03켜짐과 꺼짐을 한 버튼이 쥔다

<main class="stage">
  <div class="tp is-demo">
    <button class="tp__btn" id="tp-btn" type="button" aria-pressed="false">
      <span class="tp__face" data-face="off">
        <span class="tp__ic" aria-hidden="true"><svg viewBox="0 0 256 256" width="20" height="20"><g fill="currentColor"><path d="M208 192H48a8 8 0 0 1-6.88-12C47.71 168.6 56 139.81 56 104a72 72 0 0 1 144 0c0 35.82 8.3 64.6 14.9 76a8 8 0 0 1-6.9 12" opacity=".2"/><path d="M53.92 34.62a8 8 0 1 0-11.84 10.76L58.82 63.8A79.6 79.6 0 0 0 48 104c0 35.34-8.26 62.38-13.81 71.94A16 16 0 0 0 48 200h40.8a40 40 0 0 0 78.4 0h15.44l19.44 21.38a8 8 0 1 0 11.84-10.76ZM128 216a24 24 0 0 1-22.62-16h45.24A24 24 0 0 1 128 216m-80-32c7.7-13.24 16-43.92 16-80a63.65 63.65 0 0 1 6.26-27.62L168.09 184Zm166-4.73a8.1 8.1 0 0 1-2.93.55a8 8 0 0 1-7.44-5.08C196.35 156.19 192 129.75 192 104a64 64 0 0 0-95.57-55.69a8 8 0 0 1-7.9-13.91A80 80 0 0 1 208 104c0 35.35 8.05 58.59 10.52 64.88a8 8 0 0 1-4.52 10.37Z"/></g></svg></span>
        <span class="tp__lab">알림 받기</span>
      </span>
      <span class="tp__face" data-face="on">
        <span class="tp__ic" aria-hidden="true"><svg viewBox="0 0 256 256" width="20" height="20"><g fill="currentColor"><path d="M208 192H48a8 8 0 0 1-6.88-12C47.71 168.6 56 139.81 56 104a72 72 0 0 1 144 0c0 35.82 8.3 64.6 14.9 76a8 8 0 0 1-6.9 12" opacity=".2"/><path d="M221.8 175.94c-5.55-9.56-13.8-36.61-13.8-71.94a80 80 0 1 0-160 0c0 35.34-8.26 62.38-13.81 71.94A16 16 0 0 0 48 200h40.81a40 40 0 0 0 78.38 0H208a16 16 0 0 0 13.8-24.06M128 216a24 24 0 0 1-22.62-16h45.24A24 24 0 0 1 128 216m-80-32c7.7-13.24 16-43.92 16-80a64 64 0 1 1 128 0c0 36.05 8.28 66.73 16 80Z"/></g></svg></span>
        <span class="tp__lab">알림 받는 중</span>
      </span>
    </button>
    <p class="tp__note">같은 버튼 하나가 두 상태를 쥡니다</p>
  </div>
</main>

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

$duration: $dur-quick;
$easing: $ease-pop;
$color: $subject-ink;

@include stage($stage-orange);

.tp {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-3;
  width: min(280px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.tp__btn {
  position: relative;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  width: 100%;
  height: 48px;
  overflow: hidden;
  border: 0;
  border-radius: $r-pill;
  background-color: $subject-cream;
  color: $color;
  cursor: pointer;
  box-shadow: $shadow-press;
}
.tp__btn:focus-visible { outline: 3px solid $subject-cream; outline-offset: 3px; }

.tp__face {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: $sp-2;
  opacity: 0;
}
.tp__ic { display: inline-flex; flex: 0 0 auto; }
.tp__ic svg { display: block; }
.tp__lab {
  font-size: 15px;
  line-height: 20px;
  font-weight: 700;
  white-space: nowrap;
}

// 눌림 여부는 aria-pressed 한 곳에만 적힌다 — 색도 아이콘도 그 값에서 갈린다
.tp:not(.is-demo) .tp__btn[aria-pressed="false"] .tp__face[data-face="off"],
.tp:not(.is-demo) .tp__btn[aria-pressed="true"] .tp__face[data-face="on"] { opacity: 1; }
.tp:not(.is-demo) .tp__btn[aria-pressed="true"] { background-color: $color; color: $stage-yellow; }

.tp__btn.is-pop {
  animation-name: tp-tap;
  animation-duration: $duration;
  animation-timing-function: $easing;
  animation-iteration-count: 1;
}
@keyframes tp-tap {
  0%   { transform: scale(.94); }
  60%  { transform: scale(1.03); }
  100% { transform: scale(1); }
}

.tp__note {
  margin: 0;
  font-size: 12px;
  line-height: 18px;
  font-weight: 500;
  color: $subject-ink;
}

// ── 자동 루프: 1초마다 켜짐과 꺼짐을 한 프레임에 끊어 바꾼다 ──
.tp.is-demo .tp__face {
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.tp.is-demo .tp__face[data-face="off"] { animation-name: tp-off; }
.tp.is-demo .tp__face[data-face="on"]  { animation-name: tp-on; }
@keyframes tp-off {
  0%   { opacity: 1; }
  40%  { opacity: 0; }
  86%  { opacity: 1; }
  100% { opacity: 1; }
}
@keyframes tp-on {
  0%   { opacity: 0; }
  40%  { opacity: 1; }
  86%  { opacity: 0; }
  100% { opacity: 0; }
}

.tp.is-demo .tp__btn {
  animation-name: tp-skin, tp-pop;
  animation-duration: $dur-loop, $dur-loop;
  animation-timing-function: steps(1, end), $easing;
  animation-iteration-count: infinite, infinite;
}
@keyframes tp-skin {
  0%   { background-color: $subject-cream; color: $color; }
  40%  { background-color: $color; color: $stage-yellow; }
  86%  { background-color: $subject-cream; color: $color; }
  100% { background-color: $subject-cream; color: $color; }
}
// 갈리는 순간마다 알약이 한 번 눌렸다 펴진다 — 컷 두 번만으로는 움직인 프레임이 안 찬다
@keyframes tp-pop {
  0%   { transform: scale(1); }
  38%  { transform: scale(1); }
  43%  { transform: scale(.94); }
  52%  { transform: scale(1.03); }
  60%  { transform: scale(1); }
  84%  { transform: scale(1); }
  89%  { transform: scale(.96); }
  96%  { transform: scale(1); }
  100% { transform: scale(1); }
}

@media (max-width: 340px) {
  .tp { gap: $sp-2; }
  .tp__btn { height: 44px; }
  .tp__lab { font-size: 13px; line-height: 18px; }
  .tp__note { font-size: 11px; line-height: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .tp.is-demo .tp__face,
  .tp.is-demo .tp__btn,
  .tp__btn.is-pop { animation: none !important; }
  .tp.is-demo .tp__face[data-face="off"] { opacity: 1; }
}

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);
}

.tp {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: min(280px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.tp__btn {
  position: relative;
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  width: 100%;
  height: 48px;
  overflow: hidden;
  border: 0;
  border-radius: 999px;
  background-color: #fff7e6;
  color: #17141a;
  cursor: pointer;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}

.tp__btn:focus-visible {
  outline: 3px solid #fff7e6;
  outline-offset: 3px;
}

.tp__face {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  opacity: 0;
}

.tp__ic {
  display: inline-flex;
  flex: 0 0 auto;
}

.tp__ic svg {
  display: block;
}

.tp__lab {
  font-size: 15px;
  line-height: 20px;
  font-weight: 700;
  white-space: nowrap;
}

.tp:not(.is-demo) .tp__btn[aria-pressed=false] .tp__face[data-face=off],
.tp:not(.is-demo) .tp__btn[aria-pressed=true] .tp__face[data-face=on] {
  opacity: 1;
}

.tp:not(.is-demo) .tp__btn[aria-pressed=true] {
  background-color: #17141a;
  color: #ffd23f;
}

.tp__btn.is-pop {
  animation-name: tp-tap;
  animation-duration: 220ms;
  animation-timing-function: cubic-bezier(0.2, 1.4, 0.4, 1);
  animation-iteration-count: 1;
}

@keyframes tp-tap {
  0% {
    transform: scale(0.94);
  }
  60% {
    transform: scale(1.03);
  }
  100% {
    transform: scale(1);
  }
}
.tp__note {
  margin: 0;
  font-size: 12px;
  line-height: 18px;
  font-weight: 500;
  color: #17141a;
}

.tp.is-demo .tp__face {
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

.tp.is-demo .tp__face[data-face=off] {
  animation-name: tp-off;
}

.tp.is-demo .tp__face[data-face=on] {
  animation-name: tp-on;
}

@keyframes tp-off {
  0% {
    opacity: 1;
  }
  40% {
    opacity: 0;
  }
  86% {
    opacity: 1;
  }
  100% {
    opacity: 1;
  }
}
@keyframes tp-on {
  0% {
    opacity: 0;
  }
  40% {
    opacity: 1;
  }
  86% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
.tp.is-demo .tp__btn {
  animation-name: tp-skin, tp-pop;
  animation-duration: 2s, 2s;
  animation-timing-function: steps(1, end), cubic-bezier(0.2, 1.4, 0.4, 1);
  animation-iteration-count: infinite, infinite;
}

@keyframes tp-skin {
  0% {
    background-color: #fff7e6;
    color: #17141a;
  }
  40% {
    background-color: #17141a;
    color: #ffd23f;
  }
  86% {
    background-color: #fff7e6;
    color: #17141a;
  }
  100% {
    background-color: #fff7e6;
    color: #17141a;
  }
}
@keyframes tp-pop {
  0% {
    transform: scale(1);
  }
  38% {
    transform: scale(1);
  }
  43% {
    transform: scale(0.94);
  }
  52% {
    transform: scale(1.03);
  }
  60% {
    transform: scale(1);
  }
  84% {
    transform: scale(1);
  }
  89% {
    transform: scale(0.96);
  }
  96% {
    transform: scale(1);
  }
  100% {
    transform: scale(1);
  }
}
@media (max-width: 340px) {
  .tp {
    gap: 8px;
  }
  .tp__btn {
    height: 44px;
  }
  .tp__lab {
    font-size: 13px;
    line-height: 18px;
  }
  .tp__note {
    font-size: 11px;
    line-height: 16px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .tp.is-demo .tp__face,
  .tp.is-demo .tp__btn,
  .tp__btn.is-pop {
    animation: none !important;
  }
  .tp.is-demo .tp__face[data-face=off] {
    opacity: 1;
  }
}

// 실제 동작: 클래스가 아니라 aria-pressed 를 뒤집는다. 보이는 색과 읽히는 상태가 한 값에서 나온다
var root = document.querySelector('.tp');
var btn = document.getElementById('tp-btn');
btn.addEventListener('click', function () {
  root.classList.remove('is-demo');
  var on = btn.getAttribute('aria-pressed') === 'true';
  btn.setAttribute('aria-pressed', String(!on));
  btn.classList.remove('is-pop');
  void btn.offsetWidth;            // 같은 방향으로 다시 눌러도 반동이 한 번 더 돌게 리플로를 강제한다
  btn.classList.add('is-pop');
});

import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./TogglePressedButton.module.scss";

export type TogglePressedButtonProps = {
  labels?: { off: string; on: string; note: string };
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

const BELL_OFF = (
  <g fill="currentColor">
    <path d="M208 192H48a8 8 0 0 1-6.88-12C47.71 168.6 56 139.81 56 104a72 72 0 0 1 144 0c0 35.82 8.3 64.6 14.9 76a8 8 0 0 1-6.9 12" opacity=".2" />
    <path d="M53.92 34.62a8 8 0 1 0-11.84 10.76L58.82 63.8A79.6 79.6 0 0 0 48 104c0 35.34-8.26 62.38-13.81 71.94A16 16 0 0 0 48 200h40.8a40 40 0 0 0 78.4 0h15.44l19.44 21.38a8 8 0 1 0 11.84-10.76ZM128 216a24 24 0 0 1-22.62-16h45.24A24 24 0 0 1 128 216m-80-32c7.7-13.24 16-43.92 16-80a63.65 63.65 0 0 1 6.26-27.62L168.09 184Zm166-4.73a8.1 8.1 0 0 1-2.93.55a8 8 0 0 1-7.44-5.08C196.35 156.19 192 129.75 192 104a64 64 0 0 0-95.57-55.69a8 8 0 0 1-7.9-13.91A80 80 0 0 1 208 104c0 35.35 8.05 58.59 10.52 64.88a8 8 0 0 1-4.52 10.37Z" />
  </g>
);

const BELL_ON = (
  <g fill="currentColor">
    <path d="M208 192H48a8 8 0 0 1-6.88-12C47.71 168.6 56 139.81 56 104a72 72 0 0 1 144 0c0 35.82 8.3 64.6 14.9 76a8 8 0 0 1-6.9 12" opacity=".2" />
    <path d="M221.8 175.94c-5.55-9.56-13.8-36.61-13.8-71.94a80 80 0 1 0-160 0c0 35.34-8.26 62.38-13.81 71.94A16 16 0 0 0 48 200h40.81a40 40 0 0 0 78.38 0H208a16 16 0 0 0 13.8-24.06M128 216a24 24 0 0 1-22.62-16h45.24A24 24 0 0 1 128 216m-80-32c7.7-13.24 16-43.92 16-80a64 64 0 1 1 128 0c0 36.05 8.28 66.73 16 80Z" />
  </g>
);

export default function TogglePressedButton({
  labels = { off: "Get alerts", on: "Alerts on", note: "One button holds both states" },
  duration = 220,
  easing = "cubic-bezier(.2,1.4,.4,1)",
  color = "#17141a",
}: TogglePressedButtonProps) {
  const [demo, setDemo] = useState(true);
  const [on, setOn] = useState(false);
  const [pop, setPop] = useState(false);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  // 클래스가 아니라 aria-pressed 를 뒤집는다. 보이는 색과 읽히는 상태가 한 값에서 나온다
  function toggle() {
    setDemo(false); // 사람이 눌렀으니 자동 루프를 끈다
    setOn((v) => !v);
    // 같은 방향으로 다시 눌러도 반동이 한 번 더 돌게 한 프레임 뒤에 다시 건다
    setPop(false);
    requestAnimationFrame(() => setPop(true));
  }

  return (
    <div className={`${styles.tp} ${demo ? styles.isDemo : ""}`} style={vars}>
      <button
        className={`${styles.btn} ${pop ? styles.isPop : ""}`}
        type="button"
        aria-pressed={on}
        onClick={toggle}
        onAnimationEnd={() => setPop(false)}
      >
        <span className={styles.face} data-face="off">
          <span className={styles.ic} aria-hidden="true">
            <svg viewBox="0 0 256 256" width="20" height="20">{BELL_OFF}</svg>
          </span>
          <span className={styles.lab}>{labels.off}</span>
        </span>
        <span className={styles.face} data-face="on">
          <span className={styles.ic} aria-hidden="true">
            <svg viewBox="0 0 256 256" width="20" height="20">{BELL_ON}</svg>
          </span>
          <span className={styles.lab}>{labels.on}</span>
        </span>
      </button>
      <p className={styles.note}>{labels.note}</p>
    </div>
  );
}