08Type scale ladder

<main class="stage">
<div class="gen is-demo" id="gen">
  <div class="gen__top">
    <div class="gen__preview" aria-hidden="true">
      <span class="gen__step gen__step--1">Step 1</span>
      <span class="gen__step gen__step--2">Step 2</span>
      <span class="gen__step gen__step--3">Step 3</span>
      <span class="gen__step gen__step--4">Step 4</span>
      <span class="gen__step gen__step--5">Step 5</span>
      <span class="gen__step gen__step--6">Step 6</span>
    </div>
    <div class="gen__grid">
      <label class="gen__row">
        <span class="gen__lab">Base</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="12" max="16" step="1" value="14" data-var="--s-base" aria-label="Base font size">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
      <label class="gen__row">
        <span class="gen__lab">Ratio</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="110" max="140" step="5" value="120" data-var="--s-ratio" aria-label="Step ratio">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
    </div>
  </div>
  <div class="gen__out">
    <code class="gen__code"><span class="gen__prop">--step-1:</span> <span class="gen__v gen__v--s1"></span>rem; <span class="gen__prop">--step-2:</span> <span class="gen__v gen__v--s2"></span>rem; <span class="gen__prop">--step-3:</span> <span class="gen__v gen__v--s3"></span>rem</code>
    <button class="gen__copy" type="button" id="copy">Copy</button>
  </div>
</div>
</main>

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

// 타이포 배율 사다리 — 기준 크기와 배율 하나로 여섯 단계가 calc 곱으로 저절로 계산된다.
// 배율은 백분율 정수(125 = 1.25 배)로 등록하고 calc 안에서 0.01 을 곱해 쓴다.
// 몇 곱이 되는지만 단계마다 다르지 식은 하나다 — JS 의 scaleText() 도 같은 식으로 rem 값을 만든다.
// 미리보기 계수 0.6 은 사다리 여섯 단계를 무대(480×300) 안에 들어가게 하는 표시 배율이다 —
// 단계 사이 비율은 그대로다(06 미리보기의 0.32 계수와 같은 관례). 복사 코드는 실제 px 값.

$duration: $dur-loop;
$easing: $ease-spring;
$color: $subject-ink;
$mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
$line: rgba(23, 20, 26, .14);
$track: rgba(23, 20, 26, .18);
$rail: 4px;
$thumb: 12px;

@property --s-base { syntax: "<integer>"; inherits: true; initial-value: 14; }
@property --s-ratio { syntax: "<integer>"; inherits: true; initial-value: 120; }

@include stage($stage-paper);

.gen {
  min-width: 0;  // stage grid item 의 자동 최소폭(min-content) 을 끊는다 — BD9
  --s-base: 14;
  --s-ratio: 120;
  display: flex; flex-direction: column; gap: $sp-3;
  box-sizing: border-box; width: min(100%, 400px);
  padding: $sp-3; border: 1px solid $line; border-radius: $r-card;
  background: rgba(23, 20, 26, .04);
}

.gen__top { display: flex; align-items: center; gap: $sp-3; }

// ── 미리보기 — 여섯 단계 사다리. calc 곱의 개수만 단계마다 다르다
.gen__preview {
  flex: 0 0 auto;
  display: flex; flex-direction: column; align-items: flex-start; gap: $sp-1;
  box-sizing: border-box; width: 148px; padding: $sp-2;
  border-radius: $r-sm;
  background: rgba(23, 20, 26, .05);
  overflow: hidden;
}
.gen__step {
  display: block; white-space: nowrap;
  color: $subject-ink;
  font-family: $mono; font-weight: 700; line-height: 1.1;
}
.gen__step--1 { font-size: calc(var(--s-base) * 0.6px); }
.gen__step--2 { font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * 0.01); }
.gen__step--3 { font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * 0.0001); }
.gen__step--4 { font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.000001); }
.gen__step--5 { font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.00000001); }
.gen__step--6 { font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.0000000001); }

.gen__grid { flex: 1 1 auto; min-width: 0; display: grid; grid-template-columns: minmax(0, 1fr); gap: $sp-1; }
.gen__row { display: flex; align-items: center; gap: $sp-1; cursor: pointer; }
.gen__lab {
  flex: 0 0 auto; width: 30px;
  color: $subject-ink;
  font-weight: 700; font-size: 10px; line-height: 1.4;
}
.gen__slot {
  position: relative; flex: 1 1 auto; min-width: 0;
  display: grid; align-items: center; height: 16px;
}
.gen__slot::before {
  content: ""; grid-area: 1 / 1;
  height: $rail; border-radius: $r-pill; background: $track;
}
.gen__rng {
  grid-area: 1 / 1; appearance: none; -webkit-appearance: none;
  width: 100%; min-width: 0; height: 16px; margin: 0; background: transparent;
  cursor: pointer;
}
.gen__rng::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: $thumb; height: $thumb; border: 0; border-radius: 50%;
  background: transparent;
}
.gen__rng::-moz-range-thumb {
  width: $thumb; height: $thumb; border: 0; border-radius: 50%;
  background: transparent;
}
.gen__rng:focus-visible { outline: 2px solid $color; outline-offset: 2px; border-radius: $r-pill; }

.gen__thumb {
  position: absolute; top: 50%; left: calc(var(--pct) * 1%);
  width: $thumb; height: $thumb; margin-top: -($thumb * .5); margin-left: -($thumb * .5);
  border-radius: 50%; background: $color;
  pointer-events: none;
}
.gen__row:nth-child(1) .gen__thumb { --pct: calc((var(--s-base) - 12) / 4 * 100); }
.gen__row:nth-child(2) .gen__thumb { --pct: calc((var(--s-ratio) - 110) / 30 * 100); }

.gen__out { display: flex; align-items: flex-start; gap: $sp-2; }
.gen__code {
  flex: 1 1 auto; min-width: 0;
  padding: $sp-2; border-radius: $r-sm;
  background: $subject-ink; color: $subject-cream;
  font-family: $mono; font-weight: 500; font-size: 10px; line-height: 1.5;
  white-space: nowrap; overflow: hidden;
}
.gen__prop { color: $subject-blue-light; }

// 코드 숫자는 rem 세 자리 소수라 counter 정수로 못 쓴다 — 첫 단계 px 값만 표시하고
// 나머지는 미리보기 사다리가 그대로 보여 준다(전체 목록은 복사로 얻는다)
.gen__v { font-weight: 700; }
.gen__v--s1::after { counter-reset: v var(--s-base); content: counter(v); }

.gen__copy {
  flex: 0 0 auto;
  padding: $sp-2 $sp-3; border: 0; border-radius: $r-sm;
  background: $subject-blue-deep; color: $subject-cream;
  font-family: inherit; font-weight: 700; font-size: 11px; line-height: 1.4;
  cursor: pointer;
}
.gen__copy:focus-visible { outline: 2px solid $color; outline-offset: 2px; }

// ── 격자 미리보기 — 기준과 배율이 오가면 사다리 전체가 숨쉰다
@keyframes sBase { 0%, 100% { --s-base: 14; } 40% { --s-base: 16; } 75% { --s-base: 12; } }
@keyframes sRatio { 0%, 100% { --s-ratio: 120; } 50% { --s-ratio: 140; } 85% { --s-ratio: 112; } }

.gen.is-demo {
  animation-name: sBase, sRatio;
  animation-duration: $duration;
  animation-timing-function: $easing;
  animation-iteration-count: infinite;
}

@media (prefers-reduced-motion: reduce) {
  .gen.is-demo { animation: none !important; }
}

@media (max-width: 340px) {
  .gen { gap: $sp-2; padding: $sp-2; }
  .gen__top { gap: $sp-2; }
  // 폰 높이(200px) 안에 들어가게 사다리 아래쪽을 자른다 — 비율은 그대로다
  .gen__preview { width: 116px; height: 92px; }
  .gen__code { font-size: 9px; }
}

@property --s-base {
  syntax: "<integer>";
  inherits: true;
  initial-value: 14;
}
@property --s-ratio {
  syntax: "<integer>";
  inherits: true;
  initial-value: 120;
}
html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffffff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.gen {
  min-width: 0;
  --s-base: 14;
  --s-ratio: 120;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-sizing: border-box;
  width: min(100%, 400px);
  padding: 12px;
  border: 1px solid rgba(23, 20, 26, 0.14);
  border-radius: 16px;
  background: rgba(23, 20, 26, 0.04);
}

.gen__top {
  display: flex;
  align-items: center;
  gap: 12px;
}

.gen__preview {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  box-sizing: border-box;
  width: 148px;
  padding: 8px;
  border-radius: 8px;
  background: rgba(23, 20, 26, 0.05);
  overflow: hidden;
}

.gen__step {
  display: block;
  white-space: nowrap;
  color: #17141a;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
  font-weight: 700;
  line-height: 1.1;
}

.gen__step--1 {
  font-size: calc(var(--s-base) * 0.6px);
}

.gen__step--2 {
  font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * 0.01);
}

.gen__step--3 {
  font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * 0.0001);
}

.gen__step--4 {
  font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.000001);
}

.gen__step--5 {
  font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.00000001);
}

.gen__step--6 {
  font-size: calc(var(--s-base) * 0.6px * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * var(--s-ratio) * 0.0000000001);
}

.gen__grid {
  flex: 1 1 auto;
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
}

.gen__row {
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
}

.gen__lab {
  flex: 0 0 auto;
  width: 30px;
  color: #17141a;
  font-weight: 700;
  font-size: 10px;
  line-height: 1.4;
}

.gen__slot {
  position: relative;
  flex: 1 1 auto;
  min-width: 0;
  display: grid;
  align-items: center;
  height: 16px;
}

.gen__slot::before {
  content: "";
  grid-area: 1/1;
  height: 4px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.18);
}

.gen__rng {
  grid-area: 1/1;
  appearance: none;
  -webkit-appearance: none;
  width: 100%;
  min-width: 0;
  height: 16px;
  margin: 0;
  background: transparent;
  cursor: pointer;
}

.gen__rng::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  border: 0;
  border-radius: 50%;
  background: transparent;
}

.gen__rng::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border: 0;
  border-radius: 50%;
  background: transparent;
}

.gen__rng:focus-visible {
  outline: 2px solid #17141a;
  outline-offset: 2px;
  border-radius: 999px;
}

.gen__thumb {
  position: absolute;
  top: 50%;
  left: calc(var(--pct) * 1%);
  width: 12px;
  height: 12px;
  margin-top: -6px;
  margin-left: -6px;
  border-radius: 50%;
  background: #17141a;
  pointer-events: none;
}

.gen__row:nth-child(1) .gen__thumb {
  --pct: calc((var(--s-base) - 12) / 4 * 100);
}

.gen__row:nth-child(2) .gen__thumb {
  --pct: calc((var(--s-ratio) - 110) / 30 * 100);
}

.gen__out {
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.gen__code {
  flex: 1 1 auto;
  min-width: 0;
  padding: 8px;
  border-radius: 8px;
  background: #17141a;
  color: #fff7e6;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Consolas, "Liberation Mono", monospace;
  font-weight: 500;
  font-size: 10px;
  line-height: 1.5;
  white-space: nowrap;
  overflow: hidden;
}

.gen__prop {
  color: #5b8cf8;
}

.gen__v {
  font-weight: 700;
}

.gen__v--s1::after {
  counter-reset: v var(--s-base);
  content: counter(v);
}

.gen__copy {
  flex: 0 0 auto;
  padding: 8px 12px;
  border: 0;
  border-radius: 8px;
  background: #0a4fe8;
  color: #fff7e6;
  font-family: inherit;
  font-weight: 700;
  font-size: 11px;
  line-height: 1.4;
  cursor: pointer;
}

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

@keyframes sBase {
  0%, 100% {
    --s-base: 14;
  }
  40% {
    --s-base: 16;
  }
  75% {
    --s-base: 12;
  }
}
@keyframes sRatio {
  0%, 100% {
    --s-ratio: 120;
  }
  50% {
    --s-ratio: 140;
  }
  85% {
    --s-ratio: 112;
  }
}
.gen.is-demo {
  animation-name: sBase, sRatio;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}

@media (prefers-reduced-motion: reduce) {
  .gen.is-demo {
    animation: none !important;
  }
}
@media (max-width: 340px) {
  .gen {
    gap: 8px;
    padding: 8px;
  }
  .gen__top {
    gap: 8px;
  }
  .gen__preview {
    width: 116px;
    height: 92px;
  }
  .gen__code {
    font-size: 9px;
  }
}

var gen = document.getElementById('gen');
var copyBtn = document.getElementById('copy');
var ranges = Array.prototype.slice.call(gen.querySelectorAll('.gen__rng'));
var COPY_LABEL = 'Copy';
var DONE_LABEL = 'Copied';

// Base 크기와 Ratio — 다섯 단계 사다리가 calc 곱으로 저절로 따라온다(scss 의 calc 랑 같은 식).
// 속성은 --s-base(정수 px) 와 --s-ratio(백분율 정수) 둘뿐이다
function readVar(name) {
  return parseInt(getComputedStyle(gen).getPropertyValue(name), 10) || 0;
}
function scaleText() {
  var base = readVar('--s-base');
  var ratio = readVar('--s-ratio') / 100;
  var lines = [];
  for (var i = 1; i <= 6; i++) {
    lines.push('--step-' + i + ': ' + (Math.round(base * Math.pow(ratio, i - 1) * 100) / 100 / 16).toFixed(3) + 'rem;');
  }
  return ':root {\n  ' + lines.join('\n  ') + '\n}';
}
// 클립보드는 iframe·http 환경에서 막힐 수 있다 — 거부된 프로미스를 반드시 catch 로 받아 선택 방식으로 떨어진다
function fallbackCopy(text) {
  var area = document.createElement('textarea');
  area.value = text;
  area.setAttribute('readonly', '');
  area.style.position = 'fixed';
  area.style.opacity = '0';
  document.body.appendChild(area);
  area.select();
  try { document.execCommand('copy'); } catch (err) { /* 여기까지 막히면 조용히 포기한다 */ }
  document.body.removeChild(area);
}
ranges.forEach(function (input) {
  input.addEventListener('input', function () {
    gen.classList.remove('is-demo');
    gen.style.setProperty(input.dataset.var, input.value);
  });
  input.addEventListener('pointerdown', function () { gen.classList.remove('is-demo'); });
});
copyBtn.addEventListener('click', function () {
  gen.classList.remove('is-demo');
  var text = scaleText();
  if (navigator.clipboard && navigator.clipboard.writeText) {
    navigator.clipboard.writeText(text).catch(function () { fallbackCopy(text); });
  } else {
    fallbackCopy(text);
  }
  copyBtn.textContent = DONE_LABEL;
  setTimeout(function () { copyBtn.textContent = COPY_LABEL; }, 1200);
});

import { useState, useMemo } from 'react';
import styles from './TypeScale.module.scss';

type Axis = { key: string; label: string; min: number; max: number; step: number };
// ambient 선언에 React 이벤트 제네릭이 없어 로컬 타입으로 받는다 (blog-demo TS7006 항)
type RangeEvt = { target: { value: string } };

const AXES: Axis[] = [
  { key: 'base', label: '기준', min: 12, max: 16, step: 1 },
  { key: 'ratio', label: '배율', min: 110, max: 140, step: 5 }
];

export type TypeScaleProps = {
  duration?: string;
  easing?: string;
  color?: string;
};

export default function TypeScale({ duration = '2s', easing = 'cubic-bezier(.2, .8, .2, 1)', color = '#17141a' }: TypeScaleProps) {
  const [values, setValues] = useState<Record<string, number>>({ base: 14, ratio: 120 });
  const [live, setLive] = useState(true);

  const codeText = useMemo(() => {
    const ratio = values.ratio / 100;
    const lines: string[] = [];
    for (let i = 1; i <= 6; i++) {
      lines.push(`--step-${i}: ${(values.base * Math.pow(ratio, i - 1) / 16).toFixed(3)}rem;`);
    }
    return `:root {\n  ${lines.join('\n  ')}\n}`;
  }, [values]);

  const stepSizes = useMemo(() => {
    // 미리보기 계수 0.6 은 사다리를 무대 안에 들어가게 하는 표시 배율이다 — 단계 비율은 그대로다
    const sizes: number[] = [];
    for (let i = 0; i < 6; i++) {
      sizes.push(values.base * Math.pow(values.ratio / 100, i) * 0.6);
    }
    return sizes;
  }, [values]);

  const style = {
    '--dur-loop': duration,
    '--ease-spring': easing,
    '--accent': color
  } as Record<string, string | number>;

  function copy() {
    setLive(false);
    try {
      navigator.clipboard.writeText(codeText);
    } catch (err) {
      /* 클립보드가 막힌 환경에서는 조용히 넘어간다 */
    }
  }

  return (
    <div className={live ? `${styles.gen} ${styles.isDemo}` : styles.gen} style={style}>
      <div className={styles.top}>
        <div className={styles.preview} aria-hidden="true">
          {stepSizes.map((size, i) => (
            <span key={i} style={{ fontSize: `${size.toFixed(2)}px` }}>{'Step ' + (i + 1)}</span>
          ))}
        </div>
        <div className={styles.grid}>
          {AXES.map((axis) => (
            <label className={styles.row} key={axis.key}>
              <span className={styles.lab}>{axis.label}</span>
              <span className={styles.slot}>
                <input
                  className={styles.rng}
                  type="range"
                  min={axis.min}
                  max={axis.max}
                  step={axis.step}
                  value={values[axis.key]}
                  aria-label={axis.label}
                  onChange={(e: RangeEvt) => {
                    setLive(false);
                    setValues((v) => ({ ...v, [axis.key]: Number(e.target.value) }));
                  }}
                />
                <span
                  className={styles.thumb}
                  aria-hidden="true"
                  style={{ left: `${((values[axis.key] - axis.min) / (axis.max - axis.min)) * 100}%` }}
                />
              </span>
            </label>
          ))}
        </div>
      </div>
      <div className={styles.out}>
        <code className={styles.code}>
          <span className={styles.prop}>--step-1:</span> {(values.base / 16).toFixed(3)}rem; <span className={styles.prop}>--step-2:</span> {(values.base * values.ratio / 100 / 16).toFixed(3)}rem; <span className={styles.prop}>--step-3:</span> {(values.base * Math.pow(values.ratio / 100, 2) / 16).toFixed(3)}rem
        </code>
        <button className={styles.copy} type="button" onClick={copy}>복사</button>
      </div>
    </div>
  );
}