/* Import elegant Google font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');

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

body {
  font-family: 'Inter', sans-serif;
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  min-height: 100vh;
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 2rem;
  text-align: center;
  transition: all 0.3s ease;
  position: relative;
  overflow-x: hidden;
}

/* Animated background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.2) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.2) 0%, transparent 50%),
    radial-gradient(circle at 40% 40%, rgba(120, 219, 255, 0.1) 0%, transparent 50%);
  z-index: -1;
  animation: backgroundShift 20s ease-in-out infinite;
}

@keyframes backgroundShift {
  0%, 100% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.1) rotate(1deg); }
}

/* Nav bar styling */
.top-nav {
  width: 100%;
  max-width: 900px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 2.5rem;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 2rem;
  box-shadow: 
    0 20px 40px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.1);
  font-weight: 700;
  color: #fff;
  font-size: 1.8rem;
  position: sticky;
  top: 1rem;
  backdrop-filter: blur(20px);
  z-index: 100;
  margin-top: 1rem;
  transition: all 0.3s ease;
}

.top-nav:hover {
  transform: translateY(-2px);
  box-shadow: 
    0 25px 50px rgba(0, 0, 0, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.2);
}

.nav-left {
  flex: 1;
  text-align: left;
  background: linear-gradient(135deg, #fff, #f0f0f0);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 800;
}

.nav-center {
  flex: 1;
  text-align: center;
  font-size: 3.5rem;
  color: #fff;
  text-shadow: 0 0 20px rgba(255, 255, 255, 0.5);
  animation: glow 3s ease-in-out infinite alternate;
}

@keyframes glow {
  from { text-shadow: 0 0 20px rgba(255, 255, 255, 0.5); }
  to { text-shadow: 0 0 30px rgba(255, 255, 255, 0.8), 0 0 40px rgba(255, 255, 255, 0.3); }
}

/* Welcome heading */
header {
  margin-top: 4rem;
  margin-bottom: 3rem;
}

.welcome-heading {
  font-size: 1.8rem;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 3rem;
  font-weight: 600;
  text-align: center;
  max-width: 800px;
  animation: fadeInUp 1s ease-out;
  line-height: 1.4;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Grid layout for nav buttons */
main {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  max-width: 900px;
  width: 100%;
  margin-bottom: 4rem;
  justify-content: center;
}

.nav-button {
  text-decoration: none;
  color: white;
  font-weight: 700;
  padding: 2rem 1.5rem;
  border-radius: 1.5rem;
  backdrop-filter: blur(20px);
  background: rgba(0, 0, 0, 0.3);
  box-shadow: 
    0 15px 35px rgba(0, 0, 0, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.1);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  font-size: 1.3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateY(30px);
  min-height: 120px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.nav-button.fade-in {
  animation: fadeInUp 0.8s ease-out forwards;
}

.nav-button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.6s ease;
}

.nav-button:hover::before {
  left: 100%;
}

.nav-button:hover {
  background: rgba(0, 0, 0, 0.4);
  transform: translateY(-8px) scale(1.02);
  box-shadow: 
    0 25px 50px rgba(0, 0, 0, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.2);
}

.nav-button:active {
  transform: translateY(-4px) scale(1.01);
}

/* Button icons */
.nav-button::after {
  content: '';
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  display: block;
  transition: transform 0.3s ease;
}

.nav-button:hover::after {
  transform: scale(1.1);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* Notification styles */
.notification {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 1.2rem 2rem;
  border-radius: 1rem;
  color: white;
  font-weight: 600;
  z-index: 1000;
  animation: slideInRight 0.4s ease-out;
  backdrop-filter: blur(20px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.notification.info {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.9), rgba(37, 99, 235, 0.9));
}

.notification.success {
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.9), rgba(22, 163, 74, 0.9));
}

.notification.error {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.9), rgba(220, 38, 38, 0.9));
}

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

/* Footer */
footer {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.8);
  text-align: center;
  margin-top: auto;
  padding: 2rem 0;
  animation: fadeIn 1.5s ease-out 0.5s both;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* Responsive design */
@media (max-width: 768px) {
  body {
    padding: 0 1rem;
  }
  
  .top-nav {
    padding: 1.2rem 1.5rem;
    font-size: 1.4rem;
    margin-top: 0.5rem;
  }
  
  .nav-center {
    font-size: 2.5rem;
  }
  
  .welcome-heading {
    font-size: 1.4rem;
    margin-top: 2rem;
  }
  
  main {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .nav-button {
    padding: 1.5rem 1rem;
    font-size: 1.2rem;
    min-height: 100px;
  }
}

@media (max-width: 480px) {
  .top-nav {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }
  
  .nav-left, .nav-center {
    text-align: center;
  }
  
  .welcome-heading {
    font-size: 1.2rem;
  }
  
  .nav-button {
    padding: 1.2rem 0.8rem;
    font-size: 1.1rem;
  }
}



/* Loading animation for buttons */
.nav-button.loading {
  position: relative;
  overflow: hidden;
}

.nav-button.loading::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  animation: loading 1.5s infinite;
}

@keyframes loading {
  0% { left: -100%; }
  100% { left: 100%; }
}