -12}px`);
    // 스포트라이트(커서 하이라이트) — 틸트는 그대로, 이 층만 얹는다
    el.style.setProperty("--mx", `${((e.clientX - r.left) / r.width) * 100}%`);
    el.style.setProperty("--my", `${((e.clientY - r.top) / r.height) * 100}%`);
    el.style.setProperty("--sp", "1");
  }, []);

  const leave = useCallback(() => {
    const el = ref.current;
    if (el) {
      el.style.removeProperty("--rx"); el.style.removeProperty("--ry"); el.style.removeProperty("--pz");
      el.style.removeProperty("--mx"); el.style.removeProperty("--my"); el.style.removeProperty("--sp");
    }
  }, []);

  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <div className={styles.frame}>
      <article
        ref={ref}
        className={styles.card}
        style={vars}
        tabIndex={0}
        onPointerMove={move}
        onPointerLeave={leave}
      >
        <span className={styles.back} aria-hidden="true" />
        <div className={styles.front}>
          <h3 className={styles.title}>{title}</h3>
          <p className={styles.meta}>{meta}</p>
        </div>
      </article>
    </div>
  );
}