/* ============================================
   Solve Engineering — Shared Design Base
   ============================================ */

:root {
  /* Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-glass: rgba(255, 255, 255, 0.95);
  --bg-input: #ffffff;
  --border-glass: rgba(0, 0, 0, 0.08);
  --border-input: rgba(0, 0, 0, 0.12);
  --border-focus: rgba(30, 58, 138, 0.5);

  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;

  --accent-blue: #1e3a8a;
  --accent-violet: #3b82f6;
  --accent-cyan: #0ea5e9;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #e11d48;

  --gradient-primary: linear-gradient(135deg, #1e3a8a, #2563eb);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e3a8a 50%, #2563eb 100%);
  --gradient-card: linear-gradient(145deg, rgba(30, 58, 138, 0.03), rgba(37, 99, 235, 0.01));

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.5rem;
  --radius-2xl: 0.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.12);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.16);
  --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.2);
  --shadow-glow: 0 0 40px rgba(59, 130, 246, 0.15);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
}

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-fast);
}

img {
  max-width: 100%;
  display: block;
}

button {
  font-family: var(--font-family);
  cursor: pointer;
  border: none;
}

:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.55);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: var(--space-3);
  left: var(--space-3);
  z-index: 2000;
  padding: var(--space-2) var(--space-4);
  background: var(--text-primary);
  color: #ffffff;
  border-radius: var(--radius-md);
  transform: translateY(-160%);
  transition: transform var(--transition-fast);
}

.skip-link:focus {
  transform: translateY(0);
}

.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;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}