/* ==================================================
   INDUSTRIAL AIR — Base Styles (Reset + Foundation)
   Adapted from Stitch base patterns.
   ================================================== */

/* ---- Modern CSS reset (from Stitch box-sizing pattern) ---- */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

html, body {
  margin: 0;
  width: 100%;
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  background: var(--color-background);
  color: var(--ia-on-surface-dim);
  font-family: var(--font-body);
  font-size: var(--text-body-md);
  line-height: 1.6;
  -webkit-tap-highlight-color: transparent;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* ---- Selection colour (airflow cyan) ---- */
::selection {
  background: var(--ia-cyan);
  color: var(--ia-navy-900);
}

/* ---- Button font inheritance ---- */
button, input, textarea, select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: 0;
  background: transparent;
  padding: 0;
  font: inherit;
  color: inherit;
}

/* ---- Skip link (from Stitch) ---- */
.skip-link {
  position: fixed;
  left: var(--space-sm);
  top: -50px;
  z-index: 200;
  background: var(--ia-on-surface-dim);
  color: var(--ia-navy-900);
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: 0.25rem;
  transition: top 0.3s var(--ia-ease);
}

.skip-link:focus {
  top: var(--space-sm);
  outline: var(--focus-ring);
  outline-offset: var(--focus-ring-offset);
}

/* ---- Focus visible (from Stitch) ---- */
:focus-visible {
  outline: var(--focus-ring);
  outline-offset: var(--focus-ring-offset);
}

/* ---- Typography: headings ---- */
h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: var(--font-display-bold);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ia-on-surface);
}

h1 { font-size: var(--text-display-hero); }
h2 { font-size: var(--text-headline-xl); }
h3 { font-size: var(--text-headline-lg); }
h4 { font-size: var(--text-headline-md); }
h5 { font-size: var(--text-headline-sm); }
h6 { font-size: var(--text-body-lg); }

/* ---- Typography: body ---- */
p {
  margin: 0;
  font-family: var(--font-body);
  font-weight: var(--font-body-regular);
  color: var(--ia-on-surface-dim);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s var(--ia-ease);
}

a:hover {
  color: var(--ia-cyan);
}

/* ---- Typography: monospace (technical data) ---- */
code, .spec-code {
  font-family: var(--font-mono);
  font-size: var(--text-spec-code);
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ia-on-surface-variant);
}

/* ---- Uppercase label pattern (from Stitch) ---- */
.label-caps {
  font-family: var(--font-mono);
  font-size: var(--text-label-caps);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ---- Layout container ---- */
.container {
  width: min(100% - 2rem, var(--container-max));
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--margin-mobile);
  padding-right: var(--margin-mobile);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--margin-desktop);
    padding-right: var(--margin-desktop);
  }
}

/* ---- Section spacing ---- */
.section {
  width: 100%;
  padding: var(--space-2xl) 0;
}

.section-compact {
  width: 100%;
  padding: var(--space-xl) 0;
}

/* ---- Background atmospheric overlay (premium light theme) ---- */
.bg-atmosphere::before {
  content: "";
  position: absolute;
  inset: 0;
  background: 
    linear-gradient(90deg, rgba(248,250,252,0.95), rgba(241,245,249,0.8) 67%),
    linear-gradient(0deg, rgba(248,250,252,0.98), transparent 48%, rgba(241,245,249,0.6));
  pointer-events: none;
  z-index: 0;
}

.bg-radial-cool::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 44%, rgba(0,229,190,0.08), transparent 48%);
  pointer-events: none;
  z-index: 0;
}

/* ---- Premium dark sections (for contrast) ---- */
.bg-dark::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, var(--ia-dark-surface-0) 0%, var(--ia-dark-surface-100) 100%);
  pointer-events: none;
  z-index: 0;
}

/* ---- Blueprint grid pattern (premium light theme) ---- */
.blueprint-grid {
  background-size: 24px 24px;
  background-image:
    linear-gradient(to right, rgba(203, 213, 225, 0.3) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(203, 213, 225, 0.3) 1px, transparent 1px);
}

.blueprint-grid--dark {
  background-size: 24px 24px;
  background-image:
    linear-gradient(to right, rgba(66, 70, 86, 0.12) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(66, 70, 86, 0.12) 1px, transparent 1px);
}

/* ---- Signal line (from Stitch signal-lines) ---- */
.signal-line--vertical {
  width: 1px;
  height: 68px;
  background: linear-gradient(var(--ia-turquoise), transparent);
}

.signal-line--horizontal {
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, var(--ia-cyan), var(--ia-turquoise), transparent);
}

/* ---- Airflow ribbon divider ---- */
.airflow-divider {
  height: 1px;
  width: 100%;
  background: var(--ia-gradient-primary);
  opacity: 0.3;
}

/* ---- Utility classes ---- */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-xs { margin-top: var(--space-xs); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }

.mb-xs { margin-bottom: var(--space-xs); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

.glow-aero-cyan {
  box-shadow: 0 0 32px -6px rgba(0, 210, 255, 0.28);
}

.glow-aero-emerald {
  box-shadow: 0 0 24px -4px rgba(16, 185, 129, 0.25);
}

/* ---- Scrollbar (from Stitch styling) ---- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--ia-surface-100);
}

::-webkit-scrollbar-thumb {
  background: rgba(0, 210, 255, 0.2);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(0, 210, 255, 0.4);
}