:root {
  /* Colors */
  --color-primary: #6200ee;
  --color-primary-dark: #3700b3;
  --color-text: #1a1a1a;
  --color-text-light: #666666;
  --color-border: #e0e0e0;
  --color-border-dark: #bdbdbd;
  --color-background: #f5f5f5;
  --color-background-dark: #e8e8e8;
  --color-white: #ffffff;

  /* Typography */
  --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: 'SF Mono', SFMono-Regular, ui-monospace, 'DejaVu Sans Mono', Menlo, Consolas, monospace;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.1);
  --shadow-md: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 8px rgba(0,0,0,0.1);
}

/* Base Styles */
body {
  margin: 0;
  padding: 0;
  font-family: var(--font-main);
  background: var(--color-background);
  color: var(--color-text);
  line-height: 1.5;
}

/* Layout */
.app-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.main-content {
  flex: 1;
  padding: var(--spacing-md);
}

/* Navigation */
.top-nav {
  background: var(--color-white);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
}

.nav-links a {
  color: var(--color-text-light);
  text-decoration: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: 4px;
  transition: all 0.2s;
}

.nav-links a:hover {
  background: var(--color-background);
}

.nav-links a.active {
  color: var(--color-primary);
  background: var(--color-background);
}

.back-link {
  color: var(--color-text-light);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.back-link:hover {
  color: var(--color-text);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--spacing-md);
  font-weight: 500;
  color: var(--color-text);
}

h2 {
  font-size: 24px;
}