09Link trong đoạn văn sáng lên khi chạm

<main class="stage">
  <p class="p">Muốn xem thêm hiệu ứng khác? <a href="#" class="p__link is-demo">Xem chi tiết</a> ở bên dưới.</p>
</main>

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

$duration: $dur-instant;                          // 배경 블록이 사라지는 시간 (0.14초)
$easing: $ease-out;
$color: $subject-blue;                            // 링크·하이라이트 색

@include stage($stage-ink);
.stage { padding: clamp(10px, 4vw, 28px); }

.p {
  max-width: 260px;
  font-weight: 500; font-size: 15px; line-height: 1.7; font-family: inherit;
  color: $subject-cream;
  margin: 0;
}
.p__link {
  position: relative;
  color: $subject-blue-light;                     // AA: 잉크 면 위 파란 링크 5.69:1 (탭 하이라이트는 $color 유지)
  text-decoration: underline;
  text-underline-offset: 3px;
  -webkit-tap-highlight-color: transparent;
  padding: 2px 3px;
  margin: -2px -3px;
  border-radius: 4px;
  background: transparent;
  transition: background $duration $easing;

  // 규칙8 한 겹: 배경 플래시와 함께 두 겹 링이 불규칙하게 번지다 감쇠
  &::after {
    content: "";
    position: absolute;
    inset: -2px;
    border-radius: inherit;
    box-shadow: inset 0 0 0 0 rgba($color, .4), inset 0 0 0 0 rgba($color, .22);
    opacity: 0;
    pointer-events: none;
  }
}
.p__link:active {
  background: rgba($color, .32);
  transition: background 0s;
}
.p__link:active::after {
  animation: ripple-wave $dur-instant $ease-out;
}
.p__link.is-demo { animation: link-flash $dur-loop cubic-bezier(0, 0, 1, 1) infinite; }
.p__link.is-demo::after { animation: ripple-loop $dur-loop cubic-bezier(0, 0, 1, 1) infinite; }

@keyframes link-flash {
  0%   { background: rgba($color, .62); }
  35%  { background: rgba($color, 0); }
  100% { background: rgba($color, 0); }
}

@keyframes ripple-wave {
  0%   { box-shadow: inset 0 0 0 0 rgba($color, .4), inset 0 0 0 0 rgba($color, .22); opacity: 1; }
  100% { box-shadow: inset 0 0 0 6px rgba($color, 0), inset 0 0 0 4px rgba($color, 0); opacity: 0; }
}

@keyframes ripple-loop {
  0%   { box-shadow: inset 0 0 0 0 rgba($color, .4), inset 0 0 0 0 rgba($color, .22); opacity: 1; }
  35%  { box-shadow: inset 0 0 0 6px rgba($color, 0), inset 0 0 0 4px rgba($color, 0); opacity: 0; }
  100% { box-shadow: inset 0 0 0 6px rgba($color, 0), inset 0 0 0 4px rgba($color, 0); opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .p__link { transition: none; }
  .p__link::after { animation: none !important; opacity: 0; }
  .p__link.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: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.stage {
  padding: clamp(10px, 4vw, 28px);
}

.p {
  max-width: 260px;
  font-weight: 500;
  font-size: 15px;
  line-height: 1.7;
  font-family: inherit;
  color: #fff7e6;
  margin: 0;
}

.p__link {
  position: relative;
  color: #5b8cf8;
  text-decoration: underline;
  text-underline-offset: 3px;
  -webkit-tap-highlight-color: transparent;
  padding: 2px 3px;
  margin: -2px -3px;
  border-radius: 4px;
  background: transparent;
  transition: background 140ms ease-out;
}
.p__link::after {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: inherit;
  box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.4), inset 0 0 0 0 rgba(47, 109, 246, 0.22);
  opacity: 0;
  pointer-events: none;
}

.p__link:active {
  background: rgba(47, 109, 246, 0.32);
  transition: background 0s;
}

.p__link:active::after {
  animation: ripple-wave 140ms ease-out;
}

.p__link.is-demo {
  animation: link-flash 2s cubic-bezier(0, 0, 1, 1) infinite;
}

.p__link.is-demo::after {
  animation: ripple-loop 2s cubic-bezier(0, 0, 1, 1) infinite;
}

@keyframes link-flash {
  0% {
    background: rgba(47, 109, 246, 0.62);
  }
  35% {
    background: rgba(47, 109, 246, 0);
  }
  100% {
    background: rgba(47, 109, 246, 0);
  }
}
@keyframes ripple-wave {
  0% {
    box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.4), inset 0 0 0 0 rgba(47, 109, 246, 0.22);
    opacity: 1;
  }
  100% {
    box-shadow: inset 0 0 0 6px rgba(47, 109, 246, 0), inset 0 0 0 4px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@keyframes ripple-loop {
  0% {
    box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.4), inset 0 0 0 0 rgba(47, 109, 246, 0.22);
    opacity: 1;
  }
  35% {
    box-shadow: inset 0 0 0 6px rgba(47, 109, 246, 0), inset 0 0 0 4px rgba(47, 109, 246, 0);
    opacity: 0;
  }
  100% {
    box-shadow: inset 0 0 0 6px rgba(47, 109, 246, 0), inset 0 0 0 4px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .p__link {
    transition: none;
  }
  .p__link::after {
    animation: none !important;
    opacity: 0;
  }
  .p__link.is-demo {
    animation: none;
  }
}

import type { CSSProperties, ReactNode } from "react";
import styles from "./TapLinkText.module.scss";

export type TapLinkTextProps = {
  before: string;
  linkText: string;
  after: string;
  href?: string;
  duration?: number;
  easing?: string;
  color?: string;
  children?: ReactNode;
};

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

export default function TapLinkText({
  before,
  linkText,
  after,
  href = "#",
  duration = 140,
  easing = "ease-out",
  color = "#5b8cf8",
}: TapLinkTextProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <p className={styles.p} style={vars}>
      {before} <a href={href} className={styles.link}>{linkText}</a>{after}
    </p>
  );
}