05Search icon expands to field

<main class="stage">
  <header class="sse is-demo">
    <span class="sse__logo">GODRICH</span>
    <div class="sse__search">
      <button class="sse__toggle" type="button" aria-label="Open search" aria-expanded="false" aria-controls="sseInput">
        <svg class="sse__icon" viewBox="0 0 24 24" aria-hidden="true"><circle cx="11" cy="11" r="6.5"/><line x1="20" y1="20" x2="15.7" y2="15.7"/></svg>
      </button>
      <input id="sseInput" class="sse__input" type="search" placeholder="Search" aria-label="Search input" tabindex="-1">
    </div>
  </header>
</main>

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

// ── 변수 3개. 변형은 이것만 바꾼다 ──────────────────────────
$duration: $dur-base;                              // 폭이 넓어지는 시간
$easing: $ease-spring;
$color: $subject-blue;                              // 아이콘·포커스 색

@include stage($stage-ink);
// 320px 데모 스테이지: stage() 믹스인은 html,body 에만 overflow:hidden 을 준다 — html(root)은
// 자기 overflow:hidden 이 scrollWidth 를 뷰포트에 눌러주지만 body 는 보통 요소라 그대로 실제 콘텐츠
// 폭을 보고한다. 검색창이 156px 로 펼쳐질 때 로고+패딩과 합쳐 90vw 보다 실측 폭이 넓어 320px 에서
// 13px 넘친다 (128-05 실측, body.scrollWidth 333 vs innerWidth 320). .stage 를 직접 잘라 위로 전파를 막는다.
.stage { overflow: hidden; }

.sse {
  width: min(380px, 90vw);
  display: flex; align-items: center; justify-content: space-between;
  padding: $sp-3 $sp-4;
  border-radius: $r-control;
  background: rgba($subject-cream, .06);
}
.sse__logo { color: $subject-cream; font-weight: 800; font-size: clamp(14px, 4vw, 18px); line-height: 1; font-family: inherit; letter-spacing: .04em; }

// 작은 요소 안에서만 폭이 바뀐다 — 아이콘→입력창은 본질적으로 width 변화라 이 항목만의 예외
.sse__search {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 36px;
  width: 36px;
  border-radius: $r-pill;
  background: rgba($subject-cream, .12);
  overflow: hidden;
  transition: width $duration $easing, background $duration $easing;

  &.is-open { width: 156px; background: $subject-cream; }
}
.sse__toggle {
  flex: none;
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border: 0; padding: 0;
  background: transparent;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}
.sse__icon {
  width: 16px; height: 16px;
  fill: none;
  stroke: $subject-cream;
  stroke-width: 2;
  stroke-linecap: round;
}
.sse__search.is-open .sse__icon { stroke: $color; }
.sse__input {
  flex: 1 1 auto;
  min-width: 0;
  border: 0; outline: 0;
  background: transparent;
  padding: 0 $sp-3 0 0;
  font-weight: 500;
  font-size: clamp(12px, 3.6vw, 13px);
  line-height: 1;
  font-family: inherit;
  color: $stage-ink;
  opacity: 0;
  transition: opacity $duration $easing;
}
.sse__search.is-open .sse__input { opacity: 1; }

// ── 데모(.is-demo): 아이콘이 클릭 한 번을 시뮬레이션해 입력창으로 넓어지는 2초 루프 ──────────────
.sse.is-demo .sse__search {
  animation: sse-expand-loop $dur-loop $easing infinite;
}
.sse.is-demo .sse__icon { animation: sse-icon-loop $dur-loop $easing infinite; }
.sse.is-demo .sse__input { animation: sse-input-loop $dur-loop $easing infinite; }
@keyframes sse-expand-loop {
  0%, 20%   { width: 36px; background: rgba($subject-cream, .12); }
  45%, 70%  { width: 156px; background: $subject-cream; }
  95%, 100% { width: 36px; background: rgba($subject-cream, .12); }
}
@keyframes sse-icon-loop {
  0%, 20%   { stroke: $subject-cream; }
  45%, 70%  { stroke: $color; }
  95%, 100% { stroke: $subject-cream; }
}
@keyframes sse-input-loop {
  0%, 20%   { opacity: 0; }
  45%, 70%  { opacity: 1; }
  95%, 100% { opacity: 0; }
}

// ── 접근성 ──────────────────────────────────────────
@media (prefers-reduced-motion: reduce) {
  .sse__search, .sse__input { transition: none; }
  .sse.is-demo {
    .sse__search, .sse__icon, .sse__input { animation: none !important; }
    .sse__search { width: 36px; background: rgba($subject-cream, .12); }
    .sse__icon { stroke: $subject-cream; }
    .sse__input { 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);
}

.stage {
  overflow: hidden;
}

.sse {
  width: min(380px, 90vw);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  border-radius: 12px;
  background: rgba(255, 247, 230, 0.06);
}

.sse__logo {
  color: #fff7e6;
  font-weight: 800;
  font-size: clamp(14px, 4vw, 18px);
  line-height: 1;
  font-family: inherit;
  letter-spacing: 0.04em;
}

.sse__search {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 36px;
  width: 36px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.12);
  overflow: hidden;
  transition: width 300ms cubic-bezier(0.2, 0.8, 0.2, 1), background 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.sse__search.is-open {
  width: 156px;
  background: #fff7e6;
}

.sse__toggle {
  flex: none;
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.sse__icon {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: #fff7e6;
  stroke-width: 2;
  stroke-linecap: round;
}

.sse__search.is-open .sse__icon {
  stroke: #2f6df6;
}

.sse__input {
  flex: 1 1 auto;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  padding: 0 12px 0 0;
  font-weight: 500;
  font-size: clamp(12px, 3.6vw, 13px);
  line-height: 1;
  font-family: inherit;
  color: #17141a;
  opacity: 0;
  transition: opacity 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.sse__search.is-open .sse__input {
  opacity: 1;
}

.sse.is-demo .sse__search {
  animation: sse-expand-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.sse.is-demo .sse__icon {
  animation: sse-icon-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.sse.is-demo .sse__input {
  animation: sse-input-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes sse-expand-loop {
  0%, 20% {
    width: 36px;
    background: rgba(255, 247, 230, 0.12);
  }
  45%, 70% {
    width: 156px;
    background: #fff7e6;
  }
  95%, 100% {
    width: 36px;
    background: rgba(255, 247, 230, 0.12);
  }
}
@keyframes sse-icon-loop {
  0%, 20% {
    stroke: #fff7e6;
  }
  45%, 70% {
    stroke: #2f6df6;
  }
  95%, 100% {
    stroke: #fff7e6;
  }
}
@keyframes sse-input-loop {
  0%, 20% {
    opacity: 0;
  }
  45%, 70% {
    opacity: 1;
  }
  95%, 100% {
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sse__search, .sse__input {
    transition: none;
  }
  .sse.is-demo .sse__search, .sse.is-demo .sse__icon, .sse.is-demo .sse__input {
    animation: none !important;
  }
  .sse.is-demo .sse__search {
    width: 36px;
    background: rgba(255, 247, 230, 0.12);
  }
  .sse.is-demo .sse__icon {
    stroke: #fff7e6;
  }
  .sse.is-demo .sse__input {
    opacity: 0;
  }
}

// 실제 페이지: 아이콘을 클릭하면 입력창 폭이 넓어지며 실제 검색창이 된다 (9줄)
var box = document.querySelector('.sse__search');
var input = document.querySelector('#sseInput');
document.querySelector('.sse__toggle').addEventListener('click', function (e) {
  var open = box.classList.toggle('is-open');
  e.currentTarget.setAttribute('aria-expanded', String(open));
  document.querySelector('.sse').classList.remove('is-demo');
  input.tabIndex = open ? 0 : -1;
  if (open) input.focus({ preventScroll: true }); else input.blur();
});

import { useRef, useState } from "react";
import type { CSSProperties } from "react";
import styles from "./SearchExpandHeader.module.scss";

export type SearchExpandHeaderProps = {
  logo: string;
  placeholder: string;
  /** 폭이 넓어지는 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function SearchExpandHeader({
  logo,
  placeholder,
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: SearchExpandHeaderProps) {
  const [open, setOpen] = useState(false);
  const inputRef = useRef<HTMLInputElement>(null);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  function toggle() {
    const next = !open;
    setOpen(next);
    if (next) inputRef.current?.focus({ preventScroll: true });
    else inputRef.current?.blur();
  }

  return (
    <header className={styles.head} style={vars}>
      <span className={styles.logo}>{logo}</span>
      <div className={open ? `${styles.search} ${styles.isOpen}` : styles.search}>
        <button type="button" className={styles.toggle} aria-label="검색 열기" aria-expanded={open} onClick={toggle}>
          <svg className={styles.icon} viewBox="0 0 24 24" aria-hidden="true">
            <circle cx="11" cy="11" r="6.5" />
            <line x1="20" y1="20" x2="15.7" y2="15.7" />
          </svg>
        </button>
        <input
          ref={inputRef}
          className={styles.input}
          type="search"
          placeholder={placeholder}
          aria-label="검색어 입력"
          tabIndex={open ? 0 : -1}
        />
      </div>
    </header>
  );
}