03Segmented step ring

<main class="stage">
  <div class="sg is-demo">
    <div class="sg__dial">
      <svg class="sg__svg" viewBox="0 0 104 104" width="104" height="104" aria-hidden="true">
        <g class="sg__segs">
          <circle class="sg__seg" style="--i:0" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:1" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:2" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:3" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:4" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:5" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:6" cx="52" cy="52" r="44"/>
          <circle class="sg__seg" style="--i:7" cx="52" cy="52" r="44"/>
        </g>
      </svg>
      <div class="sg__center">
        <span class="sg__ic" aria-hidden="true"><svg viewBox="0 0 256 256" width="14" height="14"><g fill="currentColor"><path d="m96 240l16-80l-64-24L160 16l-16 80l64 24Z" opacity=".2"/><path d="M215.79 118.17a8 8 0 0 0-5-5.66L153.18 90.9l14.66-73.33a8 8 0 0 0-13.69-7l-112 120a8 8 0 0 0 3 13l57.63 21.61l-14.62 73.25a8 8 0 0 0 13.69 7l112-120a8 8 0 0 0 1.94-7.26M109.37 214l10.47-52.38a8 8 0 0 0-5-9.06L62 132.71l84.62-90.66l-10.46 52.38a8 8 0 0 0 5 9.06l52.8 19.8Z"/></g></svg></span>
        <span class="sg__frac" role="status" aria-label="Completed steps"></span>
        <span class="sg__cap">Steps</span>
      </div>
    </div>
    <button class="sg__btn" type="button">Next step</button>
  </div>
</main>

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

$duration: $dur-loop;
$easing: $ease-out;
$color: $subject-cream;

@include stage($stage-orange);

@property --n {
  syntax: "<integer>";
  inherits: true;
  initial-value: 0;
}

// 한 칸의 몫: C = 2π × 44 = 276.460 → 8칸이면 34.5575. 그중 26 을 칠하고 8.5575 를 비운다
$C: 276.460;
$slot: 34.5575;
$dash: 26;

.sg {
  --n: 0;
  box-sizing: border-box;
  display: grid;
  justify-items: center;
  gap: $sp-3;
  color: $color;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.sg__dial { position: relative; display: grid; place-items: center; }
.sg__svg {
  width: clamp(92px, 28vw, 104px);
  height: clamp(92px, 28vw, 104px);
  transform: rotate(-90deg);
}

.sg__seg {
  fill: none;
  stroke: $color;
  stroke-width: 10;
  stroke-linecap: butt;
  stroke-dasharray: $dash ($C - $dash);
  stroke-dashoffset: calc(var(--i) * -#{$slot});
  opacity: .18;
  transition: opacity $dur-quick $easing;
}
.sg__seg.is-on { opacity: 1; }

.sg__center { position: absolute; display: grid; justify-items: center; gap: $sp-1; pointer-events: none; }
.sg__ic { display: inline-flex; opacity: .7; }
.sg__frac {
  font-size: clamp(18px, 6vw, 22px);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}
.sg__frac::after {
  counter-reset: n var(--n);
  content: counter(n) "/8";
}
.sg__cap { font-size: 10px; font-weight: 700; opacity: .66; }

.sg__btn {
  border: 0;
  border-radius: $r-pill;
  background: $stage-ink;
  color: $color;
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  padding: $sp-2 $sp-4;
  cursor: pointer;
  transition: transform $dur-quick $ease-pop;
}
.sg__btn:hover, .sg__btn:focus-visible { transform: translateY(-2px); }

// ── 자동 루프: 한 칸씩 켜졌다가 켜진 역순으로 꺼진다. 8칸이 한꺼번에 꺼지지 않는다 ──
.sg.is-demo .sg__seg { animation: $duration linear infinite; }
@for $i from 0 through 7 {
  $on: $i * 5;
  $off: 50 + (7 - $i) * 5;
  .sg.is-demo .sg__seg:nth-child(#{$i + 1}) { animation-name: sg-seg-#{$i}; }
  @keyframes sg-seg-#{$i} {
    0%            { opacity: .18; }
    @if $on > 0 {
      #{$on}%     { opacity: .18; }
    }
    #{$on + 2}%   { opacity: 1; }
    #{$off}%      { opacity: 1; }
    #{$off + 2}%  { opacity: .18; }
    100%          { opacity: .18; }
  }
}
.sg.is-demo { animation: sg-count $duration linear infinite; }
// 분수는 칸이 켜지고 꺼지는 일정(마지막 칸 37% 점등 · 첫 칸 87% 소등)에 맞춘다.
// 45/55 로 두면 되감기 구간에서 켜진 칸 수와 가운데 숫자가 어긋난다
@keyframes sg-count {
  0%        { --n: 0; }
  37%, 50%  { --n: 8; }
  87%, 100% { --n: 0; }
}

@media (max-width: 340px) {
  .sg__cap { font-size: 9px; }
}

@media (prefers-reduced-motion: reduce) {
  .sg.is-demo, .sg.is-demo .sg__seg { animation: none !important; }
  .sg.is-demo { --n: 5; }
  .sg.is-demo .sg__seg:nth-child(-n + 5) { opacity: 1; }
  .sg__seg, .sg__btn { transition: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

@property --n {
  syntax: "<integer>";
  inherits: true;
  initial-value: 0;
}
.sg {
  --n: 0;
  box-sizing: border-box;
  display: grid;
  justify-items: center;
  gap: 12px;
  color: #fff7e6;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.sg__dial {
  position: relative;
  display: grid;
  place-items: center;
}

.sg__svg {
  width: clamp(92px, 28vw, 104px);
  height: clamp(92px, 28vw, 104px);
  transform: rotate(-90deg);
}

.sg__seg {
  fill: none;
  stroke: #fff7e6;
  stroke-width: 10;
  stroke-linecap: butt;
  stroke-dasharray: 26 250.46;
  stroke-dashoffset: calc(var(--i) * -34.5575);
  opacity: 0.18;
  transition: opacity 220ms ease-out;
}

.sg__seg.is-on {
  opacity: 1;
}

.sg__center {
  position: absolute;
  display: grid;
  justify-items: center;
  gap: 4px;
  pointer-events: none;
}

.sg__ic {
  display: inline-flex;
  opacity: 0.7;
}

.sg__frac {
  font-size: clamp(18px, 6vw, 22px);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}

.sg__frac::after {
  counter-reset: n var(--n);
  content: counter(n) "/8";
}

.sg__cap {
  font-size: 10px;
  font-weight: 700;
  opacity: 0.66;
}

.sg__btn {
  border: 0;
  border-radius: 999px;
  background: #17141a;
  color: #fff7e6;
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  padding: 8px 16px;
  cursor: pointer;
  transition: transform 220ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

.sg__btn:hover, .sg__btn:focus-visible {
  transform: translateY(-2px);
}

.sg.is-demo .sg__seg {
  animation: 2s linear infinite;
}

.sg.is-demo .sg__seg:nth-child(1) {
  animation-name: sg-seg-0;
}

@keyframes sg-seg-0 {
  0% {
    opacity: 0.18;
  }
  2% {
    opacity: 1;
  }
  85% {
    opacity: 1;
  }
  87% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(2) {
  animation-name: sg-seg-1;
}

@keyframes sg-seg-1 {
  0% {
    opacity: 0.18;
  }
  5% {
    opacity: 0.18;
  }
  7% {
    opacity: 1;
  }
  80% {
    opacity: 1;
  }
  82% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(3) {
  animation-name: sg-seg-2;
}

@keyframes sg-seg-2 {
  0% {
    opacity: 0.18;
  }
  10% {
    opacity: 0.18;
  }
  12% {
    opacity: 1;
  }
  75% {
    opacity: 1;
  }
  77% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(4) {
  animation-name: sg-seg-3;
}

@keyframes sg-seg-3 {
  0% {
    opacity: 0.18;
  }
  15% {
    opacity: 0.18;
  }
  17% {
    opacity: 1;
  }
  70% {
    opacity: 1;
  }
  72% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(5) {
  animation-name: sg-seg-4;
}

@keyframes sg-seg-4 {
  0% {
    opacity: 0.18;
  }
  20% {
    opacity: 0.18;
  }
  22% {
    opacity: 1;
  }
  65% {
    opacity: 1;
  }
  67% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(6) {
  animation-name: sg-seg-5;
}

@keyframes sg-seg-5 {
  0% {
    opacity: 0.18;
  }
  25% {
    opacity: 0.18;
  }
  27% {
    opacity: 1;
  }
  60% {
    opacity: 1;
  }
  62% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(7) {
  animation-name: sg-seg-6;
}

@keyframes sg-seg-6 {
  0% {
    opacity: 0.18;
  }
  30% {
    opacity: 0.18;
  }
  32% {
    opacity: 1;
  }
  55% {
    opacity: 1;
  }
  57% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo .sg__seg:nth-child(8) {
  animation-name: sg-seg-7;
}

@keyframes sg-seg-7 {
  0% {
    opacity: 0.18;
  }
  35% {
    opacity: 0.18;
  }
  37% {
    opacity: 1;
  }
  50% {
    opacity: 1;
  }
  52% {
    opacity: 0.18;
  }
  100% {
    opacity: 0.18;
  }
}
.sg.is-demo {
  animation: sg-count 2s linear infinite;
}

@keyframes sg-count {
  0% {
    --n: 0;
  }
  37%, 50% {
    --n: 8;
  }
  87%, 100% {
    --n: 0;
  }
}
@media (max-width: 340px) {
  .sg__cap {
    font-size: 9px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sg.is-demo, .sg.is-demo .sg__seg {
    animation: none !important;
  }
  .sg.is-demo {
    --n: 5;
  }
  .sg.is-demo .sg__seg:nth-child(-n+5) {
    opacity: 1;
  }
  .sg__seg, .sg__btn {
    transition: none;
  }
}

// 실제 동작: 누를 때마다 칸 하나를 더 켜고 가운데 분수를 바꾼다. 8칸을 다 채우면 처음으로 되돌린다.
var sg = document.querySelector('.sg');
var segs = sg.querySelectorAll('.sg__seg');
var n = 0;
sg.querySelector('.sg__btn').addEventListener('click', function () {
  sg.classList.remove('is-demo');
  n = n >= segs.length ? 0 : n + 1;
  for (var i = 0; i < segs.length; i++) segs[i].classList.toggle('is-on', i < n);
  sg.style.setProperty('--n', String(n));
});

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

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

type Vars = CSSProperties & {
  "--duration"?: string;
  "--easing"?: string;
  "--color"?: string;
  "--n"?: number;
};

type SegVars = CSSProperties & { "--i"?: number };

const TOTAL = 8;
const SEGS = [0, 1, 2, 3, 4, 5, 6, 7];

export default function SegmentedStepRing({
  duration = 220,
  easing = "ease-out",
  color = "#fff7e6",
}: SegmentedStepRingProps) {
  const [n, setN] = useState(0);

  const vars: Vars = {
    "--duration": `${duration}ms`,
    "--easing": easing,
    "--color": color,
    "--n": n,
  };

  return (
    <div className={styles.sg} style={vars}>
      <div className={styles.dial}>
        <svg className={styles.svg} viewBox="0 0 104 104" width="104" height="104" aria-hidden="true">
          <g>
            {SEGS.map((i) => {
              const seg: SegVars = { "--i": i };
              return (
                <circle
                  key={i}
                  className={`${styles.seg} ${i < n ? styles.on : ""}`}
                  style={seg}
                  cx="52"
                  cy="52"
                  r="44"
                />
              );
            })}
          </g>
        </svg>
        <div className={styles.center}>
          <span className={styles.ic} aria-hidden="true">
            <svg viewBox="0 0 256 256" width="14" height="14">
              <g fill="currentColor">
                <path d="m96 240l16-80l-64-24L160 16l-16 80l64 24Z" opacity=".2" />
                <path d="M215.79 118.17a8 8 0 0 0-5-5.66L153.18 90.9l14.66-73.33a8 8 0 0 0-13.69-7l-112 120a8 8 0 0 0 3 13l57.63 21.61l-14.62 73.25a8 8 0 0 0 13.69 7l112-120a8 8 0 0 0 1.94-7.26M109.37 214l10.47-52.38a8 8 0 0 0-5-9.06L62 132.71l84.62-90.66l-10.46 52.38a8 8 0 0 0 5 9.06l52.8 19.8Z" />
              </g>
            </svg>
          </span>
          <span className={styles.frac} role="status" aria-label="Completed steps" />
          <span className={styles.cap}>Steps</span>
        </div>
      </div>
      <button
        type="button"
        className={styles.btn}
        onClick={() => setN((v) => (v >= TOTAL ? 0 : v + 1))}
      >
        Next step
      </button>
    </div>
  );
}