03Date input with auto-slash

<main class="stage">
  <div class="dt is-demo" id="wrap">
    <label class="dt__label" for="dt-input">Birthdate</label>
    <input class="dt__input" id="dt-input" type="text" inputmode="numeric" placeholder="YYYY/MM/DD" aria-describedby="dt-hint">
    <p class="dt__hint" id="dt-hint">Type digits only — slashes are added automatically</p>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-quick;     // 테두리 색 전환 시간
$easing: $ease-out;        // 포커스 이징
$color: $stage-orange;     // 포커스 강조 색

// ── 데모 무대 ──────────────────────────────────────────
@include stage($stage-orange);

.dt {
  box-sizing: border-box;
  width: min(272px, 84vw);
  background: #fff;
  border-radius: $r-card;
  padding: $sp-4;
  box-shadow: $shadow-raised;

  &__label {
    display: block;
    margin: 0 0 $sp-1;
    font-weight: 700;
    font-size: 12px;
    line-height: 1;
    font-family: inherit;
    color: $stage-ink;
  }

  &__input {
    box-sizing: border-box;
    width: 100%;
    border: 2px solid transparent;
    border-radius: $r-control;
    padding: $sp-3 $sp-4;
    font-weight: 600;
    font-size: clamp(14px, 4.2vw, 18px);
    font-family: inherit;
    letter-spacing: .04em;
    color: $stage-ink;
    background: rgba(23, 20, 26, .06);
    transition: border-color $duration $easing, background $duration $easing;

    &:focus {
      outline: none;
      border-color: $color;
      background: #fff;
    }
  }

  &__hint {
    margin: $sp-1 0 0;
    font-size: 11px;
    line-height: 1.4;
    font-family: inherit;
    color: rgba($stage-ink, .72);
  }
}

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

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);
}

.dt {
  box-sizing: border-box;
  width: min(272px, 84vw);
  background: #fff;
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}
.dt__label {
  display: block;
  margin: 0 0 4px;
  font-weight: 700;
  font-size: 12px;
  line-height: 1;
  font-family: inherit;
  color: #17141a;
}
.dt__input {
  box-sizing: border-box;
  width: 100%;
  border: 2px solid transparent;
  border-radius: 12px;
  padding: 12px 16px;
  font-weight: 600;
  font-size: clamp(14px, 4.2vw, 18px);
  font-family: inherit;
  letter-spacing: 0.04em;
  color: #17141a;
  background: rgba(23, 20, 26, 0.06);
  transition: border-color 220ms ease-out, background 220ms ease-out;
}
.dt__input:focus {
  outline: none;
  border-color: #ff4d1f;
  background: #fff;
}
.dt__hint {
  margin: 4px 0 0;
  font-size: 11px;
  line-height: 1.4;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.72);
}

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

(function () {
  var wrap = document.getElementById('wrap');
  var input = document.getElementById('dt-input');

  function format(raw) {
    var digits = raw.replace(/\D/g, '').slice(0, 8);
    var out = digits.slice(0, 4);
    if (digits.length > 4) out += '/' + digits.slice(4, 6);
    if (digits.length > 6) out += '/' + digits.slice(6, 8);
    return out;
  }

  input.addEventListener('input', function () {
    input.value = format(input.value);
  });

  function stopDemo() {
    if (!wrap.classList.contains('is-demo')) return;
    wrap.classList.remove('is-demo');
    clearInterval(timer);
  }
  input.addEventListener('pointerdown', stopDemo);
  input.addEventListener('keydown', stopDemo);

  var digits = '20260911';
  var raw = '';
  var phase = 'focus';
  var pauseUntil = 0;

  var timer = setInterval(function () {
    var now = Date.now();
    if (now < pauseUntil) return;

    if (phase === 'focus') {
      input.focus({ preventScroll: true });
      phase = 'type';
      return;
    }
    if (phase === 'type') {
      if (raw.length < digits.length) {
        raw += digits[raw.length];
        input.value = raw;
        input.dispatchEvent(new Event('input', { bubbles: true }));
      } else {
        phase = 'hold';
        pauseUntil = now + 900;
      }
      return;
    }
    if (phase === 'hold') {
      raw = '';
      input.value = '';
      input.dispatchEvent(new Event('input', { bubbles: true }));
      input.blur();
      phase = 'blurhold';
      pauseUntil = now + 500;
      return;
    }
    if (phase === 'blurhold') {
      phase = 'focus';
    }
  }, 140);
})();

import { useState } from "react";
import styles from "./DateAutoSlashInput.module.scss";

export type DateAutoSlashInputProps = {
  label?: string;
  hint?: string;
};

function formatDate(raw: string): string {
  const digits = raw.replace(/\D/g, "").slice(0, 8);
  let out = digits.slice(0, 4);
  if (digits.length > 4) out += "/" + digits.slice(4, 6);
  if (digits.length > 6) out += "/" + digits.slice(6, 8);
  return out;
}

export default function DateAutoSlashInput({
  label = "생년월일",
  hint = "숫자만 입력하면 슬래시가 자동으로 붙어요",
}: DateAutoSlashInputProps) {
  const [value, setValue] = useState("");

  const onChange = (e: any) => {
    setValue(formatDate(e.target.value));
  };

  return (
    <div className={styles.dt}>
      <label className={styles.label} htmlFor="dt-input">
        {label}
      </label>
      <input
        className={styles.input}
        id="dt-input"
        type="text"
        inputMode="numeric"
        placeholder="YYYY/MM/DD"
        aria-describedby="dt-hint"
        value={value}
        onChange={onChange}
      />
      <p className={styles.hint} id="dt-hint">
        {hint}
      </p>
    </div>
  );
}