Off-Canvas Push Menu — Free HTML CSS JS Sliding Navigation Snippet

<div class="app" id="app">
  <nav class="off-canvas" id="offCanvas" aria-hidden="true">
    <div class="oc-header">
      <span class="oc-brand">Acme Inc.</span>
      <button class="oc-close" onclick="closeMenu()" aria-label="Close menu">&times;</button>
    </div>
    <a href="#" class="oc-link">Home</a>
    <a href="#" class="oc-link">Products</a>
    <a href="#" class="oc-link">Pricing</a>
    <a href="#" class="oc-link">About</a>
    <a href="#" class="oc-link">Contact</a>
  </nav>
  <div class="page-wrap" id="pageWrap">
    <header class="topbar">
      <button class="hamburger" id="hamburger" onclick="toggleMenu()" aria-label="Open menu" aria-expanded="false" aria-controls="offCanvas">
        <span></span><span></span><span></span>
      </button>
      <span class="brand">Acme Inc.</span>
    </header>
    <main class="content">
      <h1>Welcome back</h1>
      <p>This is the page content. When the menu opens, this entire wrapper slides sideways on the X axis instead of a drawer sliding over it — a push-style off-canvas layout.</p>
      <div class="card">Some page content block</div>
      <div class="card">Another content block</div>
    </main>
  </div>
  <div class="scrim" id="scrim" onclick="closeMenu()"></div>
</div>

* { box-sizing: border-box; }
body { font-family: system-ui, sans-serif; margin: 0; }

.app {
  position: relative;
  overflow-x: hidden;
  min-height: 100vh;
  background: #0f172a;
}

.off-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 240px;
  height: 100%;
  background: #0f172a;
  color: #e2e8f0;
  padding: 20px 0;
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  z-index: 1;
}

.oc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px 16px;
  border-bottom: 1px solid #1e293b;
  margin-bottom: 12px;
}
.oc-brand { font-weight: 700; font-size: 15px; }
.oc-close {
  background: none;
  border: none;
  color: #94a3b8;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
}

.oc-link {
  display: block;
  padding: 12px 20px;
  color: #cbd5e1;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
}
.oc-link:hover { background: #1e293b; color: #fff; }

.page-wrap {
  position: relative;
  background: #f8fafc;
  min-height: 100vh;
  transition: transform 0.3s ease;
  z-index: 2;
}
.page-wrap.shifted { transform: translateX(240px); }

.topbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 20px;
  background: #fff;
  border-bottom: 1px solid #e2e8f0;
}

.hamburger {
  width: 34px;
  height: 34px;
  border: none;
  background: #f1f5f9;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.hamburger span {
  width: 16px;
  height: 2px;
  background: #1e293b;
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}
.hamburger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.hamburger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.brand { font-weight: 700; font-size: 15px; color: #1e293b; }

.content { padding: 28px 20px; max-width: 480px; }
.content h1 { font-size: 22px; color: #1e293b; margin: 0 0 10px; }
.content p { font-size: 14px; color: #64748b; line-height: 1.6; margin: 0 0 16px; }
.card {
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 12px;
  font-size: 13px;
  color: #475569;
}

.scrim {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  z-index: 1;
}
.scrim.visible { opacity: 1; pointer-events: auto; }

function toggleMenu() {
  const menu = document.getElementById('offCanvas');
  const wrap = document.getElementById('pageWrap');
  const hamburger = document.getElementById('hamburger');
  const scrim = document.getElementById('scrim');
  const isOpen = menu.classList.contains('open');
  if (isOpen) {
    closeMenu();
  } else {
    menu.classList.add('open');
    menu.style.transform = 'translateX(0)';
    wrap.classList.add('shifted');
    scrim.classList.add('visible');
    hamburger.setAttribute('aria-expanded', 'true');
    menu.setAttribute('aria-hidden', 'false');
  }
}

function closeMenu() {
  const menu = document.getElementById('offCanvas');
  const wrap = document.getElementById('pageWrap');
  const hamburger = document.getElementById('hamburger');
  const scrim = document.getElementById('scrim');
  menu.classList.remove('open');
  menu.style.transform = 'translateX(-100%)';
  wrap.classList.remove('shifted');
  scrim.classList.remove('visible');
  hamburger.setAttribute('aria-expanded', 'false');
  menu.setAttribute('aria-hidden', 'true');
}