Utilities are single-purpose classes that you combine directly in markup. Stack several on one element, add a breakpoint infix such as d-md-flex to change behaviour from a screen size up, and tune colour states through CSS variables like --ui-bg-opacity, --ui-border-opacity and --ui-link-opacity. The recipes below build complete interface pieces without writing any custom CSS.
1A card made only of utilities
Background, border, radius, padding and shadow utilities stacked on a plain div give you a card without the card component.
Health
Hope starts with you
We measure success by how many donors come back and tell their friends.
<div class="bg-page border rounded-lg p-4 shadow-sm" style="max-width:22rem">
<p class="small text-muted uppercase font-semibold mb-1">Health</p>
<h3 class="h5 mb-2">Hope starts with you</h3>
<p class="mb-0 text-muted">We measure success by how many donors come back and tell their friends.</p>
</div>2Responsive display: d-none d-md-flex
Breakpoint infixes switch a utility on from a screen size up. Resize the window: the toolbar row appears from md, the compact button below it.
d-none d-md-flex and d-flex d-md-none
<div class="border rounded-lg p-4 bg-surface-3">
<div class="hidden md:flex gap-2">
<button type="button" class="btn btn-sm btn-primary"><i class="bi bi-pencil-square" aria-hidden="true"></i> Edit</button>
<button type="button" class="btn btn-sm btn-outline-secondary"><i class="bi bi-share" aria-hidden="true"></i> Share</button>
<button type="button" class="btn btn-sm btn-outline-danger"><i class="bi bi-trash3" aria-hidden="true"></i> Delete</button>
</div>
<div class="flex md:hidden">
<button type="button" class="btn btn-sm btn-primary w-full"><i class="bi bi-three-dots" aria-hidden="true"></i> Actions</button>
</div>
<p class="small text-muted mt-2 mb-0"><code>d-none d-md-flex</code> and <code>d-flex d-md-none</code></p>
</div>3State via --ui-bg-opacity
Every bg-{colour} reads the --ui-bg-opacity variable, so one inline variable fades the fill (the labels sit under it, so they stay readable on every step).
<div class="flex flex-wrap gap-4 small text-center">
<div>
<div class="bg-primary rounded-md mb-1" style="width:3.5rem;height:2.5rem;--ui-bg-opacity:1">
</div>
1
</div>
<div>
<div class="bg-primary rounded-md mb-1" style="width:3.5rem;height:2.5rem;--ui-bg-opacity:.6">
</div>
.6
</div>
<div>
<div class="bg-primary rounded-md mb-1" style="width:3.5rem;height:2.5rem;--ui-bg-opacity:.35">
</div>
.35
</div>
<div>
<div class="bg-primary rounded-md mb-1" style="width:3.5rem;height:2.5rem;--ui-bg-opacity:.15">
</div>
.15
</div>
<div>
<div class="bg-primary rounded-md mb-1 border" style="width:3.5rem;height:2.5rem;--ui-bg-opacity:.05">
</div>
.05
</div>
</div>4State via --ui-border-opacity
Border colour utilities read --ui-border-opacity; set it inline for values between the border-opacity-* steps.
<div class="row g-2">
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-lg p-4 text-center small" style="--ui-border-opacity:1">
1
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-lg p-4 text-center small" style="--ui-border-opacity:.6">
.6
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-lg p-4 text-center small" style="--ui-border-opacity:.3">
.3
</div>
</div>
<div class="col-6 col-md-3">
<div class="border border-2 border-success rounded-lg p-4 text-center small" style="--ui-border-opacity:.1">
.1
</div>
</div>
</div>5State via --ui-link-opacity
Coloured links read --ui-link-opacity: fade a link that is not available yet, or fade on hover - a link people must read stays at full strength.
- Volunteer programs --ui-link-opacity:.5, not available
- Tax receipts 100, 75 on hover
- Join a community that cares link-danger, faint underline
<ul class="list-unstyled mb-0 grid gap-2">
<li><a href="#" class="link-primary pointer-events-none" style="--ui-link-opacity:.5" aria-disabled="true" tabindex="-1">Volunteer programs</a> <span class="small text-muted">--ui-link-opacity:.5, not available</span></li>
<li><a href="#" class="link-primary link-opacity-100 link-opacity-75-hover">Tax receipts</a> <span class="small text-muted">100, 75 on hover</span></li>
<li><a href="#" class="link-danger link-underline-opacity-25">Join a community that cares</a> <span class="small text-muted">link-danger, faint underline</span></li>
</ul>6Media object
d-flex with gap, flex-shrink-0 on the image and flex-grow-1 on the text is the classic comment or list row.
Every detail is handled by people who care about getting it right.
<div class="flex gap-4 items-start border rounded-lg p-4">
<img src="../assets/img/avatar-5.svg" alt="Chloe Harlow" width="48" height="48" class="rounded-full shrink-0">
<div class="grow">
<div class="flex justify-between">
<strong>Chloe Harlow</strong><small class="text-muted">8 hours ago</small>
</div>
<p class="mb-0 small">Every detail is handled by people who care about getting it right.</p>
</div>
</div>7Status badges without the badge component
Subtle backgrounds, emphasis text, small padding and rounded-pill compose a soft status label.
<div class="flex flex-wrap gap-2">
<span class="inline-flex items-center gap-1 px-2 py-1 rounded-full small font-medium bg-success-subtle text-success-emphasis border border-success/30"><i class="bi bi-check-circle-fill" aria-hidden="true"></i> Active</span> <span class="inline-flex items-center gap-1 px-2 py-1 rounded-full small font-medium bg-warning-subtle text-warning-emphasis border border-warning/30"><i class="bi bi-clock" aria-hidden="true"></i> Pending</span> <span class="inline-flex items-center gap-1 px-2 py-1 rounded-full small font-medium bg-danger-subtle text-danger-emphasis border border-danger/30"><i class="bi bi-x-circle-fill" aria-hidden="true"></i> Blocked</span>
</div>8Stat tile
Font size, weight, line height and colour utilities turn three lines of text into a dashboard metric.
<div class="row g-3">
<div class="col-sm-6 col-lg-4">
<div class="p-4 rounded-xl bg-surface-3 border">
<div class="flex justify-between items-center mb-2">
<span class="small text-muted font-medium">Revenue</span><span class="text-primary-ink text-lg"><i class="bi bi-graph-up-arrow" aria-hidden="true"></i></span>
</div>
<div class="text-2xl font-bold leading-none">
$22,476.51
</div>
<div class="small text-success-emphasis mt-1">
<i class="bi bi-arrow-up" aria-hidden="true"></i> +87% this month
</div>
</div>
</div>
<div class="col-sm-6 col-lg-4">
<div class="p-4 rounded-xl bg-surface-3 border">
<div class="flex justify-between items-center mb-2">
<span class="small text-muted font-medium">Customers</span><span class="text-info-emphasis text-lg"><i class="bi bi-people" aria-hidden="true"></i></span>
</div>
<div class="text-2xl font-bold leading-none">
8.4k
</div>
<div class="small text-danger-emphasis mt-1">
<i class="bi bi-arrow-down" aria-hidden="true"></i> -5% this month
</div>
</div>
</div>
</div>9Avatar with a status dot
position-relative on the wrapper, then position-absolute, bottom-0 / end-0 and a white border for the online dot.
Online
Away
<div class="flex gap-6 items-center">
<div class="relative inline-block">
<img src="../assets/img/avatar-9.svg" alt="Freya Mensah" width="56" height="56" class="rounded-full"> <span class="absolute bottom-0 end-0 p-2 bg-success border border-2 border-white rounded-full"><span class="sr-only">Online</span></span>
</div>
<div class="relative inline-block">
<img src="../assets/img/avatar-3.svg" alt="Jonah Haddad" width="56" height="56" class="rounded-full"> <span class="absolute bottom-0 end-0 p-2 bg-secondary border border-2 border-white rounded-full"><span class="sr-only">Away</span></span>
</div>
</div>10Responsive alignment
text-center on phones and text-md-start from md: a hero block that centres only where it should.
Be part of the change
Volunteers give their time in schools, shelters and food banks every week.
Get started<div class="p-6 rounded-xl bg-primary-subtle text-center md:text-start">
<h3 class="h4 font-bold text-primary-emphasis">Be part of the change</h3>
<p class="mb-4 text-primary-emphasis">Volunteers give their time in schools, shelters and food banks every week.</p>
<a href="#" class="btn btn-primary">Get started</a>
</div>11Stack on phones, row on tablets
flex-column flex-md-row with gap-3: three blocks stack on small screens and line up from md.
<div class="flex flex-col md:flex-row gap-4">
<div class="flex-auto p-4 rounded-lg border bg-surface-3">
<i class="bi bi-lightning-charge-fill" aria-hidden="true"></i> <strong>Secure giving</strong>
</div>
<div class="flex-auto p-4 rounded-lg border bg-surface-3">
<i class="bi bi-shield-check" aria-hidden="true"></i> <strong>Transparent reports</strong>
</div>
<div class="flex-auto p-4 rounded-lg border bg-surface-3">
<i class="bi bi-cloud-arrow-up" aria-hidden="true"></i> <strong>Impact tracking</strong>
</div>
</div>12Callout from border-start
A single side border with a thick width and a theme colour makes a note or warning callout.
You receive photos and updates showing exactly what your donation achieved.
<div class="border-s border-4 border-warning bg-warning-subtle rounded-end-3 p-4">
<div class="font-semibold text-warning-emphasis mb-1">
<i class="bi bi-exclamation-triangle-fill" aria-hidden="true"></i> Heads up
</div>
<p class="mb-0 small text-warning-emphasis">You receive photos and updates showing exactly what your donation achieved.</p>
</div>13Settings row
justify-content-between and align-items-center place a label on the left and a control on the right.
<div class="border rounded-lg">
<div class="flex justify-between items-center p-4 border-b">
<div>
<div class="font-medium">
Email alerts
</div>
<div class="small text-muted">
Daily summary at 18:00
</div>
</div>
<span class="px-2 py-1 rounded-full small bg-success text-white">On</span>
</div>
<div class="flex justify-between items-center p-4">
<div>
<div class="font-medium">
Push notifications
</div>
<div class="small text-muted">
Only mentions
</div>
</div>
<span class="px-2 py-1 rounded-full small bg-surface-2 text-muted">Off</span>
</div>
</div>14Announcement bar
text-bg-dark sets a contrasting text colour with the background; small and gap utilities do the rest.
<div class="text-bg-dark rounded-lg px-4 py-2 flex flex-wrap items-center justify-center gap-2 small">
<span class="badge text-bg-warning">New</span> <span>Giving that you can see</span> <a href="#" class="link-light link-offset-2 font-semibold">Read more</a>
</div>15Filter chips that wrap
flex-wrap with gap-2 lets a row of chips flow onto new lines without margin hacks.
<div class="flex flex-wrap gap-2">
<span class="px-4 py-1 rounded-full text-bg-primary small">All</span> <span class="px-4 py-1 rounded-full border small">news</span> <span class="px-4 py-1 rounded-full border small">Education</span> <span class="px-4 py-1 rounded-full border small">clear</span> <span class="px-4 py-1 rounded-full border small">routine</span>
</div>16Product line item
A thumbnail, a truncated title and a right-aligned price: overflow-hidden on the middle column lets text-truncate work in flex.
<div class="flex items-center gap-4 border rounded-lg p-2" style="max-width:28rem">
<img src="../assets/img/product-6.svg" alt="Emergency fund" width="56" height="56" class="rounded-md object-cover shrink-0">
<div class="grow overflow-hidden">
<div class="font-medium truncate">
Emergency fund - calm edition
</div>
<div class="small text-muted">
Relief
</div>
</div>
<div class="font-bold whitespace-nowrap">
$51.00
</div>
</div>17Responsive spacing
p-2 p-md-4 and mb-2 mb-md-3: tighter padding on phones, roomier from md, no media query needed.
Stories from the families we support
Our annual report is independently audited and published in full. We listen first, then build a plan around what you actually need.
<div class="border rounded-xl p-2 md:p-6 bg-surface-3">
<h3 class="h6 mb-2 md:mb-4">Stories from the families we support</h3>
<p class="mb-0 small">Our annual report is independently audited and published in full. We listen first, then build a plan around what you actually need.</p>
</div>18Underline that appears on hover
link-underline-opacity-0 hides the underline, the -hover variants bring it back with a little offset.
<nav class="flex flex-wrap gap-4" aria-label="Footer">
<a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">About</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Pricing</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Support</a> <a href="#" class="link-body-emphasis link-offset-2 link-underline-opacity-0 link-underline-opacity-100-hover">Careers</a>
</nav>19Image with a text overlay
position-relative wrapper, an absolutely placed caption at bottom-0 and bg-dark with --ui-bg-opacity for the scrim.
<div class="relative rounded-xl overflow-hidden" style="max-width:26rem">
<img src="https://images.unsplash.com/photo-1758599668338-4c55a3bd0ce0?auto=format&fit=crop&w=1200&h=800&q=70" alt="Every donation makes a difference" class="w-full block">
<div class="absolute bottom-0 start-0 end-0 bg-dark text-white p-4" style="--ui-bg-opacity:.6">
<div class="small text-white/50">
Copenhagen
</div>
<div class="font-semibold">
Small acts, big impact
</div>
</div>
</div>20Empty state panel
A centred flex column with a large icon, muted text and one action, built from spacing and text utilities.
No files yet
Our team has done this many times, so you never have to guess.
<div class="flex flex-col items-center text-center py-12 px-4 border rounded-xl bg-surface-3">
<div class="text-4xl text-tertiary mb-2">
<i class="bi bi-folder2-open" aria-hidden="true"></i>
</div>
<h3 class="h6 font-semibold mb-1">No files yet</h3>
<p class="small text-muted mb-4">Our team has done this many times, so you never have to guess.</p>
<button type="button" class="btn btn-sm btn-primary"><i class="bi bi-cloud-arrow-up" aria-hidden="true"></i> Upload</button>
</div>