08Tiến trình dạng stepper

<main class="stage">
  <div class="stepper is-demo" role="list" aria-label="Bước tiến trình">
    <div class="step" role="listitem"><span class="step__dot">1</span><span class="step__label">Thông tin</span></div>
    <div class="line"></div>
    <div class="step" role="listitem"><span class="step__dot">2</span><span class="step__label">Giao hàng</span></div>
    <div class="line"></div>
    <div class="step" role="listitem"><span class="step__dot">3</span><span class="step__label">Thanh toán</span></div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 400ms;                                 // 원 하나·선 하나가 채워지는 시간
$easing: $ease-spring;
$color: $subject-cream;                           // 완료된 원·선 색

@include stage($stage-ink);

.stepper { display: flex; align-items: center; }
.step { display: flex; flex-direction: column; align-items: center; gap: 6px; }
.step__dot {
  width: clamp(30px, 9vw, 40px);
  height: clamp(30px, 9vw, 40px);
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, .14);
  color: rgba(255, 255, 255, .72);
  font-weight: 700; font-size: 13px; line-height: 1; font-family: inherit;
  transform: scale(.85);
}
.step__label { font-weight: 600; font-size: 11px; line-height: 1; font-family: inherit; color: rgba(255, 255, 255, .55); }
.line {
  width: clamp(30px, 8vw, 44px);
  height: 3px;
  border-radius: 2px;
  background: rgba(255, 255, 255, .14);
  transform: scaleX(0);
  transform-origin: left; // 규칙8: 좌변서 차오름
}
// 원 → 선 → 원 → 선 → 원 순서로, 앞 단계가 끝나야 다음이 채워진다 (동시에 시작하지 않는다)
.stepper.is-demo .step__dot { animation: dot-fill $duration $easing both; }
.stepper.is-demo .line { animation: line-grow $duration linear both; }
.stepper.is-demo > :nth-child(1) .step__dot { animation-delay: 0ms; }
.stepper.is-demo > :nth-child(2) { animation-delay: 400ms; }
.stepper.is-demo > :nth-child(3) .step__dot { animation-delay: 800ms; }
.stepper.is-demo > :nth-child(4) { animation-delay: 1200ms; }
.stepper.is-demo > :nth-child(5) .step__dot { animation-delay: 1600ms; }

@keyframes dot-fill {
  from { background: rgba(255, 255, 255, .14); color: rgba(255, 255, 255, .72); transform: scale(.85); }
  to   { background: $color; color: $stage-ink; transform: scale(1); }
}
@keyframes line-grow { from { transform: scaleX(0); } to { transform: scaleX(1); } }

@media (prefers-reduced-motion: reduce) {
  .stepper.is-demo .step__dot,
  .stepper.is-demo .line { animation: none; background: $color; transform: none; }
  .stepper.is-demo .step__dot { color: $stage-ink; }
}

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);
}

.stepper {
  display: flex;
  align-items: center;
}

.step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.step__dot {
  width: clamp(30px, 9vw, 40px);
  height: clamp(30px, 9vw, 40px);
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.14);
  color: rgba(255, 255, 255, 0.72);
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
  transform: scale(0.85);
}

.step__label {
  font-weight: 600;
  font-size: 11px;
  line-height: 1;
  font-family: inherit;
  color: rgba(255, 255, 255, 0.55);
}

.line {
  width: clamp(30px, 8vw, 44px);
  height: 3px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.14);
  transform: scaleX(0);
  transform-origin: left;
}

.stepper.is-demo .step__dot {
  animation: dot-fill 400ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.stepper.is-demo .line {
  animation: line-grow 400ms linear both;
}

.stepper.is-demo > :nth-child(1) .step__dot {
  animation-delay: 0ms;
}

.stepper.is-demo > :nth-child(2) {
  animation-delay: 400ms;
}

.stepper.is-demo > :nth-child(3) .step__dot {
  animation-delay: 800ms;
}

.stepper.is-demo > :nth-child(4) {
  animation-delay: 1200ms;
}

.stepper.is-demo > :nth-child(5) .step__dot {
  animation-delay: 1600ms;
}

@keyframes dot-fill {
  from {
    background: rgba(255, 255, 255, 0.14);
    color: rgba(255, 255, 255, 0.72);
    transform: scale(0.85);
  }
  to {
    background: #fff7e6;
    color: #17141a;
    transform: scale(1);
  }
}
@keyframes line-grow {
  from {
    transform: scaleX(0);
  }
  to {
    transform: scaleX(1);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stepper.is-demo .step__dot,
  .stepper.is-demo .line {
    animation: none;
    background: #fff7e6;
    transform: none;
  }
  .stepper.is-demo .step__dot {
    color: #17141a;
  }
}

import type { CSSProperties, ReactNode } from "react";
import styles from "./StepperProgress.module.scss";

export type StepperProgressProps = {
  /** 완료된 단계 수 (0~labels.length) */
  step: number;
  labels?: string[];
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function StepperProgress({
  step,
  labels = ["Info", "Shipping", "Payment"],
  duration = 400,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#fff7e6",
}: StepperProgressProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  const nodes: ReactNode[] = [];
  labels.forEach((l, i) => {
    if (i > 0) {
      nodes.push(<span key={`line-${i}`} className={i <= step - 1 ? `${styles.line} ${styles.on}` : styles.line} />);
    }
    nodes.push(
      <div key={`step-${i}`} className={styles.step} role="listitem">
        <span className={i < step ? `${styles.dot} ${styles.on}` : styles.dot}>{i + 1}</span>
        <span className={styles.label}>{l}</span>
      </div>
    );
  });

  return (
    <div className={styles.stepper} style={vars} role="list" aria-label="progress steps">
      {nodes}
    </div>
  );
}