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/structures/_RoomSearch.pcss

@@ -0,0 +1,106 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+// Note: this component expects to be contained within a flexbox
+.mx_RoomSearch {
+    flex: 1;
+    min-width: 0;
+    border-radius: 8px;
+    background-color: $panel-actions;
+    // keep border thickness consistent to prevent movement
+    border: 1px solid transparent;
+    height: 28px;
+    padding: 1px;
+
+    // Create a flexbox for the icons (easier to manage)
+    display: flex;
+    align-items: center;
+
+    cursor: pointer;
+
+    .mx_RoomSearch_icon {
+        width: 16px;
+        height: 16px;
+        mask: url('$(res)/img/element-icons/roomlist/search.svg');
+        mask-repeat: no-repeat;
+        background-color: $secondary-content;
+        margin-left: 7px;
+        margin-bottom: 2px;
+        flex-shrink: 0;
+    }
+
+    .mx_RoomSearch_spotlightTriggerText {
+        font-size: $font-12px;
+        line-height: $font-16px;
+        color: $tertiary-content;
+        flex: 1;
+        min-width: 0;
+        // the following rules are to match that of a real input field
+        overflow: hidden;
+        margin: 9px;
+        font-weight: $font-semi-bold;
+    }
+
+    .mx_RoomSearch_shortcutPrompt {
+        border-radius: 6px;
+        background-color: $panel-actions;
+        padding: 2px 4px;
+        user-select: none;
+        font-size: $font-12px;
+        line-height: $font-15px;
+        font-family: inherit;
+        font-weight: $font-semi-bold;
+        color: $light-fg-color;
+        margin-right: 6px;
+        white-space: nowrap;
+        overflow: hidden;
+        text-overflow: ellipsis;
+    }
+
+    &.mx_RoomSearch_minimized {
+        height: 32px;
+        min-height: 32px;
+        width: 32px;
+        box-sizing: border-box;
+
+        .mx_RoomSearch_icon {
+            margin: 0 auto;
+            padding: 1px;
+            align-self: center;
+        }
+
+        .mx_RoomSearch_shortcutPrompt {
+            display: none;
+        }
+    }
+
+    &:hover {
+        background-color: $tertiary-content;
+
+        .mx_RoomSearch_spotlightTriggerText {
+            color: $background;
+        }
+
+        .mx_RoomSearch_shortcutPrompt {
+            background-color: $background;
+            color: $secondary-content;
+        }
+
+        .mx_RoomSearch_icon {
+            background-color: $background;
+        }
+    }
+}