.calendar {
  width: 350px;
  border: 1px solid #ccc;
  border-radius: 10px;
  overflow: hidden;
  font-family: sans-serif;
}

.calendar_nav {
  display: flex;
  justify-content: space-between;
  background: #f2f2f2;
  padding: 8px;
}

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

.calendar_header div {
  background: #eaeaea;
  padding: 6px 0;
  text-align: center;
  font-weight: bold;
  border-bottom: 1px solid #ddd;
}

.day_btn {
  border: 1px solid #ddd;
  padding: 8px;
  text-align: center;
  cursor: pointer;
  font-size: 14px;
}

.day_btn:hover {
  background: #f0f0f0;
}

.month_select, .year_select {
  padding: 8px;
  margin: 4px;
  width: 100%;
}