body {
}
#bg {
  position: fixed; 
  top: 0; 
  left: 0; 
  z-index: -100;
  /* Preserve aspet ratio */
  min-width: 100%;
  min-height: 100%;
}
div.horizontal {
    display: flex;
    justify-content: center;
}

div.vertical {
    display: flex;
    flex-direction: column;
    justify-content: center;
}


.btn {
    margin-top: 100px;
    border: none;
    color: white;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
}

.btn-base {
    background-color: #428BCA!important;
    border-color: #428BCA;
}
.btn-base:hover {
    background-color: #1B6AAA!important;
    border-color: #428BCA;
}

.btn-success {
    background-color: #87B87F!important;
    border-color: #87B87F;
}
.btn-success:hover {
    background-color: #629B58!important;
    border-color: #87B87F;
}

.btn-danger {
    background-color: #D15B47!important;
    border-color: #D15B47;
}
.btn-danger:hover {
    background-color: #B74635!important;
    border-color: #D15B47;
}

.btn:disabled {
    background-color: gray;
}

.hidden {
    display: none;
}

.centered {
    display: block;
    margin: auto;
}