06上限が近づくと警告に変わる文字数カウンタ

<main class="stage">
  <div class="cc is-demo" id="cc" data-level="ok">
    <div class="cc__field">
      <textarea class="cc__input" id="cc-input" rows="2" maxlength="60" aria-describedby="cc-out" placeholder="一言レビューを書いてください"></textarea>
      <span class="cc__ghost" aria-hidden="true">配送は1日で届き、梱包も丁寧でした</span>
    </div>
    <div class="cc__bar" aria-hidden="true"><span class="cc__fill"></span></div>
    <p class="cc__out" id="cc-out">
      <span class="cc__nums" aria-hidden="true">
        <span class="cc__n" data-n="0">残り44文字</span><span class="cc__n" data-n="1">残り26文字</span><span class="cc__n" data-n="2">残り8文字</span><span class="cc__n" data-n="3">残り0文字</span>
      </span>
      <span class="cc__live" id="cc-left">残り44文字</span>
      <span class="cc__notes" aria-hidden="true">
        <span class="cc__note" data-note="near">もうすぐ上限です</span><span class="cc__note" data-note="full">これ以上書けません</span>
      </span>
      <span class="cc__say" id="cc-say" role="status" aria-live="polite">60文字中16文字を使いました</span>
    </p>
  </div>
</main>

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

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

@include stage($stage-yellow);

$warn: #96734a;
$stop: $error;

.cc {
  box-sizing: border-box;
  width: min(300px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.cc__field { position: relative; }
.cc__input {
  box-sizing: border-box;
  display: block;
  width: 100%;
  padding: $sp-2 $sp-3;
  border: 2px solid rgba(23, 20, 26, .22);
  border-radius: $r-card;
  background: $stage-paper;
  color: $color;
  font-family: inherit;
  font-size: 13px; line-height: 18px; font-weight: 600;
  resize: none;
}
.cc__input::placeholder { color: rgba(23, 20, 26, .38); }
.cc__input:focus-visible { outline: 2px solid $subject-blue; outline-offset: 2px; }
.cc[data-level="near"] .cc__input { border-color: $warn; }
.cc[data-level="full"] .cc__input { border-color: $stop; }

// 자동 루프에서만 보이는 "쳐 넣는 글자". 진짜 placeholder 와 겹치지 않게 지운다
.cc.is-demo .cc__input::placeholder { color: transparent; }
.cc__ghost {
  position: absolute;
  left: 14px; top: 10px;
  width: 268px;
  color: $color;
  font-size: 13px; line-height: 18px; font-weight: 600;
  pointer-events: none;
  opacity: 0;
}

// ── 진행 막대 ────────────────────────────────────────
.cc__bar {
  position: relative;
  height: 6px;
  margin-top: $sp-2;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .16);
  overflow: hidden;
}
.cc__fill {
  position: absolute;
  inset: 0;
  border-radius: $r-pill;
  background: $color;
  transform: scaleX(.27);
  transform-origin: left center; // 규칙8: 진행 막대 좌측 채움
  transition: transform $duration $easing, background $duration $easing;
}
.cc[data-level="near"] .cc__fill { background: $warn; }
.cc[data-level="full"] .cc__fill { background: $stop; }

// ── 남은 글자 줄 — 숫자와 경고 문구를 겹쳐 두고 하나만 켠다 ─
.cc__out {
  display: flex;
  align-items: center;
  gap: $sp-2;
  height: 16px;
  margin: $sp-2 0 0;
  font-size: 11px; line-height: 16px; font-weight: 700;
}
.cc__nums, .cc__notes {
  position: relative;
  display: inline-block;
  flex: 0 0 auto;
  height: 16px;
}
.cc__nums  { width: 56px; }
.cc__notes { width: 88px; }
.cc__n, .cc__note {
  position: absolute;
  left: 0; top: 0;
  white-space: nowrap;
  opacity: 0;
}
.cc__n { color: rgba(23, 20, 26, .72); }
.cc__note[data-note="near"] { color: $warn; }
.cc__note[data-note="full"] { color: $stop; }
.cc[data-level="near"] .cc__note[data-note="near"],
.cc[data-level="full"] .cc__note[data-note="full"] { opacity: 1; }

// 자동 루프는 겹쳐 둔 숫자를 갈아 끼우고, 사람이 칠 때는 JS 가 적어 넣는 한 줄만 남긴다
.cc__live {
  display: none;
  flex: 0 0 auto;
  width: 56px;
  color: rgba(23, 20, 26, .72);
}
.cc[data-level="near"] .cc__live { color: $warn; }
.cc[data-level="full"] .cc__live { color: $stop; }
.cc:not(.is-demo) .cc__live { display: inline-block; }
.cc:not(.is-demo) .cc__nums { display: none; }
.cc__say {
  // 숫자는 눈으로 읽고, 문장은 낭독기 쪽으로만 보낸다
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
}

// ── 자동 루프 (2s) ────────────────────────────────────
// 0~18% 넉넉한 상태 → 26% 절반 → 46% 경계를 지나 경고색(컷) → 62% 한도에 닿아 정지색
// → 76% 경고 문구 내리고 82% 막대·색 되돌린 뒤 86% 글자 되감기. 셋으로 흩어야 복귀 프레임이 poster 를 뺏지 않는다.
.cc.is-demo .cc__ghost {
  opacity: 1;
  animation-name: cc-type;
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.cc.is-demo .cc__fill {
  transition: none;
  animation-name: cc-fill;
  animation-duration: $dur-loop;
  animation-timing-function: $easing;
  animation-iteration-count: infinite;
}
.cc.is-demo .cc__input {
  animation-name: cc-input;
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.cc.is-demo .cc__n,
.cc.is-demo .cc__note {
  animation-duration: $dur-loop;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.cc.is-demo .cc__n[data-n="0"] { animation-name: cc-n0; }
.cc.is-demo .cc__n[data-n="1"] { animation-name: cc-n1; }
.cc.is-demo .cc__n[data-n="2"] { animation-name: cc-n2; }
.cc.is-demo .cc__n[data-n="3"] { animation-name: cc-n3; }
.cc.is-demo .cc__note[data-note="near"] { animation-name: cc-near; }
.cc.is-demo .cc__note[data-note="full"] { animation-name: cc-full; }

@keyframes cc-type {
  0%   { clip-path: inset(0 74% 0 0); }
  26%  { clip-path: inset(0 46% 0 0); }
  46%  { clip-path: inset(0 18% 0 0); }
  62%  { clip-path: inset(0 0 0 0); }
  86%  { clip-path: inset(0 74% 0 0); }
  100% { clip-path: inset(0 74% 0 0); }
}
@keyframes cc-fill {
  0%     { transform: scaleX(.27); background: $color; }
  26%    { transform: scaleX(.57); background: $color; }
  45.4%  { transform: scaleX(.86); background: $color; }
  46%    { transform: scaleX(.86); background: $warn; }
  61.4%  { transform: scaleX(1); background: $warn; }
  62%    { transform: scaleX(1); background: $stop; }
  81%    { transform: scaleX(1); background: $stop; }
  82%    { transform: scaleX(.27); background: $color; }
  100%   { transform: scaleX(.27); background: $color; }
}
@keyframes cc-input {
  0%   { border-color: rgba(23, 20, 26, .22); }
  46%  { border-color: $warn; }
  62%  { border-color: $stop; }
  82%  { border-color: rgba(23, 20, 26, .22); }
  100% { border-color: rgba(23, 20, 26, .22); }
}
@keyframes cc-n0 {
  0%   { opacity: 1; color: rgba(23, 20, 26, .72); }
  26%  { opacity: 0; color: rgba(23, 20, 26, .72); }
  82%  { opacity: 1; color: rgba(23, 20, 26, .72); }
  100% { opacity: 1; color: rgba(23, 20, 26, .72); }
}
@keyframes cc-n1 {
  0%   { opacity: 0; }
  26%  { opacity: 1; }
  46%  { opacity: 0; }
  100% { opacity: 0; }
}
@keyframes cc-n2 {
  0%   { opacity: 0; color: $warn; }
  46%  { opacity: 1; color: $warn; }
  62%  { opacity: 0; color: $warn; }
  100% { opacity: 0; color: $warn; }
}
@keyframes cc-n3 {
  0%   { opacity: 0; color: $stop; }
  62%  { opacity: 1; color: $stop; }
  82%  { opacity: 0; color: $stop; }
  100% { opacity: 0; color: $stop; }
}
@keyframes cc-near {
  0%   { opacity: 0; }
  46%  { opacity: 1; }
  62%  { opacity: 0; }
  100% { opacity: 0; }
}
@keyframes cc-full {
  0%   { opacity: 0; }
  62%  { opacity: 1; }
  76%  { opacity: 0; }
  100% { opacity: 0; }
}

// 320×200 — 무대 여백을 뺀 174px 안에 들어가도록 간격을 내린다(올리지 않는다)
@media (max-width: 360px) {
  .cc__ghost { width: 228px; }
  .cc__bar { margin-top: $sp-1; }
  .cc__out { margin-top: $sp-1; }
}

@media (prefers-reduced-motion: reduce) {
  .cc.is-demo .cc__ghost,
  .cc.is-demo .cc__fill,
  .cc.is-demo .cc__input,
  .cc.is-demo .cc__n,
  .cc.is-demo .cc__note { animation: none !important; }
  .cc.is-demo .cc__ghost { opacity: 1; clip-path: inset(0 0 0 0); }
  .cc.is-demo .cc__fill { transform: scaleX(1); background: $stop; }
  .cc.is-demo .cc__input { border-color: $stop; }
  .cc.is-demo .cc__n[data-n="3"] { opacity: 1; color: $stop; }
  .cc.is-demo .cc__note[data-note="full"] { opacity: 1; }
  .cc__fill { 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);
}

.cc {
  box-sizing: border-box;
  width: min(300px, 86vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.cc__field {
  position: relative;
}

.cc__input {
  box-sizing: border-box;
  display: block;
  width: 100%;
  padding: 8px 12px;
  border: 2px solid rgba(23, 20, 26, 0.22);
  border-radius: 16px;
  background: #ffffff;
  color: #17141a;
  font-family: inherit;
  font-size: 13px;
  line-height: 18px;
  font-weight: 600;
  resize: none;
}

.cc__input::placeholder {
  color: rgba(23, 20, 26, 0.38);
}

.cc__input:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: 2px;
}

.cc[data-level=near] .cc__input {
  border-color: #96734a;
}

.cc[data-level=full] .cc__input {
  border-color: #c2361a;
}

.cc.is-demo .cc__input::placeholder {
  color: transparent;
}

.cc__ghost {
  position: absolute;
  left: 14px;
  top: 10px;
  width: 268px;
  color: #17141a;
  font-size: 13px;
  line-height: 18px;
  font-weight: 600;
  pointer-events: none;
  opacity: 0;
}

.cc__bar {
  position: relative;
  height: 6px;
  margin-top: 8px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.16);
  overflow: hidden;
}

.cc__fill {
  position: absolute;
  inset: 0;
  border-radius: 999px;
  background: #17141a;
  transform: scaleX(0.27);
  transform-origin: left center;
  transition: transform 220ms ease-out, background 220ms ease-out;
}

.cc[data-level=near] .cc__fill {
  background: #96734a;
}

.cc[data-level=full] .cc__fill {
  background: #c2361a;
}

.cc__out {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 16px;
  margin: 8px 0 0;
  font-size: 11px;
  line-height: 16px;
  font-weight: 700;
}

.cc__nums, .cc__notes {
  position: relative;
  display: inline-block;
  flex: 0 0 auto;
  height: 16px;
}

.cc__nums {
  width: 56px;
}

.cc__notes {
  width: 88px;
}

.cc__n, .cc__note {
  position: absolute;
  left: 0;
  top: 0;
  white-space: nowrap;
  opacity: 0;
}

.cc__n {
  color: rgba(23, 20, 26, 0.72);
}

.cc__note[data-note=near] {
  color: #96734a;
}

.cc__note[data-note=full] {
  color: #c2361a;
}

.cc[data-level=near] .cc__note[data-note=near],
.cc[data-level=full] .cc__note[data-note=full] {
  opacity: 1;
}

.cc__live {
  display: none;
  flex: 0 0 auto;
  width: 56px;
  color: rgba(23, 20, 26, 0.72);
}

.cc[data-level=near] .cc__live {
  color: #96734a;
}

.cc[data-level=full] .cc__live {
  color: #c2361a;
}

.cc:not(.is-demo) .cc__live {
  display: inline-block;
}

.cc:not(.is-demo) .cc__nums {
  display: none;
}

.cc__say {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
}

.cc.is-demo .cc__ghost {
  opacity: 1;
  animation-name: cc-type;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

.cc.is-demo .cc__fill {
  transition: none;
  animation-name: cc-fill;
  animation-duration: 2s;
  animation-timing-function: ease-out;
  animation-iteration-count: infinite;
}

.cc.is-demo .cc__input {
  animation-name: cc-input;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

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

.cc.is-demo .cc__n[data-n="0"] {
  animation-name: cc-n0;
}

.cc.is-demo .cc__n[data-n="1"] {
  animation-name: cc-n1;
}

.cc.is-demo .cc__n[data-n="2"] {
  animation-name: cc-n2;
}

.cc.is-demo .cc__n[data-n="3"] {
  animation-name: cc-n3;
}

.cc.is-demo .cc__note[data-note=near] {
  animation-name: cc-near;
}

.cc.is-demo .cc__note[data-note=full] {
  animation-name: cc-full;
}

@keyframes cc-type {
  0% {
    clip-path: inset(0 74% 0 0);
  }
  26% {
    clip-path: inset(0 46% 0 0);
  }
  46% {
    clip-path: inset(0 18% 0 0);
  }
  62% {
    clip-path: inset(0 0 0 0);
  }
  86% {
    clip-path: inset(0 74% 0 0);
  }
  100% {
    clip-path: inset(0 74% 0 0);
  }
}
@keyframes cc-fill {
  0% {
    transform: scaleX(0.27);
    background: #17141a;
  }
  26% {
    transform: scaleX(0.57);
    background: #17141a;
  }
  45.4% {
    transform: scaleX(0.86);
    background: #17141a;
  }
  46% {
    transform: scaleX(0.86);
    background: #96734a;
  }
  61.4% {
    transform: scaleX(1);
    background: #96734a;
  }
  62% {
    transform: scaleX(1);
    background: #c2361a;
  }
  81% {
    transform: scaleX(1);
    background: #c2361a;
  }
  82% {
    transform: scaleX(0.27);
    background: #17141a;
  }
  100% {
    transform: scaleX(0.27);
    background: #17141a;
  }
}
@keyframes cc-input {
  0% {
    border-color: rgba(23, 20, 26, 0.22);
  }
  46% {
    border-color: #96734a;
  }
  62% {
    border-color: #c2361a;
  }
  82% {
    border-color: rgba(23, 20, 26, 0.22);
  }
  100% {
    border-color: rgba(23, 20, 26, 0.22);
  }
}
@keyframes cc-n0 {
  0% {
    opacity: 1;
    color: rgba(23, 20, 26, 0.72);
  }
  26% {
    opacity: 0;
    color: rgba(23, 20, 26, 0.72);
  }
  82% {
    opacity: 1;
    color: rgba(23, 20, 26, 0.72);
  }
  100% {
    opacity: 1;
    color: rgba(23, 20, 26, 0.72);
  }
}
@keyframes cc-n1 {
  0% {
    opacity: 0;
  }
  26% {
    opacity: 1;
  }
  46% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
@keyframes cc-n2 {
  0% {
    opacity: 0;
    color: #96734a;
  }
  46% {
    opacity: 1;
    color: #96734a;
  }
  62% {
    opacity: 0;
    color: #96734a;
  }
  100% {
    opacity: 0;
    color: #96734a;
  }
}
@keyframes cc-n3 {
  0% {
    opacity: 0;
    color: #c2361a;
  }
  62% {
    opacity: 1;
    color: #c2361a;
  }
  82% {
    opacity: 0;
    color: #c2361a;
  }
  100% {
    opacity: 0;
    color: #c2361a;
  }
}
@keyframes cc-near {
  0% {
    opacity: 0;
  }
  46% {
    opacity: 1;
  }
  62% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
@keyframes cc-full {
  0% {
    opacity: 0;
  }
  62% {
    opacity: 1;
  }
  76% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
@media (max-width: 360px) {
  .cc__ghost {
    width: 228px;
  }
  .cc__bar {
    margin-top: 4px;
  }
  .cc__out {
    margin-top: 4px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cc.is-demo .cc__ghost,
  .cc.is-demo .cc__fill,
  .cc.is-demo .cc__input,
  .cc.is-demo .cc__n,
  .cc.is-demo .cc__note {
    animation: none !important;
  }
  .cc.is-demo .cc__ghost {
    opacity: 1;
    clip-path: inset(0 0 0 0);
  }
  .cc.is-demo .cc__fill {
    transform: scaleX(1);
    background: #c2361a;
  }
  .cc.is-demo .cc__input {
    border-color: #c2361a;
  }
  .cc.is-demo .cc__n[data-n="3"] {
    opacity: 1;
    color: #c2361a;
  }
  .cc.is-demo .cc__note[data-note=full] {
    opacity: 1;
  }
  .cc__fill {
    transition: none;
  }
}

// 실제 동작: maxlength 가 더 못 치게 막고, 남은 글자가 경계를 지나면 숫자와 막대가 함께 경고색으로 넘어간다.
var cc = document.getElementById('cc');
var ccInput = document.getElementById('cc-input');
var ccFill = document.querySelector('.cc__fill');
var ccSay = document.getElementById('cc-say');
var ccLeft = document.getElementById('cc-left');
var CC_MAX = 60, CC_NEAR = 12;
function ccPaint() {
  cc.classList.remove('is-demo'); // 사람이 손대면 자동 루프를 멈춘다
  var used = ccInput.value.length, left = CC_MAX - used;
  cc.setAttribute('data-level', left === 0 ? 'full' : left <= CC_NEAR ? 'near' : 'ok');
  ccFill.style.transform = 'scaleX(' + (used / CC_MAX).toFixed(3) + ')';
  ccLeft.textContent = left + '文字残り';
  ccSay.textContent = CC_MAX + '文字中 ' + used + '文字を使いました';
}
ccInput.addEventListener('input', ccPaint);
ccInput.addEventListener('focus', ccPaint);

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

export type CharLimitCounterProps = {
  placeholder?: string;
  max?: number;
  /** 남은 글자가 이 수 이하로 떨어지면 경고색으로 넘어간다 */
  nearAt?: number;
  nearNote?: string;
  fullNote?: string;
  /** 자동 재생 루프 (갤러리용). 사람이 손대면 꺼진다 */
  demo?: boolean;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function CharLimitCounter({
  placeholder = "Leave a one-line review",
  max = 60,
  nearAt = 12,
  nearNote = "Almost at the limit",
  fullNote = "No room left",
  demo = true,
  duration = 220,
  easing = "ease-out",
  color = "#17141a",
}: CharLimitCounterProps) {
  const [value, setValue] = useState("");
  const [live, setLive] = useState(demo);

  const used = value.length;
  const left = max - used;
  const level = left === 0 ? "full" : left <= nearAt ? "near" : "ok";
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  const fill: CSSProperties = { transform: `scaleX(${(used / max).toFixed(3)})` };

  return (
    <div className={`${styles.root} ${live ? styles.isDemo : ""}`} style={vars} data-level={level}>
      <div className={styles.field}>
        <textarea
          className={styles.input}
          id="cc-input"
          rows={2}
          maxLength={max}
          placeholder={placeholder}
          aria-describedby="cc-out"
          value={value}
          onChange={(e: ChangeEvt) => { setValue(e.target.value); setLive(false); }}
          onFocus={() => setLive(false)}
        />
        <span className={styles.ghost} aria-hidden="true">It arrived in a day and the packaging was careful</span>
      </div>
      <div className={styles.bar} aria-hidden="true"><span className={styles.fill} style={fill} /></div>
      <p className={styles.out} id="cc-out">
        <span className={styles.nums} aria-hidden="true">
          {[44, 26, 8, 0].map((n, i) => (
            <span key={n} className={styles.n} data-n={i}>{n} left</span>
          ))}
        </span>
        <span className={styles.live}>{`${left} left`}</span>
        <span className={styles.notes} aria-hidden="true">
          <span className={styles.note} data-note="near">{nearNote}</span>
          <span className={styles.note} data-note="full">{fullNote}</span>
        </span>
        <span className={styles.say} role="status" aria-live="polite">{`${used} of ${max} characters used`}</span>
      </p>
    </div>
  );
}