body {
  background-color: #111;
  color: white;
  font-family: 'Segoe UI', sans-serif;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  align-items: center;
  padding-top: 4rem;
  height: 100vh;
}

h1 {
  font-size: 3rem;
  letter-spacing: 0.2em;
  margin-bottom: 2rem;
}

.letter {
  display: inline-block;
  opacity: 0;
  transform: translateY(30px);
}

/* Nouveau rectangle de présentation */
.presentation-box {
  background-color: #333;
  border-radius: 20px;
  padding: 2rem;
  max-width: 600px;
  width: 90%;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.8s ease;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.presentation-box.show {
  opacity: 1;
  transform: translateY(0);
}

.presentation-box p {
  font-size: 1.1rem;
  line-height: 1.6;
  margin: 0;
  text-align: center;
}