04Captcha step-up — the captcha cell-count value grows each time the failure count crosses a threshold value

<main class="stage">
<div class="ace is-demo" id="ace">
  <div class="ace__row">
    <span class="ace__label">Fail <b id="aceFails">0</b>times</span>
    <span class="ace__stage" id="aceStage">No captcha</span>
  </div>
  <div class="ace__grid" id="aceGrid"></div>
  <button class="ace__btn" id="aceBtn" type="button">Simulate failed login</button>
</div>
</main>

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

// 계산 겹: 캡차 단계 = floor(실패÷STAGE_THRESHOLD), 칸수 = CELL_STEPS[단계] — index.html 참조
@include stage($stage-ink);

.ace {
  width: 100%;
  max-width: 300px;
  display: grid;
  gap: $sp-3;
  justify-items: center;
}

.ace__row {
  width: 100%;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-cream;
}

.ace__row b { font-size: 16px; font-variant-numeric: tabular-nums; }

.ace__grid {
  display: grid;
  grid-template-columns: repeat(var(--cols, 1), 1fr);
  gap: $sp-2;
  width: 132px;
  min-height: 8px;
}

.ace__cell {
  aspect-ratio: 1;
  border-radius: $r-xs;
  background: $subject-lilac;
  animation: ace-pop $dur-quick $ease-pop backwards;
}

@keyframes ace-pop {
  from { transform: scale(.4); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.ace__btn {
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $subject-cream;
  color: $stage-ink;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

  &:active { transform: scale(.96); }
}

@media (max-width: 340px) {
  .ace { max-width: 220px; }
  .ace__grid { width: 100px; }
}

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

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);
}

.ace {
  width: 100%;
  max-width: 300px;
  display: grid;
  gap: 12px;
  justify-items: center;
}

.ace__row {
  width: 100%;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #fff7e6;
}

.ace__row b {
  font-size: 16px;
  font-variant-numeric: tabular-nums;
}

.ace__grid {
  display: grid;
  grid-template-columns: repeat(var(--cols, 1), 1fr);
  gap: 8px;
  width: 132px;
  min-height: 8px;
}

.ace__cell {
  aspect-ratio: 1;
  border-radius: 4px;
  background: #b9a0ff;
  animation: ace-pop 220ms cubic-bezier(0.2, 1.4, 0.4, 1) backwards;
}

@keyframes ace-pop {
  from {
    transform: scale(0.4);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}
.ace__btn {
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #fff7e6;
  color: #17141a;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.ace__btn:active {
  transform: scale(0.96);
}

@media (max-width: 340px) {
  .ace {
    max-width: 220px;
  }
  .ace__grid {
    width: 100px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ace__btn {
    transition: none;
  }
  .ace__cell {
    animation: none;
  }
}

(function () {
  var root = document.getElementById('ace');
  var btn = document.getElementById('aceBtn');
  var failsEl = document.getElementById('aceFails');
  var stageEl = document.getElementById('aceStage');
  var grid = document.getElementById('aceGrid');

  // 상수: Captcha 단계 승격 기준 Failure count · 단계별 칸 수(제곱수라야 격자가 맞는다) · 자동재생 리셋 주기
  var STAGE_THRESHOLD = 2;
  var CELL_STEPS = [0, 4, 9, 16]; // 단계 0=없음, 1=2x2, 2=3x3, 3(상한)=4x4
  var AUTOPLAY_RESET_TICKS = 7;

  var fails = 0;

  function render() {
    // 계산 겹: 단계 = min(상한, floor(Fail÷기준)), 칸수 = CELL_STEPS[단계]
    var stage = Math.min(CELL_STEPS.length - 1, Math.floor(fails / STAGE_THRESHOLD));
    var cells = CELL_STEPS[stage];
    var cols = Math.round(Math.sqrt(cells)) || 0;
    failsEl.textContent = String(fails);
    stageEl.textContent = stage === 0 ? 'No captcha' : ('Captcha ' + cols + '×' + cols);
    grid.style.setProperty('--cols', cols || 1);
    grid.innerHTML = '';
    for (var i = 0; i < cells; i++) {
      var c = document.createElement('div');
      c.className = 'ace__cell';
      grid.appendChild(c);
    }
  }

  function fail() {
    fails += 1;
    render();
  }

  function reset() {
    fails = 0;
    render();
  }

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    stopAutoplay();
    fail();
  });
  render();

  var autoTimer = null;
  var tick = 0;
  function autoTick() {
    tick += 1;
    if (tick > AUTOPLAY_RESET_TICKS) { reset(); tick = 0; return; }
    fail();
  }
  function stopAutoplay() { if (autoTimer) { clearInterval(autoTimer); autoTimer = null; } }
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (!reduce) { autoTimer = setInterval(autoTick, 300); }
})();

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

type Box<T> = { current: T };

export default function AuthAttemptCaptchaEscalate() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLButtonElement | null;
    const failsEl = root.querySelector(`.${styles.fails}`) as HTMLElement | null;
    const stageEl = root.querySelector(`.${styles.stagelabel}`) as HTMLElement | null;
    const grid = root.querySelector(`.${styles.grid}`) as HTMLElement | null;
    if (!btn || !failsEl || !stageEl || !grid) return;

    // 상수: 캡차 단계 승격 기준 실패 횟수 · 단계별 칸 수(제곱수라야 격자가 맞는다) · 자동재생 리셋 주기
    const STAGE_THRESHOLD = 2;
    const CELL_STEPS = [0, 4, 9, 16];
    const AUTOPLAY_RESET_TICKS = 7;

    let fails = 0;

    function render() {
      // 계산 겹: 단계 = min(상한, floor(실패÷기준)), 칸수 = CELL_STEPS[단계]
      const stage = Math.min(CELL_STEPS.length - 1, Math.floor(fails / STAGE_THRESHOLD));
      const cells = CELL_STEPS[stage];
      const cols = Math.round(Math.sqrt(cells)) || 0;
      failsEl!.textContent = String(fails);
      stageEl!.textContent = stage === 0 ? "캡차 없음" : "캡차 " + cols + "×" + cols;
      grid!.style.setProperty("--cols", String(cols || 1));
      grid!.innerHTML = "";
      for (let i = 0; i < cells; i++) {
        const c = document.createElement("div");
        c.className = styles.cell;
        grid!.appendChild(c);
      }
    }

    function fail() { fails += 1; render(); }
    function reset() { fails = 0; render(); }

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      stopAutoplay();
      fail();
    }
    btn.addEventListener("click", onClick);
    render();

    let autoTimer: number | null = null;
    let tick = 0;
    function autoTick() {
      tick += 1;
      if (tick > AUTOPLAY_RESET_TICKS) { reset(); tick = 0; return; }
      fail();
    }
    function stopAutoplay() { if (autoTimer !== null) { window.clearInterval(autoTimer); autoTimer = null; } }
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (!reduce) { autoTimer = window.setInterval(autoTick, 300); }

    return () => {
      stopAutoplay();
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.ace} ${styles["is-demo"]}`}>
      <div className={styles.row}>
        <span className={styles.label}>실패 <b className={styles.fails}>0</b>회</span>
        <span className={styles.stagelabel}>캡차 없음</span>
      </div>
      <div className={styles.grid} />
      <button className={styles.btn} type="button">로그인 실패 시도</button>
    </div>
  );
}