/**********************************************
                Global styles
**********************************************/
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  height: 100vh;
}

/**********************************************
                Specific styles
**********************************************/
body {
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-content: center;
}

header h1 {
  text-align: center;
  background-color: #000;
  color: #ffffff;
  padding: 10px 0;
  font-size: 18pt;
  letter-spacing: 10px;
}

#calendar {
  border-collapse: collapse;
  margin: 10px auto;
}

#calendar thead tr th {
  font-size: 12pt;
  background-color: #000;
  color: #ffffff;
}

#calendar tbody tr td {
  border: 1px solid white;
  background-color: #000;
  color: #ffffff;
  padding: 5px;
  width: 45px;
  height: 45px;
  font-size: 18pt;
  text-align: center;
}

#calendar tbody tr:nth-child(odd) td {
  background-color: #202020;
}

#calendar tbody tr td:last-child {
  color: red;
}

#calendar tbody tr td:nth-child(6) {
  color: rgb(134, 134, 134);
}

#calendar tbody tr td.current-day {
  color: #1eff00;
}

.form-group {
  width: 315px;
  margin: 10px auto;
  text-align: center;
}

.form-group>input {
  width: 20%;
}

#month::placeholder,
#years::placeholder {
  color: #ddd;
}

#setDate,
#resetDate {
  width: 49%;
  height: 30px;
  background-color: #000;
  color: #ffffff;
}

#myFooter {
  background-color: #000;
  color: #fff;
  text-align: center;
  padding: 18px 0;
  margin-top: 10px;
}

#myFooter small a {
  text-decoration: none;
  color: #ffffff;
}

/**************************************
            @media Queries
**************************************/

@media all and (min-width: 360px) {
  #calendar thead tr th {
    margin: 20px auto;
    font-size: 16pt;
  }

  #calendar tbody tr td {
    border: 2px solid white;
    width: 49px;
    height: 49px;
    font-size: 22pt;
  }

  .form-group {
    width: 343px;
  }

  .form-group>input,
  label {
    width: 60px;
    height: 25px;
    font-size: 14pt;
    padding: 5px;
  }

  #setDate,
  #resetDate {
    height: 35px;
    font-size: 12pt;
  }

  #myFooter {
    margin-top: 20px;
  }
}

@media all and (min-width: 576px) {
  header h1 {
    font-size: 30pt;
    letter-spacing: 10px;
  }

  #calendar thead tr th {
    font-size: 26pt;
  }

  #calendar tbody tr td {
    border: 5px solid white;
    width: 80px;
    height: 80px;
    font-size: 32pt;
  }

  .form-group {
    width: 560px;
  }

  .form-group>input,
  label {
    width: 80px;
    height: 30px;
    font-size: 17pt;
  }

  #setDate,
  #resetDate {
    height: 40px;
    font-size: 14pt;
  }
}

@media all and (min-width: 768px) {
  #calendar tbody tr td {
    width: 90px;
    height: 90px;
  }

  .form-group {
    width: 630px;
  }

  #myFooter {
    padding: 15px 0;
    margin-top: 0;
  }
}