/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Brand Colors - Scientific Britain */
  --primary: #222222;
  --primary-dark: #000000;
  --accent: #669BBC;
  --accent-hover: #5A8AAF;
  --bg-primary: #FDF0D5;
  --bg-secondary: #F5E6C8;
  --bg-card: #FFFFFF;
  --text-primary: #222222;
  --text-secondary: #555555;
  --border-color: #E0D0B7;
  --oxblood: #780000;
  --signal: #C1121F;
  --prussian: #669BBC;
  
  /* Typography */
  --font-heading: 'Libre Baskerville', serif;
  --font-body: 'Montserrat', sans-serif;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-xxl: 4rem;
  
  /* Layout */
  --max-width: 1200px;
  --header-height: 80px;
  
  /* Transitions */
  --transition: 0.3s ease;
}

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

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  padding-top: var(--header-height);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
  color: var(--primary);
}

h1 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
}

h2 {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: 1.5rem;
}

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: var(--spacing-sm);
  font-family: var(--font-heading);
  font-size: 1rem;
  line-height: 1.7;
}

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

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

/* Layout utilities */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section-padding {
  padding: var(--spacing-xxl) 0;
}

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

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

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

.margin-bottom-lg {
  margin-bottom: var(--spacing-lg);
}

.margin-bottom-xl {
  margin-bottom: var(--spacing-xl);
}

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

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

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

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(200px, 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-column {
  flex-direction: column;
}

.flex-wrap {
  flex-wrap: wrap;
}

/* Hide/show utilities */
.hidden {
  display: none;
}

.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;
}

/* Responsive utilities */
@media (max-width: 768px) {
  :root {
    --spacing-xxl: 2rem;
    --spacing-xl: 1.5rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.75rem;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.75rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
}

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

/* Focus styles */
:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Selection styles */
::selection {
  background: var(--accent);
  color: white;
}