09Inline input validation

<main class="stage">
  <div class="valid is-demo" id="wrap">
    <label class="valid__label" for="email-input">Email</label>
    <div class="valid__frame" id="frame">
      <input class="valid__input" id="email-input" type="email" placeholder="[email protected]" aria-describedby="email-msg">
      <span class="valid__icon" id="icon" aria-hidden="true"></span>
    </div>
    <p class="valid__msg" id="email-msg" role="status"></p>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-quick;
$easing: $ease-pop;
$color: $error;           // 오류 색 (성공은 토큰 blue 대신 아래 green 사용)

$ok: #4b976b;

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

.valid {
  box-sizing: border-box;
  width: min(270px, 86vw);
  background: $subject-cream;
  border-radius: $r-card;
  padding: $sp-5 $sp-5 $sp-4;
  box-shadow: $shadow-raised;

  &__label {
    display: block;
    margin: 0 0 $sp-2;
    font-weight: 700;
    font-size: 13px;
    line-height: 1;
    font-family: inherit;
    color: $stage-ink;
  }

  &__frame {
    position: relative;
    border: 2px solid transparent;
    border-radius: $r-control;
    background: #fff;
    transition: border-color $duration $easing;

    &.is-ok { border-color: $ok; }
    &.is-bad { border-color: $color; }
  }

  &__input {
    box-sizing: border-box;
    width: 100%;
    border: 0;
    border-radius: inherit;
    padding: $sp-3 $sp-8 $sp-3 $sp-4;
    font-weight: 500;
    font-size: clamp(13px, 3.8vw, 15px);
    font-family: inherit;
    color: $stage-ink;
    background: transparent;
    &:focus { outline: none; }
  }

  &__icon {
    position: absolute;
    right: $sp-3;
    top: 50%;
    transform: translateY(-50%) scale(0);
    font-weight: 800;
    font-size: 15px;
    line-height: 1;
    transition: transform $duration $easing;
  }

  &__frame.is-ok &__icon { color: $ok; transform: translateY(-50%) scale(1); }
  &__frame.is-bad &__icon { color: $color; transform: translateY(-50%) scale(1); }

  &__msg {
    margin: $sp-2 0 0;
    min-height: 14px;
    font-size: 12px;
    line-height: 1.4;
    font-weight: 600;
    font-family: inherit;
    color: $color;
  }
}

@media (prefers-reduced-motion: reduce) {
  .valid__frame, .valid__icon { transition: 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);
}

.valid {
  box-sizing: border-box;
  width: min(270px, 86vw);
  background: #fff7e6;
  border-radius: 16px;
  padding: 20px 20px 16px;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}
.valid__label {
  display: block;
  margin: 0 0 8px;
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
  color: #17141a;
}
.valid__frame {
  position: relative;
  border: 2px solid transparent;
  border-radius: 12px;
  background: #fff;
  transition: border-color 220ms cubic-bezier(0.2, 1.4, 0.4, 1);
}
.valid__frame.is-ok {
  border-color: #4b976b;
}
.valid__frame.is-bad {
  border-color: #c2361a;
}
.valid__input {
  box-sizing: border-box;
  width: 100%;
  border: 0;
  border-radius: inherit;
  padding: 12px 32px 12px 16px;
  font-weight: 500;
  font-size: clamp(13px, 3.8vw, 15px);
  font-family: inherit;
  color: #17141a;
  background: transparent;
}
.valid__input:focus {
  outline: none;
}
.valid__icon {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%) scale(0);
  font-weight: 800;
  font-size: 15px;
  line-height: 1;
  transition: transform 220ms cubic-bezier(0.2, 1.4, 0.4, 1);
}
.valid__frame.is-ok .valid__icon {
  color: #4b976b;
  transform: translateY(-50%) scale(1);
}
.valid__frame.is-bad .valid__icon {
  color: #c2361a;
  transform: translateY(-50%) scale(1);
}
.valid__msg {
  margin: 8px 0 0;
  min-height: 14px;
  font-size: 12px;
  line-height: 1.4;
  font-weight: 600;
  font-family: inherit;
  color: #c2361a;
}

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

(function () {
  var wrap = document.getElementById('wrap');
  var frame = document.getElementById('frame');
  var input = document.getElementById('email-input');
  var icon = document.getElementById('icon');
  var msg = document.getElementById('email-msg');
  var RE = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

  function check(v) {
    frame.classList.remove('is-ok', 'is-bad');
    if (!v) { icon.textContent = ''; msg.textContent = ''; return; }
    if (RE.test(v)) {
      frame.classList.add('is-ok'); icon.textContent = '✓'; msg.textContent = '';
    } else {
      frame.classList.add('is-bad'); icon.textContent = '!'; msg.textContent = 'Check the email format';
    }
  }

  input.addEventListener('input', function () { check(input.value); });
  input.addEventListener('pointerdown', stopDemo);
  input.addEventListener('keydown', stopDemo);

  function stopDemo() {
    if (!wrap.classList.contains('is-demo')) return;
    wrap.classList.remove('is-demo');
    clearInterval(timer);
    input.value = ''; check('');
  }

  var script = ['g', 'go', 'god', 'godrich', 'godrich@', 'godrich@mail', '[email protected]'];
  var i = 0;
  var timer = setInterval(function () {
    if (i >= script.length) { i = 0; input.value = ''; check(''); return; }
    input.value = script[i]; check(script[i]); i++;
  }, 260);
})();

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

export type InlineValidationProps = {
  label?: string;
};

const RE = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

export default function InlineValidation({ label = "이메일" }: InlineValidationProps) {
  const [value, setValue] = useState("");
  const state = value === "" ? "idle" : RE.test(value) ? "ok" : "bad";

  return (
    <div className={styles.valid}>
      <label className={styles.label} htmlFor="email-field">{label}</label>
      <div className={`${styles.frame} ${state === "ok" ? styles.ok : ""} ${state === "bad" ? styles.badState : ""}`}>
        <input
          className={styles.input}
          id="email-field"
          type="email"
          placeholder="[email protected]"
          aria-describedby="email-field-msg"
          value={value}
          onChange={(e: any) => setValue(e.target.value)}
        />
        <span className={styles.icon} aria-hidden="true">
          {state === "ok" ? "✓" : state === "bad" ? "!" : ""}
        </span>
      </div>
      <p className={styles.msg} id="email-field-msg" role="status">
        {state === "bad" ? "이메일 형식을 확인해 주세요" : ""}
      </p>
    </div>
  );
}