:root {
  /* Colors */
  --primary-color: #2563EB; /* Blue */
  --primary-color-hover: #1D4ED8;
  --secondary-color: #3B82F6;
  --gradient-bg: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 50%, #FFFFFF 100%);
  --gradient-primary: linear-gradient(135deg, #2563EB 0%, #3B82F6 100%);
  --text-main: #0F172A;
  --text-muted: #64748B;
  --bg-color: #FAFAFA;
  --bg-card: rgba(255, 255, 255, 0.85); /* Glassmorphism */
  --border-color: #E2E8F0;
  --white: #FFFFFF;
  --success: #10B981;
  --warning: #F59E0B;
  --error: #EF4444;

  /* Typography */
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  
  /* 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);
  --shadow-glow: 0 0 15px rgba(59, 130, 246, 0.4);

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-pill: 9999px;
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  background: var(--gradient-bg);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.5em;
  color: var(--text-main);
}

p {
  color: var(--text-muted);
  margin-bottom: 1rem;
}

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

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

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  width: 100%;
}

/* Glassmorphism Classes */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-pill);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-normal);
  border: none;
  font-size: 1rem;
  text-align: center;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--white);
  box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(37, 99, 235, 0.3);
  color: var(--white);
}

.btn-secondary {
  background: var(--white);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: #F8FAFC;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

.btn-outline:hover {
  background: var(--primary-color);
  color: var(--white);
}

/* Header & Nav */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.header.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo span {
  color: var(--text-main);
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-main);
  font-weight: 500;
}

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

/* Main Content */
main {
  flex: 1;
  padding-top: 80px; /* offset header */
}

/* Footer */
footer {
  background: var(--white);
  padding: 4rem 0 2rem;
  border-top: 1px solid var(--border-color);
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-col h4 {
  margin-bottom: 1rem;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 0.5rem;
}

.footer-col a {
  color: var(--text-muted);
}

.footer-col a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
}

/* Utilities */
.text-center { text-align: center; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mb-5 { margin-bottom: 3rem; }
.mt-4 { margin-top: 2rem; }
.mt-5 { margin-top: 3rem; }

/* Responsive Grid */
.grid {
  display: grid;
  gap: 2rem;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

@media (max-width: 768px) {
  .nav-links {
    display: none; /* simple mobile hide for now */
  }
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
  .container {
    padding: 0 1rem;
  }
}