```css
body {
  font-family: Arial, sans-serif;
  background-color: #f0f0f0;
  margin: 0;
  padding: 20px;
}

h1, h2 {
  color: #6200ea;
}

input, textarea, button {
  display: block;
  margin: 10px 0;
  padding: 10px;
  width: 100%;
  max-width: 500px;
}

button {
  background-color: #6200ea;
  color: white;
  border: none;
  padding: 10px;
  cursor: pointer;
  margin: 10px 0;
}

#start-screen button {
  display: block !important; /* Forcer l'affichage */
  width: 100%;
  max-width: 500px;
  box-sizing: border-box;
  font-size: 16px;
  border-radius: 4px;
  transition: background-color 0.3s;
  visibility: visible; /* Assurer la visibilité */
}

#start-screen button:hover {
  background-color: #7c3aed;
}

#start-screen button.import-button {
  background-color: #4b00b3; /* Couleur distincte */
  margin-top: 10px;
  z-index: 1; /* Éviter tout chevauchement */
}

ul {
  list-style: none;
  padding: 0;
}

li {
  background: white;
  padding: 10px;
  margin: 10px 0;
  border-radius: 4px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  cursor: grab;
}

#start-screen, #editor {
  max-width: 600px;
  margin: auto;
}

#map {
  height: 400px;
}

#details-preview img {
  max-width: 100px;
  margin: 5px;
}
```