Responsive design with media queries and mobile-first approach

                  /* Mobile-first base styles (no media query needed) */
.container {
  width: 100%;
  padding: 1rem;
  margin: 0 auto;
}

.grid {
  display: grid;
  grid-template-columns: 1fr; /* Single column on mobile */
  gap: 1rem;
}

.nav {
  flex-direction: column;
}

/* Small tablets - 640px */
@media (min-width: 640px) {
  .container {
    max-width: 640px;
  }

  .grid {
    grid-template-columns: repeat(2, 1fr); /* 2 columns */
  }

  .text-sm-center {
    text-align: center;
  }
}

/* Tablets - 768px */
@media (min-width: 768px) {
  .container {
    max-width: 768px;
    padding: 1.5rem;
  }

  .grid {
    grid-template-columns: repeat(3, 1fr); /* 3 columns */
  }

  .nav {
    flex-direction: row;
  }

  .sidebar {
    display: block; /* Show sidebar on tablets */
  }

  h1 {
    font-size: 2.5rem;
  }
}

/* Desktop - 1024px */
@media (min-width: 1024px) {
  .container {
    max-width: 1024px;
    padding: 2rem;
  }

  .grid {
    grid-template-columns: repeat(4, 1fr); /* 4 columns */
    gap: 2rem;
  }

  .two-column-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
  }

  h1 {
    font-size: 3rem;
  }
}

/* Large desktop - 1280px */
@media (min-width: 1280px) {
  .container {
    max-width: 1280px;
  }

  .grid-wide {
    grid-template-columns: repeat(6, 1fr);
  }
}

/* Extra large - 1536px */
@media (min-width: 1536px) {
  .container {
    max-width: 1536px;
  }
}

/* Max-width queries (desktop-first approach - less common) */
@media (max-width: 767px) {
  .hide-on-mobile {
    display: none;
  }
}

/* Range queries (between two breakpoints) */
@media (min-width: 768px) and (max-width: 1023px) {
  .tablet-only {
    display: block;
  }
}

/* Orientation queries */
@media (orientation: portrait) {
  .portrait-layout {
    flex-direction: column;
  }
}

@media (orientation: landscape) {
  .landscape-layout {
    flex-direction: row;
  }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #1a1a1a;
    --text-color: #ffffff;
    --border-color: #444;
  }

  body {
    background-color: var(--bg-color);
    color: var(--text-color);
  }

  .card {
    background: #2a2a2a;
    border-color: var(--border-color);
  }
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-color: #ffffff;
    --text-color: #000000;
    --border-color: #ddd;
  }
}

/* Reduced motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* High contrast mode */
@media (prefers-contrast: high) {
  .button {
    border: 2px solid currentColor;
  }
}

/* Print styles */
@media print {
  .no-print {
    display: none;
  }

  body {
    font-size: 12pt;
    color: black;
    background: white;
  }

  a {
    text-decoration: underline;
    color: black;
  }

  a[href]::after {
    content: " (" attr(href) ")";
  }
}

/* Hover capability detection */
@media (hover: hover) and (pointer: fine) {
  .button:hover {
    background: blue;
  }
}

/* Touch device detection */
@media (hover: none) and (pointer: coarse) {
  .button {
    padding: 1rem; /* Larger touch targets */
    min-height: 44px;
  }
}

/* Container queries (modern approach) */
.card-container {
  container-type: inline-size;
  container-name: card;
}

@container card (min-width: 400px) {
  .card {
    display: grid;
    grid-template-columns: 150px 1fr;
  }
}

/* Fluid typography with clamp() */
h1 {
  font-size: clamp(1.5rem, 5vw, 3rem);
  /* min: 1.5rem, preferred: 5vw, max: 3rem */
}

p {
  font-size: clamp(1rem, 2vw + 0.5rem, 1.25rem);
}

/* Responsive spacing */
.section {
  padding: clamp(1rem, 5vw, 3rem);
  margin-bottom: clamp(2rem, 10vh, 5rem);
}

/* Aspect ratio for responsive media */
.video-container {
  aspect-ratio: 16 / 9;
}

@media (max-width: 767px) {
  .video-container {
    aspect-ratio: 4 / 3;
  }
}

/* Responsive utilities */
@media (min-width: 768px) {
  .md\:hidden { display: none; }
  .md\:block { display: block; }
  .md\:flex { display: flex; }
  .md\:grid { display: grid; }
}

@media (min-width: 1024px) {
  .lg\:w-1\/2 { width: 50%; }
  .lg\:w-1\/3 { width: 33.333333%; }
  .lg\:w-2\/3 { width: 66.666667%; }
}

/* Responsive images */
img {
  max-width: 100%;
  height: auto;
}

.responsive-img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

@media (min-width: 768px) {
  .responsive-img {
    width: 50%;
  }
}