#title { text-align: center; font-size: 36 }
.subtitle { text-align: center; font-weight: bold }
#duedate { text-align: center; }
h1 { font-size : 110% }
table {border: 1px solid; border-spacing: 0; cell-spacing: 0; }
td { border: 1px solid; padding: 2px}

.exercise { font-weight: bold }
pre.listing   { padding: 1em; border : 1px solid #555555  }
.solution { color: blue; padding-bottom: 1em }
.solution .listing { border-color: blue }