wagtail/wagtail/admin/static_src/wagtailadmin/scss/layouts/404.scss

@import '../../../../../../client/scss/settings';
@import '../../../../../../client/scss/tools';

.page404__bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: $color-teal-darker;
    font-family: $font-sans;
    color: $color-white;
}

.page404__wrapper {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    justify-content: center;
    align-items: center;
}

.wagtail-logo-container__desktop {
    float: left;
    width: 400px;
    height: 500px;
}

.page404__text-container {
    float: right;
    width: 600px;
    height: 500px;
    text-align: center;
}

.page404__header {
    font-size: 6.8em;
    margin-bottom: 0.2em;
    color: inherit;
}

.page404__text {
    font-size: 2.25em;
    line-height: 1.25em;
    color: inherit;
}

a.button.page404__button { // more specific to override standard button styles
    font-size: 1.5em;
    line-height: 2em;
    height: 2.5em;
    padding: 0 0.5em;
    background-color: $color-teal-darker;
    border: 4px solid $color-teal;
    color: inherit;

    &:hover {
        background-color: $color-teal;
    }
}

// SMALL DESKTOP CHANGES:
@include media-breakpoint-down(sm) {
    .wagtail-logo-container__desktop {
        display: none;
    }
}

// MOBILE CHANGES:
@include media-breakpoint-down(xs) {
    .page404__text-container {
        width: 400px;
    }

    .page404__header {
        font-size: 5em;
    }
}