07Active slide scale up

<main class="stage">
  <div class="as is-demo">
    <input type="radio" name="as-tab" id="as-1" class="as__radio" checked>
    <input type="radio" name="as-tab" id="as-2" class="as__radio">
    <input type="radio" name="as-tab" id="as-3" class="as__radio">
    <div class="as__track">
      <label class="as__slide as__slide--1" for="as-1" aria-label="Slide 1"></label>
      <label class="as__slide as__slide--2" for="as-2" aria-label="Slide 2"></label>
      <label class="as__slide as__slide--3" for="as-3" aria-label="Slide 3"></label>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-base;
$easing: $ease-spring;
$color: $stage-orange;

@include stage($stage-ink);

.as { width: min(400px, 92vw); }
.as__radio { position: absolute; opacity: 0; pointer-events: none; }

.as__track {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: $sp-3;
}
.as__slide {
  flex: 0 0 30%;
  aspect-ratio: 3 / 4;
  border-radius: $r-card;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  transform: scale(.82);
  opacity: .5;
  transition: transform $duration $easing, opacity $duration $easing;
  z-index: 0;
}
.as__slide--1 { background: linear-gradient(160deg, $subject-blue, #d6ddeb); }
.as__slide--2 { background: linear-gradient(160deg, $color, #ebdbd6); }
.as__slide--3 { background: linear-gradient(160deg, #c2ae82, $stage-yellow); }
.as__slide::before {
  content: ""; position: absolute; top: $sp-2; right: $sp-2;
  width: $sp-6; height: $sp-6; border-radius: 50%;
  background: rgba(255, 255, 255, .85);
}
.as__slide::after {
  content: ""; position: absolute; left: -10%; right: -10%; bottom: -6%; height: 46%;
  background: rgba(23, 20, 26, .26);
  clip-path: polygon(0% 100%, 22% 40%, 42% 66%, 60% 26%, 78% 60%, 100% 34%, 100% 100%);
}

// ── 실제 동작: 고른 라디오의 슬라이드만 커지고 진해진다. 나머지는 작고 흐리다 ──
#as-1:checked ~ .as__track .as__slide--1,
#as-2:checked ~ .as__track .as__slide--2,
#as-3:checked ~ .as__track .as__slide--3 {
  transform: scale(1.08);
  opacity: 1;
  z-index: 1;
}

// ── 데모 루프: 클릭 전까지 라디오가 스스로 1→2→3→1 순으로 커진다 (라디오 상태는 그대로 1번) ──
.as.is-demo .as__slide--1 { animation: as-1 $dur-loop $easing infinite; }
.as.is-demo .as__slide--2 { animation: as-2 $dur-loop $easing infinite; }
.as.is-demo .as__slide--3 { animation: as-3 $dur-loop $easing infinite; }
// 1번은 0%에서 작은 상태로 시작해 0→4% 동안 커진다(3번이 96→100%에서 작아지는 것과 이어진다) —
// 루프 경계에서 1번이 순간이동으로 팝 커지던 티를 없앤다 (끝→처음 텔레포트 금지)
@keyframes as-1 {
  0%       { transform: scale(.82); opacity: .5; }
  4%, 29%  { transform: scale(1.08); opacity: 1; }
  54%, 100% { transform: scale(.82); opacity: .5; }
}
@keyframes as-2 {
  0%, 29%  { transform: scale(.82); opacity: .5; }
  33%, 62% { transform: scale(1.08); opacity: 1; }
  66%, 100% { transform: scale(.82); opacity: .5; }
}
@keyframes as-3 {
  0%, 62%  { transform: scale(.82); opacity: .5; }
  66%, 96% { transform: scale(1.08); opacity: 1; }
  100%     { transform: scale(.82); opacity: .5; }
}

// ── 접근성 ──────────────────────────────────────────
@media (prefers-reduced-motion: reduce) {
  .as__slide { transition: none; }
  .as.is-demo .as__slide--1,
  .as.is-demo .as__slide--2,
  .as.is-demo .as__slide--3 { animation: 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);
}

.as {
  width: min(400px, 92vw);
}

.as__radio {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.as__track {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.as__slide {
  flex: 0 0 30%;
  aspect-ratio: 3/4;
  border-radius: 16px;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  transform: scale(0.82);
  opacity: 0.5;
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1), opacity 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
  z-index: 0;
}

.as__slide--1 {
  background: linear-gradient(160deg, #2f6df6, #d6ddeb);
}

.as__slide--2 {
  background: linear-gradient(160deg, #ff4d1f, #ebdbd6);
}

.as__slide--3 {
  background: linear-gradient(160deg, #c2ae82, #ffd23f);
}

.as__slide::before {
  content: "";
  position: absolute;
  top: 8px;
  right: 8px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.85);
}

.as__slide::after {
  content: "";
  position: absolute;
  left: -10%;
  right: -10%;
  bottom: -6%;
  height: 46%;
  background: rgba(23, 20, 26, 0.26);
  clip-path: polygon(0% 100%, 22% 40%, 42% 66%, 60% 26%, 78% 60%, 100% 34%, 100% 100%);
}

#as-1:checked ~ .as__track .as__slide--1,
#as-2:checked ~ .as__track .as__slide--2,
#as-3:checked ~ .as__track .as__slide--3 {
  transform: scale(1.08);
  opacity: 1;
  z-index: 1;
}

.as.is-demo .as__slide--1 {
  animation: as-1 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.as.is-demo .as__slide--2 {
  animation: as-2 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.as.is-demo .as__slide--3 {
  animation: as-3 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes as-1 {
  0% {
    transform: scale(0.82);
    opacity: 0.5;
  }
  4%, 29% {
    transform: scale(1.08);
    opacity: 1;
  }
  54%, 100% {
    transform: scale(0.82);
    opacity: 0.5;
  }
}
@keyframes as-2 {
  0%, 29% {
    transform: scale(0.82);
    opacity: 0.5;
  }
  33%, 62% {
    transform: scale(1.08);
    opacity: 1;
  }
  66%, 100% {
    transform: scale(0.82);
    opacity: 0.5;
  }
}
@keyframes as-3 {
  0%, 62% {
    transform: scale(0.82);
    opacity: 0.5;
  }
  66%, 96% {
    transform: scale(1.08);
    opacity: 1;
  }
  100% {
    transform: scale(0.82);
    opacity: 0.5;
  }
}
@media (prefers-reduced-motion: reduce) {
  .as__slide {
    transition: none;
  }
  .as.is-demo .as__slide--1,
  .as.is-demo .as__slide--2,
  .as.is-demo .as__slide--3 {
    animation: none !important;
  }
}

// 실제 동작은 :checked 만으로 끝난다(0줄). 이 3줄은 미리보기 자동 재생만 멈춘다.
document.querySelectorAll('.as__radio').forEach(function (r) {
  r.addEventListener('pointerdown', function () { document.querySelector('.as').classList.remove('is-demo'); });
});

import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./ActiveSlideScale.module.scss";

export type ActiveSlideScaleProps = {
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function ActiveSlideScale({ duration = 300, easing = "cubic-bezier(.2,.8,.2,1)", color = "#ff4d1f" }: ActiveSlideScaleProps) {
  const [active, setActive] = useState(0);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <div className={styles.as} style={vars}>
      <div className={styles.track}>
        {[0, 1, 2].map((i) => (
          <button
            key={i}
            type="button"
            aria-label={`슬라이드 ${i + 1}`}
            className={`${styles.slide} ${styles["slide" + (i + 1)]} ${i === active ? styles.isActive : ""}`}
            onClick={() => setActive(i)}
          />
        ))}
      </div>
    </div>
  );
}