/* Variables */
:root {
  /* Colors */
  --color-background: #ffffff; /* clean white */
  --color-text: #2c2c2c; /* graphite black */
  --color-primary: #b22222; /* deep red */
  --color-success: #228b22; /* green for success */
  --color-warning: #ffa500; /* orange for warning */
  --color-danger: #dc143c; /* crimson for danger */
  --color-gray-100: #f5f5f5; /* light steel gray */
  --color-gray-200: #e0e0e0; /* metallic silver light */
  --color-gray-300: #b0b0b0; /* steel gray */
  --color-gray-400: #808080; /* steel gray medium */
  --color-gray-500: #505050; /* graphite black light */
  --color-gray-600: #404040; /* graphite black */
  --color-gray-700: #303030; /* deep graphite */
  --color-gray-800: #202020; /* dark graphite */
  --color-gray-900: #101010; /* very dark graphite */

  /* Typography */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; /* modern sans-serif */
  --font-family-secondary: 'Roboto Condensed', sans-serif; /* for headings, tech feel */
  --font-size-xs: 0.75rem; /* 12px */
  --font-size-sm: 0.875rem; /* 14px */
  --font-size-base: 1rem; /* 16px */
  --font-size-lg: 1.125rem; /* 18px */
  --font-size-xl: 1.25rem; /* 20px */
  --font-size-2xl: 1.5rem; /* 24px */
  --font-size-3xl: 1.875rem; /* 30px */
  --font-size-4xl: 2.25rem; /* 36px */
  --font-size-5xl: 3rem; /* 48px */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing */
  --spacing-0: 0;
  --spacing-1: 0.25rem; /* 4px */
  --spacing-2: 0.5rem; /* 8px */
  --spacing-3: 0.75rem; /* 12px */
  --spacing-4: 1rem; /* 16px */
  --spacing-5: 1.25rem; /* 20px */
  --spacing-6: 1.5rem; /* 24px */
  --spacing-8: 2rem; /* 32px */
  --spacing-10: 2.5rem; /* 40px */
  --spacing-12: 3rem; /* 48px */
  --spacing-16: 4rem; /* 64px */
  --spacing-20: 5rem; /* 80px */
  --spacing-24: 6rem; /* 96px */

  /* Border Radius */
  --radius-sm: 0.25rem; /* 4px */
  --radius-md: 0.5rem; /* 8px */
  --radius-lg: 0.75rem; /* 12px */
  --radius-xl: 1rem; /* 16px */

  /* 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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 400ms ease-in-out;
}

/* Reset / Normalize */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-family-secondary);
  font-weight: 700;
  line-height: var(--line-height-tight);
}

p {
  margin: 0 0 var(--spacing-4) 0;
  /* comfortable line length */
}

img, video {
  max-width: 100%;
  height: auto;
}

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

a:hover {
  color: var(--color-gray-700);
}

/* Base */
/* Body styles */
body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Headings */
h1 { font-size: var(--font-size-4xl); margin-bottom: var(--spacing-4); }
h2 { font-size: var(--font-size-3xl); margin-bottom: var(--spacing-3); }
h3 { font-size: var(--font-size-2xl); margin-bottom: var(--spacing-3); }
h4 { font-size: var(--font-size-xl); margin-bottom: var(--spacing-2); }
h5 { font-size: var(--font-size-lg); margin-bottom: var(--spacing-2); }
h6 { font-size: var(--font-size-base); margin-bottom: var(--spacing-2); }

/* Links */
a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Utilities */
/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding-left: var(--spacing-4);
  padding-right: var(--spacing-4);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--spacing-8);
    padding-right: var(--spacing-8);
  }
}

/* Flex helpers */
.flex {
  display: flex;
}

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

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

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

/* Grid helpers */
.grid {
  display: grid;
}

.grid-cols-1 {
  grid-template-columns: repeat(1, minmax(0, 1fr));
}

.grid-cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid-cols-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.gap-4 {
  gap: var(--spacing-4);
}

.gap-6 {
  gap: var(--spacing-6);
}

/* 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;
}

/* Components */
/* Button */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3) var(--spacing-6);
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: var(--color-background)!important;
  background-color: var(--color-primary);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.btn:hover {
  background-color: var(--color-gray-700);
  border-color: var(--color-gray-700);
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-secondary {
  color: var(--color-primary)!important;
  background-color: transparent;
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  color: var(--color-background)!important;
  background-color: var(--color-primary);
}

/* Input */
.input {
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(178, 34, 34, 0.1);
}

/* Card */
.card {
  padding: var(--spacing-6);
  background-color: var(--color-background);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: box-shadow var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-lg);
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus visible */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}