02Spinning border light

<main class="stage">
  <article class="card is-demo" tabindex="0">
    <span class="card__ring" aria-hidden="true"></span>
    <div class="card__inner">
      <h3 class="card__title">Premium Plan</h3>
      <p class="card__meta">Includes AI features</p>
    </div>
  </article>
</main>

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

$duration: $dur-loop;                                 // 빛이 한 바퀴 도는 시간
$easing: linear;                                       // 회전은 일정 속도로
$color: $subject-blue;                                 // 빛 색

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

@property --angle {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}
// 스포트라이트(커서 하이라이트) + 미세 3D 틸트 — 기존 테두리 회전 효과 위에 얹는 층
@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; }
@property --rx { syntax: "<angle>"; inherits: true; initial-value: 0deg; }
@property --ry { syntax: "<angle>"; inherits: true; initial-value: 0deg; }

.card {
  position: relative;
  width: min(190px, 58vw);
  padding: 2px;
  border-radius: $r-card;
  outline: none;
  cursor: pointer;
  overflow: hidden;                                    // 빛이 카드 테두리 밖으로 안 번지게, 얇은 띠만 보이게
  isolation: isolate;
  transform: rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
  transition: transform $dur-base $ease-spring;
}
.card::after {
  content: '';
  position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: radial-gradient(120px circle at var(--mx) var(--my), rgba(255, 255, 255, .32), transparent 70%);
  opacity: var(--sp);
}
.card__ring {
  position: absolute;
  inset: -50%;
  background: conic-gradient(from var(--angle), transparent 0deg, $color 40deg, transparent 100deg);
  opacity: 0;
  transition: opacity $dur-quick $ease-out;
  z-index: -1;
}
.card__inner {
  position: relative;
  z-index: 1;
  border-radius: $r-card - 2px;
  background: $stage-ink;
  padding: 16px 14px;
}
.card__title { margin: 0 0 4px; font-weight: 700; font-size: clamp(12px, 3.4vw, 14px); line-height: 1.3; font-family: inherit; color: $subject-cream; }
.card__meta { margin: 0; font-weight: 500; font-size: clamp(11px, 3vw, 12px); line-height: 1.3; font-family: inherit; color: rgba($subject-cream, .7); }

.card:hover .card__ring,
.card:focus-visible .card__ring,
.card:active .card__ring,
.card.is-demo .card__ring {
  opacity: 1;
  animation: spin $duration $easing infinite;
}
.card.is-demo { animation: tilt-loop $dur-loop $easing infinite, spot-loop $dur-loop $easing infinite; }

@keyframes spin { to { --angle: 360deg; } }
@keyframes tilt-loop {
  0%, 15%   { --rx: 0deg; --ry: 0deg; }
  35%       { --rx: -4deg; --ry: 5deg; }
  65%       { --rx: 3deg; --ry: -5deg; }
  85%, 100% { --rx: 0deg; --ry: 0deg; }
}
@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 .card__ring { opacity: 1; animation: spin $duration $easing infinite; }
}
@media (prefers-reduced-motion: reduce) {
  .card__ring { transition: none; animation: none !important; opacity: .55; }
  .card { transition: none; }
  .card.is-demo { animation: none; --rx: 0deg; --ry: 0deg; --sp: 0; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

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

@property --angle {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}
@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;
}
@property --rx {
  syntax: "<angle>";
  inherits: true;
  initial-value: 0deg;
}
@property --ry {
  syntax: "<angle>";
  inherits: true;
  initial-value: 0deg;
}
.card {
  position: relative;
  width: min(190px, 58vw);
  padding: 2px;
  border-radius: 16px;
  outline: none;
  cursor: pointer;
  overflow: hidden;
  isolation: isolate;
  transform: rotateX(var(--rx, 0deg)) rotateY(var(--ry, 0deg));
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  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__ring {
  position: absolute;
  inset: -50%;
  background: conic-gradient(from var(--angle), transparent 0deg, #2f6df6 40deg, transparent 100deg);
  opacity: 0;
  transition: opacity 220ms ease-out;
  z-index: -1;
}

.card__inner {
  position: relative;
  z-index: 1;
  border-radius: 14px;
  background: #17141a;
  padding: 16px 14px;
}

.card__title {
  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 {
  margin: 0;
  font-weight: 500;
  font-size: clamp(11px, 3vw, 12px);
  line-height: 1.3;
  font-family: inherit;
  color: rgba(255, 247, 230, 0.7);
}

.card:hover .card__ring,
.card:focus-visible .card__ring,
.card:active .card__ring,
.card.is-demo .card__ring {
  opacity: 1;
  animation: spin 2s linear infinite;
}

.card.is-demo {
  animation: tilt-loop 2s linear infinite, spot-loop 2s linear infinite;
}

@keyframes spin {
  to {
    --angle: 360deg;
  }
}
@keyframes tilt-loop {
  0%, 15% {
    --rx: 0deg;
    --ry: 0deg;
  }
  35% {
    --rx: -4deg;
    --ry: 5deg;
  }
  65% {
    --rx: 3deg;
    --ry: -5deg;
  }
  85%, 100% {
    --rx: 0deg;
    --ry: 0deg;
  }
}
@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 .card__ring {
    opacity: 1;
    animation: spin 2s linear infinite;
  }
}
@media (prefers-reduced-motion: reduce) {
  .card__ring {
    transition: none;
    animation: none !important;
    opacity: 0.55;
  }
  .card {
    transition: none;
  }
  .card.is-demo {
    animation: none;
    --rx: 0deg;
    --ry: 0deg;
    --sp: 0;
  }
}

// 커서 위치로 스포트라이트(--mx/--my/--sp)와 미세 3D 틸트(--rx/--ry)를 얹는다. 기존 테두리 회전 효과는 :hover 로 그대로 유지.
var card = document.querySelector('.card');
card.addEventListener('pointermove', function (e) {
  card.classList.remove('is-demo');
  var r = card.getBoundingClientRect();
  var px = (e.clientX - r.left) / r.width - .5, py = (e.clientY - r.top) / r.height - .5;
  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.style.setProperty('--rx', (-py * 6) + 'deg');
  card.style.setProperty('--ry', (px * 7) + 'deg');
});
card.addEventListener('pointerleave', function () {
  card.style.setProperty('--sp', 0);
  card.style.setProperty('--rx', '0deg');
  card.style.setProperty('--ry', '0deg');
});

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

export type BorderLightSpinCardProps = {
  title: string;
  meta: string;
  /** 한 바퀴 도는 시간 (기본 2000ms) */
  duration?: number;
  easing?: string;
  /** 빛 색 */
  color?: string;
};

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

export default function BorderLightSpinCard({
  title,
  meta,
  duration = 2000,
  easing = "linear",
  color = "#2f6df6",
}: BorderLightSpinCardProps) {
  const ref = useRef<HTMLElement>(null);

  // 커서 위치로 스포트라이트(--mx/--my/--sp)와 미세 3D 틸트(--rx/--ry)를 얹는다.
  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("--mx", `${((e.clientX - r.left) / r.width) * 100}%`);
    el.style.setProperty("--my", `${((e.clientY - r.top) / r.height) * 100}%`);
    el.style.setProperty("--sp", "1");
    el.style.setProperty("--rx", `${-py * 6}deg`);
    el.style.setProperty("--ry", `${px * 7}deg`);
  }, []);

  const leave = useCallback(() => {
    const el = ref.current;
    if (!el) return;
    el.style.setProperty("--sp", "0");
    el.style.setProperty("--rx", "0deg");
    el.style.setProperty("--ry", "0deg");
  }, []);

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

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