Bootstrap 5 Mobile Navigation Drawer with Submenu

<section class="wdw-stage py-4">
  <div class="container d-flex justify-content-center">
    <div class="mn-phone wdw-card d-flex flex-column" id="mnPhone">
      <header class="mn-bar d-flex align-items-center justify-content-between px-3 flex-shrink-0" id="mnHeader">
        <button class="btn btn-link text-body-emphasis p-0 mn-burger" type="button" id="mnOpen" aria-label="Open menu" aria-expanded="false" aria-controls="mnDrawer">
          <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" aria-hidden="true"><path d="M4 7h16M4 12h16M4 17h16"/></svg>
        </button>
        <a href="#" class="text-decoration-none fw-bold text-primary">Streamly</a>
        <span class="wdw-icon" style="width:2.25rem;height:2.25rem" aria-hidden="true">
          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"><circle cx="11" cy="11" r="7"/><path d="m20 20-3.5-3.5"/></svg>
        </span>
      </header>
      <main class="mn-page flex-grow-1 overflow-hidden" id="mnPage">
        <div class="mn-hero d-flex flex-column justify-content-end p-4 text-white">
          <span class="wdw-eyebrow text-white-50">Now streaming</span>
          <h1 class="h3 fw-bold mb-1">Midnight Harbour</h1>
          <p class="small mb-3 text-white-50">Season 2 · 8 episodes</p>
          <a href="#" class="btn btn-light rounded-pill align-self-start px-4">Watch now</a>
        </div>
        <div class="p-3">
          <h2 class="h6 fw-bold mb-2">Trending now</h2>
          <div class="row g-2">
            <div class="col-4"><div class="mn-poster wdw-aurora rounded-3 p-2 d-flex align-items-end small fw-semibold">Salt & Static</div></div>
            <div class="col-4"><div class="mn-poster mn-poster-2 rounded-3 p-2 d-flex align-items-end small fw-semibold text-white">Paper Moons</div></div>
            <div class="col-4"><div class="mn-poster wdw-aurora rounded-3 p-2 d-flex align-items-end small fw-semibold">Last Signal</div></div>
          </div>
        </div>
      </main>
      <div class="mn-backdrop" id="mnBackdrop"></div>
      <nav class="offcanvas offcanvas-start mn-drawer" id="mnDrawer" tabindex="-1" aria-label="Mobile navigation" data-bs-backdrop="false" data-bs-scroll="true">
        <div class="offcanvas-header border-bottom">
          <span class="offcanvas-title fw-bold text-primary">Menu</span>
          <button class="btn-close" type="button" data-bs-dismiss="offcanvas" aria-label="Close menu"></button>
        </div>
        <div class="offcanvas-body p-2">
          <ul class="nav flex-column">
            <li class="nav-item"><a class="nav-link text-body-emphasis fw-semibold" href="#">Home</a></li>
            <li class="nav-item">
              <button class="nav-link text-body-emphasis fw-semibold w-100 d-flex justify-content-between align-items-center bg-transparent border-0" type="button" data-bs-toggle="collapse" data-bs-target="#mnBrowse" aria-expanded="true" aria-controls="mnBrowse">
                Browse
                <svg class="mn-chev" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="m6 9 6 6 6-6"/></svg>
              </button>
              <ul id="mnBrowse" class="nav flex-column collapse show ms-3 ps-2 border-start">
                <li class="nav-item"><a class="nav-link" href="#">TV shows</a></li>
                <li class="nav-item"><a class="nav-link" href="#">Movies</a></li>
                <li class="nav-item"><a class="nav-link" href="#">Documentaries</a></li>
              </ul>
            </li>
            <li class="nav-item"><a class="nav-link text-body-emphasis fw-semibold" href="#">My list</a></li>
            <li class="nav-item"><a class="nav-link text-body-emphasis fw-semibold" href="#">Downloads</a></li>
            <li class="nav-item"><a class="nav-link text-body-emphasis fw-semibold" href="#">Help centre</a></li>
          </ul>
        </div>
        <div class="p-3 border-top d-grid gap-2">
          <a href="#" class="btn btn-primary rounded-pill">Start free trial</a>
          <a href="#" class="btn btn-outline-primary rounded-pill">Sign in</a>
        </div>
      </nav>
    </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 */
/* The drawer is a real Bootstrap .offcanvas, pinned inside the phone frame (absolute instead of fixed) so the demo stays contained. */
.mn-phone { position: relative; height: min(700px, calc(100svh - 2rem)); aspect-ratio: 19 / 35; max-width: 100%; overflow: hidden; border-radius: 2rem; }
.mn-page { min-height: 0; }
.mn-bar { height: 64px; }
.mn-burger { width: 44px; height: 44px; display: inline-flex; align-items: center; justify-content: center; }
.mn-hero { height: 300px; background: linear-gradient(to top, rgba(15, 17, 23, .92), rgba(15, 17, 23, .25) 70%), url("https://images.unsplash.com/photo-1536440136628-849c177e76a1?auto=format&fit=crop&w=800&q=70") center / cover; }
.mn-poster { aspect-ratio: 2 / 3; color: #fff; }
.mn-poster-2 { background: linear-gradient(160deg, #312e81, #1e1b4b); }
.mn-backdrop { position: absolute; inset: 0; z-index: 1040; background: rgba(15, 17, 23, .5); opacity: 0; pointer-events: none; transition: opacity .3s ease; }
.mn-phone.is-open .mn-backdrop { opacity: 1; pointer-events: auto; }
.mn-drawer { position: absolute; --bs-offcanvas-width: 72%; --bs-offcanvas-zindex: 1045; }
.mn-drawer .nav-link { min-height: 48px; display: flex; align-items: center; border-radius: .75rem; text-align: left; }
.mn-drawer .nav-link:hover { background: var(--bs-tertiary-bg); }
.mn-chev { transition: transform .2s ease; }
[aria-expanded="false"] > .mn-chev { transform: rotate(-90deg); }
@media (prefers-reduced-motion: reduce) { .mn-backdrop, .mn-chev { transition: none; } }

(function () {
  function initMobileNav() {
    var phone = document.getElementById('mnPhone');
    var openBtn = document.getElementById('mnOpen');
    var drawerEl = document.getElementById('mnDrawer');
    if (!phone || !openBtn || !drawerEl) return;
    var behind = [document.getElementById('mnHeader'), document.getElementById('mnPage')];
    var drawer = bootstrap.Offcanvas.getOrCreateInstance(drawerEl);
    function setOpen(open) {
      phone.classList.toggle('is-open', open);
      openBtn.setAttribute('aria-expanded', String(open));
      behind.forEach(function (el) { if (el) el.inert = open; });
    }
    drawerEl.addEventListener('show.bs.offcanvas', function () { setOpen(true); });
    drawerEl.addEventListener('hide.bs.offcanvas', function () { setOpen(false); });
    drawerEl.addEventListener('hidden.bs.offcanvas', function () { openBtn.focus(); });
    openBtn.addEventListener('click', function () { drawer.show(); });
    document.getElementById('mnBackdrop').addEventListener('click', function () { drawer.hide(); });
    drawer.show();
  }
  initMobileNav();
})();