🌱 A Calendar in Three Lines of CSS

<div class="calendar-wrapper">
  <h1>Decemeber</h1>
  <ul class="calendar">
    <li class="weekday">Sun</li>
    <li class="weekday">Mon</li>
    <li class="weekday">Tue</li>
    <li class="weekday">Wed</li>
    <li class="weekday">Thu</li>
    <li class="weekday">Fri</li>
    <li class="weekday">Sat</li>

    <li class="first-day">1</li>
    <li>2</li>
    <li>3</li>
    <!-- ... -->
    <li>29</li>
    <li>30</li>
    <li>31</li>
  </ul>
</div>

.calendar {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
}

.first-day {
  grid-column-start: 3;
}