Responsive Web Design: One Website, Every Screen

The Multi-Device Reality

Your users arrive on 320px phones, 768px tablets, 1920px desktops, and 4K monitors. Responsive design handles all with one codebase.

Mobile-First CSS

/* Mobile base styles */
.container { padding: 1rem; }
.nav { flex-direction: column; }

/* Tablet */
@media (min-width: 768px) {
    .container { max-width: 720px; margin: 0 auto; }
    .nav { flex-direction: row; }
}

/* Desktop */
@media (min-width: 1200px) {
    .container { max-width: 1140px; }
    .grid { grid-template-columns: repeat(3, 1fr); }
}

Auto-Responsive Grid

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

Fluid Typography

h1 {
    font-size: clamp(1.5rem, 4vw, 3rem);
    /* Min: 1.5rem, Preferred: 4vw, Max: 3rem */
}

Responsive Images

img {
    max-width: 100%;
    height: auto;
}

Testing

• Chrome DevTools device toolbar (Ctrl+Shift+M)
• Test on real devices when possible
• Ensure touch targets are 44x44px minimum