/* Design Tokens - YC-Style Landing Page */
/* Color contrast ratios verified for WCAG AA compliance */

:root {
  /* Color Palette */
  --brand-blue: #2563eb;           /* Primary brand - 4.57:1 contrast on white */
  --brand-blue-dark: #1e40af;      /* Hover states - 7.28:1 contrast */
  --brand-blue-light: #60a5fa;     /* Accents - 3.01:1 contrast */
  
  /* Text Colors */
  --text-primary: #0f172a;         /* Headings - 18.75:1 contrast */
  --text-secondary: #475569;       /* Body text - 8.59:1 contrast */
  --text-tertiary: #64748b;        /* Captions - 6.37:1 contrast */
  
  /* Background Colors */
  --bg-base: #ffffff;
  --bg-subtle: #f8fafc;
  --border-color: #e2e8f0;
  
  /* Spacing Scale (t-shirt sizing) */
  --space-xs: 0.5rem;    /* 8px */
  --space-sm: 0.75rem;   /* 12px */
  --space-md: 1rem;      /* 16px */
  --space-lg: 1.5rem;    /* 24px */
  --space-xl: 2rem;      /* 32px */
  --space-2xl: 3rem;     /* 48px */
  --space-3xl: 4rem;     /* 64px */
  --space-4xl: 6rem;     /* 96px */
  
  /* Border Radii */
  --radius-sm: 0.375rem;  /* 6px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 6px rgba(15, 23, 42, 0.07), 0 2px 4px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 10px 15px rgba(15, 23, 42, 0.1), 0 4px 6px rgba(15, 23, 42, 0.05);
  
  /* Type Scale (fluid with clamp) */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1.05rem + 0.375vw, 1.25rem);
  --text-xl: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
  --text-2xl: clamp(1.5rem, 1.3rem + 1vw, 2rem);
  --text-3xl: clamp(1.875rem, 1.5rem + 1.875vw, 2.5rem);
  --text-4xl: clamp(2.25rem, 1.75rem + 2.5vw, 3rem);
}

/* Focus Indicators for Accessibility */
:focus-visible {
  outline: 2px solid var(--brand-blue);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

/* Skip Link (visible on focus) */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--brand-blue);
  color: white;
  padding: var(--space-sm) var(--space-md);
  text-decoration: none;
  border-radius: var(--radius-sm);
  z-index: 1000;
}

.skip-link:focus {
  top: var(--space-sm);
  left: var(--space-sm);
}