07X 포스트 임베드 프레임 — 테두리 밝기를 주기적으로 다시 구해 빛나는 카드

<main class="stage">
<section class="panel">
  <div class="card" id="card">
    <div class="frameLine" aria-hidden="true"></div>
    <div class="avatarRow">
      <canvas class="avatar" id="avatar" width="32" height="32" aria-hidden="true"></canvas>
      <div class="who">
        <span class="name">Channel A</span>
        <span class="handle">@channel_a</span>
      </div>
    </div>
    <p class="quoteBody">임베드로 가져온 인용 문장이 이 자리에 들어갑니다.</p>
    <p class="meta">오후 2:14 · 인용됨</p>
  </div>
  <div class="readout" id="readout" aria-live="polite">
    <span class="readoutLabel">테두리 밝기</span>
    <span class="readoutValue" id="glowValue">50%</span>
  </div>
</section>
</main>

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

@include stage($stage-orange);

.panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-4;
}

.card {
  position: relative;
  box-sizing: border-box;
  width: 240px;
  padding: $sp-4;
  border-radius: $r-card;
  background: $stage-paper;
  box-shadow: $shadow-raised;
  color: $subject-ink;
}

.frameLine {
  position: absolute;
  inset: 0;
  border: 2px solid $subject-ink;
  border-radius: $r-card;
  // 계산 겹: JS 가 매 프레임 사인파로 다시 구한 --glow 값을 opacity 로 반영해 테두리를 맥동시킨다
  opacity: calc(0.14 + 0.5 * var(--glow, 0));
  pointer-events: none;
}

.avatarRow {
  display: flex;
  align-items: center;
  gap: $sp-2;
  margin-bottom: $sp-3;
}

.avatar {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  border-radius: $r-pill;
}

.who {
  display: flex;
  flex-direction: column;
  gap: $sp-1;
}

.name {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 700;
  font-size: 13px;
  line-height: 1.3;
}

.handle {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 12px;
  line-height: 1.3;
  opacity: .72;
}

.quoteBody {
  margin: 0 0 $sp-2;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 14px;
  line-height: 1.5;
}

.meta {
  margin: 0;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 11px;
  line-height: 1.3;
  opacity: .78;
}

.readout {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: $subject-cream;
  color: $subject-ink;
}

.readoutLabel {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 500;
  font-size: 11px;
  line-height: 1.3;
  opacity: .84;
}

.readoutValue {
  font-family: "Space Mono", ui-monospace, monospace;
  font-weight: 700;
  font-size: 13px;
  line-height: 1.3;
}

@media (max-width: 340px) {
  .panel { gap: $sp-2; }
  .card { width: 200px; padding: $sp-2 $sp-3; }
  .avatar { width: 26px; height: 26px; }
  .avatarRow { margin-bottom: $sp-2; }
  .name { font-size: 12px; }
  .handle { font-size: 11px; }
  .quoteBody { margin-bottom: $sp-1; font-size: 12px; }
  .meta { font-size: 10px; }
  .readoutLabel { font-size: 10px; }
  .readoutValue { font-size: 11px; }
}

@media (prefers-reduced-motion: reduce) {
  .frameLine { opacity: .3; }
}

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);
}

.panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.card {
  position: relative;
  box-sizing: border-box;
  width: 240px;
  padding: 16px;
  border-radius: 16px;
  background: #ffffff;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  color: #17141a;
}

.frameLine {
  position: absolute;
  inset: 0;
  border: 2px solid #17141a;
  border-radius: 16px;
  opacity: calc(0.14 + 0.5 * var(--glow, 0));
  pointer-events: none;
}

.avatarRow {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

.avatar {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  border-radius: 999px;
}

.who {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.name {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 700;
  font-size: 13px;
  line-height: 1.3;
}

.handle {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 12px;
  line-height: 1.3;
  opacity: 0.72;
}

.quoteBody {
  margin: 0 0 8px;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 14px;
  line-height: 1.5;
}

.meta {
  margin: 0;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 400;
  font-size: 11px;
  line-height: 1.3;
  opacity: 0.78;
}

.readout {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border-radius: 999px;
  background: #fff7e6;
  color: #17141a;
}

.readoutLabel {
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 500;
  font-size: 11px;
  line-height: 1.3;
  opacity: 0.84;
}

.readoutValue {
  font-family: "Space Mono", ui-monospace, monospace;
  font-weight: 700;
  font-size: 13px;
  line-height: 1.3;
}

@media (max-width: 340px) {
  .panel {
    gap: 8px;
  }
  .card {
    width: 200px;
    padding: 8px 12px;
  }
  .avatar {
    width: 26px;
    height: 26px;
  }
  .avatarRow {
    margin-bottom: 8px;
  }
  .name {
    font-size: 12px;
  }
  .handle {
    font-size: 11px;
  }
  .quoteBody {
    margin-bottom: 4px;
    font-size: 12px;
  }
  .meta {
    font-size: 10px;
  }
  .readoutLabel {
    font-size: 10px;
  }
  .readoutValue {
    font-size: 11px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .frameLine {
    opacity: 0.3;
  }
}

// 인용 게시물 임베드(07) — 카드 테두리 발광 강도를 매 프레임 사인파로 다시 계산해
// CSS 변수로 주입한다. 실키·실서버 요청 없음, 리스너 없음(자동 재생만).
(function () {
  var cardEl = document.getElementById('card');
  var avatarEl = document.getElementById('avatar');
  var glowValueEl = document.getElementById('glowValue');
  if (!cardEl || !avatarEl || !glowValueEl) return;
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var CYCLE_MS = 2000;
  var GLOW_MS = 900;

  function mulberry32(seed) {
    var a = seed >>> 0;
    return function () {
      a |= 0; a = (a + 0x6D2B79F5) | 0;
      var t = Math.imul(a ^ (a >>> 15), 1 | a);
      t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
      return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
    };
  }

  function drawSeedThumb(canvas, seed) {
    var ctx = canvas.getContext('2d');
    if (!ctx) return;
    var rnd = mulberry32(seed);
    var w = canvas.width, h = canvas.height;
    var hues = [216, 32, 268, 168];
    ctx.fillStyle = 'hsl(' + hues[Math.floor(rnd() * hues.length)] + ', 38%, 22%)';
    ctx.fillRect(0, 0, w, h);
    for (var i = 0; i < 6; i++) {
      var cx = rnd() * w, cy = rnd() * h, r = (0.18 + rnd() * 0.3) * Math.min(w, h);
      ctx.fillStyle = 'hsla(' + hues[Math.floor(rnd() * hues.length)] + ', ' + (44 + rnd() * 22).toFixed(1) + '%, ' + (38 + rnd() * 26).toFixed(1) + '%, .5)';
      ctx.beginPath(); ctx.arc(cx, cy, r, 0, Math.PI * 2); ctx.fill();
    }
    ctx.fillStyle = 'rgba(255, 247, 230, .06)';
    for (var j = 0; j < h; j += 4) ctx.fillRect(0, j, w, 1);
  }

  drawSeedThumb(avatarEl, 107);

  // 계산 겹: 테두리 밝기를 사인파로 매 프레임 재계산해 --glow 로 주입, opacity 로 맥동시킨다
  function apply(t) {
    var glow = 0.5 + 0.5 * Math.sin(2 * Math.PI * t / GLOW_MS);
    cardEl.style.setProperty('--glow', glow.toFixed(3));
    glowValueEl.textContent = Math.round(glow * 100) + '%';
  }

  if (reduce) {
    apply(0);
    return;
  }

  var start = null;
  function loop(ts) {
    if (start === null) start = ts;
    var t = (ts - start) % CYCLE_MS;
    apply(t);
    requestAnimationFrame(loop);
  }
  requestAnimationFrame(loop);
})();

import { useEffect, useRef } from "react";
import styles from "./EmbedXPost.module.scss";

// 인용 게시물 임베드 — 카드 테두리 발광 강도를 매 프레임 사인파로 다시 계산해
// CSS 변수로 주입한다. 실키·실서버 요청 없음. 리스너 없음(자동 재생만).
const CYCLE_MS = 2000;
const GLOW_MS = 900;

function mulberry32(seed: number) {
  let a = seed >>> 0;
  return function () {
    a |= 0;
    a = (a + 0x6d2b79f5) | 0;
    let t = Math.imul(a ^ (a >>> 15), 1 | a);
    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

function drawSeedThumb(canvas: HTMLCanvasElement, seed: number) {
  const ctx = canvas.getContext("2d");
  if (!ctx) return;
  const rnd = mulberry32(seed);
  const w = canvas.width;
  const h = canvas.height;
  const hues = [216, 32, 268, 168];
  ctx.fillStyle = "hsl(" + hues[Math.floor(rnd() * hues.length)] + ", 38%, 22%)";
  ctx.fillRect(0, 0, w, h);
  for (let i = 0; i < 6; i++) {
    const cx = rnd() * w;
    const cy = rnd() * h;
    const r = (0.18 + rnd() * 0.3) * Math.min(w, h);
    ctx.fillStyle =
      "hsla(" +
      hues[Math.floor(rnd() * hues.length)] +
      ", " +
      (44 + rnd() * 22).toFixed(1) +
      "%, " +
      (38 + rnd() * 26).toFixed(1) +
      "%, .5)";
    ctx.beginPath();
    ctx.arc(cx, cy, r, 0, Math.PI * 2);
    ctx.fill();
  }
  ctx.fillStyle = "rgba(255, 247, 230, .06)";
  for (let j = 0; j < h; j += 4) ctx.fillRect(0, j, w, 1);
}

export default function EmbedXPost() {
  const cardRef = useRef<HTMLDivElement>(null);
  const avatarRef = useRef<HTMLCanvasElement>(null);
  const glowValueRef = useRef<HTMLSpanElement>(null);

  useEffect(() => {
    const card = cardRef.current;
    const avatar = avatarRef.current;
    const glowValueEl = glowValueRef.current;
    if (!card || !avatar || !glowValueEl) return;
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;

    drawSeedThumb(avatar, 107);

    function apply(t: number) {
      const glow = 0.5 + 0.5 * Math.sin((2 * Math.PI * t) / GLOW_MS);
      card!.style.setProperty("--glow", glow.toFixed(3));
      glowValueEl!.textContent = Math.round(glow * 100) + "%";
    }

    if (reduce) {
      apply(0);
      return;
    }

    let start: number | null = null;
    let raf = 0;
    function loop(ts: number) {
      if (start === null) start = ts;
      const t = (ts - start) % CYCLE_MS;
      apply(t);
      raf = requestAnimationFrame(loop);
    }
    raf = requestAnimationFrame(loop);
    return () => cancelAnimationFrame(raf);
  }, []);

  return (
    <div className={styles.stage}>
      <section className={styles.panel}>
        <div className={styles.card} ref={cardRef}>
          <div className={styles.frameLine} aria-hidden="true" />
          <div className={styles.avatarRow}>
            <canvas className={styles.avatar} ref={avatarRef} width={32} height={32} aria-hidden="true" />
            <div className={styles.who}>
              <span className={styles.name}>Channel A</span>
              <span className={styles.handle}>@channel_a</span>
            </div>
          </div>
          <p className={styles.quoteBody}>임베드로 가져온 인용 문장이 이 자리에 들어갑니다.</p>
          <p className={styles.meta}>오후 2:14 · 인용됨</p>
        </div>
        <div className={styles.readout} aria-live="polite">
          <span className={styles.readoutLabel}>테두리 밝기</span>
          <span className={styles.readoutValue} ref={glowValueRef}>50%</span>
        </div>
      </section>
    </div>
  );
}