Bootstrap 5 Navbar with Animated Hover Border

<section class="wdw-stage">
  <div class="container" style="max-width:960px">
    <div class="wdw-aurora rounded-4 overflow-hidden text-center">
      <header class="px-4 px-md-5 pt-4 pb-0 text-start d-none d-md-block"><span class="fw-bold fs-4">Studio North</span></header>
      <nav class="navbar navbar-expand-md navbar-dark py-3 px-md-3 fx-nav" aria-label="Primary">
        <div class="container-fluid px-4 flex-wrap">
          <a class="navbar-brand fw-bold d-md-none" href="#">Studio North</a>
          <button class="navbar-toggler fx-toggle" type="button" data-bs-toggle="collapse" data-bs-target="#fxMenu" aria-controls="fxMenu" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
          <div class="collapse navbar-collapse justify-content-center" id="fxMenu">
            <ul class="navbar-nav gap-md-3 align-items-center py-3 py-md-0">
              <li class="nav-item"><a class="nav-link fx-link active" aria-current="page" href="#">Home</a></li>
              <li class="nav-item"><a class="nav-link fx-link" href="#">Work</a></li>
              <li class="nav-item"><a class="nav-link fx-link" href="#">Services</a></li>
              <li class="nav-item"><a class="nav-link fx-link" href="#">About</a></li>
              <li class="nav-item"><a class="nav-link fx-link" href="#">Contact</a></li>
            </ul>
          </div>
        </div>
      </nav>
      <div class="px-4 pt-4 pb-5">
        <h1 class="display-6 fw-bold mb-2">Brand and web design for ambitious teams</h1>
        <p class="text-white-50 mb-4 mx-auto" style="max-width:34rem">We craft identities and websites that help young companies look established from day one.</p>
        <a href="#" class="btn btn-light rounded-pill px-4">Start a project</a>
      </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 */
.fx-link { position: relative; color: #fff; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; font-size: 1rem; padding: 1rem 1.6rem; min-height: 44px; display: inline-flex; align-items: center; transition: color .2s; }
.fx-link::before, .fx-link::after { content: ""; position: absolute; width: 0; height: 0; border: 0 solid #fff; transition: width .25s ease, height .25s ease .25s; }
.fx-link::before { top: 0; left: 0; transition: width .25s ease, height .25s ease .25s; }
.fx-link::after { bottom: 0; right: 0; transition: width .25s ease .5s, height .25s ease .75s; }
.fx-link:hover::before, .fx-link:focus-visible::before, .fx-link:hover::after, .fx-link:focus-visible::after { width: 100%; height: 100%; }
.fx-link:hover::before, .fx-link:focus-visible::before { border-top-width: 2px; border-left-width: 2px; }
.fx-link:hover::after, .fx-link:focus-visible::after { border-bottom-width: 2px; border-right-width: 2px; }
.fx-link::before, .fx-link::after { box-sizing: border-box; }
.fx-link.active { box-shadow: inset 0 -3px 0 #fff; }
.fx-link:hover, .fx-link:focus-visible { color: #fff; }
.fx-link:focus-visible, .fx-toggle:focus-visible { outline: 2px solid #fff; outline-offset: 3px; box-shadow: none; }
.fx-toggle { border-color: rgba(255,255,255,.4); min-height: 44px; min-width: 44px; }
@media (prefers-reduced-motion: reduce) { .fx-link::before, .fx-link::after { transition: none !important; } }

function initNavActive() {
  const links = document.querySelectorAll('.fx-link');
  if (!links.length) return;
  links.forEach((link) => link.addEventListener('click', (e) => {
    e.preventDefault();
    links.forEach((l) => { l.classList.remove('active'); l.removeAttribute('aria-current'); });
    link.classList.add('active');
    link.setAttribute('aria-current', 'page');
  }));
}
initNavActive();