body {
  font-family: Arial, sans-serif;
  background-color: #f7f7f7;
  color: #222;
  margin: 40px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}

thead {
  background-color: #222;
  color: #fff;
}

th,
td {
  border: 1px solid #aaa;
  padding: 10px;
  text-align: center;
}

/* Tres estilos distintos alternados por renglón */
tbody tr:nth-child(3n + 1) {
  background-color: #ffffff; /* blanco */
}
tbody tr:nth-child(3n + 2) {
  background-color: #e8f0fe; /* azul claro */
}
tbody tr:nth-child(3n + 3) {
  background-color: #fef9e7; /* amarillo suave */
}

tr:hover {
  background-color: #d1ecf1; /* efecto al pasar el mouse */
}