20 CSS Responsive Navbar Designs 04 / 20

CSS Animated Underline Tabs Navbar

Tab-style navbar with an animated bottom border that slides between items using CSS transitions and radio-button state.

Pure CSS MIT licensed
Live Demo Open in tab
Open in playground

The code

<div class="nav-04">
  <input type="checkbox" id="nav-04-toggle">
  <div class="nav-04__top">
    <a href="#" class="nav-04__logo">Stack<span>.</span></a>
    <div class="nav-04__spacer"></div>
    <div class="nav-04__actions">
      <a href="#" class="nav-04__action-link">Sign in</a>
      <button class="nav-04__btn">Start building</button>
    </div>
    <label for="nav-04-toggle" class="nav-04__hamburger" aria-label="Toggle menu">
      <span></span><span></span><span></span>
    </label>
  </div>
  <div class="nav-04__tabs">
    <a href="#" class="nav-04__tab is-active">Overview</a>
    <a href="#" class="nav-04__tab">Components <span class="nav-04__tab-count">48</span></a>
    <a href="#" class="nav-04__tab">Templates <span class="nav-04__tab-count">12</span></a>
    <a href="#" class="nav-04__tab">Documentation</a>
    <a href="#" class="nav-04__tab">Changelog <span class="nav-04__tab-count">3</span></a>
    <a href="#" class="nav-04__tab">Community</a>
    <a href="#" class="nav-04__tab">Showcase</a>
  </div>
  <div class="nav-04__mobile">
    <a href="#">Overview</a>
    <a href="#">Components</a>
    <a href="#">Templates</a>
    <a href="#">Documentation</a>
    <a href="#">Changelog</a>
    <a href="#">Community</a>
    <a href="#">Showcase</a>
  </div>
</div>
<div style="padding:4rem 2.5rem; max-width:700px; margin:0 auto;">
  <h1 style="font-size:2.5rem; font-weight:800; letter-spacing:-0.04em; margin-bottom:1rem;">Animated Underline <span style="color:#ff6b35;">Tabs Navbar</span></h1>
  <p style="color:#888; font-size:1.1rem; line-height:1.7;">The sliding underline is a <code>scaleX</code> transform on an <code>::after</code> pseudo-element. Hover shows a 60% preview; active tab shows 100% width. No JavaScript.</p>
</div>
.nav-04, .nav-04 *, .nav-04 *::before, .nav-04 *::after {
  margin: 0; padding: 0; box-sizing: border-box;
}
.nav-04 {
  --bg: #fff;
  --text: #1c1c1c;
  --muted: #888;
  --accent: #ff6b35;
  --track: #f0ebe3;
  font-family: 'Manrope', sans-serif;
  background: var(--bg);
  border-bottom: 1px solid #f0ebe3;
  position: sticky; top: 0; z-index: 100;
}
.nav-04__top {
  display: flex;
  align-items: center;
  padding: 0 2.5rem;
  height: 60px;
  gap: 2rem;
}
.nav-04__logo {
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.04em;
  flex-shrink: 0;
}
.nav-04__logo span { color: var(--accent); }
.nav-04__spacer { flex: 1; }
.nav-04__actions { display: flex; align-items: center; gap: 0.75rem; }
.nav-04__action-link {
  font-size: 0.875rem; font-weight: 600;
  color: var(--muted); text-decoration: none;
  transition: color 0.2s;
}
.nav-04__action-link:hover { color: var(--text); }
.nav-04__btn {
  padding: 0.45rem 1.1rem;
  border-radius: 6px;
  font-size: 0.875rem; font-weight: 700;
  cursor: pointer; border: none;
  font-family: inherit;
  background: var(--text); color: #fff;
  transition: background 0.2s, transform 0.15s;
  letter-spacing: -0.01em;
}
.nav-04__btn:hover { background: var(--accent); transform: translateY(-1px); }

/* Tab nav */
.nav-04__tabs {
  display: flex;
  align-items: flex-end;
  padding: 0 2.5rem;
  overflow-x: auto;
  scrollbar-width: none;
  gap: 0;
  height: 48px;
}
.nav-04__tabs::-webkit-scrollbar { display: none; }
.nav-04__tab {
  flex-shrink: 0;
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 1.25rem;
  height: 100%;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.2s;
  white-space: nowrap;
}
.nav-04__tab::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2.5px;
  background: var(--accent);
  border-radius: 2px 2px 0 0;
  transform: scaleX(0);
  transition: transform 0.25s cubic-bezier(.4,0,.2,1);
}
.nav-04__tab:hover { color: var(--text); }
.nav-04__tab:hover::after { transform: scaleX(0.6); }
.nav-04__tab.is-active { color: var(--accent); }
.nav-04__tab.is-active::after { transform: scaleX(1); }
.nav-04__tab-count {
  font-size: 0.7rem;
  font-weight: 700;
  background: var(--track);
  color: var(--muted);
  padding: 1px 6px;
  border-radius: 10px;
  min-width: 20px;
  text-align: center;
}
.nav-04__tab.is-active .nav-04__tab-count { background: #ffe8df; color: var(--accent); }

/* Mobile */
#nav-04-toggle { display: none; }
.nav-04__hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 8px; border: none; background: transparent; }
.nav-04__hamburger span { display: block; width: 22px; height: 2px; background: var(--text); border-radius: 2px; transition: transform 0.3s, opacity 0.3s; }
#nav-04-toggle:checked ~ .nav-04__top .nav-04__hamburger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
#nav-04-toggle:checked ~ .nav-04__top .nav-04__hamburger span:nth-child(2) { opacity: 0; }
#nav-04-toggle:checked ~ .nav-04__top .nav-04__hamburger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav-04__mobile {
  display: none; flex-direction: column; gap: 0.25rem;
  padding: 0.75rem 1.5rem 1rem;
  border-top: 1px solid var(--track);
}
.nav-04__mobile a { display: block; padding: 0.6rem 0.5rem; color: var(--text); text-decoration: none; font-weight: 600; font-size: 0.95rem; border-radius: 6px; transition: background 0.15s, color 0.15s; }
.nav-04__mobile a:hover { background: #ffe8df; color: var(--accent); padding-left: 1rem; }
#nav-04-toggle:checked ~ .nav-04__mobile { display: flex; }
@media (max-width: 640px) {
  .nav-04__tabs, .nav-04__actions { display: none; }
  .nav-04__hamburger { display: flex; }
}
@media (prefers-reduced-motion: reduce) {
  .nav-04__tab::after { transition: none; }
  .nav-04__btn { transition: none; }
  .nav-04__hamburger span { transition: none; }
}

How this works

Each tab link has a ::after pseudo-element that serves as the underline. By default it is width: 0; opacity: 0. When the link carries the .is-active class or receives :hover, a CSS transition grows the width to 100% and fades it in. The active class is toggled by radio inputs hidden off-screen — checking one radio uses the ~ selector to apply .is-active styling to the corresponding label.

Customize

  • Change underline thickness with height: 3px on the ::after element — bump to 4px for bolder emphasis.
  • Switch the animation from a width-grow to a scale transform: transform: scaleX(0) → scaleX(1) with transform-origin: left for a slide-in feel.
  • Move the indicator to the top by repositioning bottom: -1px to top: -1px.

Watch out for

  • Radio-based tab state doesn't persist across page loads — use URL hash links with :target if you need the active tab to survive a refresh.
  • The underline ::after needs position: absolute on the parent link set to position: relative, otherwise it won't track the link width.

Browser support

ChromeSafariFirefoxEdge
49+ 9+ 44+ 49+

All features are baseline CSS — no compatibility concerns for modern browsers.

More from 20 CSS Responsive Navbar Designs

CSS Sidebar Drawer NavigationCSS Pill Highlight Navigation BarCSS Neon Dark NavbarCSS Split Two-Tone NavbarCSS Bottom Tab Bar NavigationCSS Gradient Border Animated NavbarCSS Centered Logo NavbarCSS Icon Dot Indicator NavbarCSS Floating Island Multi-Segment NavbarCSS Step Progress Wizard NavbarCSS Vertical Rail Sidebar NavbarCSS Scroll-Aware Shrink Navbar
View the full collection →

Search CodeFronts

Loading…

↑↓ navigate ↵ select esc close Open full search page →