DEV Community: Proof Matcher

Free SaaS Landing Page Templates for Startups 2026

Proof Matcher — Fri, 01 May 2026 00:54:17 +0000

Free SaaS Landing Page Templates 2026

ProofMatcher has 197 website templates including SaaS landing pages with dark mode, glassmorphism, and mobile-first layouts.

What Every Great SaaS Landing Page Needs

Hero — clear headline + CTA above the fold
Feature grid — 3-6 benefits with icons
Social proof — logos, testimonials, usage numbers
Pricing table — clear, transparent tiers
FAQ — address objections before checkout

SaaS Hero CSS

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(180deg, #050505, #0d0505);
  padding: 0 5%;
}
.hero h1 {
  font-size: clamp(2.2rem, 6vw, 5rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.hero p {
  font-size: 1.125rem;
  color: rgba(255,255,255,0.5);
  max-width: 580px;
  margin: 1.25rem auto 2rem;
}
.hero-cta {
  background: #e53e3e;
  color: #fff;
  padding: 14px 32px;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
}

Feature Grid CSS

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
  padding: 80px 5%;
}
.feature-card {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 16px;
  padding: 28px;
}

Free SaaS Templates

➡ proofmatcher.com/templates

Also: UI Components · CSS Button CTAs · Form Templates

Dark Mode Website Template: Free Downloads 2026

Proof Matcher — Fri, 01 May 2026 00:54:01 +0000

Free Dark Mode Website Templates 2026

ProofMatcher offers 197 free and premium dark mode templates for SaaS, fintech, portfolios, and dashboards.

Why Dark Mode?

82% of smartphone users prefer dark interfaces
Reduces battery usage on OLED screens
Makes glassmorphism and gradient effects stand out
Signals premium quality to visitors

Dark Mode CSS Foundation

:root {
  --bg: #050505;
  --surface: #111;
  --border: rgba(255,255,255,0.08);
  --text: #f0f0f0;
  --muted: rgba(255,255,255,0.45);
  --accent: #e53e3e;
}
body { background: var(--bg); color: var(--text); }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 24px; }

Glassmorphism Card

.glass {
  background: rgba(255,255,255,0.05);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 20px;
  padding: 32px;
}

Dark Grid Background

.dark-grid {
  background-color: #050505;
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 32px 32px;
}

Template Categories Available

SaaS landing pages (dark glassmorphism)
Fintech dashboards (data-dense, high contrast)
Developer portfolios (minimal, clean)
Healthcare apps (professional, accessible)
Creative agencies (bold, animated)

Browse 197 Free Dark Mode Templates

➡ proofmatcher.com/templates

Also: CSS Patterns · Dark Buttons · 273+ Free UI Components

Free CSS Toggle Switch: 29 Animated Designs 2026

Proof Matcher — Fri, 01 May 2026 00:53:45 +0000

29 Free CSS Toggle Switch Components 2026

ProofMatcher has 29 free CSS toggle switches — iOS-style, neon, material, and more. Zero JavaScript needed.

iOS-Style Toggle

<label class="ios-toggle">
  <input type="checkbox">
  <span class="track"></span>
</label>

.ios-toggle { position:relative; width:52px; height:28px; display:inline-block; }
.ios-toggle input { display:none; }
.track {
  position: absolute; inset: 0;
  background: #3a3a3a;
  border-radius: 28px;
  cursor: pointer;
  transition: background .25s;
}
.track::before {
  content: '';
  position: absolute;
  height: 22px; width: 22px;
  left: 3px; top: 3px;
  background: #fff;
  border-radius: 50%;
  transition: transform .25s;
  box-shadow: 0 2px 6px rgba(0,0,0,.3);
}
.ios-toggle input:checked + .track { background: #e53e3e; }
.ios-toggle input:checked + .track::before { transform: translateX(24px); }

Neon Toggle

.neon-track { background:#1a1a1a; border:1px solid rgba(0,255,204,.3); }
.ios-toggle input:checked + .neon-track { background:#00332b; border-color:#00ffcc; }
.ios-toggle input:checked + .neon-track::before { background:#00ffcc; box-shadow:0 0 10px rgba(0,255,204,.6); }

Slim Material Toggle

.mat-toggle { position:relative; width:36px; height:14px; display:inline-block; }
.mat-track { position:absolute; inset:0; background:rgba(255,255,255,.2); border-radius:7px; cursor:pointer; }
.mat-thumb {
  position:absolute;
  width:20px; height:20px;
  top:-3px; left:-3px;
  background:#888; border-radius:50%;
  transition:transform .2s, background .2s;
  box-shadow:0 2px 4px rgba(0,0,0,.4);
}
input:checked ~ .mat-thumb { transform:translateX(22px); background:#e53e3e; }

All 29 Toggle Switches Free

➡ proofmatcher.com/components/category/toggle-switches

Related: Checkboxes · Radio Buttons · Inputs

React UI Components: 273 Free Copy-Paste Designs 2026

Proof Matcher — Fri, 01 May 2026 00:53:17 +0000

273 Free React UI Components 2026 — No npm Install

ProofMatcher offers 273+ free React components — copy-paste JSX, no package install, no config, no version conflicts.

Why Use Copy-Paste React Components?

Zero added dependencies — keeps your bundle lean
Full control over styles — edit anything directly
Works with Vite, Next.js, CRA, Remix, Astro
No breaking changes when a library updates
No @layer conflicts or specificity wars

React Toggle Switch

const Toggle = ({ on, setOn }) => (
  <div
    onClick={() => setOn(!on)}
    style={{
      width: 52, height: 28,
      background: on ? '#e53e3e' : '#3a3a3a',
      borderRadius: 14, cursor: 'pointer',
      position: 'relative', transition: 'background .25s'
    }}
  >
    <div style={{
      position: 'absolute', top: 3,
      left: on ? 27 : 3,
      width: 22, height: 22,
      background: 'white', borderRadius: '50%',
      transition: 'left .25s',
      boxShadow: '0 2px 6px rgba(0,0,0,.3)'
    }}/>
  </div>
);

React Checkbox

const Checkbox = ({ label, checked, onChange }) => (
  <label style={{ display:'flex', alignItems:'center', gap:10, cursor:'pointer' }}>
    <div style={{
      width: 20, height: 20,
      background: checked ? '#e53e3e' : 'transparent',
      border: `2px solid ${checked ? '#e53e3e' : 'rgba(255,255,255,.3)'}`,
      borderRadius: 4,
      display: 'flex', alignItems: 'center', justifyContent: 'center',
      transition: 'all .2s'
    }}>
      {checked && <span style={{ color:'white', fontSize:12, fontWeight:700 }}>✓</span>}
    </div>
    <span style={{ color:'rgba(255,255,255,.7)', fontSize:14 }}>{label}</span>
  </label>
);

React Gradient Button

const Button = ({ children, onClick, variant = 'primary' }) => {
  const bg = variant === 'primary'
    ? 'linear-gradient(135deg,#e53e3e,#9b2c2c)'
    : 'rgba(255,255,255,0.07)';
  return (
    <button
      onClick={onClick}
      style={{
        background: bg, color: 'white',
        padding: '11px 24px', border: 'none',
        borderRadius: 8, cursor: 'pointer', fontWeight: 600
      }}
    >
      {children}
    </button>
  );
};

Browse All 273 Free React Components

Categories: Buttons · Forms · Checkboxes · Cards · Inputs · Toggle Switches

➡ proofmatcher.com/components

Also: 197 Free Website Templates

CSS Checkbox Styles: 34 Free Animated Designs 2026

Proof Matcher — Fri, 01 May 2026 00:52:56 +0000

34 Free Custom CSS Checkbox Styles 2026

ProofMatcher has 34 free CSS checkbox components replacing ugly browser defaults with animated, stylish designs.

Animated Checkmark

<label class="cb-wrap">
  <input type="checkbox" id="cb1">
  <span class="cb"></span>
  Accept terms and conditions
</label>

.cb-wrap { display:flex; align-items:center; gap:10px; cursor:pointer; user-select:none; }
.cb-wrap input { display:none; }
.cb {
  width: 22px; height: 22px;
  border: 2px solid rgba(255,255,255,.25);
  border-radius: 5px;
  background: transparent;
  transition: all .2s;
  display: flex; align-items: center; justify-content: center;
}
.cb-wrap input:checked + .cb { background: #e53e3e; border-color: #e53e3e; }
.cb-wrap input:checked + .cb::after { content: '✓'; color: #fff; font-size: 13px; font-weight: 700; }

Sliding Toggle Checkbox

.toggle { position:relative; width:48px; height:26px; display:inline-block; }
.toggle input { opacity:0; width:0; height:0; }
.slider { position:absolute; inset:0; background:#333; border-radius:26px; cursor:pointer; transition:.3s; }
.slider::before {
  content:'';
  position:absolute;
  height:20px; width:20px;
  left:3px; bottom:3px;
  background:#fff;
  border-radius:50%;
  transition:.3s;
}
.toggle input:checked + .slider { background: #e53e3e; }
.toggle input:checked + .slider::before { transform: translateX(22px); }

Pill Checkbox

.pill-wrap { display:flex; align-items:center; gap:8px; cursor:pointer; }
.pill-wrap input { display:none; }
.pill {
  width: 44px; height: 24px;
  background: #333; border-radius: 12px;
  transition: background .25s; position: relative;
}
.pill::before {
  content:''; position:absolute;
  top:3px; left:3px;
  width:18px; height:18px;
  background:#fff; border-radius:50%;
  transition:transform .25s;
}
.pill-wrap input:checked + .pill { background:#e53e3e; }
.pill-wrap input:checked + .pill::before { transform:translateX(20px); }

All 34 CSS Checkboxes Free

➡ proofmatcher.com/components/category/checkboxes

CSS Background Patterns: 31 Free Pure-CSS Examples 2026

Proof Matcher — Fri, 01 May 2026 00:52:46 +0000

31 Free CSS Background Patterns 2026

ProofMatcher has 31 pure CSS background patterns — no image files, no SVG imports, infinitely scalable.

Dot Grid

.dots {
  background-color: #050505;
  background-image: radial-gradient(rgba(255,255,255,0.15) 1px, transparent 1px);
  background-size: 24px 24px;
}

Line Grid

.grid {
  background-image:
    linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 32px 32px;
}

Diagonal Stripes

.stripes {
  background: repeating-linear-gradient(
    45deg,
    transparent, transparent 10px,
    rgba(255,255,255,0.03) 10px, rgba(255,255,255,0.03) 20px
  );
}

Checkerboard

.checker {
  background-color: #111;
  background-image:
    linear-gradient(45deg, #1a1a1a 25%, transparent 25%),
    linear-gradient(-45deg, #1a1a1a 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #1a1a1a 75%),
    linear-gradient(-45deg, transparent 75%, #1a1a1a 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

Topographic Lines

.topo {
  background:
    radial-gradient(ellipse at center, rgba(229,62,62,0.08) 0%, transparent 70%),
    repeating-linear-gradient(
      0deg, transparent, transparent 30px,
      rgba(255,255,255,0.03) 30px, rgba(255,255,255,0.03) 31px
    );
}

All 31 CSS Patterns Free

➡ proofmatcher.com/components/category/patterns

Related: Free Templates · CSS Cards · CSS Buttons

Free CSS Card Components: Glassmorphism and Dark Mode 2026

Proof Matcher — Fri, 01 May 2026 00:51:02 +0000

Free CSS Card Components 2026

ProofMatcher has free CSS card components with hover animations, glassmorphism effects, and dark mode designs — copy-paste HTML & React.

Glassmorphism Card

.glass-card {
  background: rgba(255,255,255,0.06);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 20px;
  padding: 28px;
  transition: transform .3s, box-shadow .3s;
}
.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 48px rgba(0,0,0,.35);
}

Dark Gradient Card

.dark-card {
  background: linear-gradient(135deg, #1a0a0a, #111);
  border: 1px solid rgba(229,62,62,0.15);
  border-radius: 16px;
  padding: 24px;
  transition: border-color .25s;
}
.dark-card:hover { border-color: rgba(229,62,62,0.35); }

3D Tilt Card (CSS Only)

.tilt-card {
  background: #111;
  border-radius: 16px;
  padding: 24px;
  transform-style: preserve-3d;
  transition: transform .3s;
}
.tilt-card:hover {
  transform: perspective(800px) rotateX(4deg) rotateY(-4deg) scale(1.02);
}

Profile Card

<div class="profile-card">
  <img src="avatar.jpg" alt="User">
  <h3>Jane Doe</h3>
  <p>UI Designer</p>
  <div class="tags"><span>React</span><span>CSS</span></div>
</div>

.profile-card {
  background: #111;
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 20px;
  padding: 32px;
  text-align: center;
  transition: transform .3s;
}
.profile-card img { width:72px; height:72px; border-radius:50%; object-fit:cover; }
.profile-card h3 { color:#fff; margin:12px 0 4px; }
.profile-card p { color:rgba(255,255,255,.45); font-size:14px; }
.profile-card:hover { transform:translateY(-4px); }

Get Free CSS Cards

➡ proofmatcher.com/components/category/cards

197 Free Website Templates for Developers 2026

Proof Matcher — Fri, 01 May 2026 00:50:57 +0000

197 Free Website Templates for Developers 2026

ProofMatcher offers 197 free and premium website templates — SaaS, fintech, healthcare, portfolios, agencies, and e-commerce. HTML, CSS & live preview included.

What's Inside Each Template

Full HTML + CSS source code
Mobile-first responsive layout (works on all devices)
React/JSX version
Live preview before you copy
Free commercial license — no attribution required

Template Categories

Category	Best For	Style
SaaS	Startups, apps	Dark mode, glassmorphism
Fintech	Banking, crypto	Data-dense, high contrast
Portfolio	Developers, designers	Minimal, clean
Healthcare	Clinics, med apps	Light, professional
Agency	Studios, marketing	Bold, creative
E-commerce	Shops, brands	Product-focused

No Install Required

# How to use any ProofMatcher template:
# 1. Visit proofmatcher.com/templates
# 2. Click any template to preview
# 3. Click "View Code"
# 4. Copy the HTML into your project
# Done! No npm, no build step, no config

Also 273+ Free UI Components

Besides 197 templates, ProofMatcher has 273+ free UI components — buttons, forms, checkboxes, inputs, CSS patterns, cards, tooltips, and loading animations.

➡ Browse 197 Templates
➡ Browse 273 Components

Most popular: CSS Buttons · Form Templates · CSS Patterns

Free HTML Form Templates: 33 Copy-Paste Designs 2026

Proof Matcher — Fri, 01 May 2026 00:50:31 +0000

33 Free HTML Form Templates 2026

ProofMatcher has 33 free HTML form templates — login, signup, contact, payment, and multi-step. HTML, CSS & React included.

Login Form

<form class="form">
  <h2>Sign In</h2>
  <label>Email<input type="email" placeholder="you@email.com"></label>
  <label>Password<input type="password" placeholder="&#x2022;&#x2022;&#x2022;&#x2022;&#x2022;&#x2022;&#x2022;&#x2022;"></label>
  <button type="submit">Sign In</button>
</form>

.form { background:#111; border:1px solid rgba(255,255,255,.08); border-radius:16px; padding:32px; max-width:400px; }
.form label { display:flex; flex-direction:column; gap:6px; font-size:13px; color:rgba(255,255,255,.5); margin-bottom:14px; }
.form input { background:rgba(255,255,255,.06); border:1px solid rgba(255,255,255,.1); border-radius:8px; padding:11px 14px; color:#fff; font-size:14px; }
.form button { width:100%; background:#e53e3e; color:#fff; border:none; border-radius:8px; padding:12px; font-weight:600; cursor:pointer; }

Contact Form

<form class="form">
  <input type="text" placeholder="Your Name">
  <input type="email" placeholder="Email">
  <textarea placeholder="Message" rows="5"></textarea>
  <button type="submit">Send Message</button>
</form>

React Login Form

const LoginForm = () => {
  const [email, setEmail] = React.useState('');
  const [pass, setPass] = React.useState('');
  return (
    <form onSubmit={e => e.preventDefault()}>
      <input value={email} onChange={e => setEmail(e.target.value)} type="email" placeholder="Email"/>
      <input value={pass} onChange={e => setPass(e.target.value)} type="password" placeholder="Password"/>
      <button type="submit">Sign In</button>
    </form>
  );
};

Accessibility Tips

Always use <label for> linked to input id
Add required and aria-required="true" to required fields
Show clear validation error messages below each field

All 33 Form Templates Free

➡ proofmatcher.com/components/category/forms

Free CSS Button Styles: 53 Copy-Paste Examples 2026

Proof Matcher — Fri, 01 May 2026 00:50:26 +0000

53 Free CSS Button Styles — HTML & React

ProofMatcher offers 53 free CSS button components with HTML, CSS and React code. No signup. Free for commercial use.

Gradient Button

.btn-grad {
  background: linear-gradient(135deg, #e53e3e, #9b2c2c);
  color: #fff;
  padding: 12px 28px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  transition: opacity .2s;
}
.btn-grad:hover { opacity: .85; }

Glassmorphism Button

.btn-glass {
  background: rgba(255,255,255,.07);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,.15);
  color: #fff;
  padding: 12px 28px;
  border-radius: 10px;
  cursor: pointer;
}

Neon Glow Button

.btn-neon {
  border: 2px solid #00ffcc;
  color: #00ffcc;
  background: transparent;
  padding: 12px 28px;
  border-radius: 6px;
  box-shadow: 0 0 12px rgba(0,255,204,.35);
  cursor: pointer;
  transition: box-shadow .3s;
}
.btn-neon:hover { box-shadow: 0 0 28px rgba(0,255,204,.65); }

3D Press Button

.btn-3d {
  background: #e53e3e;
  color: #fff;
  padding: 12px 28px;
  border: none;
  border-radius: 8px;
  box-shadow: 0 6px 0 #9b2c2c;
  cursor: pointer;
  transition: transform .1s, box-shadow .1s;
}
.btn-3d:active { transform: translateY(4px); box-shadow: 0 2px 0 #9b2c2c; }

React Button Component

const GradButton = ({ children, onClick }) => (
  <button
    onClick={onClick}
    style={{
      background: 'linear-gradient(135deg,#e53e3e,#9b2c2c)',
      color: 'white', padding: '12px 28px',
      border: 'none', borderRadius: 8,
      cursor: 'pointer', fontWeight: 600
    }}
  >
    {children}
  </button>
);

Accessibility

Always add :focus-visible outline and use semantic <button> not <div>.

.btn:focus-visible { outline: 2px solid #e53e3e; outline-offset: 3px; }

Get All 53 CSS Buttons Free

Browse gradient, glassmorphism, neon, outlined, pill-shaped, icon, loading-state and animated buttons.

➡ proofmatcher.com/components/category/buttons

Also free: Form Templates · Checkboxes · 197 Website Templates

React State Management: Context vs Zustand vs Redux (2026)

Proof Matcher — Mon, 27 Apr 2026 06:36:40 +0000

The State Management Landscape Has Simplified

The React state management ecosystem has consolidated significantly in 2026. Redux, once the default choice for any non-trivial React application, is now used primarily for applications that specifically need its middleware ecosystem, DevTools, or time-travel debugging. Zustand has emerged as the practical default for most new applications — it provides global state without boilerplate, excellent TypeScript support, and a simple mental model. Context API handles truly static global state well. The question is no longer "Redux or not" but "which minimal state solution fits this specific use case."

React Context API: For Static or Infrequent Updates

React Context is built-in, requires no additional dependencies, and works well for data that changes infrequently — authentication state, theme, user preferences, feature flags. The critical limitation: every component that consumes a context re-renders when any value in that context changes. Splitting contexts by update frequency mitigates this — separate AuthContext, ThemeContext, and UserPreferencesContext rather than one GlobalContext. For frequently-updating state (form values, animation state, real-time data), Context causes unnecessary re-renders and Zustand or another external store is more appropriate.

Zustand: The 2026 Practical Default

Zustand is a minimal state management library built on React hooks. Define a store with create(), combining state and actions in a single object. Components subscribe to specific state slices using selector functions — a component that reads only the user.name re-renders only when user.name changes, not when unrelated state updates. The store is defined outside React's component tree, enabling access from anywhere including non-component code. Bundle size: 1KB gzipped. The simplicity-to-power ratio is exceptional for 80% of state management use cases.

Redux Toolkit: For Complex Middleware Requirements

Redux Toolkit (RTK) is the official, opinionated Redux package that eliminates the boilerplate of raw Redux — no more action type constants, action creators, and verbose reducers. RTK Query, included with Redux Toolkit, provides data fetching and caching comparable to React Query with the advantage of living in the Redux store. Choose Redux Toolkit when: the team has deep Redux expertise, the application needs complex middleware (offline sync, undo/redo, complex side effects via Redux Saga), or RTK Query's integration with existing Redux state is valuable.

Jotai and Recoil: Atomic State

Jotai and Recoil implement atomic state — state composed of small, independent atoms that components subscribe to individually. This model produces very granular re-renders (only components subscribed to changed atoms re-render) and enables derived state through computed atoms. Jotai is simpler and more actively maintained than Recoil in 2026. Choose atomic state management for applications with many independent state values that different component trees subscribe to independently. Download React state management boilerplates at proofmatcher.com.

Originally published at https://proofmatcher.com/blogs/react-state-management-2026

Responsive Web Design: Complete Guide for 2026

Proof Matcher — Mon, 27 Apr 2026 06:36:04 +0000

Responsive Design in 2026: Beyond Media Queries

Responsive web design has evolved significantly since Ethan Marcotte coined the term in 2010. The core principle — designs that adapt to any viewport size — remains, but the tools have expanded dramatically. Container queries enable component-level responsiveness independent of viewport size. Fluid typography using clamp() eliminates the need for typography-specific breakpoints. The has() CSS selector enables parent-based responsive logic. CSS Grid with auto-fill and auto-fit creates fully responsive layouts without any breakpoints at all. Modern responsive design is less about breakpoints and more about fluid, intrinsic layouts.

Mobile-First: The Correct Approach

Mobile-first means writing base CSS for the smallest screen size and adding complexity for larger screens with min-width media queries. This approach produces cleaner CSS than desktop-first (which requires overriding desktop styles for mobile) and matches how browsers process stylesheets — simpler styles load first on all devices. The mobile layout is typically a single column with maximum content width; larger viewports add columns, increase font sizes, and reveal navigation elements hidden on mobile.

Fluid Typography with clamp()

clamp(minimum, preferred, maximum) produces values that scale smoothly between a minimum and maximum based on the viewport width. font-size: clamp(1rem, 2.5vw, 1.5rem) scales from 16px on small screens to 24px on large screens without any media queries. The preferred value uses viewport units (vw, vh, vmin) or calc() expressions to create the fluid range. Fluid typography eliminates the jarring font size jumps that occur with breakpoint-based typography changes and produces more visually polished results at every screen size.

Container Queries: The Future is Here

Container queries change a component's styles based on the size of its parent container, not the viewport. A card component can display as a horizontal layout when inside a wide container and a vertical layout when inside a narrow sidebar — without any JavaScript and without knowing anything about the viewport. Apply container-type: inline-size to the parent, then use @container (min-width: 400px) to define styles for the component when its container is wide enough. Container queries are now baseline across all major browsers and should be the default approach for component-level responsive design.

Responsive Images

Use the srcset and sizes attributes to serve correctly-sized images at every viewport size. The browser downloads only the appropriate image variant, saving bandwidth on mobile devices. The picture element enables art direction — showing a cropped portrait image on mobile and a wide landscape on desktop. Next.js's Image component handles all of this automatically including WebP conversion and lazy loading. ProofMatcher's responsive templates implement all these patterns — download free at proofmatcher.com.

Originally published at https://proofmatcher.com/blogs/responsive-web-design-guide-2026