04길게 누르면 나타나는 지연 반응

<main class="stage">
  <div class="card is-demo" tabindex="0">더보기</div>
</main>

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

$duration: $dur-quick;                            // 문턱을 넘은 뒤 반응이 실제로 펼쳐지는 시간
$hold: $dur-enter;                                // 반응이 시작되기까지 참는 시간 (누르는 순간엔 아무 일도 없다)
$easing: $ease-pop;
$color: $subject-blue;

@include stage($stage-paper);
.stage { padding: clamp(8px, 4vw, 24px); }

.card {
  position: relative;
  width: min(180px, 60vw);
  border-radius: $r-card;
  background: $subject-cream;
  border: 2px solid rgba($stage-ink, .12);
  padding: 22px 16px;
  text-align: center;
  font-weight: 600; font-size: 15px; line-height: 1.4; font-family: inherit;
  color: $stage-ink;
  cursor: pointer;
  touch-action: none;                             // 누르는 동안 스크롤 제스처와 겹치지 않게
  transform: scale(1);
  box-shadow: none;
  // transition-delay 가 곧 "길게 눌러야만" 반응하는 문턱이다. 진행바를 채우지 않는다.
  transition: transform $duration $easing $hold,
              box-shadow $duration $easing $hold,
              border-color $duration $easing $hold;

  // 규칙8 한 겹: 문턱을 넘어 반응이 펼쳐지는 순간 카드 바깥으로 두 겹 링이 불규칙하게 번지다 감쇠
  &::after {
    content: "";
    position: absolute;
    inset: -2px;
    border-radius: inherit;
    box-shadow: 0 0 0 0 rgba($color, .45), 0 0 0 0 rgba($color, .26);
    opacity: 0;
    pointer-events: none;
  }
}

.card:active {
  transform: scale(1.06);
  box-shadow: $shadow-raised;
  border-color: $color;
}
.card:active::after {
  animation: ripple-wave $dur-enter $easing $hold;
}

.card:focus-visible {
  outline: 3px solid $color;
  outline-offset: 3px;
}

.card.is-demo {
  animation: long-press-loop $dur-loop $easing infinite;
}
.card.is-demo::after {
  animation: ripple-loop $dur-loop $easing infinite;
}

@keyframes long-press-loop {
  0%, 30%  { transform: scale(1);     box-shadow: none;             border-color: rgba($stage-ink, .12); }
  70%, 85% { transform: scale(1.06);  box-shadow: $shadow-raised;   border-color: $color; }
  100%     { transform: scale(1);     box-shadow: none;             border-color: rgba($stage-ink, .12); }
}

@keyframes ripple-wave {
  0%   { box-shadow: 0 0 0 0 rgba($color, .45), 0 0 0 0 rgba($color, .26); opacity: 1; }
  38%  { box-shadow: 0 0 0 10px rgba($color, .2), 0 0 0 4px rgba($color, .24); opacity: .72; }
  66%  { box-shadow: 0 0 0 17px rgba($color, .09), 0 0 0 11px rgba($color, .14); opacity: .34; }
  100% { box-shadow: 0 0 0 24px rgba($color, 0), 0 0 0 20px rgba($color, 0); opacity: 0; }
}

@keyframes ripple-loop {
  0%, 30%  { box-shadow: 0 0 0 0 rgba($color, .45), 0 0 0 0 rgba($color, .26); opacity: 1; }
  50%      { box-shadow: 0 0 0 10px rgba($color, .2), 0 0 0 4px rgba($color, .24); opacity: .72; }
  67%      { box-shadow: 0 0 0 17px rgba($color, .09), 0 0 0 11px rgba($color, .14); opacity: .34; }
  85%, 100% { box-shadow: 0 0 0 24px rgba($color, 0), 0 0 0 20px rgba($color, 0); opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .card { transition: none; }
  .card::after { animation: none !important; opacity: 0; }
  .card.is-demo { animation: none; }
}

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

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

.stage {
  padding: clamp(8px, 4vw, 24px);
}

.card {
  position: relative;
  width: min(180px, 60vw);
  border-radius: 16px;
  background: #fff7e6;
  border: 2px solid rgba(23, 20, 26, 0.12);
  padding: 22px 16px;
  text-align: center;
  font-weight: 600;
  font-size: 15px;
  line-height: 1.4;
  font-family: inherit;
  color: #17141a;
  cursor: pointer;
  touch-action: none;
  transform: scale(1);
  box-shadow: none;
  transition: transform 220ms cubic-bezier(0.2, 1.4, 0.4, 1) 600ms, box-shadow 220ms cubic-bezier(0.2, 1.4, 0.4, 1) 600ms, border-color 220ms cubic-bezier(0.2, 1.4, 0.4, 1) 600ms;
}
.card::after {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: inherit;
  box-shadow: 0 0 0 0 rgba(47, 109, 246, 0.45), 0 0 0 0 rgba(47, 109, 246, 0.26);
  opacity: 0;
  pointer-events: none;
}

.card:active {
  transform: scale(1.06);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  border-color: #2f6df6;
}

.card:active::after {
  animation: ripple-wave 600ms cubic-bezier(0.2, 1.4, 0.4, 1) 600ms;
}

.card:focus-visible {
  outline: 3px solid #2f6df6;
  outline-offset: 3px;
}

.card.is-demo {
  animation: long-press-loop 2s cubic-bezier(0.2, 1.4, 0.4, 1) infinite;
}

.card.is-demo::after {
  animation: ripple-loop 2s cubic-bezier(0.2, 1.4, 0.4, 1) infinite;
}

@keyframes long-press-loop {
  0%, 30% {
    transform: scale(1);
    box-shadow: none;
    border-color: rgba(23, 20, 26, 0.12);
  }
  70%, 85% {
    transform: scale(1.06);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
    border-color: #2f6df6;
  }
  100% {
    transform: scale(1);
    box-shadow: none;
    border-color: rgba(23, 20, 26, 0.12);
  }
}
@keyframes ripple-wave {
  0% {
    box-shadow: 0 0 0 0 rgba(47, 109, 246, 0.45), 0 0 0 0 rgba(47, 109, 246, 0.26);
    opacity: 1;
  }
  38% {
    box-shadow: 0 0 0 10px rgba(47, 109, 246, 0.2), 0 0 0 4px rgba(47, 109, 246, 0.24);
    opacity: 0.72;
  }
  66% {
    box-shadow: 0 0 0 17px rgba(47, 109, 246, 0.09), 0 0 0 11px rgba(47, 109, 246, 0.14);
    opacity: 0.34;
  }
  100% {
    box-shadow: 0 0 0 24px rgba(47, 109, 246, 0), 0 0 0 20px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@keyframes ripple-loop {
  0%, 30% {
    box-shadow: 0 0 0 0 rgba(47, 109, 246, 0.45), 0 0 0 0 rgba(47, 109, 246, 0.26);
    opacity: 1;
  }
  50% {
    box-shadow: 0 0 0 10px rgba(47, 109, 246, 0.2), 0 0 0 4px rgba(47, 109, 246, 0.24);
    opacity: 0.72;
  }
  67% {
    box-shadow: 0 0 0 17px rgba(47, 109, 246, 0.09), 0 0 0 11px rgba(47, 109, 246, 0.14);
    opacity: 0.34;
  }
  85%, 100% {
    box-shadow: 0 0 0 24px rgba(47, 109, 246, 0), 0 0 0 20px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .card {
    transition: none;
  }
  .card::after {
    animation: none !important;
    opacity: 0;
  }
  .card.is-demo {
    animation: none;
  }
}

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

export type LongPressCardProps = {
  label: string;
  /** 문턱을 넘은 뒤 반응이 펼쳐지는 시간 (기본 220ms) */
  duration?: number;
  /** 반응이 시작되기까지 참는 시간 — 누르는 순간엔 아무 일도 없다 (기본 600ms) */
  hold?: number;
  easing?: string;
  color?: string;
};

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

export default function LongPressCard({
  label,
  duration = 220,
  hold = 600,
  easing = "cubic-bezier(.2,1.4,.4,1)",
  color = "#2f6df6",
}: LongPressCardProps) {
  const vars: Vars = {
    "--duration": `${duration}ms`,
    "--hold": `${hold}ms`,
    "--easing": easing,
    "--color": color,
  };
  return (
    <div className={styles.card} style={vars} tabIndex={0}>
      {label}
    </div>
  );
}