/* ============================================================
   AMERICAN AIR CONTROL — Base (Reset + Typography + Grid)
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--fg);
  background: var(--bg-dark);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  position: relative;
}

/* Atmospheric gradient background */
body::before {
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(0, 180, 216, 0.06) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(249, 115, 22, 0.04) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(0, 119, 182, 0.03) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
  animation: bgShift 20s ease-in-out infinite alternate;
}

@keyframes bgShift {
  0% { opacity: 0.8; }
  50% { opacity: 1; }
  100% { opacity: 0.8; }
}

/* Subtle grid pattern */
body::after {
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image:
    linear-gradient(rgba(0, 180, 216, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 180, 216, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
}

/* Ensure all content sits above background effects */
.site-header, main, .site-footer, #air-particles ~ * {
  position: relative;
  z-index: 1;
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--bg-glass-strong); border-radius: var(--radius-full); }

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: color var(--duration) var(--ease); }
a:hover { color: var(--primary-light); }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font: inherit; color: inherit; }
input, textarea, select { font: inherit; color: inherit; }

/* Container */
.container { width: 100%; max-width: var(--max-w); margin: 0 auto; padding: 0 var(--space-6); }
.container-sm { max-width: var(--max-w-sm); }
.container-md { max-width: var(--max-w-md); }

/* Grid */
.grid { display: grid; gap: var(--space-6); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
}

/* Flex */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* Text */
.text-center { text-align: center; }
.text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }
.text-muted { color: var(--fg-muted); }
.text-primary { color: var(--primary); }
.text-accent { color: var(--accent); }
.font-display { font-family: var(--font-display); }
.font-mono { font-family: var(--font-mono); }
.font-bold { font-weight: var(--weight-bold); }
.font-black { font-weight: var(--weight-black); }
.uppercase { text-transform: uppercase; letter-spacing: 0.05em; }

/* Spacing */
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }
.w-full { width: 100%; }

/* Section */
.section { padding: var(--space-20) 0; }
.section-sm { padding: var(--space-12) 0; }

/* Scroll Reveal */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.6s var(--ease), transform 0.6s var(--ease); }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* Screen reader only */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}