02Binary bit swap

<main class="stage">
  <p class="bn-word is-demo" aria-label="SIGNAL">
    <span class="bn-c" style="animation-delay:0ms"><span class="bn-bin">01010011</span><span class="bn-ch">S</span></span><span class="bn-c" style="animation-delay:120ms"><span class="bn-bin">01001001</span><span class="bn-ch">I</span></span><span class="bn-c" style="animation-delay:240ms"><span class="bn-bin">01000111</span><span class="bn-ch">G</span></span><span class="bn-c" style="animation-delay:360ms"><span class="bn-bin">01001110</span><span class="bn-ch">N</span></span><span class="bn-c" style="animation-delay:480ms"><span class="bn-bin">01000001</span><span class="bn-ch">A</span></span><span class="bn-c" style="animation-delay:600ms"><span class="bn-bin">01001100</span><span class="bn-ch">L</span></span>
  </p>
</main>

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

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

@include stage($stage-yellow);

.bn-word {
  margin: 0;
  display: flex;
  gap: 0;
  font: 800 clamp(20px, 6vw, 30px)/1.2 "Space Mono", "Courier New", monospace;
}

.bn-c {
  position: relative;
  display: inline-block;
  min-width: 1.1ch;
}

.bn-bin,
.bn-ch {
  display: block;
}

.bn-bin {
  font-size: .32em;
  letter-spacing: -0.04em;
  color: $color;
  opacity: .55;
}

.bn-ch {
  position: absolute;
  inset: 0;
  color: $color;
  opacity: 0;
  transform: scale(.85);
}

// 데모 루프: 이진수 여덟 자리가 잠깐 보이다가 크로스페이드로 실제 글자가 겹쳐 떠오른다
@keyframes bn-bin-out {
  0%, 40% { opacity: .55; }
  55%, 100% { opacity: 0; }
}
@keyframes bn-ch-in {
  0%, 40% { opacity: 0; transform: scale(.85); }
  55%, 90% { opacity: 1; transform: scale(1); }
  100% { opacity: 0; transform: scale(.85); }
}

.bn-word.is-demo .bn-bin { animation: bn-bin-out $duration $easing infinite; animation-delay: inherit; }
.bn-word.is-demo .bn-ch { animation: bn-ch-in $duration $easing infinite; animation-delay: inherit; }

@media (prefers-reduced-motion: reduce) {
  .bn-bin, .bn-word.is-demo .bn-bin { animation: none !important; opacity: 0 !important; }
  .bn-ch, .bn-word.is-demo .bn-ch { animation: none !important; opacity: 1 !important; transform: none !important; }
}

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);
}

.bn-word {
  margin: 0;
  display: flex;
  gap: 0;
  font: 800 clamp(20px, 6vw, 30px)/1.2 "Space Mono", "Courier New", monospace;
}

.bn-c {
  position: relative;
  display: inline-block;
  min-width: 1.1ch;
}

.bn-bin,
.bn-ch {
  display: block;
}

.bn-bin {
  font-size: 0.32em;
  letter-spacing: -0.04em;
  color: #17141a;
  opacity: 0.55;
}

.bn-ch {
  position: absolute;
  inset: 0;
  color: #17141a;
  opacity: 0;
  transform: scale(0.85);
}

@keyframes bn-bin-out {
  0%, 40% {
    opacity: 0.55;
  }
  55%, 100% {
    opacity: 0;
  }
}
@keyframes bn-ch-in {
  0%, 40% {
    opacity: 0;
    transform: scale(0.85);
  }
  55%, 90% {
    opacity: 1;
    transform: scale(1);
  }
  100% {
    opacity: 0;
    transform: scale(0.85);
  }
}
.bn-word.is-demo .bn-bin {
  animation: bn-bin-out 2s ease-out infinite;
  animation-delay: inherit;
}

.bn-word.is-demo .bn-ch {
  animation: bn-ch-in 2s ease-out infinite;
  animation-delay: inherit;
}

@media (prefers-reduced-motion: reduce) {
  .bn-bin, .bn-word.is-demo .bn-bin {
    animation: none !important;
    opacity: 0 !important;
  }
  .bn-ch, .bn-word.is-demo .bn-ch {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

import { CSSProperties, useEffect, useRef, useState } from "react";
import styles from "./BinaryBitSwap.module.scss";

export interface BinaryBitSwapProps {
  text?: string;
  duration?: string;
  easing?: string;
}

function toBinary(ch: string) {
  return ch.charCodeAt(0).toString(2).padStart(8, "0");
}

// 실사용: 뷰포트에 들어오면 이진수 여덟 자리가 잠깐 보이다가 크로스페이드로 실제 글자가 겹쳐 떠오른다.
export default function BinaryBitSwap({
  text = "SIGNAL",
  duration = "480ms",
  easing = "ease-out",
}: BinaryBitSwapProps) {
  const ref = useRef<HTMLParagraphElement>(null);
  const [revealed, setRevealed] = useState(false);

  useEffect(() => {
    const el = ref.current;
    if (!el) return;
    const io = new IntersectionObserver((entries) => {
      entries.forEach((e) => { if (e.isIntersecting) { setRevealed(true); io.unobserve(e.target); } });
    }, { threshold: 0.3 });
    io.observe(el);
    return () => io.disconnect();
  }, []);

  const style = { "--duration": duration, "--easing": easing } as CSSProperties;

  return (
    <p className={styles.word} style={style} ref={ref}>
      {text.split("").map((ch, i) => (
        <span key={i} className={styles.c} style={{ transitionDelay: `${i * 90}ms` }}>
          <span className={`${styles.bin} ${revealed ? styles.hide : ""}`}>{toBinary(ch)}</span>
          <span className={`${styles.ch} ${revealed ? styles.show : ""}`}>{ch}</span>
        </span>
      ))}
    </p>
  );
}