05Alternating card slide

<main class="stage">
  <div class="ts05-timeline is-demo">
    <div class="ts05-row ts05-row--l"><div class="ts05-card">2024.01</div></div>
    <div class="ts05-row ts05-row--r"><div class="ts05-card">2024.06</div></div>
    <div class="ts05-row ts05-row--l"><div class="ts05-card">2024.12</div></div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;
$easing: $ease-spring;
$color: $subject-blue-deep;   // 크림 글자가 얹히므로 진한 파랑

@include stage($stage-ink);

.ts05-timeline {
  position: relative;
  width: min(280px, 84vw);
  display: flex;
  flex-direction: column;
  gap: $sp-4;

  // 가운데 세로선
  &::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 0;
    width: 2px;
    height: 100%;
    background: rgba(255, 247, 230, .18);
    transform: translateX(-50%);
  }
}

.ts05-row {
  display: flex;
  &--l { justify-content: flex-start; }
  &--r { justify-content: flex-end; }
}

.ts05-card {
  width: 44%;
  box-sizing: border-box;
  padding: $sp-2 $sp-3;
  border-radius: $r-sm;
  background: $color;
  color: $subject-cream;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  opacity: 0;
}

// 실제 사용 코드: 뷰포트에 들어오면 홀수는 왼쪽, 짝수는 오른쪽에서 모인다
.ts05-row--l .ts05-card { transform: translateX(-24px); }
.ts05-row--r .ts05-card { transform: translateX(24px); }

@supports (animation-timeline: view()) {
  .ts05-row--l .ts05-card { animation: ts05-in-l $duration $easing both; animation-timeline: view(); animation-range: entry 0% cover 60%; }
  .ts05-row--r .ts05-card { animation: ts05-in-r $duration $easing both; animation-timeline: view(); animation-range: entry 0% cover 60%; }
}
@supports not (animation-timeline: view()) {
  .ts05-card { opacity: 1; transform: none; }
}

@keyframes ts05-in-l { from { opacity: 0; transform: translateX(-24px); } to { opacity: 1; transform: translateX(0); } }
@keyframes ts05-in-r { from { opacity: 0; transform: translateX(24px); } to { opacity: 1; transform: translateX(0); } }

// 데모 루프: 위에서부터 순서대로
.ts05-timeline.is-demo .ts05-row--l .ts05-card { animation: ts05-in-l $duration $easing infinite; }
.ts05-timeline.is-demo .ts05-row--r .ts05-card { animation: ts05-in-r $duration $easing infinite; animation-delay: .18s; }
.ts05-timeline.is-demo .ts05-row:nth-child(3) .ts05-card { animation-delay: .36s; }

@media (prefers-reduced-motion: reduce) {
  .ts05-card, .ts05-timeline.is-demo .ts05-card { animation: none !important; opacity: 1 !important; transform: none !important; }
}

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);
}

.ts05-timeline {
  position: relative;
  width: min(280px, 84vw);
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.ts05-timeline::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  width: 2px;
  height: 100%;
  background: rgba(255, 247, 230, 0.18);
  transform: translateX(-50%);
}

.ts05-row {
  display: flex;
}
.ts05-row--l {
  justify-content: flex-start;
}
.ts05-row--r {
  justify-content: flex-end;
}

.ts05-card {
  width: 44%;
  box-sizing: border-box;
  padding: 8px 12px;
  border-radius: 8px;
  background: #0a4fe8;
  color: #fff7e6;
  font: 700 12px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  opacity: 0;
}

.ts05-row--l .ts05-card {
  transform: translateX(-24px);
}

.ts05-row--r .ts05-card {
  transform: translateX(24px);
}

@supports (animation-timeline: view()) {
  .ts05-row--l .ts05-card {
    animation: ts05-in-l 2s cubic-bezier(0.2, 0.8, 0.2, 1) both;
    animation-timeline: view();
    animation-range: entry 0% cover 60%;
  }
  .ts05-row--r .ts05-card {
    animation: ts05-in-r 2s cubic-bezier(0.2, 0.8, 0.2, 1) both;
    animation-timeline: view();
    animation-range: entry 0% cover 60%;
  }
}
@supports not (animation-timeline: view()) {
  .ts05-card {
    opacity: 1;
    transform: none;
  }
}
@keyframes ts05-in-l {
  from {
    opacity: 0;
    transform: translateX(-24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}
@keyframes ts05-in-r {
  from {
    opacity: 0;
    transform: translateX(24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}
.ts05-timeline.is-demo .ts05-row--l .ts05-card {
  animation: ts05-in-l 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.ts05-timeline.is-demo .ts05-row--r .ts05-card {
  animation: ts05-in-r 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
  animation-delay: 0.18s;
}

.ts05-timeline.is-demo .ts05-row:nth-child(3) .ts05-card {
  animation-delay: 0.36s;
}

@media (prefers-reduced-motion: reduce) {
  .ts05-card, .ts05-timeline.is-demo .ts05-card {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

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

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

export interface AlternatingCardSlideProps {
  duration?: string;
  easing?: string;
  color?: string;
  dates?: string[];
}

export default function AlternatingCardSlide({
  duration = "2s",
  easing = "cubic-bezier(.2, .8, .2, 1)",
  color = "#0a4fe8",
  dates = ["2024.01", "2024.06", "2024.12"],
}: AlternatingCardSlideProps) {
  const style: Vars = { "--duration": duration, "--easing": easing, "--color": color };
  return (
    <div className={styles.timeline} style={style}>
      {dates.map((d, i) => (
        <div key={d} className={`${styles.row} ${i % 2 === 0 ? styles.rowL : styles.rowR}`}>
          <div className={styles.card} style={{ animationDelay: `${i * 180}ms` }}>{d}</div>
        </div>
      ))}
    </div>
  );
}