03리스트 → 상세 슬라이드 전환

<main class="stage">
  <div class="ltd-viewport is-demo">
    <div class="ltd-track">
      <ul class="ltd-list" aria-label="설정">
        <li>
          <button class="ltd-list__row" type="button">
            <span>알림 설정</span>
            <svg viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="m176 128l-80 80V48Z" opacity=".2"/><path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z"/></g></svg>
          </button>
        </li>
        <li>
          <button class="ltd-list__row" type="button">
            <span>개인정보 보호</span>
            <svg viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="m176 128l-80 80V48Z" opacity=".2"/><path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z"/></g></svg>
          </button>
        </li>
      </ul>
      <div class="ltd-detail">
        <button class="ltd-detail__back" type="button">
          <svg viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="M112 56v144l-72-72Z" opacity=".2"/><path d="M216 120h-96V56a8 8 0 0 0-13.66-5.66l-72 72a8 8 0 0 0 0 11.32l72 72A8 8 0 0 0 120 200v-64h96a8 8 0 0 0 0-16m-112 60.69L51.31 128L104 75.31Z"/></g></svg>
          목록
        </button>
        <h2>알림 설정</h2>
        <p>푸시·이메일·문자 알림을 항목별로 켜고 끌 수 있습니다.</p>
      </div>
    </div>
  </div>
</main>

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

$duration: $dur-base;                                  // 패널 슬라이드 시간
$easing: $ease-spring;
$color: $subject-blue;

@include stage($stage-ink);

.ltd-viewport {
  width: min(260px, 80vw);
  height: 168px;
  overflow: hidden;
  border-radius: $r-card;
  background: $stage-paper;
  position: relative;
}

.ltd-track {
  display: flex;
  width: 200%;
  height: 100%;
  transition: transform $duration $easing;
}
.ltd-viewport.is-open .ltd-track { transform: translateX(-50%); }

.ltd-list, .ltd-detail {
  width: 50%;
  flex: 0 0 auto;
  box-sizing: border-box;
  padding: $sp-4;
}

.ltd-list { list-style: none; margin: 0; display: flex; flex-direction: column; gap: $sp-2; }
.ltd-list__row {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 0;
  background: rgba(23, 20, 26, .04);
  border-radius: $r-sm;
  padding: $sp-3;
  font-size: 13px;
  color: $stage-ink;
  cursor: pointer;
  font-family: inherit;
}
.ltd-list__row:focus-visible { outline: 2px solid $color; outline-offset: 2px; }
.ltd-list__row svg { width: 14px; height: 14px; color: $color; }

.ltd-detail { display: flex; flex-direction: column; gap: $sp-2; }
.ltd-detail h2 { margin: 0; font-size: 15px; color: $stage-ink; }
.ltd-detail p { margin: 0; font-size: 12px; color: rgba(23, 20, 26, .65); }
.ltd-detail__back {
  display: inline-flex;
  align-items: center;
  gap: $sp-1;
  align-self: flex-start;
  border: 0;
  background: none;
  color: $subject-blue-deep;   // 페이퍼 패널 위 파란 글자 — $subject-blue 는 4.25:1
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
  padding: $sp-1 0;
  font-family: inherit;
}
.ltd-detail__back:focus-visible { outline: 2px solid $subject-blue-deep; outline-offset: 2px; }
.ltd-detail__back svg { width: 14px; height: 14px; }

// 데모 강제 루프 — track 을 keyframes 로 자동 왕복
.ltd-viewport.is-demo .ltd-track { animation: ltd-loop $dur-loop $easing infinite; }
@keyframes ltd-loop {
  0%, 10%   { transform: translateX(0); }
  45%, 65%  { transform: translateX(-50%); }
  95%, 100% { transform: translateX(0); }
}

@media (prefers-reduced-motion: reduce) {
  .ltd-track { transition: 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);
}

.ltd-viewport {
  width: min(260px, 80vw);
  height: 168px;
  overflow: hidden;
  border-radius: 16px;
  background: #ffffff;
  position: relative;
}

.ltd-track {
  display: flex;
  width: 200%;
  height: 100%;
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.ltd-viewport.is-open .ltd-track {
  transform: translateX(-50%);
}

.ltd-list, .ltd-detail {
  width: 50%;
  flex: 0 0 auto;
  box-sizing: border-box;
  padding: 16px;
}

.ltd-list {
  list-style: none;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ltd-list__row {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 0;
  background: rgba(23, 20, 26, 0.04);
  border-radius: 8px;
  padding: 12px;
  font-size: 13px;
  color: #17141a;
  cursor: pointer;
  font-family: inherit;
}

.ltd-list__row:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: 2px;
}

.ltd-list__row svg {
  width: 14px;
  height: 14px;
  color: #2f6df6;
}

.ltd-detail {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ltd-detail h2 {
  margin: 0;
  font-size: 15px;
  color: #17141a;
}

.ltd-detail p {
  margin: 0;
  font-size: 12px;
  color: rgba(23, 20, 26, 0.65);
}

.ltd-detail__back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  align-self: flex-start;
  border: 0;
  background: none;
  color: #0a4fe8;
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
  padding: 4px 0;
  font-family: inherit;
}

.ltd-detail__back:focus-visible {
  outline: 2px solid #0a4fe8;
  outline-offset: 2px;
}

.ltd-detail__back svg {
  width: 14px;
  height: 14px;
}

.ltd-viewport.is-demo .ltd-track {
  animation: ltd-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes ltd-loop {
  0%, 10% {
    transform: translateX(0);
  }
  45%, 65% {
    transform: translateX(-50%);
  }
  95%, 100% {
    transform: translateX(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .ltd-track {
    transition: none;
  }
}

(function () {
  var view = document.querySelector('.ltd-viewport');
  function open() { view.classList.remove('is-demo'); view.classList.add('is-open'); view.querySelector('.ltd-detail__back').focus({ preventScroll: true }); }
  function close() { view.classList.remove('is-demo'); view.classList.remove('is-open'); view.querySelector('.ltd-list__row').focus({ preventScroll: true }); }
  view.querySelectorAll('.ltd-list__row').forEach(function (row) {
    row.addEventListener('click', open);
  });
  view.querySelector('.ltd-detail__back').addEventListener('click', close);
  view.addEventListener('keydown', function (e) {
    if (e.key === 'Escape' && view.classList.contains('is-open')) close();
  });
})();

import { useRef, useState, type CSSProperties } from "react";
import styles from "./ListToDetailSlideTransition.module.scss";

export type ListRow = { title: string; heading: string; body: string };

export type ListToDetailSlideTransitionProps = {
  rows: ListRow[];
  /** 패널 슬라이드 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
  color?: string;
};

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

/** 목록 패널과 상세 패널을 나란히 두고 track 전체를 translateX 로 밀어 전환한다 */
export default function ListToDetailSlideTransition({
  rows,
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: ListToDetailSlideTransitionProps) {
  const [open, setOpen] = useState<ListRow | null>(null);
  const backRef = useRef<HTMLButtonElement>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <div
      className={styles.viewport}
      style={vars}
      onKeyDown={(e: any) => { if (e.key === "Escape" && open) setOpen(null); }}
    >
      <div className={styles.track} style={{ transform: open ? "translateX(-50%)" : undefined }}>
        <ul className={styles.list}>
          {rows.map((row) => (
            <li key={row.title}>
              <button className={styles.row} type="button" onClick={() => setOpen(row)}>
                <span>{row.title}</span>
                <svg viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="m176 128l-80 80V48Z" opacity=".2" /><path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z" /></g></svg>
              </button>
            </li>
          ))}
        </ul>
        <div className={styles.detail}>
          <button ref={backRef} className={styles.back} type="button" onClick={() => setOpen(null)}>
            <svg viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="M112 56v144l-72-72Z" opacity=".2" /><path d="M216 120h-96V56a8 8 0 0 0-13.66-5.66l-72 72a8 8 0 0 0 0 11.32l72 72A8 8 0 0 0 120 200v-64h96a8 8 0 0 0 0-16m-112 60.69L51.31 128L104 75.31Z" /></g></svg>
            목록
          </button>
          {open && <><h2>{open.heading}</h2><p>{open.body}</p></>}
        </div>
      </div>
    </div>
  );
}