:root {
    --input-padding-x: .75rem;
    --input-padding-y: .75rem
}

html,
body {
    margin: 0 auto;
    height: 100%
}

.form-signin {
    width: 100%;
    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)
}

.form-label-group>label {
    position: absolute;
    top: 0;
    left: 0;
    display: block;
    width: 100%;
    margin-bottom: 0;
    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
}