.calendar_container header {
    display: flex;
    align-items: center;
    font-size:2em;
    justify-content: center;
    margin-bottom: 1em;
    background: #000;
    color: #fff;
    text-align: center;
  }
  
  .calendar_container :is(ul, ol) {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    grid-gap: 0.25em;
    margin: 0 auto;
    max-width: 64em;
    padding: 0;
  }
  
  .calendar_container li {
    display: flex;
    align-items: center;
    justify-content: center;
    list-style: none;
    margin-left: 0;
    font-size:1em;
  }
  
  .calendar_container ul.weekdays {
    margin-bottom: 1em;
  }
  
  .calendar_container ul.weekdays li {
    min-height: 2em;
  }
  
  .calendar_container ol.day-grid li {
    background-color: #eaeaea;
    border: 1px solid #eaeaea;
    height:1em;
    padding: 1em;
  }

  h1.calendar_month_title.title {
    margin: 0;
    padding: 0.5em;
}
  
  .calendar_container ul.weekdays abbr[title] {
    border: none;
    font-weight: 800;
    text-decoration: none;
  }
  
  ol.day-grid li:nth-child(1),
  ol.day-grid li:nth-child(2),
  ol.day-grid li:nth-child(3),
  ol.day-grid li:nth-child(34),
  ol.day-grid li:nth-child(35) {
    background-color: #fff;
  }

  ul.weekdays li {
    font-size: 0;
  }
  
  ul.weekdays > li abbr:after {
      content: attr(title);
      font-size: 1rem;
        text-align: center;
    }