/* Material UI風のPWAトップページ用CSS */
body {
  background: #f5f5f5;
  font-family: 'Roboto', 'Helvetica Neue', Arial, 'メイリオ', sans-serif;
  margin: 0;
  min-height: 100vh;
}
.container {
  max-width: 400px;
  margin: 60px auto;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.10), 0 1.5px 4px rgba(0,0,0,0.08);
  padding: 40px 32px 32px 32px;
  text-align: center;
}
h1 {
  font-size: 2.2rem;
  font-weight: 500;
  color: #1976d2;
  margin-bottom: 16px;
}
p {
  color: #555;
  font-size: 1.1rem;
  margin-bottom: 32px;
}
#install-btn {
  background: linear-gradient(90deg, #1976d2 0%, #42a5f5 100%);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1.1rem;
  font-weight: 500;
  padding: 14px 0;
  width: 100%;
  box-shadow: 0 2px 8px rgba(25, 118, 210, 0.15);
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s;
  margin-bottom: 8px;
}
#install-btn:hover {
  background: linear-gradient(90deg, #1565c0 0%, #1976d2 100%);
  box-shadow: 0 4px 16px rgba(25, 118, 210, 0.18);
}