02Floating label input

<main class="stage">
  <div class="fl is-demo" id="wrap">
    <div class="fl__control">
      <input class="fl__input" id="fl-name" type="text" placeholder=" ">
      <label class="fl__label" for="fl-name">Name</label>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-quick;     // 라벨이 뜨는 시간
$easing: $ease-spring;     // 스프링 이징
$color: $subject-lilac;    // 포커스·라벨 강조 색

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

.fl {
  box-sizing: border-box;
  width: min(260px, 82vw);
  background: #fff;
  border-radius: $r-card;
  padding: $sp-5;
  box-shadow: $shadow-raised;

  &__control {
    position: relative;
  }

  &__input {
    box-sizing: border-box;
    width: 100%;
    border: 2px solid rgba(23, 20, 26, .12);
    border-radius: $r-control;
    padding: $sp-5 $sp-4 $sp-2;
    font-weight: 500;
    font-size: clamp(14px, 4.2vw, 16px);
    font-family: inherit;
    color: $stage-ink;
    background: #fff;
    transition: border-color $duration $easing;

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

  &__label {
    position: absolute;
    left: $sp-4;
    top: 50%;
    transform: translateY(-50%) scale(1);
    transform-origin: left center; // 규칙8: 라벨 왼쪽 붙어 축소
    font-size: 16px;
    font-weight: 500;
    font-family: inherit;
    color: rgba(23, 20, 26, .48);
    pointer-events: none;
    transition: transform $duration $easing, color $duration $easing;
  }

  &__input:focus + &__label,
  &__input:not(:placeholder-shown) + &__label {
    transform: translateY(-14px) scale(.78);
    color: $color;
  }
}

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

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);
}

.fl {
  box-sizing: border-box;
  width: min(260px, 82vw);
  background: #fff;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}
.fl__control {
  position: relative;
}
.fl__input {
  box-sizing: border-box;
  width: 100%;
  border: 2px solid rgba(23, 20, 26, 0.12);
  border-radius: 12px;
  padding: 20px 16px 8px;
  font-weight: 500;
  font-size: clamp(14px, 4.2vw, 16px);
  font-family: inherit;
  color: #17141a;
  background: #fff;
  transition: border-color 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.fl__input:focus {
  outline: none;
  border-color: #b9a0ff;
}
.fl__label {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%) scale(1);
  transform-origin: left center;
  font-size: 16px;
  font-weight: 500;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.48);
  pointer-events: none;
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), color 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.fl__input:focus + .fl__label, .fl__input:not(:placeholder-shown) + .fl__label {
  transform: translateY(-14px) scale(0.78);
  color: #b9a0ff;
}

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

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

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

  function fireInput() {
    input.dispatchEvent(new Event('input', { bubbles: true }));
  }

  var word = 'Jane Doe';
  var chars = '';
  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 (chars.length < word.length) {
        chars += word[chars.length];
        input.value = chars;
        fireInput();
      } else {
        phase = 'hold';
        pauseUntil = now + 260;
      }
      return;
    }
    if (phase === 'hold') {
      phase = 'clear';
      return;
    }
    if (phase === 'clear') {
      chars = '';
      input.value = '';
      fireInput();
      input.blur();
      phase = 'blurhold';
      pauseUntil = now + 220;
      return;
    }
    if (phase === 'blurhold') {
      phase = 'focus';
    }
  }, 90);
})();

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

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

export default function FloatingLabelInput({ label = "이름" }: FloatingLabelInputProps) {
  const [value, setValue] = useState("");

  return (
    <div className={styles.fl}>
      <div className={styles.control}>
        <input
          className={styles.input}
          id="fl-name"
          type="text"
          placeholder=" "
          value={value}
          onChange={(e: any) => setValue(e.target.value)}
        />
        <label className={styles.label} htmlFor="fl-name">
          {label}
        </label>
      </div>
    </div>
  );
}