03Eight-handle corner radius

<main class="stage">
<div class="gen is-demo" id="gen">
  <div class="gen__top">
    <div class="gen__preview-wrap" aria-hidden="true">
      <div class="gen__preview"></div>
      <span class="gen__dot gen__dot--tl"></span><span class="gen__dot gen__dot--tr"></span>
      <span class="gen__dot gen__dot--br"></span><span class="gen__dot gen__dot--bl"></span>
    </div>
    <div class="gen__grid">
      <label class="gen__row">
        <span class="gen__lab">Top L</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="0" max="80" step="4" value="12" data-var="--r-tl" aria-label="Top-left corner radius">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
      <label class="gen__row">
        <span class="gen__lab">Top R</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="0" max="80" step="4" value="48" data-var="--r-tr" aria-label="Top-right corner radius">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
      <label class="gen__row">
        <span class="gen__lab">Bot R</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="0" max="80" step="4" value="12" data-var="--r-br" aria-label="Bottom-right corner radius">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
      <label class="gen__row">
        <span class="gen__lab">Bot L</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="0" max="80" step="4" value="48" data-var="--r-bl" aria-label="Bottom-left corner radius">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
      <label class="gen__row">
        <span class="gen__lab">Vert radius</span>
        <span class="gen__slot">
          <input class="gen__rng" type="range" min="0" max="80" step="4" value="28" data-var="--r-vy" aria-label="Corner vertical radius">
          <span class="gen__thumb" aria-hidden="true"></span>
        </span>
      </label>
    </div>
  </div>
  <div class="gen__out">
    <code class="gen__code"><span class="gen__prop">border-radius:</span> <span class="gen__v gen__v--tl"></span>px <span class="gen__v gen__v--tr"></span>px <span class="gen__v gen__v--br"></span>px <span class="gen__v gen__v--bl"></span>px / <span class="gen__v gen__v--vy"></span>px</code>
    <button class="gen__copy" type="button" id="copy">Copy</button>
  </div>
</div>
</main>

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

// 여덟 손잡이 모서리 — 네 모서리 가로 반경 + 공통 세로 반경을 사용자 지정 속성에 모은다.
// 슬래시 문법(/ 뒤 세로 반경)이 비대칭 블롭을 만든다. 모서리 점 네 개가 미리보기 위에
// 반경 값을 따라 붙는다 — 어느 모서리가 움직이는지 눈으로 보인다.

$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 --r-tl { syntax: "<integer>"; inherits: true; initial-value: 12; }
@property --r-tr { syntax: "<integer>"; inherits: true; initial-value: 48; }
@property --r-br { syntax: "<integer>"; inherits: true; initial-value: 12; }
@property --r-bl { syntax: "<integer>"; inherits: true; initial-value: 48; }
@property --r-vy { syntax: "<integer>"; inherits: true; initial-value: 28; }

@include stage($stage-yellow);

.gen {
  min-width: 0;  // stage grid item 의 자동 최소폭(min-content) 을 끊는다 — BD9
  --r-tl: 12;
  --r-tr: 48;
  --r-br: 12;
  --r-bl: 48;
  --r-vy: 28;
  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(255, 255, 255, .5);
}

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

// ── 미리보기 — 슬래시 문법 그대로
.gen__preview-wrap { position: relative; flex: 0 0 auto; width: 124px; height: 84px; }
.gen__preview {
  box-sizing: border-box; width: 124px; height: 84px;
  background: $subject-blue;
  // 모서리별 longhand 두 값(가로 세로)은 슬래시 문법과 동치다 — 값이 속성마다 붙어 있어
  // 어느 모서리가 움직이는지 읽기도 쉽다
  border-top-left-radius: calc(var(--r-tl) * 1px) calc(var(--r-vy) * 1px);
  border-top-right-radius: calc(var(--r-tr) * 1px) calc(var(--r-vy) * 1px);
  border-bottom-right-radius: calc(var(--r-br) * 1px) calc(var(--r-vy) * 1px);
  border-bottom-left-radius: calc(var(--r-bl) * 1px) calc(var(--r-vy) * 1px);
}
// 모서리 점 — 각 모서리 반경만큼 안쪽으로 붙는다
.gen__dot {
  position: absolute; width: 8px; height: 8px; margin: -4px;
  border-radius: 50%; background: $subject-ink;
}
.gen__dot--tl { left: calc(var(--r-tl) * 1px); top: calc(var(--r-vy) * 1px); }
.gen__dot--tr { right: calc(var(--r-tr) * 1px); top: calc(var(--r-vy) * 1px); }
.gen__dot--br { right: calc(var(--r-br) * 1px); bottom: calc(var(--r-vy) * 1px); }
.gen__dot--bl { left: calc(var(--r-bl) * 1px); bottom: calc(var(--r-vy) * 1px); }

.gen__grid { flex: 1 1 auto; min-width: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: $sp-1 $sp-2; }
.gen__row { display: flex; align-items: center; gap: $sp-1; cursor: pointer; }
.gen__lab {
  flex: 0 0 auto; width: 42px;
  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(--r-tl) / 80 * 100); }
.gen__row:nth-child(2) .gen__thumb { --pct: calc(var(--r-tr) / 80 * 100); }
.gen__row:nth-child(3) .gen__thumb { --pct: calc(var(--r-br) / 80 * 100); }
.gen__row:nth-child(4) .gen__thumb { --pct: calc(var(--r-bl) / 80 * 100); }
.gen__row:nth-child(5) .gen__thumb { --pct: calc(var(--r-vy) / 80 * 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; }
.gen__v { font-weight: 700; }
.gen__v--tl::after { counter-reset: v var(--r-tl); content: counter(v); }
.gen__v--tr::after { counter-reset: v var(--r-tr); content: counter(v); }
.gen__v--br::after { counter-reset: v var(--r-br); content: counter(v); }
.gen__v--bl::after { counter-reset: v var(--r-bl); content: counter(v); }
.gen__v--vy::after { counter-reset: v var(--r-vy); 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 — 왼위/오아 가 한 쌍, 오위/왼아 가 다른 쌍으로 엇갈려 찌그러진다
@keyframes rTL { 0%, 100% { --r-tl: 12; } 50% { --r-tl: 64; } }
@keyframes rTR { 0%, 100% { --r-tr: 48; } 50% { --r-tr: 8; } }
@keyframes rBR { 0%, 100% { --r-br: 12; } 50% { --r-br: 64; } }
@keyframes rBL { 0%, 100% { --r-bl: 48; } 50% { --r-bl: 8; } }
@keyframes rVY { 0%, 100% { --r-vy: 28; } 40% { --r-vy: 68; } 80% { --r-vy: 16; } }

.gen.is-demo {
  animation-name: rTL, rTR, rBR, rBL, rVY;
  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; }
  .gen__preview-wrap, .gen__preview { width: 100px; height: 72px; }
  .gen__code { font-size: 9px; }
}

@property --r-tl {
  syntax: "<integer>";
  inherits: true;
  initial-value: 12;
}
@property --r-tr {
  syntax: "<integer>";
  inherits: true;
  initial-value: 48;
}
@property --r-br {
  syntax: "<integer>";
  inherits: true;
  initial-value: 12;
}
@property --r-bl {
  syntax: "<integer>";
  inherits: true;
  initial-value: 48;
}
@property --r-vy {
  syntax: "<integer>";
  inherits: true;
  initial-value: 28;
}
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);
}

.gen {
  min-width: 0;
  --r-tl: 12;
  --r-tr: 48;
  --r-br: 12;
  --r-bl: 48;
  --r-vy: 28;
  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(255, 255, 255, 0.5);
}

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

.gen__preview-wrap {
  position: relative;
  flex: 0 0 auto;
  width: 124px;
  height: 84px;
}

.gen__preview {
  box-sizing: border-box;
  width: 124px;
  height: 84px;
  background: #2f6df6;
  border-top-left-radius: calc(var(--r-tl) * 1px) calc(var(--r-vy) * 1px);
  border-top-right-radius: calc(var(--r-tr) * 1px) calc(var(--r-vy) * 1px);
  border-bottom-right-radius: calc(var(--r-br) * 1px) calc(var(--r-vy) * 1px);
  border-bottom-left-radius: calc(var(--r-bl) * 1px) calc(var(--r-vy) * 1px);
}

.gen__dot {
  position: absolute;
  width: 8px;
  height: 8px;
  margin: -4px;
  border-radius: 50%;
  background: #17141a;
}

.gen__dot--tl {
  left: calc(var(--r-tl) * 1px);
  top: calc(var(--r-vy) * 1px);
}

.gen__dot--tr {
  right: calc(var(--r-tr) * 1px);
  top: calc(var(--r-vy) * 1px);
}

.gen__dot--br {
  right: calc(var(--r-br) * 1px);
  bottom: calc(var(--r-vy) * 1px);
}

.gen__dot--bl {
  left: calc(var(--r-bl) * 1px);
  bottom: calc(var(--r-vy) * 1px);
}

.gen__grid {
  flex: 1 1 auto;
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 8px;
}

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

.gen__lab {
  flex: 0 0 auto;
  width: 42px;
  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(--r-tl) / 80 * 100);
}

.gen__row:nth-child(2) .gen__thumb {
  --pct: calc(var(--r-tr) / 80 * 100);
}

.gen__row:nth-child(3) .gen__thumb {
  --pct: calc(var(--r-br) / 80 * 100);
}

.gen__row:nth-child(4) .gen__thumb {
  --pct: calc(var(--r-bl) / 80 * 100);
}

.gen__row:nth-child(5) .gen__thumb {
  --pct: calc(var(--r-vy) / 80 * 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--tl::after {
  counter-reset: v var(--r-tl);
  content: counter(v);
}

.gen__v--tr::after {
  counter-reset: v var(--r-tr);
  content: counter(v);
}

.gen__v--br::after {
  counter-reset: v var(--r-br);
  content: counter(v);
}

.gen__v--bl::after {
  counter-reset: v var(--r-bl);
  content: counter(v);
}

.gen__v--vy::after {
  counter-reset: v var(--r-vy);
  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 rTL {
  0%, 100% {
    --r-tl: 12;
  }
  50% {
    --r-tl: 64;
  }
}
@keyframes rTR {
  0%, 100% {
    --r-tr: 48;
  }
  50% {
    --r-tr: 8;
  }
}
@keyframes rBR {
  0%, 100% {
    --r-br: 12;
  }
  50% {
    --r-br: 64;
  }
}
@keyframes rBL {
  0%, 100% {
    --r-bl: 48;
  }
  50% {
    --r-bl: 8;
  }
}
@keyframes rVY {
  0%, 100% {
    --r-vy: 28;
  }
  40% {
    --r-vy: 68;
  }
  80% {
    --r-vy: 16;
  }
}
.gen.is-demo {
  animation-name: rTL, rTR, rBR, rBL, rVY;
  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-wrap, .gen__preview {
    width: 100px;
    height: 72px;
  }
  .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';

// 네 모서리 X 반경 + 공통 Vert radius — 다섯 값이면 슬래시 문법이 성립한다
function readVar(name) {
  return parseInt(getComputedStyle(gen).getPropertyValue(name), 10) || 0;
}
function radiusText() {
  return 'border-radius: ' + readVar('--r-tl') + 'px ' + readVar('--r-tr') + 'px ' + readVar('--r-br') + 'px ' + readVar('--r-bl') + 'px / ' + readVar('--r-vy') + 'px;';
}
// 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 = radiusText();
  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 './RadiusHandles.module.scss';

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

const AXES: Axis[] = [
  { key: 'tl', label: '왼위', min: 0, max: 80 },
  { key: 'tr', label: '오위', min: 0, max: 80 },
  { key: 'br', label: '오아', min: 0, max: 80 },
  { key: 'bl', label: '왼아', min: 0, max: 80 },
  { key: 'vy', label: '세로 반경', min: 0, max: 80 }
];

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

export default function RadiusHandles({ duration = '2s', easing = 'cubic-bezier(.2, .8, .2, 1)', color = '#17141a' }: RadiusHandlesProps) {
  const [values, setValues] = useState<Record<string, number>>({ tl: 12, tr: 48, br: 12, bl: 48, vy: 28 });
  const [live, setLive] = useState(true);

  const codeText = useMemo(() => {
    return `border-radius: ${values.tl}px ${values.tr}px ${values.br}px ${values.bl}px / ${values.vy}px;`;
  }, [values]);

  const style = {
    '--dur-loop': duration,
    '--ease-spring': easing,
    '--accent': color,
    '--r-tl': values.tl,
    '--r-tr': values.tr,
    '--r-br': values.br,
    '--r-bl': values.bl,
    '--r-vy': values.vy
  } 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} ${styles.isDemo}` : styles.gen} style={style}>
      <div className={styles.top}>
        <div className={styles.previewWrap} aria-hidden="true">
          <div className={styles.preview}></div>
          <span className={styles.dot} style={{ left: values.tl, top: values.vy }}></span>
          <span className={styles.dot} style={{ right: values.tr, top: values.vy }}></span>
          <span className={styles.dot} style={{ right: values.br, bottom: values.vy }}></span>
          <span className={styles.dot} style={{ left: values.bl, bottom: values.vy }}></span>
        </div>
        <div className={styles.grid}>
          {AXES.map((axis) => (
            <label className={styles.row} key={axis.key}>
              <span className={styles.lab}>{axis.label}</span>
              <span className={styles.slot}>
                <input
                  className={styles.rng}
                  type="range"
                  min={axis.min}
                  max={axis.max}
                  step={4}
                  value={values[axis.key]}
                  aria-label={axis.label}
                  onChange={(e: RangeEvt) => {
                    setLive(false);
                    setValues((v) => ({ ...v, [axis.key]: Number(e.target.value) }));
                  }}
                />
                <span
                  className={styles.thumb}
                  aria-hidden="true"
                  style={{ left: `${(values[axis.key] / axis.max) * 100}%` }}
                />
              </span>
            </label>
          ))}
        </div>
      </div>
      <div className={styles.out}>
        <code className={styles.code}>
          <span className={styles.prop}>border-radius:</span> {values.tl}px {values.tr}px {values.br}px {values.bl}px / {values.vy}px
        </code>
        <button className={styles.copy} type="button" onClick={copy}>복사</button>
      </div>
    </div>
  );
}