:root {
  /* Color System - Light Mode */
  --bg-primary: #ffffff;
  --bg-secondary: #f4f5f7;
  --bg-tertiary: #eaecf0;
  --text-primary: #101828;
  --text-secondary: #475467;
  --text-tertiary: #667085;
  --accent-primary: #4f46e5;
  --accent-hover: #4338ca;
  --border-color: #e4e7ec;
  
  /* Glassmorphism System - Light */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.4);
  --glass-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);

  /* Typography System */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;

  /* Spacing System */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;

  /* Animation System */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* 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);
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: #0a0a0a;
  --bg-secondary: #171717;
  --bg-tertiary: #262626;
  --text-primary: #ededed;
  --text-secondary: #a3a3a3;
  --text-tertiary: #737373;
  --accent-primary: #6366f1;
  --accent-hover: #818cf8;
  --border-color: #262626;
  
  /* Glassmorphism System - Dark */
  --glass-bg: rgba(10, 10, 10, 0.7);
  --glass-border: rgba(255, 255, 255, 0.05);
  --glass-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

/* Resets & Base Typography */
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 { font-weight: 600; line-height: 1.2; color: var(--text-primary); }
a { color: var(--text-primary); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--accent-primary); }

/* Layout & Spacing */
.container { max-width: 1200px; margin: 0 auto; padding: 0 var(--spacing-6); }
.py-8 { padding-top: var(--spacing-8); padding-bottom: var(--spacing-8); }
.py-16 { padding-top: var(--spacing-16); padding-bottom: var(--spacing-16); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-8 { margin-bottom: var(--spacing-8); }

/* Glassmorphism Class */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

/* Base Components */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: 6px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  font-family: var(--font-sans);
}
.btn-primary { background: var(--accent-primary); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); }

/* Sticky Header */
.sticky-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border-color);
}
.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}
.logo { font-size: var(--text-xl); font-weight: 700; display: flex; align-items: center; gap: var(--spacing-2);}
.desktop-nav { display: none; gap: var(--spacing-6); }
@media (min-width: 768px) { .desktop-nav { display: flex; } }
.nav-link { color: var(--text-secondary); font-weight: 500; }
.nav-link:hover { color: var(--text-primary); }
.header-actions { display: flex; align-items: center; gap: var(--spacing-4); }

/* Mobile Navigation */
.mobile-nav-toggle { display: block; background: none; border: none; color: var(--text-primary); cursor: pointer; font-size: var(--text-xl); }
@media (min-width: 768px) { .mobile-nav-toggle { display: none; } }
.mobile-nav-menu {
  display: none; position: absolute; top: 64px; left: 0; right: 0;
  background: var(--bg-primary); border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-4); flex-direction: column; gap: var(--spacing-4);
}
.mobile-nav-menu.active { display: flex; }

/* Premium Footer */
.premium-footer { background: var(--bg-secondary); border-top: 1px solid var(--border-color); padding: var(--spacing-12) 0; margin-top: auto; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: var(--spacing-8); }
.footer-heading { font-weight: 600; margin-bottom: var(--spacing-4); color: var(--text-primary); }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: var(--spacing-2); }
.footer-links a { color: var(--text-secondary); }

/* Command Palette */
.cmd-palette-overlay {
  position: fixed; top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5); z-index: 999;
  display: none; align-items: flex-start; justify-content: center; padding-top: 10vh;
  backdrop-filter: blur(4px);
}
.cmd-palette-overlay.active { display: flex; }
.cmd-palette {
  width: 100%; max-width: 600px; background: var(--bg-primary);
  border-radius: 12px; border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg); overflow: hidden;
}
.cmd-input {
  width: 100%; padding: var(--spacing-4) var(--spacing-6); border: none;
  border-bottom: 1px solid var(--border-color); background: transparent;
  color: var(--text-primary); font-size: var(--text-lg); outline: none;
}
.cmd-results { max-height: 300px; overflow-y: auto; padding: var(--spacing-2); }
.cmd-item {
  padding: var(--spacing-3) var(--spacing-4); border-radius: 6px;
  cursor: pointer; display: flex; align-items: center; gap: var(--spacing-3); color: var(--text-secondary);
}
.cmd-item:hover, .cmd-item.selected { background: var(--bg-secondary); color: var(--text-primary); }

/* Grid Layouts for Hubs & Collections */
.grid-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: var(--spacing-6); }
.card {
  background: var(--bg-secondary); border: 1px solid var(--border-color);
  border-radius: 12px; padding: var(--spacing-6); transition: var(--transition-normal);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--accent-primary); }

/* Theme Toggle Button */
.theme-toggle { background: none; border: none; color: var(--text-primary); cursor: pointer; font-size: 1.2rem; padding: var(--spacing-1); border-radius: 50%; transition: background var(--transition-fast);}
.theme-toggle:hover { background: var(--bg-tertiary); }