09Spotlight circle

<main class="stage">
  <div class="sl">
    <div class="sl__scroll">
      <div class="sl__inner">
        <div class="sl__pin">
          <div class="sl__dim"><span class="sl__dimm">Still a secret</span></div>
          <div class="sl__spot is-demo"><span class="sl__cap">Now revealed</span></div>
        </div>
      </div>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;
$easing: $ease-out;
$color: $subject-blue;

@include stage($stage-ink);

.sl {
  width: min(390px, 88vw);
  height: clamp(150px, 62vh, 216px);
  border-radius: $r-card;
  overflow: hidden;
  box-shadow: $shadow-raised;
}

.sl__scroll {
  height: 100%;
  overflow-y: auto;
  scroll-timeline: --sl-scroll block;
  scrollbar-width: none;
  &::-webkit-scrollbar { display: none; }
}

.sl__inner { height: 280%; }

.sl__pin {
  position: sticky;
  top: 0;
  height: calc(100% / 2.8);
  display: grid;
  overflow: hidden;
}

// 감춰둔 화면(어두운 데 갈무리 무늬) — 스포트라이트가 자라면 삼켜지는 자리
.sl__dim {
  grid-area: 1 / 1;
  display: grid;
  background: repeating-linear-gradient(45deg, #241f2b 0 12px, #1d1924 12px 24px);
}
.sl__dimm {
  align-self: start;
  justify-self: center;
  margin-top: 14%;
  padding: $sp-1 $sp-4;
  border-radius: $r-pill;
  color: rgba(255, 247, 230, .5);
  border: 1px dashed rgba(255, 247, 230, .35);
  font: 700 13px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

// ── 실제 동작: 스포트라이트 = 위에 얹은 밝은 화면의 원형 창. 스크롤이 반지름을 키운다 ──
.sl__spot {
  grid-area: 1 / 1;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 50% 42%, rgba(255, 247, 230, .28), transparent 58%),
    linear-gradient(135deg, $color, #d6ddeb);
  clip-path: circle(14% at 50% 50%);
}
.sl__cap {
  padding: $sp-1 $sp-4;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .45);
  color: $subject-cream;
  font: 700 14px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}
@supports (animation-timeline: scroll()) {
  .sl__spot:not(.is-demo) {
    animation: sl-open linear both;
    animation-timeline: --sl-scroll;
  }
}
@supports not (animation-timeline: scroll()) {
  // 미지원 브라우저(Firefox·Safari): 원이 처음부터 활짝 열려 있다
  .sl__spot:not(.is-demo) { clip-path: circle(75% at 50% 50%); }
}
@keyframes sl-open {
  from { clip-path: circle(14% at 50% 50%); }
  to   { clip-path: circle(75% at 50% 50%); }
}

// 데모 루프: 실제 스크롤 대신 원이 열렸다 닫히는 걸 흉내(캡처용)
.sl__spot.is-demo { animation: sl-loop $duration $easing infinite; }
@keyframes sl-loop {
  0%, 10%  { clip-path: circle(14% at 50% 50%); }
  55%, 88% { clip-path: circle(75% at 50% 50%); }
  100%     { clip-path: circle(14% at 50% 50%); }
}

@media (prefers-reduced-motion: reduce) {
  .sl__spot.is-demo { animation: none !important; clip-path: circle(75% at 50% 50%) !important; }
  .sl__scroll { scroll-behavior: auto; }
}

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);
}

.sl {
  width: min(390px, 88vw);
  height: clamp(150px, 62vh, 216px);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.sl__scroll {
  height: 100%;
  overflow-y: auto;
  scroll-timeline: --sl-scroll block;
  scrollbar-width: none;
}
.sl__scroll::-webkit-scrollbar {
  display: none;
}

.sl__inner {
  height: 280%;
}

.sl__pin {
  position: sticky;
  top: 0;
  height: 35.7142857143%;
  display: grid;
  overflow: hidden;
}

.sl__dim {
  grid-area: 1/1;
  display: grid;
  background: repeating-linear-gradient(45deg, #241f2b 0 12px, #1d1924 12px 24px);
}

.sl__dimm {
  align-self: start;
  justify-self: center;
  margin-top: 14%;
  padding: 4px 16px;
  border-radius: 999px;
  color: rgba(255, 247, 230, 0.5);
  border: 1px dashed rgba(255, 247, 230, 0.35);
  font: 700 13px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.sl__spot {
  grid-area: 1/1;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at 50% 42%, rgba(255, 247, 230, 0.28), transparent 58%), linear-gradient(135deg, #2f6df6, #d6ddeb);
  clip-path: circle(14% at 50% 50%);
}

.sl__cap {
  padding: 4px 16px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.45);
  color: #fff7e6;
  font: 700 14px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

@supports (animation-timeline: scroll()) {
  .sl__spot:not(.is-demo) {
    animation: sl-open linear both;
    animation-timeline: --sl-scroll;
  }
}
@supports not (animation-timeline: scroll()) {
  .sl__spot:not(.is-demo) {
    clip-path: circle(75% at 50% 50%);
  }
}
@keyframes sl-open {
  from {
    clip-path: circle(14% at 50% 50%);
  }
  to {
    clip-path: circle(75% at 50% 50%);
  }
}
.sl__spot.is-demo {
  animation: sl-loop 2s ease-out infinite;
}

@keyframes sl-loop {
  0%, 10% {
    clip-path: circle(14% at 50% 50%);
  }
  55%, 88% {
    clip-path: circle(75% at 50% 50%);
  }
  100% {
    clip-path: circle(14% at 50% 50%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .sl__spot.is-demo {
    animation: none !important;
    clip-path: circle(75% at 50% 50%) !important;
  }
  .sl__scroll {
    scroll-behavior: auto;
  }
}

// 실제 동작: 스크롤 상자의 scroll-timeline 이 clip-path 원 반지름을 키운다(0줄).
// is-demo 클래스는 캡처용 미리보기 루프일 뿐 — 실제 스크롤 반응은 그대로 살아있다.

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

export type SpotlightCircleProps = {
  duration?: number;
  easing?: string;
  color?: string;
  secret?: string;
  reveal?: string;
};

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

export default function SpotlightCircle({
  duration = 300,
  easing = "linear",
  color = "#2f6df6",
  secret = "아직 비밀",
  reveal = "지금 공개",
}: SpotlightCircleProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <div className={styles.sl} style={vars}>
      {/* 스포트라이트 = 위에 얹은 밝은 화면의 원형 창. 스크롤이 반지름을 키운다 */}
      <div className={styles.scroll}>
        <div className={styles.inner}>
          <div className={styles.pin}>
            <div className={styles.dim}>
              <span className={styles.dimm}>{secret}</span>
            </div>
            <div className={styles.spot}>
              <span className={styles.cap}>{reveal}</span>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}