gmx.css/src/_field.css

A micro Material Design 3 based CSS-only framework.

.field {
    position: relative;
}

.field:not(:last-child, :is(nav, .row) .field, .grid>.field) {
    margin-bottom: 1rem;
}

.field :is(input, textarea) {
    display: block;
    border: none;
    outline: none;
    min-width: 15.5rem;
    border-bottom: 1px solid var(--m3-scheme-outline);
    background: var(--m3-scheme-surface-container-highest);
    border-radius: var(--m3-textfield-filled-shape) var(--m3-textfield-filled-shape) 0 0;
    box-sizing: border-box;
    font: inherit;
    padding: 1.5rem 1rem .5rem;
    transition: all 0.15s ease-out;
}

.field :is(input, textarea):hover {
    background: rgb(from var(--m3-scheme-on-surface) r g b / 15%);
}

.field label {
    position: absolute;
    top: 1rem;
    bottom: 0;
    left: 1rem;
    display: flex;
    align-items: self-start;
    pointer-events: none;
}

.field label span {
    transition: all 0.15s ease-out;
}

.field :is(input, textarea):focus {
    outline: none;
    border-bottom: 2px solid var(--m3-scheme-primary);
}

.field :is(input, textarea):focus+label span,
.field :not(:is(input, textarea):placeholder-shown)+label span {
    font-size: .75rem;
    transform: translate(0, -50%);
}

.field :is(input, textarea):focus+label span {
    color: var(--m3-scheme-primary);
}

.field:has(i) :is(input, textarea) {
    padding: 1.5rem 1rem .5rem 2.85rem;
}

.field:has(i) label {
    left: 2.85rem;
}

.field i {
    position: absolute;
    pointer-events: none;
    left: .65rem;
}

.field i * {
    font-size: 1.5rem;
}