05Conic-gradient sweep

<main class="stage">
  <div class="spinner" role="status" aria-label="Loading"></div>
</main>

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

$duration: 1.1s;                                  // 한 바퀴 도는 시간
$easing: linear;
$color: $subject-blue;                            // 그라디언트 진한 구간

@include stage($stage-ink);

.spinner {
  width: clamp(56px, 16vw, 84px);
  height: clamp(56px, 16vw, 84px);
  border-radius: 50%;
  background: conic-gradient($color 0deg 270deg, rgba($subject-cream, .18) 270deg 360deg);
  // 가운데를 뚫어 링으로 보이게 한다 — 그라디언트 자체는 그대로 두고 통째로 돌린다
  -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 8px), #000 calc(100% - 8px));
          mask: radial-gradient(farthest-side, transparent calc(100% - 8px), #000 calc(100% - 8px));
  animation: spin $duration $easing infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .spinner { animation: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.spinner {
  width: clamp(56px, 16vw, 84px);
  height: clamp(56px, 16vw, 84px);
  border-radius: 50%;
  background: conic-gradient(#2f6df6 0deg 270deg, rgba(255, 247, 230, 0.18) 270deg 360deg);
  -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 8px), #000 calc(100% - 8px));
  mask: radial-gradient(farthest-side, transparent calc(100% - 8px), #000 calc(100% - 8px));
  animation: spin 1.1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .spinner {
    animation: none;
  }
}

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

export type ConicSweepSpinnerProps = {
  /** 스피너 지름 (기본 68px) */
  size?: number;
  /** 한 바퀴 도는 시간 (기본 1100ms) */
  duration?: number;
  /** 그라디언트 진한 구간 색 */
  color?: string;
  label?: string;
};

type Vars = CSSProperties & { "--size"?: string; "--duration"?: string; "--color"?: string };

export default function ConicSweepSpinner({
  size = 68,
  duration = 1100,
  color = "#2f6df6",
  label = "Loading",
}: ConicSweepSpinnerProps) {
  const vars: Vars = {
    "--size": `${size}px`,
    "--duration": `${duration}ms`,
    "--color": color,
  };
  return <div className={styles.spinner} style={vars} role="status" aria-label={label} />;
}