body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background: #f0f0f0;
  overflow: hidden;
  position: relative;
}

.background {
  position: absolute;
  width: 100%;
  height: 100vh;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 0.5s ease-in-out;
  z-index: 0;
}

.background.auto {
  background-image: url('voiture.png');
  opacity: 0.5;
}

.background.habitat {
  background-image: url('maison.png');
  opacity: 0.5;
}

.button-container {
  position: relative;
  z-index: 1;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 60px;
}

.opti-button {
  position: relative;
  width: 240px;
  height: auto;
  padding: 25px;
  background-color: #ffffff;
  color: #1e1e1e;
  text-align: center;
  text-decoration: none;
  border: 2px solid #1e1e1e;
  border-radius: 12px;
  transition: transform 0.3s ease;
  font-size: 20px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.opti-button:hover {
  transform: scale(1.05);
}

.opti-button span {
  display: block;
}

.opti-button .hover-text {
  margin-top: 8px;
  font-size: 16px;
  color: #555;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.opti-button:hover .hover-text {
  opacity: 1;
}