calendar.css

body {
    font-family: helvetica, arial, sans-serif;
    padding: 0 20px;
    min-width: 355px;
    max-width: 600px;
    margin: 10px auto;
    height: 530px;
    position: relative;
  }
  
  .calendar {
    font-family: cursive, Helvetica, sans-serif;
  }
  
    h1 {
      position: relative;
      background-color: green;
      padding: 10px;
      text-align: center;
      color: #fff;
      border-radius: 20px 0;
    }
      .btn {
        position: absolute;
        top: 15px;
        padding: 2px;
        font-family: "Goudy Old Style", monospace;
        font-size: 0.8em;
        border: 2px solid;
        border-radius: 5px;
        text-shadow: 0 0 10px blue;
        color: #5e5e5e;
      }
        &:active {
          font-weight: 1000;
          text-shadow: 2px 0 2px blue;
        }
  
        &:hover {
          background-color: #ccc;
        }
  
      .prev {
        left: 25px;
      }
  
      .next {
        right: 20px;
      }
  
    ul {
      list-style-type: none;
      display: grid;
      grid-template-columns: repeat(7, 1fr);
      gap: 1px;
      padding-left: 0;
    }
      li:nth-child(7n) {
        color: blue;
      }
  
      li:nth-child(7n-1) {
        color: red;
      }
    
  
    .weekdays {
      text-align: center;
      background-color: rgba(0, 0, 0, 0.1);
      border-top: 2px solid;
      border-bottom: 2px solid;
      color: green;
      padding: 5px;
    }
  
    .days li {
      text-align: right;
      border: 2px solid green;
      background-color: rgba(0, 200, 0, 0.1);
      border-radius: 10px 0;
      padding: 5px 30% 5px 5px;
    }
  
    fieldset {
      border-radius: 10px;
      padding: 0 20px;
    }
  
    legend {
      background-color: black;
      color: #ffffff;
      padding: 8px;
    }
  
    input:invalid:required {
      background-color: lightpink;
    }
  
    ul {
      list-style-type: none;
      padding-left: 0;
    }
  
    .form {
      display: flex;
      gap: 5px;
    }
      li {
        flex: 1 auto;
        background-color: lightgreen;
  
        button {
          width: 100%;
          height: 100%;
        }
  
        label {
          display: inline-block;
          padding: 5px;
        }
      }
  
  footer {
    display: inline;
    font-family: Helvetica, monospace;
    font-size: 12px;
    padding: 3px;
    text-decoration: underline;
    color: red;
    font-weight: 600;
    position: absolute;
    bottom: 0;
    left: 20px;
  }
    &:hover {
      cursor: pointer;
      background-color: white;
      text-decoration: none;
    }