/* Base styles */
:root {
  --primary: #0d142d;
  --secondary: #2d3a5c;
  --accent: rgba(255, 255, 255, 0.1);
  --text: rgba(255, 255, 255, 0.9);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', system-ui, sans-serif;
}

body {
  background: var(--primary);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

/* Animated background layer */
body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    45deg,
    var(--primary) 0%,
    var(--secondary) 100%
  );
  opacity: 0.1;
  z-index: -1;
  animation: gradientShift 15s ease infinite;
}

/* Navigation */
.navbar {
  background: rgba(13, 20, 45, 0.95);
  backdrop-filter: blur(10px);
  padding: 1rem 2rem;
  position: fixed;
  width: 100%;
  top: 0;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

.navbar.scrolled {
  padding: 0.75rem 2rem;
}

/* Buttons */
.btn {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border: none;
  padding: 0.8rem 2rem;
  color: white;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(13, 20, 45, 0.3);
}

.btn:active {
  transform: translateY(0);
  transition: all 0.1s ease;
}

.btn::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.1),
    transparent
  );
  transition: 0.5s;
}

.btn:hover::after {
  left: 100%;
}

/* Cards */
.card {
  background: rgba(13, 20, 45, 0.6);
  backdrop-filter: blur(12px);
  border-radius: 16px;
  padding: 2rem;
  margin: 1rem;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(13, 20, 45, 0.4);
}

/* Animations */
@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.fade-in {
  animation: fadeIn 1.2s ease forwards;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--primary);
}

::-webkit-scrollbar-thumb {
  background: var(--secondary);
  border-radius: 4px;
}

/* Responsive design */
@media (max-width: 768px) {
  .navbar {
    padding: 0.75rem 1rem;
  }
  
  .card {
    margin: 1rem 0;
    padding: 1.5rem;
  }
}