Draft: Resolve "[New data model] PDF export for "regular" timetable"

Closes #46

aleksis/apps/lesrooster/static/css/lesrooster/timetable_print.css

+.timetable-plan .row,
+.timetable-plan .col {
+  display: flex;
+  padding: 0;
+}
+
+.timetable-plan .row {
+  margin-bottom: 0;
+}
+
+.lesson-card,
+.timetable-title-card {
+  display: flex;
+  flex-grow: 1;
+  min-height: 40px;
+  box-shadow: none;
+  border: 1px solid black;
+  margin: -1px -1px 0 0;
+  border-radius: 0;
+  font-size: 11px;
+}
+
+.timetable-title-card .card-title {
+  margin-bottom: 0 !important;
+}
+
+.supervision-card {
+  min-height: 10px;
+  border-left: none;
+  border-right: none;
+}
+
+.lesson-card .card-content {
+  padding: 0;
+  text-align: center;
+  width: 100%;
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+}
+
+.lesson-card .card-content > div {
+  padding: 0;
+  flex: auto;
+  width: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.timetable-title-card .card-content {
+  padding: 7px;
+  text-align: center;
+  width: 100%;
+}
+
+.lesson-card a {
+  color: inherit;
+}
+
+.card .card-title {
+  font-size: 18px;
+}