03Conic-gradient ring

<main class="stage">
  <div class="ring is-demo" role="progressbar" aria-valuemin="0" aria-valuemax="100" aria-valuenow="76" aria-label="Usage"></div>
  <p class="cap">Usage</p>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;                             // 0 → 100 까지 차는 시간
$easing: $ease-out;
$color: $subject-blue;                            // 낮은 구간(0~40%) 색. 변형은 이 값만 바꾼다

@include stage($stage-orange);

// 채움 각도(--percent)와 구간 색(--zone)을 각각 등록한다. 숫자는 매끄럽게, 색은 구간이 바뀔 때 한 번에 전환한다
@property --percent {
  syntax: "<number>";
  inherits: false;
  initial-value: 0;
}

.ring {
  --percent: 0;
  --zone: #{$color};
  position: relative;
  width: clamp(84px, 22vw, 108px);
  aspect-ratio: 1;
  border-radius: 50%;
  background: conic-gradient(var(--zone) calc(var(--percent) * 1%), rgba(255, 255, 255, .35) 0);
}
.ring::before {                                    // 도넛 구멍 — 숫자를 보여주지 않고 색으로만 구간을 말한다
  content: "";
  position: absolute;
  inset: 16%;
  border-radius: 50%;
  background: $stage-orange;
}
.ring.is-demo {
  animation: sweep $duration $easing infinite, zone $duration steps(1) infinite;
}

@keyframes sweep { 0% { --percent: 0; } 100% { --percent: 100; } }
@keyframes zone {
  0%   { --zone: #{$color}; }         // 낮음
  40%  { --zone: #{$color}; }
  41%  { --zone: #{$stage-yellow}; }  // 중간
  74%  { --zone: #{$stage-yellow}; }
  75%  { --zone: #{$subject-ink}; }         // 높음(경고) — 주황 무대라 빨강 대신 잉크 (대비)
  100% { --zone: #{$subject-ink}; }
}

.cap {
  margin: 14px 0 0;
  color: $subject-ink;                            // AA: 주황 무대 위 글자 5.50:1
  font: 600 clamp(12px, 3.2vw, 14px)/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

@media (prefers-reduced-motion: reduce) {
  .ring.is-demo { animation: none; --percent: 76; --zone: #{$subject-ink}; }
}

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 --percent {
  syntax: "<number>";
  inherits: false;
  initial-value: 0;
}
.ring {
  --percent: 0;
  --zone: #2f6df6;
  position: relative;
  width: clamp(84px, 22vw, 108px);
  aspect-ratio: 1;
  border-radius: 50%;
  background: conic-gradient(var(--zone) calc(var(--percent) * 1%), rgba(255, 255, 255, 0.35) 0);
}

.ring::before {
  content: "";
  position: absolute;
  inset: 16%;
  border-radius: 50%;
  background: #ff4d1f;
}

.ring.is-demo {
  animation: sweep 2s ease-out infinite, zone 2s steps(1) infinite;
}

@keyframes sweep {
  0% {
    --percent: 0;
  }
  100% {
    --percent: 100;
  }
}
@keyframes zone {
  0% {
    --zone: #2f6df6;
  }
  40% {
    --zone: #2f6df6;
  }
  41% {
    --zone: #ffd23f;
  }
  74% {
    --zone: #ffd23f;
  }
  75% {
    --zone: #17141a;
  }
  100% {
    --zone: #17141a;
  }
}
.cap {
  margin: 14px 0 0;
  color: #17141a;
  font: 600 clamp(12px, 3.2vw, 14px)/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

@media (prefers-reduced-motion: reduce) {
  .ring.is-demo {
    animation: none;
    --percent: 76;
    --zone: #17141a;
  }
}

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

export type ConicRingProps = {
  /** 0~100 */
  percent: number;
  duration?: number;
  easing?: string;
  /** 낮음 구간(0~40) 색 */
  color?: string;
  /** 중간 구간(40~75) 색 */
  zoneMid?: string;
  /** 높음 구간(75~100) 색 */
  zoneHigh?: string;
  label?: string;
};

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

export default function ConicRing({
  percent,
  duration = 600,
  easing = "ease-out",
  color = "#2f6df6",
  zoneMid = "#ffd23f",
  zoneHigh = "#17141a",
  label,
}: ConicRingProps) {
  const p = Math.max(0, Math.min(100, percent));
  const zone = p < 40 ? color : p < 75 ? zoneMid : zoneHigh;
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--percent": p, "--zone": zone };

  return (
    <div
      className={styles.ring}
      style={vars}
      role="progressbar"
      aria-valuemin={0}
      aria-valuemax={100}
      aria-valuenow={p}
      aria-label={label}
    />
  );
}