07Session expired — a notice that recomputes badge intensity from elapsed time since expiry

<main class="stage">
<section class="card" id="card">
  <p class="eyebrow">Session notice</p>
  <span class="badgeWrap">
    <span class="badge" id="badge" role="status">Session expired</span>
  </span>
  <p class="message">Time since disconnect <span id="elapsedSeconds">0</span>s</p>
  <button type="button" class="btn" id="reloginBtn">Log in again</button>
</section>
</main>

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

$duration: $dur-loop;
$easing: $ease-out;
$color: $subject-blue-deep;

@include stage($stage-orange);

.card {
  position: relative;
  width: 100%;
  max-width: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-3;
  padding: $sp-6 $sp-4;
  border-radius: $r-card;
  background: $stage-paper;
  box-shadow: 0 $sp-2 $sp-6 rgba($subject-ink, .18);
  text-align: center;
}

.eyebrow {
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba($subject-ink, .08);
  color: $subject-ink;
  font-weight: 600;
  font-size: 11px;
  letter-spacing: .04em;
}

.badgeWrap {
  position: relative;
  display: inline-flex;
}

.badgeWrap::before {
  content: "";
  position: absolute;
  inset: -6px;
  border-radius: $r-pill;
  background: rgba($error, .28);
  animation: badgeHalo $duration $easing infinite;
}

.badge {
  --paper: #{$stage-paper};
  --error: #{$error};
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: $sp-1 $sp-4;
  border: 1px solid rgba($subject-ink, .16);
  border-radius: $r-pill;
  background: $stage-paper;
  color: $subject-ink;
  font-weight: 700;
  font-size: 13px;
  transition: color .2s $easing;
}

.badge.isHot {
  color: $subject-cream;
}

.message {
  margin: 0;
  color: $subject-ink;
  font-weight: 500;
  font-size: 14px;
  line-height: 1.5;
}

.btn {
  border: none;
  border-radius: $r-control;
  padding: $sp-2 $sp-6;
  background: $subject-blue-deep;
  color: $subject-cream;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transform-origin: center;
  transition: transform .2s $easing;
}

@keyframes badgeHalo {
  0%, 100% { transform: scale(.9); opacity: .4; }
  50% { transform: scale(1.18); opacity: .9; }
}

@media (max-width: 340px) {
  .card { max-width: 264px; padding: $sp-4 $sp-3; gap: $sp-2; }
  .message { font-size: 12px; }
  .badge { font-size: 12px; padding: $sp-1 $sp-3; }
  .btn { font-size: 12px; padding: $sp-2 $sp-4; }
}

@media (prefers-reduced-motion: reduce) {
  .badgeWrap::before { animation: none; opacity: .55; }
}

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);
}

.card {
  position: relative;
  width: 100%;
  max-width: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 24px 16px;
  border-radius: 16px;
  background: #ffffff;
  box-shadow: 0 8px 24px rgba(23, 20, 26, 0.18);
  text-align: center;
}

.eyebrow {
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.08);
  color: #17141a;
  font-weight: 600;
  font-size: 11px;
  letter-spacing: 0.04em;
}

.badgeWrap {
  position: relative;
  display: inline-flex;
}

.badgeWrap::before {
  content: "";
  position: absolute;
  inset: -6px;
  border-radius: 999px;
  background: rgba(194, 54, 26, 0.28);
  animation: badgeHalo 2s ease-out infinite;
}

.badge {
  --paper: #ffffff;
  --error: #c2361a;
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 4px 16px;
  border: 1px solid rgba(23, 20, 26, 0.16);
  border-radius: 999px;
  background: #ffffff;
  color: #17141a;
  font-weight: 700;
  font-size: 13px;
  transition: color 0.2s ease-out;
}

.badge.isHot {
  color: #fff7e6;
}

.message {
  margin: 0;
  color: #17141a;
  font-weight: 500;
  font-size: 14px;
  line-height: 1.5;
}

.btn {
  border: none;
  border-radius: 12px;
  padding: 8px 24px;
  background: #0a4fe8;
  color: #fff7e6;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transform-origin: center;
  transition: transform 0.2s ease-out;
}

@keyframes badgeHalo {
  0%, 100% {
    transform: scale(0.9);
    opacity: 0.4;
  }
  50% {
    transform: scale(1.18);
    opacity: 0.9;
  }
}
@media (max-width: 340px) {
  .card {
    max-width: 264px;
    padding: 16px 12px;
    gap: 8px;
  }
  .message {
    font-size: 12px;
  }
  .badge {
    font-size: 12px;
    padding: 4px 12px;
  }
  .btn {
    font-size: 12px;
    padding: 8px 16px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .badgeWrap::before {
    animation: none;
    opacity: 0.55;
  }
}

// Session expired(07) — 세션이 끊긴 뒤 흐른 시간을 매 프레임 다시 구해(elapsedRatio),
// 그 값을 강조 곡선(INTENSITY_POW)에 태워 배지 배경을 paper 에서 error 로 채널 보간하고
// 재로그인 버튼을 중심에서 살짝 키운다. 실키·실서버 요청 없음 — 전부 클라이언트 시뮬레이션.
(function () {
  var INTENSITY_POW = 1; // 변형: 1 → 3
  var RAMP_MS = 1800;
  var CYCLE_MS = 2000;

  var badge = document.getElementById('badge');
  var elapsedSeconds = document.getElementById('elapsedSeconds');
  var btn = document.getElementById('reloginBtn');
  if (!badge || !elapsedSeconds || !btn) return;

  function clamp(v, min, max) { return Math.max(min, Math.min(max, v)); }
  function hexToRgb(hex) {
    hex = String(hex).trim().replace('#', '');
    return [
      parseInt(hex.substring(0, 2), 16),
      parseInt(hex.substring(2, 4), 16),
      parseInt(hex.substring(4, 6), 16)
    ];
  }
  function elapsedRatio(t) { return clamp(t / RAMP_MS, 0, 1); }

  var cs = getComputedStyle(badge);
  var paperRgb = hexToRgb(cs.getPropertyValue('--paper'));
  var errorRgb = hexToRgb(cs.getPropertyValue('--error'));

  function apply(t) {
    var ratio = elapsedRatio(t);
    var intensity = Math.pow(ratio, INTENSITY_POW);

    var r = Math.round(paperRgb[0] + (errorRgb[0] - paperRgb[0]) * intensity);
    var g = Math.round(paperRgb[1] + (errorRgb[1] - paperRgb[1]) * intensity);
    var b = Math.round(paperRgb[2] + (errorRgb[2] - paperRgb[2]) * intensity);
    badge.style.backgroundColor = 'rgb(' + r + ',' + g + ',' + b + ')';
    badge.classList.toggle('isHot', intensity > 0.5);

    btn.style.transform = 'scale(' + (1 + intensity * 0.04) + ')';

    elapsedSeconds.textContent = String(Math.round(ratio * (RAMP_MS / 1000)));
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (reduce) {
    apply(RAMP_MS);
    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 "./SessionExpired.module.scss";

// 세션 만료(07) — 세션이 끊긴 뒤 흐른 시간을 매 프레임 다시 구해(elapsedRatio),
// 그 값을 강조 곡선(INTENSITY_POW)에 태워 배지 배경을 paper 에서 error 로 채널 보간하고
// 재로그인 버튼을 중심에서 살짝 키운다. 실키·실서버 요청 없음 — 전부 클라이언트 시뮬레이션.
const INTENSITY_POW = 1; // 변형: 1 → 3
const RAMP_MS = 1800;
const CYCLE_MS = 2000;

function clamp(v: number, min: number, max: number) {
  return Math.max(min, Math.min(max, v));
}

function hexToRgb(hex: string): [number, number, number] {
  const h = hex.trim().replace("#", "");
  return [
    parseInt(h.substring(0, 2), 16),
    parseInt(h.substring(2, 4), 16),
    parseInt(h.substring(4, 6), 16),
  ];
}

export default function SessionExpired() {
  const badgeRef = useRef<HTMLSpanElement>(null);
  const elapsedRef = useRef<HTMLSpanElement>(null);
  const btnRef = useRef<HTMLButtonElement>(null);

  useEffect(() => {
    const badge = badgeRef.current;
    const elapsedEl = elapsedRef.current;
    const btn = btnRef.current;
    if (!badge || !elapsedEl || !btn) return;

    const cs = getComputedStyle(badge);
    const paperRgb = hexToRgb(cs.getPropertyValue("--paper"));
    const errorRgb = hexToRgb(cs.getPropertyValue("--error"));

    function apply(t: number) {
      const ratio = clamp(t / RAMP_MS, 0, 1);
      const intensity = Math.pow(ratio, INTENSITY_POW);

      const r = Math.round(paperRgb[0] + (errorRgb[0] - paperRgb[0]) * intensity);
      const g = Math.round(paperRgb[1] + (errorRgb[1] - paperRgb[1]) * intensity);
      const b = Math.round(paperRgb[2] + (errorRgb[2] - paperRgb[2]) * intensity);
      badge!.style.backgroundColor = "rgb(" + r + "," + g + "," + b + ")";
      badge!.classList.toggle(styles.isHot, intensity > 0.5);

      btn!.style.transform = "scale(" + (1 + intensity * 0.04) + ")";

      elapsedEl!.textContent = String(Math.round(ratio * (RAMP_MS / 1000)));
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (reduce) {
      apply(RAMP_MS);
      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 (
    <main className={styles.stage}>
      <section className={styles.card}>
        <p className={styles.eyebrow}>세션 안내</p>
        <span className={styles.badgeWrap}>
          <span className={styles.badge} ref={badgeRef} role="status">세션 만료</span>
        </span>
        <p className={styles.message}>
          세션이 끊긴 지 <span ref={elapsedRef}>0</span>초
        </p>
        <button type="button" className={styles.btn} ref={btnRef}>다시 로그인</button>
      </section>
    </main>
  );
}