08空のフィードが最初の活動に変わる瞬間

<main class="stage">
  <section class="ef is-demo" id="ef" aria-label="アクティビティフィード">
    <header class="ef__h">
      <h2 class="ef__t">アクティビティフィード</h2>
      <span class="ef__phase" id="ef-phase" data-t1="アクティビティ{n}件" data-t2="空です" aria-live="polite">空です</span>
    </header>
    <div class="ef__empty" id="ef-empty">
      <span class="ef__ic" aria-hidden="true"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="M216 48v112h-36.69a8 8 0 0 0-5.66 2.34l-19.31 19.32a8 8 0 0 1-5.66 2.34h-41.37a8 8 0 0 1-5.66-2.34l-19.31-19.32a8 8 0 0 0-5.66-2.34H40V48a8 8 0 0 1 8-8h160a8 8 0 0 1 8 8" opacity=".2"/><path d="M208 32H48a16 16 0 0 0-16 16v160a16 16 0 0 0 16 16h160a16 16 0 0 0 16-16V48a16 16 0 0 0-16-16m0 16v104h-28.7a15.86 15.86 0 0 0-11.3 4.69L148.69 176h-41.38L88 156.68A15.9 15.9 0 0 0 76.69 152H48V48Zm0 160H48v-40h28.69L96 187.32a15.9 15.9 0 0 0 11.31 4.68h41.38a15.86 15.86 0 0 0 11.31-4.69L179.31 168H208z"/></g></svg></span>
      <p class="ef__e1">まだ活動がありません</p>
      <p class="ef__e2">最初の活動ができるとここに積まれます</p>
    </div>
    <ul class="ef__list" role="log" aria-live="polite" id="ef-list">
      <li class="ef__row ef__row--first" data-row="first">
        <div class="ef__fold"><div class="ef__cell">
          <span class="ef__av" style="--a:#93a4ca">金</span>
          <p class="ef__line"><b>キム・ハヌル</b>がチームに参加しました</p>
          <time class="ef__tm">たった今</time>
        </div></div>
      </li>
      <li class="ef__row ef__row--second" data-row="second">
        <div class="ef__fold"><div class="ef__cell">
          <span class="ef__av" style="--a:#ff9ebb">李</span>
          <p class="ef__line"><b>イ・ジュン</b>がはじめのガイドを開きました</p>
          <time class="ef__tm">たった今</time>
        </div></div>
      </li>
    </ul>
    <div class="ef__btns">
      <button class="ef__b ef__b--main" type="button" id="ef-add">新しい活動</button>
      <button class="ef__b" type="button" id="ef-clear">空にする</button>
    </div>
  </section>
</main>
<template id="ef-tpl"><li class="ef__row is-in"><div class="ef__fold"><div class="ef__cell">
  <span class="ef__av" style="--a:#90c8b5">朴</span>
  <p class="ef__line"><b>パク・ソア</b>が最初の文書を作りました</p>
  <time class="ef__tm">たった今</time>
</div></div></li></template>

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

$duration: $dur-quick;
$easing: $ease-spring;
$color: $subject-blue;

@include stage($stage-yellow);

$ink: $subject-ink;
$line: rgba(23, 20, 26, .22);
$soft: rgba(255, 255, 255, .55);

.ef {
  box-sizing: border-box;
  width: min(304px, 92vw);
  padding: $sp-3;
  border: 1px solid $ink;
  border-radius: $r-card;
  background: $stage-yellow;
  color: $ink;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-size: 12px;
  line-height: 1.3;
}

.ef__h {
  display: flex;
  align-items: center;
  gap: $sp-2;
  margin: 0 0 $sp-2;
}
.ef__t { margin: 0; font-size: 12px; font-weight: 700; }
.ef__phase {
  margin-left: auto;
  padding: 0 $sp-2;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .1);
  color: $ink;
  font-size: 10px;
  font-weight: 700;
  line-height: 1.7;
}

// ── 빈 상태 ───────────────────────────────────────
.ef__empty {
  display: grid;
  justify-items: center;
  gap: $sp-1;
  padding: $sp-4 0 $sp-2;
}
.ef__ic {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, .6);
  color: $ink;
}
.ef__ic svg { width: 24px; height: 24px; }
.ef__e1 { margin: 0; font-size: 12px; font-weight: 700; }
.ef__e2 { margin: 0; color: rgba(23, 20, 26, .72); font-size: 10px; }

// 정적 경로 — 활동이 생기면 빈 상태는 사라진다
.ef.has-act .ef__empty { display: none; }

// ── 활동 줄 ───────────────────────────────────────
.ef__list {
  display: grid;
  gap: $sp-1;
  margin: 0;
  padding: 0;
  list-style: none;
}
.ef__fold { display: grid; grid-template-rows: 1fr; }
.ef__row--first .ef__fold,
.ef__row--second .ef__fold { grid-template-rows: 0fr; }
.ef.has-act .ef__row--first .ef__fold { grid-template-rows: 1fr; } // 첫 활동 자리
.ef__cell {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: $sp-2;
  min-height: 0;
  overflow: hidden;
  padding: $sp-1 $sp-2;
  border-radius: $r-sm;
  background: #ffffff;
  color: $ink;
}
.ef__av {
  display: inline-grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--a);
  color: $ink;
  font-size: 11px;
  font-weight: 700;
}
.ef__line { margin: 0; }
.ef__line b { font-weight: 700; }
.ef__tm { color: rgba(23, 20, 26, .72); font-size: 10px; }

// 사람이 눌러 넣은 줄: 아래에서 떠오른다 (is-in 동안만)
.ef__row.is-in .ef__cell { animation: ef-rise $dur-base $ease-pop both; }
@keyframes ef-rise {
  from { transform: translateY(8px); }
  to { transform: translateY(0); }
}

.ef__btns {
  display: flex;
  gap: $sp-1;
  margin: $sp-2 0 0;
}
.ef__b {
  padding: $sp-1 $sp-3;
  border: 1px solid $ink;
  border-radius: $r-pill;
  background: transparent;
  color: $ink;
  font-family: inherit;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.6;
  cursor: pointer;
}
.ef__b:focus-visible { outline: 2px solid $color; outline-offset: 2px; }
.ef__b:active { transform: scale(.94); }
.ef__b--main { background: $ink; color: $stage-yellow; }

// ── 격자 미리보기 전용 2초 루프 ─────────────────────
// 빈 상태 → 첫 활동: 상태 교체는 steps 컷, 등장은 fold + translateY
@keyframes ef-empty-out {
  0%, 17% { visibility: visible; }
  18%, 86% { visibility: hidden; }
  87%, 100% { visibility: visible; }
}
@keyframes ef-first-in {
  0%, 17% { grid-template-rows: 0fr; }
  18% { grid-template-rows: 1fr; }
  18.1%, 86% { grid-template-rows: 1fr; }
  87%, 100% { grid-template-rows: 0fr; }
}
@keyframes ef-first-rise {
  0%, 18% { transform: translateY(8px); }
  25%, 86% { transform: translateY(0); }
  87%, 100% { transform: translateY(8px); }
}
@keyframes ef-av-pop {
  0%, 18% { transform: scale(.4); }
  24%, 86% { transform: scale(1); }
  87%, 100% { transform: scale(.4); }
}
@keyframes ef-second-in {
  0%, 54% { grid-template-rows: 0fr; }
  55% { grid-template-rows: 1fr; }
  55.1%, 86% { grid-template-rows: 1fr; }
  87%, 100% { grid-template-rows: 0fr; }
}
@keyframes ef-second-rise {
  0%, 55% { transform: translateY(8px); }
  62%, 86% { transform: translateY(0); }
  87%, 100% { transform: translateY(8px); }
}
@keyframes ef-ic-bob {
  0%, 17% { transform: translateY(0); }
  6% { transform: translateY(-3px); }
  12% { transform: translateY(0); }
  18%, 100% { transform: translateY(0); }
}
@keyframes ef-add-pop {
  0%, 17% { transform: translateY(0); }
  20% { transform: scale(.92); }
  24%, 86% { transform: scale(1); }
  87%, 100% { transform: scale(1); }
}
@keyframes ef-phase-cut {
  0%, 17% { transform: scale(1); }
  18%, 86% { transform: scale(1.08); }
  87%, 100% { transform: scale(1); }
}

.ef.is-demo {
  .ef__empty {
    animation-name: ef-empty-out, ef-ic-bob;
    animation-duration: $dur-loop, $dur-loop;
    animation-timing-function: steps(1, end), $easing;
    animation-iteration-count: infinite, infinite;
  }
  .ef__row--first .ef__fold {
    animation-name: ef-first-in;
    animation-duration: $dur-loop;
    animation-timing-function: steps(1, end);
    animation-iteration-count: infinite;
  }
  .ef__row--first .ef__cell {
    animation-name: ef-first-rise;
    animation-duration: $dur-loop;
    animation-timing-function: $easing;
    animation-iteration-count: infinite;
  }
  .ef__row--first .ef__av {
    animation-name: ef-av-pop;
    animation-duration: $dur-loop;
    animation-timing-function: $easing;
    animation-iteration-count: infinite;
  }
  .ef__row--second .ef__fold {
    animation-name: ef-second-in;
    animation-duration: $dur-loop;
    animation-timing-function: steps(1, end);
    animation-iteration-count: infinite;
  }
  .ef__row--second .ef__cell {
    animation-name: ef-second-rise;
    animation-duration: $dur-loop;
    animation-timing-function: $easing;
    animation-iteration-count: infinite;
  }
  .ef__b--main {
    animation-name: ef-add-pop;
    animation-duration: $dur-loop;
    animation-timing-function: $easing;
    animation-iteration-count: infinite;
  }
  .ef__phase {
    animation-name: ef-phase-cut;
    animation-duration: $dur-loop;
    animation-timing-function: steps(1, end);
    animation-iteration-count: infinite;
  }
}

@media (max-width: 340px) {
  .ef { padding: $sp-2; font-size: 11px; }
  .ef__h { margin-bottom: $sp-1; }
  .ef__empty { padding: $sp-3 0 $sp-1; }
  .ef__ic { width: 36px; height: 36px; }
  .ef__ic svg { width: 20px; height: 20px; }
  .ef__cell { padding: 0 $sp-2; }
  .ef__b { padding: 0 $sp-3; font-size: 11px; }
}

@media (prefers-reduced-motion: reduce) {
  .ef__row.is-in .ef__cell { animation: none !important; }
  .ef__b:active { transform: none; }
  .ef.is-demo .ef__empty,
  .ef.is-demo .ef__row .ef__fold,
  .ef.is-demo .ef__row .ef__cell,
  .ef.is-demo .ef__av,
  .ef.is-demo .ef__b--main,
  .ef.is-demo .ef__phase { animation: none !important; transform: none !important; }
  // 움직임만 끄고 결과 상태는 남긴다 — 첫 활동이 들어온 뒤의 모습
  .ef.is-demo .ef__empty { visibility: hidden !important; }
  .ef.is-demo .ef__row--first .ef__fold,
  .ef.is-demo .ef__row--second .ef__fold { grid-template-rows: 1fr !important; }
  .ef.is-demo .ef__row .ef__av { transform: scale(1) !important; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.ef {
  box-sizing: border-box;
  width: min(304px, 92vw);
  padding: 12px;
  border: 1px solid #17141a;
  border-radius: 16px;
  background: #ffd23f;
  color: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-size: 12px;
  line-height: 1.3;
}

.ef__h {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 8px;
}

.ef__t {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
}

.ef__phase {
  margin-left: auto;
  padding: 0 8px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.1);
  color: #17141a;
  font-size: 10px;
  font-weight: 700;
  line-height: 1.7;
}

.ef__empty {
  display: grid;
  justify-items: center;
  gap: 4px;
  padding: 16px 0 8px;
}

.ef__ic {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.6);
  color: #17141a;
}

.ef__ic svg {
  width: 24px;
  height: 24px;
}

.ef__e1 {
  margin: 0;
  font-size: 12px;
  font-weight: 700;
}

.ef__e2 {
  margin: 0;
  color: rgba(23, 20, 26, 0.72);
  font-size: 10px;
}

.ef.has-act .ef__empty {
  display: none;
}

.ef__list {
  display: grid;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.ef__fold {
  display: grid;
  grid-template-rows: 1fr;
}

.ef__row--first .ef__fold,
.ef__row--second .ef__fold {
  grid-template-rows: 0fr;
}

.ef.has-act .ef__row--first .ef__fold {
  grid-template-rows: 1fr;
}

.ef__cell {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 8px;
  min-height: 0;
  overflow: hidden;
  padding: 4px 8px;
  border-radius: 8px;
  background: #ffffff;
  color: #17141a;
}

.ef__av {
  display: inline-grid;
  place-items: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--a);
  color: #17141a;
  font-size: 11px;
  font-weight: 700;
}

.ef__line {
  margin: 0;
}

.ef__line b {
  font-weight: 700;
}

.ef__tm {
  color: rgba(23, 20, 26, 0.72);
  font-size: 10px;
}

.ef__row.is-in .ef__cell {
  animation: ef-rise 300ms cubic-bezier(0.2, 1.4, 0.4, 1) both;
}

@keyframes ef-rise {
  from {
    transform: translateY(8px);
  }
  to {
    transform: translateY(0);
  }
}
.ef__btns {
  display: flex;
  gap: 4px;
  margin: 8px 0 0;
}

.ef__b {
  padding: 4px 12px;
  border: 1px solid #17141a;
  border-radius: 999px;
  background: transparent;
  color: #17141a;
  font-family: inherit;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.6;
  cursor: pointer;
}

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

.ef__b:active {
  transform: scale(0.94);
}

.ef__b--main {
  background: #17141a;
  color: #ffd23f;
}

@keyframes ef-empty-out {
  0%, 17% {
    visibility: visible;
  }
  18%, 86% {
    visibility: hidden;
  }
  87%, 100% {
    visibility: visible;
  }
}
@keyframes ef-first-in {
  0%, 17% {
    grid-template-rows: 0fr;
  }
  18% {
    grid-template-rows: 1fr;
  }
  18.1%, 86% {
    grid-template-rows: 1fr;
  }
  87%, 100% {
    grid-template-rows: 0fr;
  }
}
@keyframes ef-first-rise {
  0%, 18% {
    transform: translateY(8px);
  }
  25%, 86% {
    transform: translateY(0);
  }
  87%, 100% {
    transform: translateY(8px);
  }
}
@keyframes ef-av-pop {
  0%, 18% {
    transform: scale(0.4);
  }
  24%, 86% {
    transform: scale(1);
  }
  87%, 100% {
    transform: scale(0.4);
  }
}
@keyframes ef-second-in {
  0%, 54% {
    grid-template-rows: 0fr;
  }
  55% {
    grid-template-rows: 1fr;
  }
  55.1%, 86% {
    grid-template-rows: 1fr;
  }
  87%, 100% {
    grid-template-rows: 0fr;
  }
}
@keyframes ef-second-rise {
  0%, 55% {
    transform: translateY(8px);
  }
  62%, 86% {
    transform: translateY(0);
  }
  87%, 100% {
    transform: translateY(8px);
  }
}
@keyframes ef-ic-bob {
  0%, 17% {
    transform: translateY(0);
  }
  6% {
    transform: translateY(-3px);
  }
  12% {
    transform: translateY(0);
  }
  18%, 100% {
    transform: translateY(0);
  }
}
@keyframes ef-add-pop {
  0%, 17% {
    transform: translateY(0);
  }
  20% {
    transform: scale(0.92);
  }
  24%, 86% {
    transform: scale(1);
  }
  87%, 100% {
    transform: scale(1);
  }
}
@keyframes ef-phase-cut {
  0%, 17% {
    transform: scale(1);
  }
  18%, 86% {
    transform: scale(1.08);
  }
  87%, 100% {
    transform: scale(1);
  }
}
.ef.is-demo .ef__empty {
  animation-name: ef-empty-out, ef-ic-bob;
  animation-duration: 2s, 2s;
  animation-timing-function: steps(1, end), cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite, infinite;
}
.ef.is-demo .ef__row--first .ef__fold {
  animation-name: ef-first-in;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__row--first .ef__cell {
  animation-name: ef-first-rise;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__row--first .ef__av {
  animation-name: ef-av-pop;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__row--second .ef__fold {
  animation-name: ef-second-in;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__row--second .ef__cell {
  animation-name: ef-second-rise;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__b--main {
  animation-name: ef-add-pop;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}
.ef.is-demo .ef__phase {
  animation-name: ef-phase-cut;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@media (max-width: 340px) {
  .ef {
    padding: 8px;
    font-size: 11px;
  }
  .ef__h {
    margin-bottom: 4px;
  }
  .ef__empty {
    padding: 12px 0 4px;
  }
  .ef__ic {
    width: 36px;
    height: 36px;
  }
  .ef__ic svg {
    width: 20px;
    height: 20px;
  }
  .ef__cell {
    padding: 0 8px;
  }
  .ef__b {
    padding: 0 12px;
    font-size: 11px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ef__row.is-in .ef__cell {
    animation: none !important;
  }
  .ef__b:active {
    transform: none;
  }
  .ef.is-demo .ef__empty,
  .ef.is-demo .ef__row .ef__fold,
  .ef.is-demo .ef__row .ef__cell,
  .ef.is-demo .ef__av,
  .ef.is-demo .ef__b--main,
  .ef.is-demo .ef__phase {
    animation: none !important;
    transform: none !important;
  }
  .ef.is-demo .ef__empty {
    visibility: hidden !important;
  }
  .ef.is-demo .ef__row--first .ef__fold,
  .ef.is-demo .ef__row--second .ef__fold {
    grid-template-rows: 1fr !important;
  }
  .ef.is-demo .ef__row .ef__av {
    transform: scale(1) !important;
  }
}

// 실제 동작: 새 활동을 누르면 빈 상태가 물러나고 첫 활동이 자라 나타난다.
// 비우기는 반대로 — 줄을 전부 치우고 빈 상태로 돌아간다. 상태 문구는 aria-live 로 읽힌다.
var ef = document.getElementById('ef');
var efEmpty = document.getElementById('ef-empty');
var efList = document.getElementById('ef-list');
var efPhase = document.getElementById('ef-phase');
var efCount = 0; // 접힌 미리보기 줄은 세지 않는다
function efSync(on) {
  ef.classList.toggle('has-act', on);
  efPhase.textContent = on
    ? efPhase.getAttribute('data-t1').replace('{n}', efCount)
    : efPhase.getAttribute('data-t2');
}
document.getElementById('ef-add').addEventListener('click', function () {
  ef.classList.remove('is-demo');
  var row = document.getElementById('ef-tpl').content.firstElementChild.cloneNode(true);
  efList.insertBefore(row, efList.firstChild);
  efCount++;
  efSync(true);
});
document.getElementById('ef-clear').addEventListener('click', function () {
  ef.classList.remove('is-demo');
  efList.innerHTML = '';
  efCount = 0;
  efSync(false);
});
efSync(false);

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

export type EmptyFirstActivityProps = {
  groupLabel?: string;
  heading?: string;
  emptyTitle?: string;
  emptySub?: string;
  emptyPhase?: string;
  countPhase?: (n: number) => string;
  addLabel?: string;
  clearLabel?: string;
  nowLabel?: string;
  demo?: boolean;
  duration?: number;
  easing?: string;
  color?: string;
};

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

type Item = { key: number; name: string; initial: string; av: string; text: string };

const NEXT: Item[] = [
  { key: 0, name: "Park Seo-a", initial: "P", av: "#4cd4a6", text: " created the first doc" },
];

function TrayIcon() {
  return (
    <svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor">
      <g>
        <path d="M216 48v112h-36.69a8 8 0 0 0-5.66 2.34l-19.31 19.32a8 8 0 0 1-5.66 2.34h-41.37a8 8 0 0 1-5.66-2.34l-19.31-19.32a8 8 0 0 0-5.66-2.34H40V48a8 8 0 0 1 8-8h160a8 8 0 0 1 8 8" opacity=".2" />
        <path d="M208 32H48a16 16 0 0 0-16 16v160a16 16 0 0 0 16 16h160a16 16 0 0 0 16-16V48a16 16 0 0 0-16-16m0 16v104h-28.7a15.86 15.86 0 0 0-11.3 4.69L148.69 176h-41.38L88 156.68A15.9 15.9 0 0 0 76.69 152H48V48Zm0 160H48v-40h28.69L96 187.32a15.9 15.9 0 0 0 11.31 4.68h41.38a15.86 15.86 0 0 0 11.31-4.69L179.31 168H208z" />
      </g>
    </svg>
  );
}

export default function EmptyFirstActivity({
  groupLabel = "Activity feed",
  heading = "Activity feed",
  emptyTitle = "No activity yet",
  emptySub = "The first activity will stack up here",
  emptyPhase = "Empty",
  countPhase = (n) => `${n} activities`,
  addLabel = "New activity",
  clearLabel = "Clear",
  nowLabel = "now",
  demo = true,
  duration = 220,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: EmptyFirstActivityProps) {
  const [live, setLive] = useState(demo);
  const [items, setItems] = useState<Item[]>([]);

  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  function add() {
    setLive(false);
    setItems((r) => [{ ...NEXT[0], key: Date.now() }, ...r]);
  }

  function clear() {
    setLive(false);
    setItems([]);
  }

  const has = items.length > 0;
  const cls = [styles.ef, live ? styles.isDemo : "", has ? styles.hasAct : ""].filter(Boolean).join(" ");

  return (
    <section className={cls} style={vars} aria-label={groupLabel}>
      <header className={styles.h}>
        <h2 className={styles.t}>{heading}</h2>
        <span className={styles.phase} aria-live="polite">
          {live ? (
            <>
              <i className={styles.pEmpty} aria-hidden="true">{emptyPhase}</i>
              <i className={styles.pCount} aria-hidden="true">{countPhase(2)}</i>
            </>
          ) : (
            (has ? countPhase(items.length) : emptyPhase)
          )}
        </span>
      </header>
      <div className={styles.empty}>
        <span className={styles.ic} aria-hidden="true"><TrayIcon /></span>
        <p className={styles.e1}>{emptyTitle}</p>
        <p className={styles.e2}>{emptySub}</p>
      </div>
      <ul className={styles.list} role="log" aria-live="polite">
        <li className={styles.rowFirst}>
          <div className={styles.fold}>
            <div className={styles.cell}>
              <span className={styles.av} style={{ background: color }}>K</span>
              <p className={styles.line}><b>Kim Haneul</b> joined the team</p>
              <time className={styles.tm}>{nowLabel}</time>
            </div>
          </div>
        </li>
        <li className={styles.rowSecond}>
          <div className={styles.fold}>
            <div className={styles.cell}>
              <span className={styles.av} style={{ background: "#ff9ebb" }}>L</span>
              <p className={styles.line}><b>Lee Jun</b> opened the getting-started guide</p>
              <time className={styles.tm}>{nowLabel}</time>
            </div>
          </div>
        </li>
        {items.map((it) => (
          <li key={it.key} className={styles.rowIn}>
            <div className={styles.fold}>
              <div className={styles.cell}>
                <span className={styles.av} style={{ background: it.av }}>{it.initial}</span>
                <p className={styles.line}><b>{it.name}</b>{it.text}</p>
                <time className={styles.tm}>{nowLabel}</time>
              </div>
            </div>
          </li>
        ))}
      </ul>
      <div className={styles.btns}>
        <button className={styles.bMain} type="button" onClick={add}>{addLabel}</button>
        <button className={styles.b} type="button" onClick={clear}>{clearLabel}</button>
      </div>
    </section>
  );
}