:root {
  /* Colors */
  --primary-color: #4361ee;
  --primary-hover: #3a56d4;
  --secondary-color: #3f37c9;
  --light-primary: #e6e9ff;
  --text-color: #2b2d42;
  --light-text: #8d99ae;
  --background-color: #f8f9fa;
  --white: #ffffff;
  --dark-bg: #1a1a2e;
  --border-color: #e9ecef;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;

  /* Typography */
  --font-base: 14px;
  --font-lg: 16px;
  --font-xl: 18px;

  /* Breakpoints */
  --bp-mobile: 480px;
  --bp-tablet: 768px;
  --bp-desktop: 1024px;
}

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

html {
  font-size: var(--font-base);
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-color);
}

@media (min-width: 768px) {
  html {
    font-size: var(--font-lg);
  }
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* Header & Navigation */
.main-header {
  background-color: var(--white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) 0;
  position: relative;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  z-index: 101;
}

.logo i {
  font-size: 1.75rem;
}

.mobile-menu-button {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-color);
  cursor: pointer;
  z-index: 101;
}

.auth-links {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

.user-welcome {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border-radius: 8px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  border: 1px solid transparent;
  min-height: 44px;
  min-width: 44px;
}

.btn span {
  display: inline-block;
}

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

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

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

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

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

.btn-secondary:hover {
  opacity: 0.9;
}

.btn-large {
  padding: var(--space-sm) var(--space-lg);
  font-size: 1.1rem;
}

/* Hero Section */
.hero {
  padding: var(--space-xl) 0;
  background-color: var(--white);
}

.hero .container {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.hero-image img {
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  max-height: 400px;
  object-fit: cover;
}

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

.hero h1 {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  color: var(--text-color);
}

.subtitle {
  font-size: 1.1rem;
  color: var(--light-text);
  margin-bottom: var(--space-lg);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.cta-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

/* Features Section */
.features {
  padding: var(--space-xl) 0;
  background-color: var(--background-color);
}

.features h2 {
  text-align: center;
  font-size: 1.75rem;
  margin-bottom: var(--space-xl);
  color: var(--text-color);
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

.feature-card {
  background: var(--white);
  padding: var(--space-lg);
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-10px);
}

.feature-icon {
  width: 60px;
  height: 60px;
  background-color: var(--light-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
}

.feature-icon i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
  color: var(--text-color);
}

.feature-card p {
  color: var(--light-text);
  line-height: 1.6;
}

/* Footer */
.main-footer {
  background-color: var(--dark-bg);
  color: var(--white);
  padding: var(--space-xl) 0 var(--space-md);
}

.footer-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand {
  max-width: 300px;
}

.footer-brand .logo {
  color: var(--white);
  margin-bottom: var(--space-sm);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  color: var(--light-text);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-md);
  text-align: center;
  color: var(--light-text);
  font-size: 0.9rem;
}

/* Messages */
.messages {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  max-width: 400px;
  width: 90%;
}

.alert {
  padding: var(--space-sm);
  margin-bottom: var(--space-sm);
  border-radius: 4px;
  color: white;
  animation: slideIn 0.3s ease-out;
}

.alert-success {
  background-color: #28a745;
}

.alert-error {
  background-color: #dc3545;
}

@keyframes slideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* Tablet Styles */
@media (min-width: 768px) {
  .hero .container {
    flex-direction: row;
    align-items: center;
  }
  
  .hero-content {
    text-align: left;
    flex: 1;
  }
  
  .hero-image {
    flex: 1;
  }
  
  .cta-buttons {
    flex-direction: row;
  }
  
  .features-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  }
  
  .footer-content {
    flex-direction: row;
    justify-content: space-between;
  }
  
  .footer-links {
    flex-direction: row;
    flex-wrap: wrap;
  }
}

/* Desktop Styles */
@media (min-width: 1024px) {
  .hero h1 {
    font-size: 2.75rem;
  }
  
  .subtitle {
    font-size: 1.25rem;
  }
  
  .features h2 {
    font-size: 2rem;
  }
}

/* Mobile Menu */
@media (max-width: 767px) {
  .mobile-menu-button {
    display: block;
  }
  
  .auth-links {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: var(--white);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transform: translateY(-100%);
    transition: transform 0.3s ease;
    z-index: 100;
    padding: var(--space-xl);
  }
  
  .auth-links.active {
    transform: translateY(0);
  }
  
  .user-welcome {
    flex-direction: column;
    width: 100%;
    max-width: 300px;
  }
  
  .user-welcome a {
    width: 100%;
  }
  
  .btn span.username {
    display: inline;
  }
}