05Liên kết ngoài xoay 45 độ

<main class="stage">
  <a class="er-link is-demo" href="#" target="_blank" rel="noopener">
    <span class="er-link__label">example.com</span>
    <span class="er-link__arrow">
      <span class="er-link__shape"></span>
      <span class="er-link__trail" aria-hidden="true"></span>
    </span>
  </a>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;   // is-demo 강제 루프 주기. 실제 호버 전환은 아래 260ms 를 쓴다
$easing: $ease-elastic;  // 고무줄식 오버슛 — 회전이 45도를 살짝 넘었다 되돌아와 멈춘다
$color: $subject-cream;

@include stage($stage-ink);

.er-link {
  display: inline-flex;
  align-items: center;
  gap: $sp-2;
  color: $color;
  text-decoration: none;
  font: 600 16px/1 -apple-system, "Segoe UI", sans-serif;
}

.er-link__arrow {
  position: relative;
  display: inline-block;
  width: 12px;
  height: 12px;
}

.er-link__shape {
  position: absolute;
  inset: 0;
  border-top: 2px solid $color;
  border-right: 2px solid $color;
  transform: rotate(0deg) translate(0, 0);
  transition: transform 260ms $easing;
}

// 트레일 파티클 — 회전하는 화살표 뒤로 흐린 잔상 하나가 따라붙는다
.er-link__trail {
  position: absolute;
  inset: 0;
  border-top: 2px solid $color;
  border-right: 2px solid $color;
  opacity: 0;
}

// 실사용: 링크에 마우스를 올리면 화살표가 45도 더 돌아가며 밖으로 살짝 빠져나가듯 움직여 "새 창에서 열림"을 암시한다
.er-link:hover .er-link__shape { transform: rotate(45deg) translate(2px, -2px); }

@keyframes er-trail-hover {
  0%   { opacity: 0; transform: rotate(0deg) translate(0, 0) scale(.7); }
  45%  { opacity: .4; transform: rotate(30deg) translate(1px, -1px) scale(1); }
  100% { opacity: 0; transform: rotate(45deg) translate(2px, -2px) scale(.5); }
}
.er-link:hover .er-link__trail { animation: er-trail-hover 300ms $ease-out forwards; }

// 데모 루프: is-demo 는 :hover 를 흉내 낸 keyframes 로 무한 반복 (헤드리스는 :hover 를 못 건다)
@keyframes er-rotate {
  0%, 20% { transform: rotate(0deg) translate(0, 0); }
  50%, 70% { transform: rotate(45deg) translate(2px, -2px); }
  100% { transform: rotate(0deg) translate(0, 0); }
}
@keyframes er-trail-loop {
  0%, 20%  { opacity: 0; transform: rotate(0deg) translate(0, 0) scale(.7); }
  40%      { opacity: .4; transform: rotate(30deg) translate(1px, -1px) scale(1); }
  50%, 70% { opacity: 0; transform: rotate(45deg) translate(2px, -2px) scale(.5); }
  100%     { opacity: 0; transform: rotate(0deg) translate(0, 0) scale(.7); }
}
.er-link.is-demo .er-link__shape { animation: er-rotate $duration $easing infinite; }
.er-link.is-demo .er-link__trail { animation: er-trail-loop $duration $ease-out infinite; }

@media (prefers-reduced-motion: reduce) {
  .er-link:hover .er-link__shape,
  .er-link.is-demo .er-link__shape {
    animation: none !important;
    transition: none !important;
    transform: rotate(0deg) translate(0, 0) !important;
  }
  .er-link__trail,
  .er-link:hover .er-link__trail,
  .er-link.is-demo .er-link__trail {
    animation: none !important;
    opacity: 0 !important;
  }
}

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);
}

.er-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #fff7e6;
  text-decoration: none;
  font: 600 16px/1 -apple-system, "Segoe UI", sans-serif;
}

.er-link__arrow {
  position: relative;
  display: inline-block;
  width: 12px;
  height: 12px;
}

.er-link__shape {
  position: absolute;
  inset: 0;
  border-top: 2px solid #fff7e6;
  border-right: 2px solid #fff7e6;
  transform: rotate(0deg) translate(0, 0);
  transition: transform 260ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

.er-link__trail {
  position: absolute;
  inset: 0;
  border-top: 2px solid #fff7e6;
  border-right: 2px solid #fff7e6;
  opacity: 0;
}

.er-link:hover .er-link__shape {
  transform: rotate(45deg) translate(2px, -2px);
}

@keyframes er-trail-hover {
  0% {
    opacity: 0;
    transform: rotate(0deg) translate(0, 0) scale(0.7);
  }
  45% {
    opacity: 0.4;
    transform: rotate(30deg) translate(1px, -1px) scale(1);
  }
  100% {
    opacity: 0;
    transform: rotate(45deg) translate(2px, -2px) scale(0.5);
  }
}
.er-link:hover .er-link__trail {
  animation: er-trail-hover 300ms ease-out forwards;
}

@keyframes er-rotate {
  0%, 20% {
    transform: rotate(0deg) translate(0, 0);
  }
  50%, 70% {
    transform: rotate(45deg) translate(2px, -2px);
  }
  100% {
    transform: rotate(0deg) translate(0, 0);
  }
}
@keyframes er-trail-loop {
  0%, 20% {
    opacity: 0;
    transform: rotate(0deg) translate(0, 0) scale(0.7);
  }
  40% {
    opacity: 0.4;
    transform: rotate(30deg) translate(1px, -1px) scale(1);
  }
  50%, 70% {
    opacity: 0;
    transform: rotate(45deg) translate(2px, -2px) scale(0.5);
  }
  100% {
    opacity: 0;
    transform: rotate(0deg) translate(0, 0) scale(0.7);
  }
}
.er-link.is-demo .er-link__shape {
  animation: er-rotate 2s cubic-bezier(0.34, 1.56, 0.64, 1) infinite;
}

.er-link.is-demo .er-link__trail {
  animation: er-trail-loop 2s ease-out infinite;
}

@media (prefers-reduced-motion: reduce) {
  .er-link:hover .er-link__shape,
  .er-link.is-demo .er-link__shape {
    animation: none !important;
    transition: none !important;
    transform: rotate(0deg) translate(0, 0) !important;
  }
  .er-link__trail,
  .er-link:hover .er-link__trail,
  .er-link.is-demo .er-link__trail {
    animation: none !important;
    opacity: 0 !important;
  }
}

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

export interface ExternalLinkRotateProps {
  duration?: string;
  easing?: string;
  color?: string;
}

export default function ExternalLinkRotate({
  duration = "260ms",
  easing = "cubic-bezier(.34, 1.56, .64, 1)",
  color = "#fff7e6",
}: ExternalLinkRotateProps) {
  const style = { "--duration": duration, "--easing": easing, "--color": color } as CSSProperties;
  return (
    <a className={styles.link} href="#" target="_blank" rel="noopener" style={style}>
      <span>example.com</span>
      <span className={styles.arrow}>
        <span className={styles.shape} />
        <span className={styles.trail} aria-hidden="true" />
      </span>
    </a>
  );
}