05Glitch text

<main class="stage">
  <h1 class="glitch" data-text="System Error">
    <span class="glitch__base">System Error</span>
    <span class="glitch__r" aria-hidden="true">System Error</span>
    <span class="glitch__b" aria-hidden="true">System Error</span>
  </h1>
</main>

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

$duration: $dur-loop;                              // 스캔라인이 어긋났다 돌아오는 한 주기
$easing: steps(2, jump-none);                       // 부드럽게 잇지 않고 뚝뚝 끊겨야 글리치답다
$color: $error;                                      // 어긋나는 레이어 한쪽 색

@include stage($stage-ink);

.glitch {
  position: relative;
  margin: 0;
  font-weight: 800; font-size: clamp(26px, 8.2vw, 42px); line-height: 1.2; font-family: inherit;
  text-align: center;
}

.glitch__base, .glitch__r, .glitch__b {
  display: block;
  grid-area: 1 / 1;
}
.glitch { display: grid; }

.glitch__base {
  background: linear-gradient(90deg, $color, $subject-blue);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  animation: hue-jump $duration $easing infinite;
}

// clip-path 로 조각내 밀어내는 대신, 가로줄 mask 를 뚝뚝 끊어 옮겨 스캔라인이 깨지는 것처럼 보이게 한다
.glitch__r, .glitch__b {
  position: absolute; inset: 0;
  mix-blend-mode: screen;
  -webkit-mask-image: repeating-linear-gradient(to bottom, #000 0 3px, transparent 3px 7px);
  mask-image: repeating-linear-gradient(to bottom, #000 0 3px, transparent 3px 7px);
}
.glitch__r { color: $color;        animation: mask-jump-r $duration $easing infinite; }
.glitch__b { color: $subject-blue; animation: mask-jump-b $duration $easing infinite; }

@keyframes mask-jump-r {
  0%, 40%, 100% { -webkit-mask-position: 0 0;    mask-position: 0 0;    opacity: 0; }
  45%, 55%      { -webkit-mask-position: 0 3px;  mask-position: 0 3px;  opacity: .9; }
}
@keyframes mask-jump-b {
  0%, 60%, 100% { -webkit-mask-position: 0 0;    mask-position: 0 0;    opacity: 0; }
  65%, 75%      { -webkit-mask-position: 0 -3px; mask-position: 0 -3px; opacity: .9; }
}
@keyframes hue-jump {
  0%, 48%, 52%, 100% { filter: hue-rotate(0deg); }
  50%                { filter: hue-rotate(35deg); }
}

@media (prefers-reduced-motion: reduce) {
  .glitch__base { animation: none; }
  .glitch__r, .glitch__b { animation: none; opacity: 0; }
}

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);
}

.glitch {
  position: relative;
  margin: 0;
  font-weight: 800;
  font-size: clamp(26px, 8.2vw, 42px);
  line-height: 1.2;
  font-family: inherit;
  text-align: center;
}

.glitch__base, .glitch__r, .glitch__b {
  display: block;
  grid-area: 1/1;
}

.glitch {
  display: grid;
}

.glitch__base {
  background: linear-gradient(90deg, #c2361a, #2f6df6);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  animation: hue-jump 2s steps(2, jump-none) infinite;
}

.glitch__r, .glitch__b {
  position: absolute;
  inset: 0;
  mix-blend-mode: screen;
  -webkit-mask-image: repeating-linear-gradient(to bottom, #000 0 3px, transparent 3px 7px);
  mask-image: repeating-linear-gradient(to bottom, #000 0 3px, transparent 3px 7px);
}

.glitch__r {
  color: #c2361a;
  animation: mask-jump-r 2s steps(2, jump-none) infinite;
}

.glitch__b {
  color: #2f6df6;
  animation: mask-jump-b 2s steps(2, jump-none) infinite;
}

@keyframes mask-jump-r {
  0%, 40%, 100% {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
    opacity: 0;
  }
  45%, 55% {
    -webkit-mask-position: 0 3px;
    mask-position: 0 3px;
    opacity: 0.9;
  }
}
@keyframes mask-jump-b {
  0%, 60%, 100% {
    -webkit-mask-position: 0 0;
    mask-position: 0 0;
    opacity: 0;
  }
  65%, 75% {
    -webkit-mask-position: 0 -3px;
    mask-position: 0 -3px;
    opacity: 0.9;
  }
}
@keyframes hue-jump {
  0%, 48%, 52%, 100% {
    filter: hue-rotate(0deg);
  }
  50% {
    filter: hue-rotate(35deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .glitch__base {
    animation: none;
  }
  .glitch__r, .glitch__b {
    animation: none;
    opacity: 0;
  }
}

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

export type GlitchTextProps = {
  text: string;
  /** 스캔라인이 어긋났다 돌아오는 한 주기 (기본 2000ms) */
  duration?: number;
  easing?: string;
  /** 어긋나는 레이어 한쪽 색 */
  color?: string;
};

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

export default function GlitchText({
  text,
  duration = 2000,
  easing = "steps(2, jump-none)",
  color = "#c2361a",
}: GlitchTextProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <h1 className={styles.glitch} style={vars}>
      <span className={styles.base}>{text}</span>
      <span className={styles.r} aria-hidden="true">{text}</span>
      <span className={styles.b} aria-hidden="true">{text}</span>
    </h1>
  );
}