09Filter tabs via :has()

<main class="stage">
  <div class="ft-frame is-demo">
    <input type="radio" name="ft-cat" id="ft-1" class="ft-radio" checked>
    <input type="radio" name="ft-cat" id="ft-2" class="ft-radio">
    <input type="radio" name="ft-cat" id="ft-3" class="ft-radio">
    <div class="ft-tabs">
      <span class="ft-indicator" aria-hidden="true"></span>
      <label class="ft-tab" for="ft-1">All</label>
      <label class="ft-tab" for="ft-2">Photo</label>
      <label class="ft-tab" for="ft-3">Video</label>
    </div>
    <div class="ft-gallery">
      <div class="ft-tile" data-cat="photo"></div>
      <div class="ft-tile" data-cat="video"></div>
      <div class="ft-tile" data-cat="photo"></div>
      <div class="ft-tile" data-cat="video"></div>
      <div class="ft-tile" data-cat="photo"></div>
      <div class="ft-tile" data-cat="video"></div>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-base;
$easing: $ease-pop;
$color: $subject-blue;

@include stage($stage-ink);

.ft-frame { width: min(260px, 78vw); }
.ft-radio { position: absolute; opacity: 0; pointer-events: none; }

.ft-tabs {
  position: relative;
  display: flex;
  gap: 0;
  width: fit-content;
  padding: $sp-1;
  margin-bottom: $sp-2;
  background: rgba(255, 255, 255, .1);
  border-radius: $r-pill;
}
// 탭은 내용 폭이 아니라 고정 64px — 인디케이터의 translateX 가 이 값의 정확한 배수가 되게 한다(BD19)
.ft-tab {
  position: relative; z-index: 1;
  flex: 0 0 64px;
  text-align: center;
  padding: $sp-2 0;
  font: 600 12px/1 -apple-system, "Segoe UI", sans-serif;
  color: $subject-cream;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}
.ft-indicator {
  position: absolute; top: $sp-1; bottom: $sp-1; left: $sp-1;
  width: 64px;
  border-radius: $r-pill;
  background: $color;
  transform: translateX(0);
  transition: transform $duration $easing;
}
#ft-1:checked ~ .ft-tabs .ft-indicator { transform: translateX(0); }
#ft-2:checked ~ .ft-tabs .ft-indicator { transform: translateX(64px); }
#ft-3:checked ~ .ft-tabs .ft-indicator { transform: translateX(128px); }

.ft-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: $sp-2;
}
.ft-tile {
  aspect-ratio: 4 / 3;
  border-radius: $r-sm;
  transition: opacity $duration $easing, transform $duration $easing;
}
.ft-tile[data-cat="photo"] { background: radial-gradient(30px circle at 35% 35%, rgba(255,255,255,.55), transparent 60%), linear-gradient(150deg, $subject-blue, $subject-ink); }
.ft-tile[data-cat="video"] { background: radial-gradient(30px circle at 60% 40%, rgba(255,255,255,.55), transparent 60%), linear-gradient(150deg, $subject-cream, $subject-blue); }

// 실사용: JS 0줄 — 숨긴 라디오와 :has() 만으로 다른 카테고리 타일이 옅어지고 줄어든다
// (.ft-frame 이 공통 조상 — 라디오와 갤러리는 형제라 :has() 로 라디오의 :checked 를 먼저 확인해야 한다)
.ft-frame:has(#ft-2:checked) .ft-tile:not([data-cat="photo"]) { opacity: .15; transform: scale(.94); pointer-events: none; }
.ft-frame:has(#ft-3:checked) .ft-tile:not([data-cat="video"]) { opacity: .15; transform: scale(.94); pointer-events: none; }

@media (prefers-reduced-motion: reduce) {
  .ft-indicator, .ft-tile { transition: 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);
}

.ft-frame {
  width: min(260px, 78vw);
}

.ft-radio {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.ft-tabs {
  position: relative;
  display: flex;
  gap: 0;
  width: fit-content;
  padding: 4px;
  margin-bottom: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 999px;
}

.ft-tab {
  position: relative;
  z-index: 1;
  flex: 0 0 64px;
  text-align: center;
  padding: 8px 0;
  font: 600 12px/1 -apple-system, "Segoe UI", sans-serif;
  color: #fff7e6;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.ft-indicator {
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: 4px;
  width: 64px;
  border-radius: 999px;
  background: #2f6df6;
  transform: translateX(0);
  transition: transform 300ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

#ft-1:checked ~ .ft-tabs .ft-indicator {
  transform: translateX(0);
}

#ft-2:checked ~ .ft-tabs .ft-indicator {
  transform: translateX(64px);
}

#ft-3:checked ~ .ft-tabs .ft-indicator {
  transform: translateX(128px);
}

.ft-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.ft-tile {
  aspect-ratio: 4/3;
  border-radius: 8px;
  transition: opacity 300ms cubic-bezier(0.2, 1.4, 0.4, 1), transform 300ms cubic-bezier(0.2, 1.4, 0.4, 1);
}

.ft-tile[data-cat=photo] {
  background: radial-gradient(30px circle at 35% 35%, rgba(255, 255, 255, 0.55), transparent 60%), linear-gradient(150deg, #2f6df6, #17141a);
}

.ft-tile[data-cat=video] {
  background: radial-gradient(30px circle at 60% 40%, rgba(255, 255, 255, 0.55), transparent 60%), linear-gradient(150deg, #fff7e6, #2f6df6);
}

.ft-frame:has(#ft-2:checked) .ft-tile:not([data-cat=photo]) {
  opacity: 0.15;
  transform: scale(0.94);
  pointer-events: none;
}

.ft-frame:has(#ft-3:checked) .ft-tile:not([data-cat=video]) {
  opacity: 0.15;
  transform: scale(0.94);
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .ft-indicator, .ft-tile {
    transition: none !important;
  }
}

var frame = document.querySelector('.ft-frame');
if (frame.classList.contains('is-demo')) {
  var radios = document.querySelectorAll('.ft-radio'), i = 0;
  var iv = setInterval(function () { i = (i + 1) % radios.length; radios[i].checked = true; }, 700);
  radios.forEach(function (r) {
    r.addEventListener('change', function () { frame.classList.remove('is-demo'); clearInterval(iv); });
  });
}

import { useState } from "react";
import styles from "./FilterTabsHas.module.scss";

export interface FilterTabsHasProps {
  duration?: string;
  easing?: string;
  color?: string;
}

const TABS = ["All", "Photo", "Video"] as const;
const TILES: { cat: "photo" | "video" }[] = [
  { cat: "photo" }, { cat: "video" }, { cat: "photo" },
  { cat: "video" }, { cat: "photo" }, { cat: "video" },
];

export default function FilterTabsHas({
  duration = "300ms",
  easing = "cubic-bezier(.2, 1.4, .4, 1)",
  color = "#2f6df6",
}: FilterTabsHasProps) {
  const [active, setActive] = useState(0);
  const filterCat = active === 1 ? "photo" : active === 2 ? "video" : null;

  return (
    <div className={styles.frame}>
      <div className={styles.tabs}>
        <span
          className={styles.indicator}
          style={{ transform: `translateX(${active * 64}px)`, transitionDuration: duration, transitionTimingFunction: easing, background: color }}
        />
        {TABS.map((label, i) => (
          <button key={label} type="button" className={styles.tab} onClick={() => setActive(i)}>{label}</button>
        ))}
      </div>
      <div className={styles.gallery}>
        {TILES.map((t, i) => {
          const dim = filterCat !== null && t.cat !== filterCat;
          return (
            <div
              key={i}
              className={`${styles.tile} ${styles["tile-" + t.cat]}`}
              style={{ opacity: dim ? 0.15 : 1, transform: dim ? "scale(.94)" : "scale(1)", transitionDuration: duration, transitionTimingFunction: easing }}
            />
          );
        })}
      </div>
    </div>
  );
}