/* Base CSS - Reset & Foundations */

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

:root {
  /* Color Palette - Cyan/Teal Theme */
  --color-primary: #0ea5e9;
  --color-secondary: #06b6d4;
  --color-accent: #14b8a6;
  --color-dark: #0f172a;
  --color-dark-lighter: #1e293b;
  --color-gray: #64748b;
  --color-gray-light: #cbd5e1;
  --color-bg: #f8fafc;
  --color-white: #ffffff;
  --color-warning: #f59e0b;
  
  /* Typography */
  --font-sans: system-ui, -apple-system, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-display: 'Georgia', 'Times New Roman', serif;
  
  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
}

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-dark);
  background-color: var(--color-bg);
  min-height: 100vh;
}

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

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

a:hover {
  color: var(--color-secondary);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style-position: inside;
}

/* Utility Classes */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.section {
  padding: var(--space-3xl) 0;
}

.section-alt {
  background-color: var(--color-white);
}

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Typography Utilities */
.heading-xl {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-dark);
  margin-bottom: var(--space-md);
}

.heading-lg {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-dark);
  margin-bottom: var(--space-md);
}

.heading-md {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-dark);
  margin-bottom: var(--space-sm);
}

.heading-sm {
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-dark);
  margin-bottom: var(--space-sm);
}

.text-gradient {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.lead {
  font-size: 1.25rem;
  line-height: 1.7;
  color: var(--color-gray);
  margin-bottom: var(--space-lg);
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* Flexbox Utilities */
.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-col {
  display: flex;
  flex-direction: column;
}

.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

/* Responsive */
@media (max-width: 768px) {
  .section {
    padding: var(--space-2xl) 0;
  }
  
  .container {
    padding: 0 var(--space-sm);
  }
}