h1{
    border: 1px black solid;
}

h1#h21{
    background-color: sandybrown;
}

body {
    font-family: Arial, sans-serif;
    margin: 30px;
}

table {
    border-collapse: collapse;
    border: 1px black solid;
    border-radius: 5px;
    width: 100%;
    margin: 0 auto;
    background-color: skyblue;
}

th, td {
    border: 1px solid black;
    padding: 10px;
}

th {
    background: plum;
}

button {
    padding: 10px 20px;
    margin: 10px;
    cursor: pointer;
}

button:hover {
    transform: scale(1.05);
}

.answer {
    margin-left: 10px;
    font-weight: bold;
}

#summary {
    margin-top: 20px;
    padding: 15px;
    border: 2px solid blue;
}