Bootstrap 5 Sign Up Form with Password Strength Meter

<section class="wdw-stage">
  <div class="container" style="max-width: 1000px">
    <div class="wdw-card overflow-hidden">
      <div class="row g-0">
        <div class="col-lg-5 wdw-aurora p-4 p-lg-5 d-none d-lg-flex flex-column justify-content-between">
          <span class="fw-bold fs-5">Northwind</span>
          <div>
            <h2 class="fw-bold display-6 mb-3" style="letter-spacing:-.02em">Start building in minutes.</h2>
            <p class="mb-0 opacity-75">Free for 14 days. No credit card required.</p>
          </div>
          <p class="small opacity-75 mb-0">Trusted by 12,000+ teams</p>
        </div>
        <div class="col-lg-7 p-4 p-md-4 p-xl-5">
          <span class="wdw-eyebrow">Get started</span>
          <h1 class="wdw-heading h2 mt-1 mb-1">Create your account</h1>
          <p class="wdw-muted mb-3">Please fill in this form to create an account.</p>
          <form id="suForm" novalidate>
            <div class="row g-3 mb-3">
              <div class="col-sm-6"><div class="form-floating"><input type="text" class="form-control" id="suFirst" placeholder="First name" required autocomplete="given-name"><label for="suFirst">First name</label><div class="invalid-feedback">Required.</div></div></div>
              <div class="col-sm-6"><div class="form-floating"><input type="text" class="form-control" id="suLast" placeholder="Last name" required autocomplete="family-name"><label for="suLast">Last name</label><div class="invalid-feedback">Required.</div></div></div>
            </div>
            <div class="form-floating mb-3"><input type="email" class="form-control" id="suEmail" placeholder="Email" required autocomplete="email"><label for="suEmail">Email</label><div class="invalid-feedback">Enter a valid email.</div></div>
            <div class="form-floating mb-1"><input type="password" class="form-control" id="suPass" placeholder="Password" required minlength="8" autocomplete="new-password"><label for="suPass">Password</label><div class="invalid-feedback">Use at least 8 characters.</div></div>
            <div class="progress mt-2 mb-1" style="height:4px" aria-hidden="true"><div class="progress-bar" id="suMeter" style="width:0"></div></div>
            <p class="small wdw-muted mb-3" id="suMeterTxt">Password strength</p>
            <div class="form-floating mb-3"><input type="password" class="form-control" id="suConf" placeholder="Confirm password" required autocomplete="new-password"><label for="suConf">Confirm password</label><div class="invalid-feedback">Passwords do not match.</div></div>
            <div class="form-check mb-3">
              <input class="form-check-input" type="checkbox" id="suTerms" required>
              <label class="form-check-label" for="suTerms">I accept the <a href="#" class="link-primary">Terms of Use</a> and <a href="#" class="link-primary">Privacy Policy</a></label>
              <div class="invalid-feedback">You must accept to continue.</div>
            </div>
            <button type="submit" class="btn btn-primary rounded-pill w-100">Create account</button>
            <div class="alert alert-success d-none mt-3 mb-0" id="suOk" role="status">Account created. Welcome aboard!</div>
          </form>
          <p class="text-center wdw-muted mt-4 mb-0">Already have an account? <a href="#" class="fw-semibold link-primary">Log in</a></p>
        </div>
      </div>
    </div>
  </div>
</section>

/* 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-aurora { min-height: 100%; }
#suMeter { transition: width .3s, background-color .3s; }

(function () {
  function initSignup() {
    var form = document.getElementById('suForm');
    if (!form) return;
    var pass = document.getElementById('suPass'), conf = document.getElementById('suConf');
    var meter = document.getElementById('suMeter'), txt = document.getElementById('suMeterTxt');
    var levels = [['Too short', 'danger', 10], ['Weak', 'danger', 30], ['Okay', 'warning', 55], ['Good', 'success', 80], ['Strong', 'success', 100]];

    pass.addEventListener('input', function () {
      var v = pass.value, s = 0;
      if (v.length >= 8) s++;
      if (/[A-Z]/.test(v) && /[a-z]/.test(v)) s++;
      if (/\d/.test(v)) s++;
      if (/[^A-Za-z0-9]/.test(v)) s++;
      var l = v ? levels[s] : null;
      meter.style.width = l ? l[2] + '%' : '0';
      meter.className = 'progress-bar' + (l ? ' bg-' + l[1] : '');
      txt.textContent = l ? 'Password strength: ' + l[0] : 'Password strength';
    });
    form.addEventListener('input', function (e) { e.target.classList.remove('is-invalid'); });
    form.addEventListener('submit', function (e) {
      e.preventDefault();
      var ok = true;
      function mark(el, bad) { el.classList.toggle('is-invalid', bad); if (bad) ok = false; }
      ['suFirst', 'suLast'].forEach(function (id) { var el = document.getElementById(id); mark(el, !el.value.trim()); });
      var em = document.getElementById('suEmail'); mark(em, !/^\S+@\S+\.\S+$/.test(em.value));
      mark(pass, pass.value.length < 8);
      mark(conf, !conf.value || conf.value !== pass.value);
      mark(document.getElementById('suTerms'), !document.getElementById('suTerms').checked);
      var bad = form.querySelector('.is-invalid');
      if (bad) { bad.focus(); return; }
      document.getElementById('suOk').classList.remove('d-none');
    });
  }
  initSignup();
})();