html, body {
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

body {
  width: 100vw;
  height: 100vh;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  transition: background-image 1s ease-in-out;
  position: relative;
}

.overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
}

.enter-btn {
  font-size: 2rem;
  padding: 1rem 3rem;
  background: rgba(255,255,255,0.85);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  letter-spacing: 2px;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  box-shadow: 0 4px 24px rgba(0,0,0,0.15);
  transition: background 0.2s, transform 0.2s;
}

.enter-btn:hover {
  background: rgba(255,255,255,1);
  transform: scale(1.05);
}



/* Adjust to mobile */

@media (max-width: 800px) {
  .gallery {
    grid-template-columns: repeat(2, 1fr);
    padding: 1rem;
    gap: 16px;
  }
  .main-menu ul {
    gap: 1rem;
    font-size: 1rem;
  }
}

@media (max-width: 500px) {
  .gallery {
    grid-template-columns: 1fr;
    padding: 0.5rem;
    gap: 10px;
  }
  header h1 {
    font-size: 1.5rem;
  }
  .main-menu a {
    font-size: 1rem;
    padding: 0.5rem;
  }
}