:root {
    --input-padding-x: .75rem;
    --input-padding-y: .75rem;
    --bs-body-bg: #e0e0e0;
    --header-height: 40px;
    --footer-height: 40px;
}

html, body {
    height: 100%; 
    width: 100%;
}

body {
    -ms-flex-align: center;
    -ms-flex-pack: center;
    -webkit-box-align: center;
    align-items: center;
    -webkit-box-pack: center;
    justify-content: center;
    padding-top: 40px;
    padding-bottom: 40px;
  }

  #ct_footer {
    position: relative;
    width: 100%;
    margin: 0px;
    padding: 0px;
    height: var(--header-height);
    line-height: var(--header-height);
  }

  #ct_header {
    position: relative;
    width: 100%;
    margin: 0px;
    padding: 0px;
    height: var(--header-height);
    line-height: var(--header-height);
  }

  #ct_main {
    position: relative;
    margin-top: 0px;
    margin-bottom: 0px;
    min-height: calc(100% - var(--header-height) - var(--footer-height));
  }
  
  .form-signin {
    width: 100%;
    max-width: 420px;
    padding: 15px;
    margin: 0 auto;
  }
  
  .form-label-group {
    position: relative;
    margin-bottom: 1rem;
  }
  
  .form-label-group > input,
  .form-label-group > label {
    padding: var(--input-padding-y) var(--input-padding-x);
    border-width: 3px;
  }

  .form-group > input {
    padding: var(--input-padding-y) var(--input-padding-x);
    border-width: 3px;
  }

  .form-group > select {
    padding: var(--input-padding-y) var(--input-padding-x);
    border-width: 3px;
  }

  .form-group > textarea {
    padding: var(--input-padding-y) var(--input-padding-x);
    border-width: 3px; 
  }

  .form-group > input:invalid,
  .form-group > select:invalid
  .form-group > textarea:invalid {
    border-color: red;
  }

  .form-label-group > input:invalid,
  .form-label-group > select:invalid
  .form-label-group > textarea:invalid {
    border-color: red;
  }
  
  .form-label-group > label {
    position: absolute;
    top: 0;
    left: 0;
    display: block;
    width: 100%;
    margin-bottom: 0; /* Override default `<label>` margin */
    line-height: 1.5;
    color: #495057;
    border: 1px solid transparent;
    border-radius: .25rem;
    transition: all .1s ease-in-out;
  }
  
  .form-label-group input::-webkit-input-placeholder {
    color: transparent;
  }
  
  .form-label-group input:-ms-input-placeholder {
    color: transparent;
  }
  
  .form-label-group input::-ms-input-placeholder {
    color: transparent;
  }
  
  .form-label-group input::-moz-placeholder {
    color: transparent;
  }
  
  .form-label-group input::placeholder {
    color: transparent;
  }
  
  .form-label-group input:not(:placeholder-shown) {
    padding-top: calc(var(--input-padding-y) + var(--input-padding-y) * (2 / 3));
    padding-bottom: calc(var(--input-padding-y) / 3);
  }
  
  .form-label-group input:not(:placeholder-shown) ~ label {
    padding-top: calc(var(--input-padding-y) / 3);
    padding-bottom: calc(var(--input-padding-y) / 3);
    font-size: 12px;
    color: #777;
  }

  .logo {
    min-width: 100px;
    max-width: 300px;
  }