17 CSS Side Menu Designs04 / 17
Expandable Icon-Only Sidebar
A persistent narrow icon rail that smoothly expands on hover to reveal full text labels and notification badges, using a CSS width transition with no toggle required.
Published
The code
<div class="sm-04">
<nav class="sm-04__rail">
<div class="sm-04__logo">Z</div>
<div class="sm-04__links">
<a class="sm-04__link sm-04__link--active" href="#">
<span class="sm-04__link-icon">⬡</span>
<span class="sm-04__link-text">Dashboard</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◈</span>
<span class="sm-04__link-text">Analytics</span>
<span class="sm-04__link-badge">5</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">▦</span>
<span class="sm-04__link-text">Projects</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◉</span>
<span class="sm-04__link-text">Messages</span>
<span class="sm-04__link-badge">9</span>
</a>
<div class="sm-04__divider"></div>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◬</span>
<span class="sm-04__link-text">Help</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">⬙</span>
<span class="sm-04__link-text">Settings</span>
</a>
</div>
<div class="sm-04__user">
<div class="sm-04__user-icon"><div class="sm-04__user-avatar">MK</div></div>
<div class="sm-04__user-info">
<div class="sm-04__user-name">M. Kowalski</div>
<div class="sm-04__user-role">Admin</div>
</div>
</div>
</nav>
<div class="sm-04__main">
<div class="sm-04__heading">Dashboard</div>
<div class="sm-04__sub">Hover the icon rail on the left to expand. Labels and badges appear without any JavaScript.</div>
<div class="sm-04__cards">
<div class="sm-04__card"><div class="sm-04__card-val">41</div><div class="sm-04__card-lbl">Active Projects</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">98%</div><div class="sm-04__card-lbl">Health Score</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">$74k</div><div class="sm-04__card-lbl">Monthly Revenue</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">1.2k</div><div class="sm-04__card-lbl">Team Members</div></div>
</div>
</div>
</div><div class="sm-04">
<nav class="sm-04__rail">
<div class="sm-04__logo">Z</div>
<div class="sm-04__links">
<a class="sm-04__link sm-04__link--active" href="#">
<span class="sm-04__link-icon">⬡</span>
<span class="sm-04__link-text">Dashboard</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◈</span>
<span class="sm-04__link-text">Analytics</span>
<span class="sm-04__link-badge">5</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">▦</span>
<span class="sm-04__link-text">Projects</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◉</span>
<span class="sm-04__link-text">Messages</span>
<span class="sm-04__link-badge">9</span>
</a>
<div class="sm-04__divider"></div>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◬</span>
<span class="sm-04__link-text">Help</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">⬙</span>
<span class="sm-04__link-text">Settings</span>
</a>
</div>
<div class="sm-04__user">
<div class="sm-04__user-icon"><div class="sm-04__user-avatar">MK</div></div>
<div class="sm-04__user-info">
<div class="sm-04__user-name">M. Kowalski</div>
<div class="sm-04__user-role">Admin</div>
</div>
</div>
</nav>
<div class="sm-04__main">
<div class="sm-04__heading">Dashboard</div>
<div class="sm-04__sub">Hover the icon rail on the left to expand. Labels and badges appear without any JavaScript.</div>
<div class="sm-04__cards">
<div class="sm-04__card"><div class="sm-04__card-val">41</div><div class="sm-04__card-lbl">Active Projects</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">98%</div><div class="sm-04__card-lbl">Health Score</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">$74k</div><div class="sm-04__card-lbl">Monthly Revenue</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">1.2k</div><div class="sm-04__card-lbl">Team Members</div></div>
</div>
</div>
</div>.sm-04,
.sm-04 *,
.sm-04 *::before,
.sm-04 *::after {
box-sizing: border-box;
margin: 0;
padding: 0;
}
.sm-04 ::selection {
background: #f59e0b;
color: #000;
}
.sm-04 {
--bg: #09090b;
--surface: #18181b;
--rail-bg: #0f0f12;
--accent: #f59e0b;
--accent2: #fbbf24;
--text: #fafafa;
--muted: #71717a;
--border: rgba(245,158,11,0.15);
--collapsed: 60px;
--expanded: 230px;
--dur: 0.35s;
--ease: cubic-bezier(0.4, 0, 0.2, 1);
font-family: 'Inter', system-ui, sans-serif;
background: var(--bg);
color: var(--text);
display: flex;
min-height: 100vh;
position: relative;
overflow: hidden;
border-radius: 12px;
}
/* Sidebar rail */
.sm-04__rail {
width: var(--collapsed);
min-height: 440px;
background: var(--rail-bg);
border-right: 1px solid var(--border);
display: flex;
flex-direction: column;
align-items: center;
padding: 16px 0;
overflow: hidden;
transition: width var(--dur) var(--ease);
flex-shrink: 0;
position: relative;
z-index: 5;
}
.sm-04__rail:hover {
width: var(--expanded);
}
/* Logo */
.sm-04__logo {
width: 36px;
height: 36px;
background: var(--accent);
border-radius: 9px;
display: flex;
align-items: center;
justify-content: center;
font-weight: 800;
font-size: 16px;
color: #000;
flex-shrink: 0;
margin-bottom: 24px;
transition: border-radius 0.3s;
}
.sm-04__rail:hover .sm-04__logo {
border-radius: 50%;
}
/* Nav items */
.sm-04__links {
width: 100%;
flex: 1;
}
.sm-04__link {
display: flex;
align-items: center;
gap: 0;
width: 100%;
padding: 0;
color: var(--muted);
cursor: pointer;
text-decoration: none;
transition: color 0.2s, background 0.2s;
position: relative;
overflow: hidden;
white-space: nowrap;
height: 48px;
}
.sm-04__link:hover,
.sm-04__link--active {
color: var(--text);
background: rgba(245,158,11,0.08);
}
.sm-04__link--active::after {
content: '';
position: absolute;
right: 0;
top: 50%;
transform: translateY(-50%);
width: 3px;
height: 60%;
background: var(--accent);
border-radius: 3px 0 0 3px;
transition: opacity 0.2s;
}
.sm-04__link-icon {
width: var(--collapsed);
height: 48px;
display: flex;
align-items: center;
justify-content: center;
font-size: 18px;
flex-shrink: 0;
transition: background 0.2s;
}
.sm-04__link:hover .sm-04__link-icon {
color: var(--accent);
}
.sm-04__link--active .sm-04__link-icon {
color: var(--accent2);
}
.sm-04__link-text {
font-size: 13px;
font-weight: 600;
opacity: 0;
transition: opacity 0.2s 0.05s;
pointer-events: none;
flex: 1;
}
.sm-04__rail:hover .sm-04__link-text {
opacity: 1;
}
.sm-04__link-badge {
margin-right: 12px;
background: rgba(245,158,11,0.2);
color: var(--accent2);
font-size: 10px;
font-weight: 700;
padding: 1px 6px;
border-radius: 99px;
opacity: 0;
transition: opacity 0.2s 0.05s;
}
.sm-04__rail:hover .sm-04__link-badge {
opacity: 1;
}
/* Divider */
.sm-04__divider {
width: 80%;
height: 1px;
background: var(--border);
margin: 8px auto;
flex-shrink: 0;
}
/* Bottom user */
.sm-04__user {
width: 100%;
display: flex;
align-items: center;
gap: 0;
overflow: hidden;
padding: 8px 0 0;
border-top: 1px solid var(--border);
}
.sm-04__user-icon {
width: var(--collapsed);
display: flex;
align-items: center;
justify-content: center;
flex-shrink: 0;
}
.sm-04__user-avatar {
width: 30px;
height: 30px;
border-radius: 50%;
background: linear-gradient(135deg, #f59e0b, #ef4444);
display: flex;
align-items: center;
justify-content: center;
font-size: 11px;
font-weight: 700;
color: #000;
}
.sm-04__user-info {
opacity: 0;
transition: opacity 0.2s 0.05s;
white-space: nowrap;
}
.sm-04__rail:hover .sm-04__user-info {
opacity: 1;
}
.sm-04__user-name {
font-size: 12px;
font-weight: 600;
}
.sm-04__user-role {
font-size: 10px;
color: var(--muted);
}
/* Main */
.sm-04__main {
flex: 1;
padding: 24px;
min-width: 0;
}
.sm-04__heading {
font-size: 20px;
font-weight: 700;
margin-bottom: 8px;
}
.sm-04__sub {
font-size: 13px;
color: var(--muted);
line-height: 1.6;
margin-bottom: 22px;
}
.sm-04__cards {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 10px;
}
.sm-04__card {
background: var(--surface);
border: 1px solid var(--border);
border-radius: 10px;
padding: 14px;
}
.sm-04__card-val {
font-size: 20px;
font-weight: 700;
color: var(--accent2);
}
.sm-04__card-lbl {
font-size: 11px;
color: var(--muted);
margin-top: 4px;
}
@media (prefers-reduced-motion: reduce) {
.sm-04__rail,
.sm-04__link-text,
.sm-04__link-badge,
.sm-04__user-info {
transition: none;
}
}.sm-04,
.sm-04 *,
.sm-04 *::before,
.sm-04 *::after {
box-sizing: border-box;
margin: 0;
padding: 0;
}
.sm-04 ::selection {
background: #f59e0b;
color: #000;
}
.sm-04 {
--bg: #09090b;
--surface: #18181b;
--rail-bg: #0f0f12;
--accent: #f59e0b;
--accent2: #fbbf24;
--text: #fafafa;
--muted: #71717a;
--border: rgba(245,158,11,0.15);
--collapsed: 60px;
--expanded: 230px;
--dur: 0.35s;
--ease: cubic-bezier(0.4, 0, 0.2, 1);
font-family: 'Inter', system-ui, sans-serif;
background: var(--bg);
color: var(--text);
display: flex;
min-height: 100vh;
position: relative;
overflow: hidden;
border-radius: 12px;
}
/* Sidebar rail */
.sm-04__rail {
width: var(--collapsed);
min-height: 440px;
background: var(--rail-bg);
border-right: 1px solid var(--border);
display: flex;
flex-direction: column;
align-items: center;
padding: 16px 0;
overflow: hidden;
transition: width var(--dur) var(--ease);
flex-shrink: 0;
position: relative;
z-index: 5;
}
.sm-04__rail:hover {
width: var(--expanded);
}
/* Logo */
.sm-04__logo {
width: 36px;
height: 36px;
background: var(--accent);
border-radius: 9px;
display: flex;
align-items: center;
justify-content: center;
font-weight: 800;
font-size: 16px;
color: #000;
flex-shrink: 0;
margin-bottom: 24px;
transition: border-radius 0.3s;
}
.sm-04__rail:hover .sm-04__logo {
border-radius: 50%;
}
/* Nav items */
.sm-04__links {
width: 100%;
flex: 1;
}
.sm-04__link {
display: flex;
align-items: center;
gap: 0;
width: 100%;
padding: 0;
color: var(--muted);
cursor: pointer;
text-decoration: none;
transition: color 0.2s, background 0.2s;
position: relative;
overflow: hidden;
white-space: nowrap;
height: 48px;
}
.sm-04__link:hover,
.sm-04__link--active {
color: var(--text);
background: rgba(245,158,11,0.08);
}
.sm-04__link--active::after {
content: '';
position: absolute;
right: 0;
top: 50%;
transform: translateY(-50%);
width: 3px;
height: 60%;
background: var(--accent);
border-radius: 3px 0 0 3px;
transition: opacity 0.2s;
}
.sm-04__link-icon {
width: var(--collapsed);
height: 48px;
display: flex;
align-items: center;
justify-content: center;
font-size: 18px;
flex-shrink: 0;
transition: background 0.2s;
}
.sm-04__link:hover .sm-04__link-icon {
color: var(--accent);
}
.sm-04__link--active .sm-04__link-icon {
color: var(--accent2);
}
.sm-04__link-text {
font-size: 13px;
font-weight: 600;
opacity: 0;
transition: opacity 0.2s 0.05s;
pointer-events: none;
flex: 1;
}
.sm-04__rail:hover .sm-04__link-text {
opacity: 1;
}
.sm-04__link-badge {
margin-right: 12px;
background: rgba(245,158,11,0.2);
color: var(--accent2);
font-size: 10px;
font-weight: 700;
padding: 1px 6px;
border-radius: 99px;
opacity: 0;
transition: opacity 0.2s 0.05s;
}
.sm-04__rail:hover .sm-04__link-badge {
opacity: 1;
}
/* Divider */
.sm-04__divider {
width: 80%;
height: 1px;
background: var(--border);
margin: 8px auto;
flex-shrink: 0;
}
/* Bottom user */
.sm-04__user {
width: 100%;
display: flex;
align-items: center;
gap: 0;
overflow: hidden;
padding: 8px 0 0;
border-top: 1px solid var(--border);
}
.sm-04__user-icon {
width: var(--collapsed);
display: flex;
align-items: center;
justify-content: center;
flex-shrink: 0;
}
.sm-04__user-avatar {
width: 30px;
height: 30px;
border-radius: 50%;
background: linear-gradient(135deg, #f59e0b, #ef4444);
display: flex;
align-items: center;
justify-content: center;
font-size: 11px;
font-weight: 700;
color: #000;
}
.sm-04__user-info {
opacity: 0;
transition: opacity 0.2s 0.05s;
white-space: nowrap;
}
.sm-04__rail:hover .sm-04__user-info {
opacity: 1;
}
.sm-04__user-name {
font-size: 12px;
font-weight: 600;
}
.sm-04__user-role {
font-size: 10px;
color: var(--muted);
}
/* Main */
.sm-04__main {
flex: 1;
padding: 24px;
min-width: 0;
}
.sm-04__heading {
font-size: 20px;
font-weight: 700;
margin-bottom: 8px;
}
.sm-04__sub {
font-size: 13px;
color: var(--muted);
line-height: 1.6;
margin-bottom: 22px;
}
.sm-04__cards {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 10px;
}
.sm-04__card {
background: var(--surface);
border: 1px solid var(--border);
border-radius: 10px;
padding: 14px;
}
.sm-04__card-val {
font-size: 20px;
font-weight: 700;
color: var(--accent2);
}
.sm-04__card-lbl {
font-size: 11px;
color: var(--muted);
margin-top: 4px;
}
@media (prefers-reduced-motion: reduce) {
.sm-04__rail,
.sm-04__link-text,
.sm-04__link-badge,
.sm-04__user-info {
transition: none;
}
}Here's a working CSS Side Menu Design from CodeFronts. Use it as-is or adapt to your framework. All classes are scoped under a unique prefix so the code won't collide with your existing styles. MIT licensed.
Demo: Expandable Icon-Only Sidebar
Source: https://codefronts.com/navigation/css-side-menu/expandable-icon-only-sidebar/
A persistent narrow icon rail that smoothly expands on hover to reveal full text labels and notification badges, using a CSS width transition with no toggle required.
## HTML
```html
<div class="sm-04">
<nav class="sm-04__rail">
<div class="sm-04__logo">Z</div>
<div class="sm-04__links">
<a class="sm-04__link sm-04__link--active" href="#">
<span class="sm-04__link-icon">⬡</span>
<span class="sm-04__link-text">Dashboard</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◈</span>
<span class="sm-04__link-text">Analytics</span>
<span class="sm-04__link-badge">5</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">▦</span>
<span class="sm-04__link-text">Projects</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◉</span>
<span class="sm-04__link-text">Messages</span>
<span class="sm-04__link-badge">9</span>
</a>
<div class="sm-04__divider"></div>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◬</span>
<span class="sm-04__link-text">Help</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">⬙</span>
<span class="sm-04__link-text">Settings</span>
</a>
</div>
<div class="sm-04__user">
<div class="sm-04__user-icon"><div class="sm-04__user-avatar">MK</div></div>
<div class="sm-04__user-info">
<div class="sm-04__user-name">M. Kowalski</div>
<div class="sm-04__user-role">Admin</div>
</div>
</div>
</nav>
<div class="sm-04__main">
<div class="sm-04__heading">Dashboard</div>
<div class="sm-04__sub">Hover the icon rail on the left to expand. Labels and badges appear without any JavaScript.</div>
<div class="sm-04__cards">
<div class="sm-04__card"><div class="sm-04__card-val">41</div><div class="sm-04__card-lbl">Active Projects</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">98%</div><div class="sm-04__card-lbl">Health Score</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">$74k</div><div class="sm-04__card-lbl">Monthly Revenue</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">1.2k</div><div class="sm-04__card-lbl">Team Members</div></div>
</div>
</div>
</div>
```
## CSS
```css
.sm-04,
.sm-04 *,
.sm-04 *::before,
.sm-04 *::after {
box-sizing: border-box;
margin: 0;
padding: 0;
}
.sm-04 ::selection {
background: #f59e0b;
color: #000;
}
.sm-04 {
--bg: #09090b;
--surface: #18181b;
--rail-bg: #0f0f12;
--accent: #f59e0b;
--accent2: #fbbf24;
--text: #fafafa;
--muted: #71717a;
--border: rgba(245,158,11,0.15);
--collapsed: 60px;
--expanded: 230px;
--dur: 0.35s;
--ease: cubic-bezier(0.4, 0, 0.2, 1);
font-family: 'Inter', system-ui, sans-serif;
background: var(--bg);
color: var(--text);
display: flex;
min-height: 100vh;
position: relative;
overflow: hidden;
border-radius: 12px;
}
/* Sidebar rail */
.sm-04__rail {
width: var(--collapsed);
min-height: 440px;
background: var(--rail-bg);
border-right: 1px solid var(--border);
display: flex;
flex-direction: column;
align-items: center;
padding: 16px 0;
overflow: hidden;
transition: width var(--dur) var(--ease);
flex-shrink: 0;
position: relative;
z-index: 5;
}
.sm-04__rail:hover {
width: var(--expanded);
}
/* Logo */
.sm-04__logo {
width: 36px;
height: 36px;
background: var(--accent);
border-radius: 9px;
display: flex;
align-items: center;
justify-content: center;
font-weight: 800;
font-size: 16px;
color: #000;
flex-shrink: 0;
margin-bottom: 24px;
transition: border-radius 0.3s;
}
.sm-04__rail:hover .sm-04__logo {
border-radius: 50%;
}
/* Nav items */
.sm-04__links {
width: 100%;
flex: 1;
}
.sm-04__link {
display: flex;
align-items: center;
gap: 0;
width: 100%;
padding: 0;
color: var(--muted);
cursor: pointer;
text-decoration: none;
transition: color 0.2s, background 0.2s;
position: relative;
overflow: hidden;
white-space: nowrap;
height: 48px;
}
.sm-04__link:hover,
.sm-04__link--active {
color: var(--text);
background: rgba(245,158,11,0.08);
}
.sm-04__link--active::after {
content: '';
position: absolute;
right: 0;
top: 50%;
transform: translateY(-50%);
width: 3px;
height: 60%;
background: var(--accent);
border-radius: 3px 0 0 3px;
transition: opacity 0.2s;
}
.sm-04__link-icon {
width: var(--collapsed);
height: 48px;
display: flex;
align-items: center;
justify-content: center;
font-size: 18px;
flex-shrink: 0;
transition: background 0.2s;
}
.sm-04__link:hover .sm-04__link-icon {
color: var(--accent);
}
.sm-04__link--active .sm-04__link-icon {
color: var(--accent2);
}
.sm-04__link-text {
font-size: 13px;
font-weight: 600;
opacity: 0;
transition: opacity 0.2s 0.05s;
pointer-events: none;
flex: 1;
}
.sm-04__rail:hover .sm-04__link-text {
opacity: 1;
}
.sm-04__link-badge {
margin-right: 12px;
background: rgba(245,158,11,0.2);
color: var(--accent2);
font-size: 10px;
font-weight: 700;
padding: 1px 6px;
border-radius: 99px;
opacity: 0;
transition: opacity 0.2s 0.05s;
}
.sm-04__rail:hover .sm-04__link-badge {
opacity: 1;
}
/* Divider */
.sm-04__divider {
width: 80%;
height: 1px;
background: var(--border);
margin: 8px auto;
flex-shrink: 0;
}
/* Bottom user */
.sm-04__user {
width: 100%;
display: flex;
align-items: center;
gap: 0;
overflow: hidden;
padding: 8px 0 0;
border-top: 1px solid var(--border);
}
.sm-04__user-icon {
width: var(--collapsed);
display: flex;
align-items: center;
justify-content: center;
flex-shrink: 0;
}
.sm-04__user-avatar {
width: 30px;
height: 30px;
border-radius: 50%;
background: linear-gradient(135deg, #f59e0b, #ef4444);
display: flex;
align-items: center;
justify-content: center;
font-size: 11px;
font-weight: 700;
color: #000;
}
.sm-04__user-info {
opacity: 0;
transition: opacity 0.2s 0.05s;
white-space: nowrap;
}
.sm-04__rail:hover .sm-04__user-info {
opacity: 1;
}
.sm-04__user-name {
font-size: 12px;
font-weight: 600;
}
.sm-04__user-role {
font-size: 10px;
color: var(--muted);
}
/* Main */
.sm-04__main {
flex: 1;
padding: 24px;
min-width: 0;
}
.sm-04__heading {
font-size: 20px;
font-weight: 700;
margin-bottom: 8px;
}
.sm-04__sub {
font-size: 13px;
color: var(--muted);
line-height: 1.6;
margin-bottom: 22px;
}
.sm-04__cards {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 10px;
}
.sm-04__card {
background: var(--surface);
border: 1px solid var(--border);
border-radius: 10px;
padding: 14px;
}
.sm-04__card-val {
font-size: 20px;
font-weight: 700;
color: var(--accent2);
}
.sm-04__card-lbl {
font-size: 11px;
color: var(--muted);
margin-top: 4px;
}
@media (prefers-reduced-motion: reduce) {
.sm-04__rail,
.sm-04__link-text,
.sm-04__link-badge,
.sm-04__user-info {
transition: none;
}
}
```Here's a working CSS Side Menu Design from CodeFronts. Use it as-is or adapt to your framework. All classes are scoped under a unique prefix so the code won't collide with your existing styles. MIT licensed.
Demo: Expandable Icon-Only Sidebar
Source: https://codefronts.com/navigation/css-side-menu/expandable-icon-only-sidebar/
A persistent narrow icon rail that smoothly expands on hover to reveal full text labels and notification badges, using a CSS width transition with no toggle required.
## HTML
```html
<div class="sm-04">
<nav class="sm-04__rail">
<div class="sm-04__logo">Z</div>
<div class="sm-04__links">
<a class="sm-04__link sm-04__link--active" href="#">
<span class="sm-04__link-icon">⬡</span>
<span class="sm-04__link-text">Dashboard</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◈</span>
<span class="sm-04__link-text">Analytics</span>
<span class="sm-04__link-badge">5</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">▦</span>
<span class="sm-04__link-text">Projects</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◉</span>
<span class="sm-04__link-text">Messages</span>
<span class="sm-04__link-badge">9</span>
</a>
<div class="sm-04__divider"></div>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">◬</span>
<span class="sm-04__link-text">Help</span>
</a>
<a class="sm-04__link" href="#">
<span class="sm-04__link-icon">⬙</span>
<span class="sm-04__link-text">Settings</span>
</a>
</div>
<div class="sm-04__user">
<div class="sm-04__user-icon"><div class="sm-04__user-avatar">MK</div></div>
<div class="sm-04__user-info">
<div class="sm-04__user-name">M. Kowalski</div>
<div class="sm-04__user-role">Admin</div>
</div>
</div>
</nav>
<div class="sm-04__main">
<div class="sm-04__heading">Dashboard</div>
<div class="sm-04__sub">Hover the icon rail on the left to expand. Labels and badges appear without any JavaScript.</div>
<div class="sm-04__cards">
<div class="sm-04__card"><div class="sm-04__card-val">41</div><div class="sm-04__card-lbl">Active Projects</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">98%</div><div class="sm-04__card-lbl">Health Score</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">$74k</div><div class="sm-04__card-lbl">Monthly Revenue</div></div>
<div class="sm-04__card"><div class="sm-04__card-val">1.2k</div><div class="sm-04__card-lbl">Team Members</div></div>
</div>
</div>
</div>
```
## CSS
```css
.sm-04,
.sm-04 *,
.sm-04 *::before,
.sm-04 *::after {
box-sizing: border-box;
margin: 0;
padding: 0;
}
.sm-04 ::selection {
background: #f59e0b;
color: #000;
}
.sm-04 {
--bg: #09090b;
--surface: #18181b;
--rail-bg: #0f0f12;
--accent: #f59e0b;
--accent2: #fbbf24;
--text: #fafafa;
--muted: #71717a;
--border: rgba(245,158,11,0.15);
--collapsed: 60px;
--expanded: 230px;
--dur: 0.35s;
--ease: cubic-bezier(0.4, 0, 0.2, 1);
font-family: 'Inter', system-ui, sans-serif;
background: var(--bg);
color: var(--text);
display: flex;
min-height: 100vh;
position: relative;
overflow: hidden;
border-radius: 12px;
}
/* Sidebar rail */
.sm-04__rail {
width: var(--collapsed);
min-height: 440px;
background: var(--rail-bg);
border-right: 1px solid var(--border);
display: flex;
flex-direction: column;
align-items: center;
padding: 16px 0;
overflow: hidden;
transition: width var(--dur) var(--ease);
flex-shrink: 0;
position: relative;
z-index: 5;
}
.sm-04__rail:hover {
width: var(--expanded);
}
/* Logo */
.sm-04__logo {
width: 36px;
height: 36px;
background: var(--accent);
border-radius: 9px;
display: flex;
align-items: center;
justify-content: center;
font-weight: 800;
font-size: 16px;
color: #000;
flex-shrink: 0;
margin-bottom: 24px;
transition: border-radius 0.3s;
}
.sm-04__rail:hover .sm-04__logo {
border-radius: 50%;
}
/* Nav items */
.sm-04__links {
width: 100%;
flex: 1;
}
.sm-04__link {
display: flex;
align-items: center;
gap: 0;
width: 100%;
padding: 0;
color: var(--muted);
cursor: pointer;
text-decoration: none;
transition: color 0.2s, background 0.2s;
position: relative;
overflow: hidden;
white-space: nowrap;
height: 48px;
}
.sm-04__link:hover,
.sm-04__link--active {
color: var(--text);
background: rgba(245,158,11,0.08);
}
.sm-04__link--active::after {
content: '';
position: absolute;
right: 0;
top: 50%;
transform: translateY(-50%);
width: 3px;
height: 60%;
background: var(--accent);
border-radius: 3px 0 0 3px;
transition: opacity 0.2s;
}
.sm-04__link-icon {
width: var(--collapsed);
height: 48px;
display: flex;
align-items: center;
justify-content: center;
font-size: 18px;
flex-shrink: 0;
transition: background 0.2s;
}
.sm-04__link:hover .sm-04__link-icon {
color: var(--accent);
}
.sm-04__link--active .sm-04__link-icon {
color: var(--accent2);
}
.sm-04__link-text {
font-size: 13px;
font-weight: 600;
opacity: 0;
transition: opacity 0.2s 0.05s;
pointer-events: none;
flex: 1;
}
.sm-04__rail:hover .sm-04__link-text {
opacity: 1;
}
.sm-04__link-badge {
margin-right: 12px;
background: rgba(245,158,11,0.2);
color: var(--accent2);
font-size: 10px;
font-weight: 700;
padding: 1px 6px;
border-radius: 99px;
opacity: 0;
transition: opacity 0.2s 0.05s;
}
.sm-04__rail:hover .sm-04__link-badge {
opacity: 1;
}
/* Divider */
.sm-04__divider {
width: 80%;
height: 1px;
background: var(--border);
margin: 8px auto;
flex-shrink: 0;
}
/* Bottom user */
.sm-04__user {
width: 100%;
display: flex;
align-items: center;
gap: 0;
overflow: hidden;
padding: 8px 0 0;
border-top: 1px solid var(--border);
}
.sm-04__user-icon {
width: var(--collapsed);
display: flex;
align-items: center;
justify-content: center;
flex-shrink: 0;
}
.sm-04__user-avatar {
width: 30px;
height: 30px;
border-radius: 50%;
background: linear-gradient(135deg, #f59e0b, #ef4444);
display: flex;
align-items: center;
justify-content: center;
font-size: 11px;
font-weight: 700;
color: #000;
}
.sm-04__user-info {
opacity: 0;
transition: opacity 0.2s 0.05s;
white-space: nowrap;
}
.sm-04__rail:hover .sm-04__user-info {
opacity: 1;
}
.sm-04__user-name {
font-size: 12px;
font-weight: 600;
}
.sm-04__user-role {
font-size: 10px;
color: var(--muted);
}
/* Main */
.sm-04__main {
flex: 1;
padding: 24px;
min-width: 0;
}
.sm-04__heading {
font-size: 20px;
font-weight: 700;
margin-bottom: 8px;
}
.sm-04__sub {
font-size: 13px;
color: var(--muted);
line-height: 1.6;
margin-bottom: 22px;
}
.sm-04__cards {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 10px;
}
.sm-04__card {
background: var(--surface);
border: 1px solid var(--border);
border-radius: 10px;
padding: 14px;
}
.sm-04__card-val {
font-size: 20px;
font-weight: 700;
color: var(--accent2);
}
.sm-04__card-lbl {
font-size: 11px;
color: var(--muted);
margin-top: 4px;
}
@media (prefers-reduced-motion: reduce) {
.sm-04__rail,
.sm-04__link-text,
.sm-04__link-badge,
.sm-04__user-info {
transition: none;
}
}
```How this works
The sidebar starts at width: var(--collapsed) (60px) and transitions to width: var(--expanded) (230px) on the :hover pseudo-class. Text labels use opacity: 0 at rest and fade in with a slight transition-delay: 0.05s after the container has begun widening, avoiding visible clipping during the opening animation.
Each icon cell uses a fixed width: var(--collapsed) so icons never shift position as the container grows. The logo transitions from border-radius: 9px to 50% on hover as a subtle micro-detail. The bottom user section mirrors the same opacity fade pattern so all text reveals in unison.
Make it yours
- Change the collapsed width by adjusting
--collapsed: 60px— 48px gives an ultra-thin strip while 72px allows larger icon targets for touch interfaces. - Add staggered label reveals by incrementing
transition-delayby 0.03s per link for a cascade animation effect. - Add a tooltip on the collapsed state:
::after { content: attr(data-label); position: absolute; left: 110%; }for keyboard accessibility. - Replace hover with a checkbox hack for persistent expand/collapse state that survives mouse movements.
- Animate the icon using
transform: scale(0.85)when collapsed andscale(1)when expanded to draw attention to the interaction.
Gotchas — read before shipping
- If the mouse briefly exits the nav bounding box, the sidebar collapses mid-interaction — add
transition-delay: 0.1son the close direction only. overflow: hiddenon the nav clips text labels during collapse but also clips tooltips or dropdowns — useclip-pathif overflow content is needed.- Screen readers will read all hidden text labels regardless of visual opacity — ensure labels have meaningful content and do not duplicate the icon aria-label.
Browser support
| Chrome | Safari | Firefox | Edge |
|---|---|---|---|
| 36+ | 9+ | 41+ | 36+ |
CSS width transitions and opacity on hover are universally supported. No prefixes needed.