02Button that unlocks when the form is valid

<main class="stage">
  <div class="eg is-demo">
    <div class="eg__field">
      <input class="eg__input" id="eg-mail" type="email" required placeholder="[email protected]" aria-label="Email address">
      <span class="eg__ghost" aria-hidden="true">[email protected]</span>
    </div>
    <div class="eg__wrap">
      <button class="eg__btn" id="eg-btn" type="button" aria-disabled="true" aria-describedby="eg-why">Sign up</button>
      <p class="eg__tip" id="eg-why" role="note">Needs a valid email</p>
    </div>
  </div>
</main>

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

$duration: $dur-base;
$easing: $ease-spring;
$color: $subject-ink;

@include stage($stage-yellow);

.eg {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: $sp-3;
  width: min(300px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $color;
}

.eg__field {
  position: relative;
  height: 40px;
}
.eg__input {
  box-sizing: border-box;
  margin: 0;
  padding: 0 $sp-3;
  width: 100%;
  height: 100%;
  border: 2px solid $color;
  border-radius: $r-sm;
  background-color: $subject-cream;
  color: $color;
  font-family: inherit;
  font-size: 13px;
  line-height: 20px;
  font-weight: 500;
}
.eg__input:focus-visible { outline: 3px solid $color; outline-offset: 2px; }

// 루프에서만 쓰는 가짜 입력 글자 — 진짜 입력칸 위에 겹쳐 한 글자씩 드러난다
.eg__ghost {
  position: absolute;
  left: 14px;
  top: 10px;
  overflow: hidden;
  white-space: nowrap;
  width: 0;
  font-size: 13px;
  line-height: 20px;
  font-weight: 500;
  color: $color;
}
.eg:not(.is-demo) .eg__ghost { display: none; }
.eg.is-demo .eg__input::placeholder { color: transparent; }

.eg__wrap {
  position: relative;
  padding-bottom: $sp-8;      // 절대 배치한 말풍선 높이만큼 자리를 미리 비워 둔다 (scrollHeight 넘침 방지)
}
.eg__btn {
  box-sizing: border-box;
  margin: 0;
  padding: 0 $sp-4;
  width: 100%;
  height: 44px;
  border: 0;
  border-radius: $r-control;
  background-color: $subject-cream;
  color: $color;
  font-family: inherit;
  font-size: 15px;
  line-height: 20px;
  font-weight: 700;
  cursor: pointer;
}
.eg__btn:focus-visible { outline: 3px solid $color; outline-offset: 3px; }
.eg__btn[aria-disabled="true"] { opacity: .45; cursor: not-allowed; }
.eg__btn[aria-disabled="false"] { background-color: $color; color: $stage-yellow; box-shadow: $shadow-raised; }
.eg__btn[data-sent="1"] { background-color: $subject-mint; color: $color; }

.eg__tip {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: $sp-1 $sp-2;
  border-radius: $r-xs;
  background-color: $color;
  color: $subject-cream;
  text-align: center;
  font-size: 11px;
  line-height: 16px;
  font-weight: 500;
  pointer-events: none;      // 말풍선이 버튼의 호버·클릭을 가로채면 안 된다
  opacity: 0;
}
.eg:not(.is-demo) .eg__btn[aria-disabled="true"]:hover + .eg__tip,
.eg:not(.is-demo) .eg__btn:focus-visible + .eg__tip,
.eg:not(.is-demo) .eg__btn[data-why="1"] + .eg__tip { opacity: 1; }

// ── 자동 루프: 잠김 → 한 글자씩 입력(20~46%) → 열림(50%) → 다시 잠김(86%) ──
.eg.is-demo .eg__ghost {
  animation-name: eg-type;
  animation-duration: $dur-loop;
  animation-timing-function: steps(8, end);
  animation-iteration-count: infinite;
}
@keyframes eg-type {
  0%   { width: 0; }
  20%  { width: 0; }
  46%  { width: 120px; }
  86%  { width: 120px; }
  87%  { width: 0; }
  100% { width: 0; }
}

.eg.is-demo .eg__btn {
  animation-name: eg-open;
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
@keyframes eg-open {
  0%   { opacity: .45; background-color: $subject-cream; color: $color; }
  50%  { opacity: 1; background-color: $color; color: $stage-yellow; }
  86%  { opacity: .45; background-color: $subject-cream; color: $color; }
  100% { opacity: .45; background-color: $subject-cream; color: $color; }
}

.eg.is-demo .eg__tip {
  animation-name: eg-tip;
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
@keyframes eg-tip {
  0%   { opacity: 1; }
  50%  { opacity: 0; }
  86%  { opacity: 1; }
  100% { opacity: 1; }
}

// 열리는 순간 버튼이 한 번 솟는다 — 컷 두 번만으로는 움직인 프레임이 모자란다
.eg.is-demo .eg__wrap {
  animation-name: eg-rise;
  animation-duration: $dur-loop;
  animation-timing-function: $easing;
  animation-iteration-count: infinite;
}
@keyframes eg-rise {
  0%   { transform: translateY(0); }
  48%  { transform: translateY(0); }
  54%  { transform: translateY(-6px); }
  66%  { transform: translateY(0); }
  100% { transform: translateY(0); }
}

@media (max-width: 340px) {
  .eg { gap: $sp-2; }
  .eg__field { height: 36px; }
  .eg__btn { height: 40px; font-size: 13px; line-height: 18px; }
  .eg__ghost { top: 8px; }
  .eg__wrap { padding-bottom: $sp-6; }
}

@media (prefers-reduced-motion: reduce) {
  .eg.is-demo .eg__ghost,
  .eg.is-demo .eg__btn,
  .eg.is-demo .eg__tip,
  .eg.is-demo .eg__wrap { animation: none !important; }
  .eg.is-demo .eg__tip { opacity: 1; }
}

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);
}

.eg {
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: min(300px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #17141a;
}

.eg__field {
  position: relative;
  height: 40px;
}

.eg__input {
  box-sizing: border-box;
  margin: 0;
  padding: 0 12px;
  width: 100%;
  height: 100%;
  border: 2px solid #17141a;
  border-radius: 8px;
  background-color: #fff7e6;
  color: #17141a;
  font-family: inherit;
  font-size: 13px;
  line-height: 20px;
  font-weight: 500;
}

.eg__input:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 2px;
}

.eg__ghost {
  position: absolute;
  left: 14px;
  top: 10px;
  overflow: hidden;
  white-space: nowrap;
  width: 0;
  font-size: 13px;
  line-height: 20px;
  font-weight: 500;
  color: #17141a;
}

.eg:not(.is-demo) .eg__ghost {
  display: none;
}

.eg.is-demo .eg__input::placeholder {
  color: transparent;
}

.eg__wrap {
  position: relative;
  padding-bottom: 32px;
}

.eg__btn {
  box-sizing: border-box;
  margin: 0;
  padding: 0 16px;
  width: 100%;
  height: 44px;
  border: 0;
  border-radius: 12px;
  background-color: #fff7e6;
  color: #17141a;
  font-family: inherit;
  font-size: 15px;
  line-height: 20px;
  font-weight: 700;
  cursor: pointer;
}

.eg__btn:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 3px;
}

.eg__btn[aria-disabled=true] {
  opacity: 0.45;
  cursor: not-allowed;
}

.eg__btn[aria-disabled=false] {
  background-color: #17141a;
  color: #ffd23f;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.eg__btn[data-sent="1"] {
  background-color: #4cd4a6;
  color: #17141a;
}

.eg__tip {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 4px 8px;
  border-radius: 4px;
  background-color: #17141a;
  color: #fff7e6;
  text-align: center;
  font-size: 11px;
  line-height: 16px;
  font-weight: 500;
  pointer-events: none;
  opacity: 0;
}

.eg:not(.is-demo) .eg__btn[aria-disabled=true]:hover + .eg__tip,
.eg:not(.is-demo) .eg__btn:focus-visible + .eg__tip,
.eg:not(.is-demo) .eg__btn[data-why="1"] + .eg__tip {
  opacity: 1;
}

.eg.is-demo .eg__ghost {
  animation-name: eg-type;
  animation-duration: 2s;
  animation-timing-function: steps(8, end);
  animation-iteration-count: infinite;
}

@keyframes eg-type {
  0% {
    width: 0;
  }
  20% {
    width: 0;
  }
  46% {
    width: 120px;
  }
  86% {
    width: 120px;
  }
  87% {
    width: 0;
  }
  100% {
    width: 0;
  }
}
.eg.is-demo .eg__btn {
  animation-name: eg-open;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes eg-open {
  0% {
    opacity: 0.45;
    background-color: #fff7e6;
    color: #17141a;
  }
  50% {
    opacity: 1;
    background-color: #17141a;
    color: #ffd23f;
  }
  86% {
    opacity: 0.45;
    background-color: #fff7e6;
    color: #17141a;
  }
  100% {
    opacity: 0.45;
    background-color: #fff7e6;
    color: #17141a;
  }
}
.eg.is-demo .eg__tip {
  animation-name: eg-tip;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes eg-tip {
  0% {
    opacity: 1;
  }
  50% {
    opacity: 0;
  }
  86% {
    opacity: 1;
  }
  100% {
    opacity: 1;
  }
}
.eg.is-demo .eg__wrap {
  animation-name: eg-rise;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}

@keyframes eg-rise {
  0% {
    transform: translateY(0);
  }
  48% {
    transform: translateY(0);
  }
  54% {
    transform: translateY(-6px);
  }
  66% {
    transform: translateY(0);
  }
  100% {
    transform: translateY(0);
  }
}
@media (max-width: 340px) {
  .eg {
    gap: 8px;
  }
  .eg__field {
    height: 36px;
  }
  .eg__btn {
    height: 40px;
    font-size: 13px;
    line-height: 18px;
  }
  .eg__ghost {
    top: 8px;
  }
  .eg__wrap {
    padding-bottom: 24px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .eg.is-demo .eg__ghost,
  .eg.is-demo .eg__btn,
  .eg.is-demo .eg__tip,
  .eg.is-demo .eg__wrap {
    animation: none !important;
  }
  .eg.is-demo .eg__tip {
    opacity: 1;
  }
}

// 실제 동작: disabled 대신 aria-disabled 를 쓴다. 초점은 받되 동작만 막아, 왜 못 누르는지 읽힐 수 있다
var root = document.querySelector('.eg');
var mail = document.getElementById('eg-mail');
var btn = document.getElementById('eg-btn');
function validate() {
  var ok = mail.checkValidity() && mail.value.length > 0;
  btn.setAttribute('aria-disabled', String(!ok));
  return ok;
}
mail.addEventListener('input', function () {
  root.classList.remove('is-demo');
  validate();
});
btn.addEventListener('click', function () {
  root.classList.remove('is-demo');
  if (!validate()) {
    btn.setAttribute('data-why', '1');           // 잠긴 이유를 한 번 흔들어 보여 준다
    setTimeout(function () { btn.removeAttribute('data-why'); }, 1400);
    return;
  }
  btn.setAttribute('data-sent', '1');
});

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

export type EnableGateButtonProps = {
  labels?: { submit: string; tip: string; placeholder: string; mail: string };
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };
type Timer = ReturnType<typeof setTimeout>;
type MailEvt = { currentTarget: { value: string; checkValidity(): boolean } };

const TIP_ID = "eg-why";
const WHY_MS = 1400; // 잠긴 이유를 보여 주는 시간

export default function EnableGateButton({
  labels = {
    submit: "Sign up",
    tip: "Enter a valid email first",
    placeholder: "[email protected]",
    mail: "Email address",
  },
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#17141a",
}: EnableGateButtonProps) {
  const [demo, setDemo] = useState(true);
  const [ok, setOk] = useState(false);
  const [why, setWhy] = useState(false);
  const [sent, setSent] = useState(false);
  const tw = useRef<Timer>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  useEffect(() => () => {
    if (tw.current !== null) clearTimeout(tw.current); // 떠날 때 예약된 타이머를 버린다
  }, []);

  // disabled 대신 aria-disabled 를 쓴다. 초점은 받되 동작만 막아, 왜 못 누르는지 읽힐 수 있다
  function check(e: MailEvt) {
    setDemo(false); // 사람이 입력했으니 자동 루프를 끈다
    const el = e.currentTarget;
    setOk(el.checkValidity() && el.value.length > 0);
  }

  function press() {
    setDemo(false);
    if (!ok) {
      setWhy(true); // 잠긴 이유를 한 번 흔들어 보여 준다
      if (tw.current !== null) clearTimeout(tw.current);
      tw.current = setTimeout(() => setWhy(false), WHY_MS);
      return;
    }
    setSent(true);
  }

  return (
    <div className={`${styles.eg} ${demo ? styles.isDemo : ""}`} style={vars}>
      <div className={styles.field}>
        <input
          className={styles.input}
          type="email"
          required
          placeholder={labels.placeholder}
          aria-label={labels.mail}
          onChange={check}
        />
        <span className={styles.ghost} aria-hidden="true">{labels.placeholder}</span>
      </div>
      <div className={styles.wrap}>
        <button
          className={styles.btn}
          type="button"
          aria-disabled={!ok}
          aria-describedby={TIP_ID}
          data-why={why ? "1" : undefined}
          data-sent={sent ? "1" : undefined}
          onClick={press}
        >
          {labels.submit}
        </button>
        <p className={styles.tip} id={TIP_ID} role="note">{labels.tip}</p>
      </div>
    </div>
  );
}