body {
  font-family: 'Poppins', sans-serif;
  background: #f8f9fa;
  color: #222;
}
header {
  background: linear-gradient(135deg, #004a9f, #0069d9);
  color: #fff;
  text-align: center;
  padding: 2rem;
  border-radius: 0 0 1rem 1rem;
}
h2 {
  color: #004a9f;
  margin-bottom: 1rem;
}
section {
  padding: 1.5rem;
  border-radius: .5rem;
  margin-bottom: 1rem;
}

/* আলাদা আলাদা রঙ */
#overview {
  background: #e8f5e9;
}
#stats {
  background: #e3f2fd;
}
#why {
  background: #fff3e0;
}
#usecases {
  background: #f3e5f5;
}
#premium {
  background: #fce4ec;
}
#offer {
  background: #ede7f6;
}
#social {
  background: #d1c4e9;
}

.social-buttons a {
  display: inline-block;
  padding: 0.4rem 0.8rem;
  margin: 0.1rem;
  color: #fff;
  border-radius: 4px;
  font-size: 0.85rem;
  text-decoration: none;
  transition: opacity 0.3s ease;
}

.social-buttons a:hover {
  opacity: 0.85;
}

.btn-facebook { background-color: #3b5998; }
.btn-twitter  { background-color: #1da1f2; }
.btn-linkedin { background-color: #0077b5; }
.btn-instagram {
  background: radial-gradient(circle at 30% 107%, #fdf497 0%, #fd5949 45%, #d6249f 60%, #285aeb 90%);
}
.btn-whatsapp { background-color: #25D366; }
.btn-telegram { background-color: #0088cc; }

.custom-footer {
  background: #004a9f;
  color: #fff;
  padding: 1rem;
  border-top-left-radius: 1rem;
  border-top-right-radius: 1rem;
}