table {
  border-collapse: collapse;
  margin: 20px 0;
}

th, td {
  border: 1px solid black;
  padding: 5px;
  text-align: center;
}

.staff {
  position: relative;
  width: 100%;
  height: 150px;
  margin: 20px 0;
}

.staff-line {
  position: absolute;
  width: 100%;
  height: 2px;
  background: black;
}

.note {
  position: absolute;
  font-size: 20px;
}

.sharp {
  color: red; /* sostenidos en rojo */
}

.error {
  color: #b00;
  font-weight: bold;
}