body {
  margin: 0;
  font-family: "Yu Gothic", "YuGothic", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  background-color: black;
  color: white;
  text-align: center;
  overflow: hidden;
}

#scene {
  background-size: cover;
  background-position: center;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 2em;
  box-sizing: border-box;
  transition: background-image 1.5s ease-in-out, background-color 1.5s ease-in-out;
  background-color: black;
  background-image: url('initial_scene.png');
}

#text {
  background-color: rgba(0,0,0,0.65);
  padding: 1.5em;
  border-radius: 10px;
  line-height: 1.7em;
  max-width: 600px;
  margin-bottom: 2em;
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: fadeIn 2s ease-in-out forwards;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

#button-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1em;
  animation: fadeIn 2s ease-in-out 0.5s forwards;
  opacity: 0;
}

button {
  padding: 1em 2em;
  font-size: 1.1em;
  font-family: inherit;
  background-color: rgba(255,255,255,0.1);
  color: white;
  border: 1px solid white;
  cursor: pointer;
  border-radius: 5px;
  transition: background-color 0.3s, transform 0.3s;
  min-width: 300px;
}

button:hover {
  background-color: rgba(255,255,255,0.3);
  transform: scale(1.05);
}

#footer {
  position: absolute;
  bottom: 1em;
  font-size: 0.8em;
  color: #ccc;
  opacity: 0.7;
}