/* General */
body {
  font-family: 'Poppins', sans-serif;
  margin: 0;
  padding: 0;
  background: #f9fbff;
  color: #333;
}

/* Header */
header {
  background: #0d47a1;
  color: white;
  padding: 15px 20px;
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 600;
}

nav {
  display: flex;
  gap: 15px;
}

nav a {
  color: white;
  text-decoration: none;
  font-size: 15px;
  transition: color 0.3s, border-bottom 0.3s;
}

nav a:hover {
  color: #bbdefb;
  border-bottom: 2px solid #90caf9;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 80px 20px;
  background: linear-gradient(to right, #1565c0, #1e88e5);
  color: white;
}

.hero h2 {
  font-size: 40px;
  margin-bottom: 15px;
  animation: float 3s ease-in-out infinite;
}

.hero button {
  padding: 12px 25px;
  font-size: 16px;
  border: none;
  background: #42a5f5;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: transform 0.3s, box-shadow 0.3s;
}

.hero button:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 15px rgba(66,165,245,0.6);
}

@keyframes float {
  0%,100%{ transform:translateY(0);}
  50%{transform:translateY(-8px);}
}

/* Categories */
.categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  padding: 40px 20px;
}

.category-card {
  background: #fff;
  padding: 20px;
  border-radius: 10px;
  text-align: center;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
  cursor: pointer;
}

.category-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 10px 20px rgba(33,150,243,0.3);
}

.category-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
  color: #0d47a1;
}

.category-card p {
  font-size: 14px;
  color: #555;
}

/* Footer */
footer {
  text-align: center;
  padding: 20px;
  background: #0d47a1;
  color: white;
}

/* Back to Top Button */
#topBtn {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: #42a5f5;
  color: white;
  border: none;
  padding: 12px 15px;
  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;
  display: none;
  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
  transition: transform 0.3s;
}

#topBtn:hover {
  background: #1e88e5;
  transform: scale(1.2);
}