01カーソル点滅

<main class="stage">
  <p class="line"><span class="line__text">何かお手伝いしましょうか?</span><span class="line__caret" aria-hidden="true"></span></p>
</main>

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

$duration: $dur-base;                      // 깜빡임 한 주기
$easing: steps(2, jump-none);              // 뚝뚝 끊어 깜빡이게 (부드럽게 섞지 않는다)
$color: $subject-blue;                     // 커서 색

@include stage($stage-ink);

.line {
  display: flex;
  align-items: baseline;
  margin: 0;
  font-weight: 700; font-size: clamp(20px, 5.6vw, 34px); line-height: 1.4; font-family: inherit;
  color: $subject-cream;

  &__caret {
    display: inline-block;
    width: clamp(8px, 2.6vw, 14px);
    height: 1.3em;
    margin-left: clamp(2px, 1vw, 6px);
    background: $color;
    animation: caret-blink $duration $easing infinite;
  }
}

@keyframes caret-blink {
  from { opacity: 1; }
  to   { opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .line__caret { animation: none; opacity: 1; }
}

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);
}

.line {
  display: flex;
  align-items: baseline;
  margin: 0;
  font-weight: 700;
  font-size: clamp(20px, 5.6vw, 34px);
  line-height: 1.4;
  font-family: inherit;
  color: #fff7e6;
}
.line__caret {
  display: inline-block;
  width: clamp(8px, 2.6vw, 14px);
  height: 1.3em;
  margin-left: clamp(2px, 1vw, 6px);
  background: #2f6df6;
  animation: caret-blink 300ms steps(2, jump-none) infinite;
}

@keyframes caret-blink {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .line__caret {
    animation: none;
    opacity: 1;
  }
}

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

export type CaretBlinkProps = {
  text: string;
  /** 깜빡임 한 주기 (기본 300ms) */
  duration?: number;
  color?: string;
};

export default function CaretBlink({ text, duration = 300, color = "#2f6df6" }: CaretBlinkProps) {
  const vars = { "--duration": `${duration}ms`, "--color": color } as CSSProperties;
  return (
    <p className={styles.line} style={vars}>
      <span className={styles.text}>{text}</span>
      <span className={styles.caret} aria-hidden="true" />
    </p>
  );
}