body {
    font-family: sans-serif;
    background-image: linear-gradient(rgba(0,0,0,0.2), rgba(0,0,0,0.2)), url('ドパガキ喜び背景.png');
    background-size: cover;
    background-repeat: no-repeat;
    padding: 20px;
}
.container { background: white; padding: 20px; border-radius: 8px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
h1 { color: #333; }
button { background-color: #007bff; color: white; border: none; padding: 10px 20px; border-radius: 5px; cursor: pointer; }
button:hover { background-color: #0056b3; }