element-web/res/css/views/elements/_Field.scss

/*
Copyright 2019 New Vector Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

/* TODO: Consider unifying with general input styles in _dharma.scss */

.mx_Field {
    position: relative;
    margin: 1em 0;
}

.mx_Field input,
.mx_Field select {
    font-weight: normal;
    border-radius: 4px;
    transition: border-color 0.25s;
    border: 1px solid $input-border-color;
    padding: 8px 9px;
}

.mx_Field input:focus,
.mx_Field select:focus {
    outline: 0;
    border-color: $input-focused-border-color;
}

.mx_Field input::placeholder {
    transition: color 0.25s ease-in 0s;
    color: transparent;
}

.mx_Field input:placeholder-shown:focus::placeholder {
    transition: color 0.25s ease-in 0.1s;
    color: $greyed-fg-color;
}

.mx_Field label {
    transition:
        font-size 0.25s ease-out 0.1s,
        color 0.25s ease-out 0.1s,
        top 0.25s ease-out 0.1s,
        background-color 0.25s ease-out 0.1s;
    color: $primary-fg-color;
    background-color: transparent;
    font-size: 14px;
    position: absolute;
    left: 0px;
    top: 0px;
    margin: 7px 8px;
    padding: 2px;
}

.mx_Field input:focus + label,
.mx_Field input:not(:placeholder-shown) + label,
.mx_Field select + label /* Always show a select's label on top to not collide with the value */ {
    transition:
        font-size 0.25s ease-out 0s,
        color 0.25s ease-out 0s,
        top 0.25s ease-out 0s,
        background-color 0.25s ease-out 0s;
    font-size: 10px;
    top: -14px;
    background-color: $field-focused-label-bg-color;
}

.mx_Field input:focus + label,
.mx_Field select:focus + label {
    color: $input-focused-border-color;
}