body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f4f4;
}
header {
  background: #0078d7;
  color: yellow;
  padding: 0.5rem;
}
nav button {
  margin-right: 1rem;
  padding: 0.5rem 1rem;
}
main {
  padding: 1rem;
}

.tile {
  background: white;
  margin: 1rem 0;
  padding: 1rem;
  box-shadow: 0 0 5px #ccc;
}

.mytable {
    width: 100%;
    border-collapse: collapse;
    border: 1px solid;
}

.mytable td,
.mytable th {
    border: 1px solid;
}
.mytable th {
    background: #cbf7c6;
}