body {
  font-family: sans-serif;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 8px;
  border: 1px solid #ddd;
}

th {
  background-color: #f4f4f4;
}

.dark th {
  background-color: #444;
}

button {
  cursor: pointer;
}

.summary {
  text-align: center;
  font-size: 2em;
}