/* CSS Variables for theming */
:root {
  --bg-color: #ffffff;
  --text-color: #333333;
  --text-secondary: #666666;
  --accent-color: #007acc;
  --border-color: #e0e0e0;
  --hover-bg: #f5f5f5;
}

[data-theme="dark"] {
  --bg-color: #0d1117;
  --text-color: #e6edf3;
  --text-secondary: #8b949e;
  --accent-color: #58a6ff;
  --border-color: #30363d;
  --hover-bg: #161b22;
}

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

html {
  font-size: 16px;
  line-height: 1.6;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s ease, color 0.3s ease;
  font-weight: 400;
  letter-spacing: -0.2px;
}

/* Container and layout */
.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 3rem 2rem;
  min-height: 100vh;
  line-height: 1.6;
}

/* Header */
.header {
  margin-bottom: 3rem;
}

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

.nav-link {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
}

.nav-link:hover {
  color: var(--accent-color);
}

.theme-toggle button {
  background: none;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 0.25rem;
  transition: background-color 0.3s ease;
}

.theme-toggle button:hover {
  background-color: var(--hover-bg);
}

/* Main content */
main {
  flex: 1;
}

/* Typography */
h1 {
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-color);
  line-height: 1.2;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  margin-top: 2.5rem;
  color: var(--text-color);
}

h3 {
  font-size: 1.1rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
  color: var(--text-color);
}

p {
  margin-bottom: 1rem;
  color: var(--text-color);
  font-size: 1.1rem;
}

/* Links */
a {
  color: var(--accent-color);
  text-decoration: none;
  transition: opacity 0.3s ease;
}

a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

/* Sections */
.section {
  margin-bottom: 2.5rem;
}

.intro {
  margin-bottom: 3rem;
}

.intro h1 {
  margin-bottom: 0.5rem;
}

.intro p {
  font-size: 1.2rem;
  line-height: 1.5;
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
  font-style: italic;
}

/* Lists */
ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

li {
  margin-bottom: 0.75rem;
  line-height: 1.6;
}

li:last-child {
  margin-bottom: 0;
}

.contact-list {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.contact-list li {
  margin-bottom: 0;
}



/* Responsive design */
@media (max-width: 768px) {
  .container {
    padding: 2rem 1.5rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.1rem;
    margin-top: 2rem;
  }
  
  .intro p {
    font-size: 1.1rem;
  }
  
  .contact-list {
    gap: 1rem;
  }
  
  nav {
    flex-direction: column;
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 1.5rem 1rem;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1rem;
  }
  
  .contact-list {
    flex-direction: column;
    gap: 0.5rem;
    align-items: flex-start;
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Focus styles for accessibility */
button:focus,
a:focus {
  outline: 2px solid var(--accent-color);
  outline-offset: 2px;
}

/* Print styles */
@media print {
  .theme-toggle {
    display: none;
  }
  
  .container {
    max-width: none;
    padding: 0;
  }
  
  a {
    color: var(--text-color);
    text-decoration: underline;
  }
}