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

body {
  font-family: "Poppins", sans-serif;
  background: linear-gradient(135deg, #001f3f, #007bff);
  color: white;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  flex-direction: column;
  overflow: hidden;
}

/* Preloader */
.preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #001f3f;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 100;
}

.spinner {
  border: 6px solid rgba(255, 255, 255, 0.3);
  border-top: 6px solid white;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Fade-in animation */
.fade-in {
  opacity: 0;
  transition: opacity 1.5s ease-in-out;
}

.fade-in.show {
  opacity: 1;
}

/* Logo */
.logo {
  width: 180px;
  margin-bottom: 25px;
  animation: fadeLogo 2s ease-in-out;
}

@keyframes fadeLogo {
  0% { opacity: 0; transform: translateY(-20px); }
  100% { opacity: 1; transform: translateY(0); }
}

/* Title */
h1 {
  font-size: 1.8rem;
  margin-bottom: 40px;
}

/* Buttons */
.button-container {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.btn {
  display: inline-block;
  background-color: white;
  color: #001f3f;
  font-weight: 600;
  padding: 14px 28px;
  border-radius: 10px;
  text-decoration: none;
  font-size: 1rem;
  transition: all 0.3s ease;
}

.btn:hover {
  background-color: #007bff;
  color: white;
  transform: translateY(-3px);
}

.btn.disabled {
  background-color: rgba(255, 255, 255, 0.3);
  color: rgba(255, 255, 255, 0.7);
  cursor: not-allowed;
  transform: none;
}

/* Footer */
footer {
  position: absolute;
  bottom: 20px;
  font-size: 0.9rem;
  opacity: 0.8;
}