Bootstrap 5 Expanding Search Input on Focus

<section class="wdw-stage">
<div class="container" style="max-width:680px">
  <div class="text-center mb-4">
    <span class="wdw-eyebrow">Search</span>
    <h2 class="wdw-heading display-6 mt-1 mb-2">Find anything, fast</h2>
    <p class="wdw-muted mb-0">The field grows as you focus it and suggests matches as you type. Press <kbd>/</kbd> to jump in.</p>
  </div>
  <div class="wdw-search" id="growSearch">
    <form class="d-flex justify-content-center" role="search" id="growForm">
      <label for="growInput" class="visually-hidden">Search components</label>
      <div class="wdw-grow input-group rounded-pill" id="growField">
        <span class="input-group-text border-0 bg-transparent ps-3 pe-1"><i class="bi bi-search" aria-hidden="true"></i></span>
        <input type="search" id="growInput" class="form-control border-0 bg-transparent shadow-none px-2" placeholder="Search components" autocomplete="off" role="combobox" aria-expanded="false" aria-controls="growResults" aria-autocomplete="list">
        <span class="spinner-border spinner-border-sm text-primary align-self-center me-2 d-none" id="growSpin" aria-hidden="true"></span>
        <kbd class="align-self-center me-3 d-none d-sm-inline" id="growHint" aria-hidden="true">/</kbd>
        <button type="button" class="btn btn-sm btn-link text-body-secondary border-0 pe-3 d-none" id="growClear" aria-label="Clear search"><i class="bi bi-x-lg" aria-hidden="true"></i></button>
      </div>
    </form>
    <div class="mt-2 d-none" id="growPanel">
      <div class="list-group wdw-card-sm overflow-hidden" id="growResults" role="listbox" aria-label="Suggestions"></div>
      <div class="d-flex justify-content-between small text-body-secondary px-2 pt-2"><span id="growCount" role="status"></span><span><kbd>↑</kbd> <kbd>↓</kbd> to move · <kbd>Esc</kbd> to close</span></div>
    </div>
    <div class="d-flex flex-wrap justify-content-center gap-2 mt-4" role="group" aria-label="Suggested searches">
      <button type="button" class="wdw-chip btn btn-sm rounded-pill border bg-body-tertiary text-body-secondary" data-suggest="Pricing tables">Pricing tables</button>
      <button type="button" class="wdw-chip btn btn-sm rounded-pill border bg-body-tertiary text-body-secondary" data-suggest="Navbars">Navbars</button>
      <button type="button" class="wdw-chip btn btn-sm rounded-pill border bg-body-tertiary text-body-secondary" data-suggest="Login forms">Login forms</button>
    </div>
  </div>
</div>
</section>

@import url("https://cdnjs.cloudflare.com/ajax/libs/bootstrap-icons/1.11.3/font/bootstrap-icons.min.css");
/* Web Designer Wall library style — shared base for every Bootstrap 5 snippet.
   Indigo accent, Plus Jakarta Sans, soft cards, pill buttons. Works in light and dark. */
@import url("https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap");

:root,
[data-bs-theme="light"] {
  --wdw-font: "Plus Jakarta Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --bs-body-font-family: var(--wdw-font);
  --bs-primary: #4f46e5;
  --bs-primary-rgb: 79, 70, 229;
  --bs-primary-text-emphasis: #3730a3;
  --bs-primary-bg-subtle: #eef2ff;
  --bs-primary-border-subtle: #c7d2fe;
  --bs-link-color: #4f46e5;
  --bs-link-color-rgb: 79, 70, 229;
  --bs-link-hover-color: #4338ca;
  --bs-link-hover-color-rgb: 67, 56, 202;
  --bs-focus-ring-color: rgba(79, 70, 229, 0.25);
  --bs-border-radius: 0.75rem;
  --bs-border-radius-lg: 1rem;
  --bs-border-radius-xl: 1.25rem;
  --wdw-radius-card: 1.25rem;
  --wdw-shadow: 0 1px 2px rgba(16, 24, 40, 0.05), 0 16px 40px -16px rgba(16, 24, 40, 0.22);
  --wdw-shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.06), 0 4px 12px -4px rgba(16, 24, 40, 0.12);
  --wdw-stage: #f5f6fb;
}

[data-bs-theme="dark"] {
  --bs-primary: #818cf8;
  --bs-primary-rgb: 129, 140, 248;
  --bs-primary-text-emphasis: #c7d2fe;
  --bs-primary-bg-subtle: rgba(129, 140, 248, 0.14);
  --bs-primary-border-subtle: rgba(129, 140, 248, 0.35);
  --bs-link-color: #a5b4fc;
  --bs-link-color-rgb: 165, 180, 252;
  --bs-link-hover-color: #c7d2fe;
  --bs-link-hover-color-rgb: 199, 210, 254;
  --bs-focus-ring-color: rgba(129, 140, 248, 0.35);
  --wdw-shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 16px 40px -16px rgba(0, 0, 0, 0.7);
  --wdw-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 12px -4px rgba(0, 0, 0, 0.5);
  --wdw-stage: #0f1117;
}

body { font-family: var(--wdw-font); -webkit-font-smoothing: antialiased; }

/* Bootstrap compiles its blue into these components; point them at the accent. */
.btn-primary {
  --bs-btn-bg: var(--bs-primary); --bs-btn-border-color: var(--bs-primary);
  --bs-btn-hover-bg: #4338ca; --bs-btn-hover-border-color: #4338ca;
  --bs-btn-active-bg: #3730a3; --bs-btn-active-border-color: #3730a3;
  --bs-btn-disabled-bg: var(--bs-primary); --bs-btn-disabled-border-color: var(--bs-primary);
  --bs-btn-focus-shadow-rgb: var(--bs-primary-rgb);
}
[data-bs-theme="dark"] .btn-primary { --bs-btn-color: #0f1117; --bs-btn-hover-bg: #a5b4fc; --bs-btn-hover-border-color: #a5b4fc; --bs-btn-hover-color: #0f1117; --bs-btn-active-color: #0f1117; }
.btn-outline-primary {
  --bs-btn-color: var(--bs-primary); --bs-btn-border-color: var(--bs-primary);
  --bs-btn-hover-bg: var(--bs-primary); --bs-btn-hover-border-color: var(--bs-primary);
  --bs-btn-active-bg: var(--bs-primary); --bs-btn-active-border-color: var(--bs-primary);
  --bs-btn-focus-shadow-rgb: var(--bs-primary-rgb);
}
.btn { --bs-btn-font-weight: 600; min-height: 44px; display: inline-flex; align-items: center; justify-content: center; gap: .5rem; }
.btn-sm { min-height: 36px; }
.form-control, .form-select { min-height: 44px; border-radius: .75rem; }
.form-control:focus, .form-select:focus, .form-check-input:focus { border-color: rgba(var(--bs-primary-rgb), .6); box-shadow: 0 0 0 .25rem var(--bs-focus-ring-color); }
.form-check-input:checked { background-color: var(--bs-primary); border-color: var(--bs-primary); }
.nav-pills { --bs-nav-pills-link-active-bg: var(--bs-primary); }
.nav { --bs-nav-link-color: var(--bs-secondary-color); --bs-nav-link-hover-color: var(--bs-emphasis-color); }
.pagination { --bs-pagination-active-bg: var(--bs-primary); --bs-pagination-active-border-color: var(--bs-primary); --bs-pagination-color: var(--bs-body-color); --bs-pagination-focus-box-shadow: 0 0 0 .25rem var(--bs-focus-ring-color); }
.progress, .progress-stacked { --bs-progress-bar-bg: var(--bs-primary); }
.list-group { --bs-list-group-active-bg: var(--bs-primary); --bs-list-group-active-border-color: var(--bs-primary); }
.dropdown-menu { --bs-dropdown-link-active-bg: var(--bs-primary); border-radius: .875rem; box-shadow: var(--wdw-shadow-sm); }
.accordion { --bs-accordion-active-bg: var(--bs-primary-bg-subtle); --bs-accordion-active-color: var(--bs-primary-text-emphasis); --bs-accordion-btn-focus-box-shadow: 0 0 0 .25rem var(--bs-focus-ring-color); }
.badge { font-weight: 600; }

/* Library building blocks — use these instead of re-inventing them per snippet. */
.wdw-stage { min-height: 100vh; display: flex; align-items: center; background: var(--wdw-stage); padding-block: 3rem; }
.wdw-card { background: var(--bs-body-bg); border: 1px solid var(--bs-border-color-translucent); border-radius: var(--wdw-radius-card); box-shadow: var(--wdw-shadow); }
.wdw-card-sm { background: var(--bs-body-bg); border: 1px solid var(--bs-border-color-translucent); border-radius: 1rem; box-shadow: var(--wdw-shadow-sm); }
.wdw-aurora { position: relative; color: #fff; background: radial-gradient(60% 55% at 100% 0, #818cf8 0, transparent 70%), radial-gradient(65% 60% at 0 100%, #ec4899 0, transparent 65%), #1e1b4b; }
.wdw-eyebrow { display: inline-block; font-size: .75rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--bs-primary); }
.wdw-heading { font-weight: 800; letter-spacing: -.02em; color: var(--bs-emphasis-color); }
.wdw-muted { color: var(--bs-secondary-color); }
.wdw-icon { width: 2.75rem; height: 2.75rem; flex: none; display: inline-flex; align-items: center; justify-content: center; border-radius: .875rem; background: var(--bs-primary-bg-subtle); color: var(--bs-primary); }

/* Component */
.wdw-grow{width:13rem;max-width:100%;flex-wrap:nowrap;background:var(--bs-tertiary-bg);border:1px solid var(--bs-border-color);transition:width .35s cubic-bezier(.4,0,.2,1),border-color .2s,box-shadow .2s,background .2s}
.wdw-grow:focus-within,.wdw-grow.is-open{width:100%;background:var(--bs-body-bg);border-color:rgba(var(--bs-primary-rgb),.6);box-shadow:0 0 0 .25rem var(--bs-focus-ring-color)}
.wdw-grow .form-control{min-width:0}
.wdw-grow .input-group-text{color:var(--bs-secondary-color)}
.wdw-grow:focus-within .input-group-text,.wdw-grow.is-open .input-group-text{color:var(--bs-primary)}
.wdw-search kbd{background:var(--bs-tertiary-bg);color:var(--bs-secondary-color);border:1px solid var(--bs-border-color);font-size:.75em}
.wdw-search .list-group-item{display:flex;align-items:center;gap:.75rem;min-height:48px;border-left:0;border-right:0;text-align:start}
.wdw-search .list-group-item:first-child{border-top:0}
.wdw-search .list-group-item:last-child{border-bottom:0}
.wdw-search .list-group-item.active{background:var(--bs-primary-bg-subtle);color:var(--bs-body-color);border-color:var(--bs-border-color)}
.wdw-search mark{background:transparent;color:var(--bs-primary-text-emphasis);font-weight:700;padding:0}
.wdw-chip:hover{background:var(--bs-secondary-bg)!important;color:var(--bs-emphasis-color)!important}
@media(prefers-reduced-motion:reduce){.wdw-grow{transition:none}}

const GROW_ITEMS = [
  { t: 'Pricing tables', c: 'Marketing', i: 'tags' },
  { t: 'Pricing toggle', c: 'Marketing', i: 'toggles' },
  { t: 'Navbars', c: 'Navigation', i: 'layout-text-window' },
  { t: 'Navigation tabs', c: 'Navigation', i: 'segmented-nav' },
  { t: 'Login forms', c: 'Forms', i: 'box-arrow-in-right' },
  { t: 'Contact forms', c: 'Forms', i: 'envelope' },
  { t: 'Team cards', c: 'Content', i: 'people' },
  { t: 'Dashboard tiles', c: 'Admin', i: 'grid' }
];

function initGrowingSearch() {
  const input = document.getElementById('growInput');
  const clear = document.getElementById('growClear');
  const field = document.getElementById('growField');
  const form = document.getElementById('growForm');
  const hint = document.getElementById('growHint');
  const spin = document.getElementById('growSpin');
  const panel = document.getElementById('growPanel');
  const list = document.getElementById('growResults');
  const count = document.getElementById('growCount');
  if (!input || !clear || !field || !form || !panel || !list) return;
  let active = -1;
  let timer = 0;

  const rows = () => [...list.querySelectorAll('[role="option"]')];
  const setActive = (n) => {
    const r = rows();
    r.forEach((el, i) => { el.classList.toggle('active', i === n); el.setAttribute('aria-selected', i === n); });
    active = n;
    if (n >= 0) input.setAttribute('aria-activedescendant', r[n].id); else input.removeAttribute('aria-activedescendant');
  };
  const setOpen = (on) => {
    panel.classList.toggle('d-none', !on);
    field.classList.toggle('is-open', on);
    input.setAttribute('aria-expanded', on);
    if (!on) setActive(-1);
  };
  const highlight = (el, text, q) => {
    const k = q ? text.toLowerCase().indexOf(q.toLowerCase()) : -1;
    if (k < 0) { el.textContent = text; return; }
    const m = document.createElement('mark');
    m.textContent = text.slice(k, k + q.length);
    el.append(text.slice(0, k), m, text.slice(k + q.length));
  };
  const render = () => {
    const q = input.value.trim();
    const hits = GROW_ITEMS.filter((x) => !q || x.t.toLowerCase().includes(q.toLowerCase()) || x.c.toLowerCase().includes(q.toLowerCase()));
    list.replaceChildren();
    if (!hits.length) {
      const empty = document.createElement('div');
      empty.className = 'list-group-item text-body-secondary';
      empty.textContent = 'No results for “' + q + '”. Try “forms” or “nav”.';
      list.append(empty);
    }
    hits.forEach((x, i) => {
      const b = document.createElement('button');
      b.type = 'button';
      b.id = 'growOpt' + i;
      b.className = 'list-group-item list-group-item-action';
      b.setAttribute('role', 'option');
      b.setAttribute('aria-selected', 'false');
      b.tabIndex = -1;
      const ic = document.createElement('span');
      ic.className = 'wdw-icon';
      ic.style.cssText = 'width:2rem;height:2rem;border-radius:.6rem';
      ic.innerHTML = '<i class="bi bi-' + x.i + '" aria-hidden="true"></i>';
      const tx = document.createElement('span');
      tx.className = 'flex-grow-1';
      highlight(tx, x.t, q);
      const cat = document.createElement('span');
      cat.className = 'small text-body-secondary';
      cat.textContent = x.c;
      b.append(ic, tx, cat);
      b.addEventListener('mousedown', (e) => e.preventDefault());
      b.addEventListener('click', () => { input.value = x.t; sync(); setOpen(false); });
      list.append(b);
    });
    count.textContent = hits.length ? hits.length + (hits.length === 1 ? ' result' : ' results') : 'No results';
    setActive(-1);
  };
  const sync = () => {
    clear.classList.toggle('d-none', !input.value);
    hint.classList.toggle('d-none', !!input.value);
  };
  const search = () => {
    sync();
    setOpen(true);
    spin.classList.remove('d-none');
    clearTimeout(timer);
    timer = setTimeout(() => { spin.classList.add('d-none'); render(); }, 250);
  };

  form.addEventListener('submit', (e) => e.preventDefault());
  input.addEventListener('input', search);
  input.addEventListener('focus', () => { render(); setOpen(true); });
  input.addEventListener('keydown', (e) => {
    const r = rows();
    if (e.key === 'ArrowDown' && r.length) { e.preventDefault(); setActive((active + 1) % r.length); }
    else if (e.key === 'ArrowUp' && r.length) { e.preventDefault(); setActive((active - 1 + r.length) % r.length); }
    else if (e.key === 'Enter' && active >= 0) { e.preventDefault(); r[active].click(); }
    else if (e.key === 'Escape') { setOpen(false); }
  });
  document.addEventListener('focusin', (e) => { if (!document.getElementById('growSearch').contains(e.target)) setOpen(false); });
  document.addEventListener('click', (e) => { if (!document.getElementById('growSearch').contains(e.target)) setOpen(false); });
  clear.addEventListener('click', () => { input.value = ''; sync(); render(); input.focus(); });
  document.querySelectorAll('[data-suggest]').forEach((btn) => {
    btn.addEventListener('click', () => { input.value = btn.dataset.suggest; sync(); render(); setOpen(true); input.focus(); });
  });
  document.addEventListener('keydown', (e) => {
    const tag = document.activeElement && document.activeElement.tagName;
    if (e.key === '/' && tag !== 'INPUT' && tag !== 'TEXTAREA') { e.preventDefault(); input.focus(); }
  });

  // Start in the expanded state so the component shows what it does.
  input.value = 'nav';
  sync();
  render();
  setOpen(true);
}
initGrowingSearch();