Rename PostCSS files to .pcss (#9013)

* Rename PostCSS files to `.pcss`

* Make Stylelint happy

* Delint

* Rename new files too

* delint

* Fix bad comment placement

res/css/views/elements/_ImageView.pcss

@@ -0,0 +1,155 @@
+/*
+Copyright 2015, 2016 OpenMarket 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.
+*/
+
+$button-size: 32px;
+$icon-size: 22px;
+$button-gap: 24px;
+
+:root {
+    --image-view-panel-height: 68px;
+}
+
+.mx_ImageView {
+    display: flex;
+    width: 100%;
+    height: 100%;
+    flex-direction: column;
+}
+
+.mx_ImageView_image_wrapper {
+    pointer-events: initial;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    height: 100%;
+    overflow: hidden;
+}
+
+.mx_ImageView_image {
+    flex-shrink: 0;
+
+    &.mx_ImageView_image_animating {
+        transition: transform 200ms ease 0s;
+    }
+
+    &.mx_ImageView_image_animatingLoading {
+        transition: transform 300ms ease 0s;
+    }
+}
+
+.mx_ImageView_panel {
+    width: 100%;
+    height: var(--image-view-panel-height);
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    animation-name: mx_ImageView_panel_keyframes;
+    animation-duration: 300ms;
+}
+
+.mx_ImageView_info_wrapper {
+    pointer-events: initial;
+    padding-left: 32px;
+    display: flex;
+    flex-direction: row;
+    align-items: center;
+    color: $lightbox-fg-color;
+}
+
+.mx_ImageView_info {
+    padding-left: 12px;
+    display: flex;
+    flex-direction: column;
+}
+
+.mx_ImageView_info_sender {
+    font-weight: bold;
+}
+
+.mx_ImageView_title {
+    color: $lightbox-fg-color;
+    font-size: $font-12px;
+}
+
+.mx_ImageView_toolbar {
+    padding-right: 16px;
+    pointer-events: initial;
+    display: flex;
+    align-items: center;
+    gap: calc($button-gap - ($button-size - $icon-size));
+}
+
+.mx_ImageView_button {
+    padding: calc(($button-size - $icon-size) / 2);
+    display: block;
+
+    &::before {
+        content: '';
+        height: $icon-size;
+        width: $icon-size;
+        mask-repeat: no-repeat;
+        mask-size: contain;
+        mask-position: center;
+        display: block;
+        background-color: $icon-button-color;
+    }
+}
+
+.mx_ImageView_button_rotateCW::before {
+    mask-image: url('$(res)/img/image-view/rotate-cw.svg');
+}
+
+.mx_ImageView_button_rotateCCW::before {
+    mask-image: url('$(res)/img/image-view/rotate-ccw.svg');
+}
+
+.mx_ImageView_button_zoomOut::before {
+    mask-image: url('$(res)/img/image-view/zoom-out.svg');
+}
+
+.mx_ImageView_button_zoomIn::before {
+    mask-image: url('$(res)/img/image-view/zoom-in.svg');
+}
+
+.mx_ImageView_button_download::before {
+    mask-image: url('$(res)/img/image-view/download.svg');
+}
+
+.mx_ImageView_button_more::before {
+    mask-image: url('$(res)/img/image-view/more.svg');
+}
+
+.mx_ImageView_button_close {
+    padding: calc($button-size - $button-size);
+    border-radius: 100%;
+    background: #21262c; // same on all themes
+    &::before {
+        width: $button-size;
+        height: $button-size;
+        mask-image: url('$(res)/img/image-view/close.svg');
+        mask-size: 40%;
+    }
+}
+
+@media (prefers-reduced-motion) {
+    .mx_ImageView_image_animating {
+        transition: none !important;
+    }
+
+    .mx_ImageView_image_animatingLoading {
+        transition: none !important;
+    }
+}