04붙여넣기를 감지해 밀려나오는 안내 배너

<main class="stage">
  <div class="pdb is-demo">
    <label class="pdb__label" for="pdb-input">비밀번호</label>
    <div class="pdb__frame">
      <input id="pdb-input" class="pdb__input" type="password" placeholder="비밀번호를 입력하세요" autocomplete="current-password">
    </div>
    <p class="pdb__banner" id="pdbBanner" aria-live="polite"></p>
  </div>
</main>

@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-paper);

.pdb {
  width: min(300px, 86vw);
  display: grid;
  gap: $sp-2;
}

.pdb__label {
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  color: $subject-ink;
}

.pdb__frame { position: relative; }

.pdb__input {
  box-sizing: border-box;
  width: 100%;
  border: 2px solid rgba($subject-ink, .18);
  border-radius: $r-control;
  padding: $sp-3 $sp-4;
  font-weight: 500;
  font-size: clamp(14px, 4vw, 16px);
  line-height: 1;
  font-family: inherit;
  color: $subject-ink;
  background: #fff;
  letter-spacing: .06em;

  &:focus { outline: none; border-color: $subject-blue-deep; }
}

.pdb__banner {
  position: relative;
  margin: 0;
  padding: $sp-2 $sp-3 $sp-2 $sp-4;
  border-radius: $r-sm;
  background: #f3f1ea;
  color: $subject-ink;
  font-weight: 500;
  font-size: 13px;
  line-height: 1.4;
  opacity: 0;
  transform: translateY(-10px);
  transition: transform var(--pdbSlideMs, 320ms) $ease-out, opacity var(--pdbSlideMs, 320ms) $ease-out;

  &::before {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 4px;
    border-radius: $r-xs 0 0 $r-xs;
    background: $subject-blue-deep;
  }

  &.is-visible {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 340px) {
  .pdb { width: min(260px, 88vw); }
}

@media (prefers-reduced-motion: reduce) {
  .pdb__banner { transition: none; }
}

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

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

.pdb {
  width: min(300px, 86vw);
  display: grid;
  gap: 8px;
}

.pdb__label {
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  color: #17141a;
}

.pdb__frame {
  position: relative;
}

.pdb__input {
  box-sizing: border-box;
  width: 100%;
  border: 2px solid rgba(23, 20, 26, 0.18);
  border-radius: 12px;
  padding: 12px 16px;
  font-weight: 500;
  font-size: clamp(14px, 4vw, 16px);
  line-height: 1;
  font-family: inherit;
  color: #17141a;
  background: #fff;
  letter-spacing: 0.06em;
}
.pdb__input:focus {
  outline: none;
  border-color: #0a4fe8;
}

.pdb__banner {
  position: relative;
  margin: 0;
  padding: 8px 12px 8px 16px;
  border-radius: 8px;
  background: #f3f1ea;
  color: #17141a;
  font-weight: 500;
  font-size: 13px;
  line-height: 1.4;
  opacity: 0;
  transform: translateY(-10px);
  transition: transform var(--pdbSlideMs, 320ms) ease-out, opacity var(--pdbSlideMs, 320ms) ease-out;
}
.pdb__banner::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  border-radius: 4px 0 0 4px;
  background: #0a4fe8;
}
.pdb__banner.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 340px) {
  .pdb {
    width: min(260px, 88vw);
  }
}
@media (prefers-reduced-motion: reduce) {
  .pdb__banner {
    transition: none;
  }
}

(function () {
  // 기법: 실제 input paste 이벤트를 그대로 트리거로 쓴다(값 자체는 읽지 않는다).
  // 배너는 슬라이드+opacity 로 필드 아래에서 나타났다가 일정 시간 뒤 같은 방식으로 사라진다.
  var PASTE_BANNER_SLIDE_MS = 320;
  var PASTE_BANNER_VISIBLE_MS = 1400;
  var BANNER_MESSAGE = '비밀번호 관리자에서 붙여넣은 값을 확인하세요';

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }

  var root = document.querySelector('.pdb');
  var input = document.getElementById('pdb-input');
  var banner = document.getElementById('pdbBanner');

  root.style.setProperty('--pdbSlideMs', PASTE_BANNER_SLIDE_MS + 'ms');

  var hideTimer = null;
  var clearTimer = null;

  function handlePaste() {
    clearTimeout(hideTimer);
    clearTimeout(clearTimer);
    banner.textContent = BANNER_MESSAGE;
    banner.classList.add('is-visible');
    hideTimer = setTimeout(function () {
      banner.classList.remove('is-visible');
      clearTimer = setTimeout(function () { banner.textContent = ''; }, PASTE_BANNER_SLIDE_MS);
    }, PASTE_BANNER_VISIBLE_MS);
  }

  input.addEventListener('paste', function () { handlePaste(); });

  var pasteRand = seedRand(426041);
  var pool = 'ABCDEFGHJKMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789';
  var fakeValue = '';
  for (var i = 0; i < 10; i += 1) fakeValue += pool[Math.floor(pasteRand() * pool.length)];

  function simulatePaste() {
    input.value = fakeValue;
    handlePaste();
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (reduce) root.classList.remove('is-demo');
  if (root.classList.contains('is-demo')) {
    setTimeout(function () {
      simulatePaste();
      setInterval(simulatePaste, 2000);
    }, 200);
  }
})();

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

export default function PasswordRevealPasteDetectBanner() {
  const rootRef = useRef<HTMLDivElement>(null);
  const inputRef = useRef<HTMLInputElement>(null);
  const bannerRef = useRef<HTMLParagraphElement>(null);

  useEffect(() => {
    const root = rootRef.current;
    const input = inputRef.current;
    const banner = bannerRef.current;
    if (!root || !input || !banner) return;

    const PASTE_BANNER_SLIDE_MS = 320;
    const PASTE_BANNER_VISIBLE_MS = 1400;
    const BANNER_MESSAGE = "비밀번호 관리자에서 붙여넣은 값을 확인하세요";

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
    }

    root.style.setProperty("--pdbSlideMs", PASTE_BANNER_SLIDE_MS + "ms");

    let hideTimer: ReturnType<typeof setTimeout> | null = null;
    let clearTimer: ReturnType<typeof setTimeout> | null = null;

    function handlePaste() {
      if (hideTimer) clearTimeout(hideTimer);
      if (clearTimer) clearTimeout(clearTimer);
      banner!.textContent = BANNER_MESSAGE;
      banner!.classList.add(styles.isVisible);
      hideTimer = setTimeout(() => {
        banner!.classList.remove(styles.isVisible);
        clearTimer = setTimeout(() => { banner!.textContent = ""; }, PASTE_BANNER_SLIDE_MS);
      }, PASTE_BANNER_VISIBLE_MS);
    }

    function onPaste() { handlePaste(); }
    input.addEventListener("paste", onPaste);

    const pasteRand = seedRand(426041);
    const pool = "ABCDEFGHJKMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789";
    let fakeValue = "";
    for (let i = 0; i < 10; i += 1) fakeValue += pool[Math.floor(pasteRand() * pool.length)];

    function simulatePaste() {
      input!.value = fakeValue;
      handlePaste();
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (reduce) root.classList.remove("is-demo");
    let loopTimer: ReturnType<typeof setTimeout> | null = null;
    let loopInterval: ReturnType<typeof setInterval> | null = null;
    if (root.classList.contains("is-demo")) {
      loopTimer = setTimeout(() => {
        simulatePaste();
        loopInterval = setInterval(simulatePaste, 2000);
      }, 200);
    }

    return () => {
      input.removeEventListener("paste", onPaste);
      if (hideTimer) clearTimeout(hideTimer);
      if (clearTimer) clearTimeout(clearTimer);
      if (loopTimer) clearTimeout(loopTimer);
      if (loopInterval) clearInterval(loopInterval);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.pdb} is-demo`} ref={rootRef}>
        <label className={styles.pdb__label} htmlFor="pdb-input-react">비밀번호</label>
        <div className={styles.pdb__frame}>
          <input
            id="pdb-input-react"
            ref={inputRef}
            className={styles.pdb__input}
            type="password"
            placeholder="비밀번호를 입력하세요"
            autoComplete="current-password"
          />
        </div>
        <p className={styles.pdb__banner} ref={bannerRef} aria-live="polite" />
      </div>
    </main>
  );
}