/* Copyright 2025 The Chromium Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file. */

/* #css_wrapper_metadata_start
 * #type=style-lit
 * #scheme=relative
 * #import=./cr_shared_vars.css.js
 * #css_wrapper_metadata_end */

/* Common CSS classes used to make an element scrollable and add anchored
 * elements at the top and bottom of the scrollable element.  The anchored top
 * and bottom elements show either a border or a shadow when the cr-scrollable
 * element is scrollable in their respective directions. */

.cr-scrollable {
  anchor-name: --cr-scrollable;
  anchor-scope: --cr-scrollable;
  container-type: scroll-state;
  overflow: auto;
}

.cr-scrollable-top,
.cr-scrollable-top-shadow,
.cr-scrollable-bottom {
  display: none;
  position: fixed;
  position-anchor: --cr-scrollable;
  left: anchor(left);
  width: anchor-size(width);
  pointer-events: none;

  &:where(.force-on) {
    display: block;
  }
}

.cr-scrollable-top {
  top: anchor(top);
  border-top: 1px solid var(--cr-scrollable-border-color);

  @container scroll-state(scrollable: top) {
    display: block;
  }
}

.cr-scrollable-bottom {
  bottom: anchor(bottom);
  border-bottom: 1px solid var(--cr-scrollable-border-color);

  @container scroll-state(scrollable: bottom) {
    display: block;
  }
}

.cr-scrollable-top-shadow {
  box-shadow: inset 0 5px 6px -3px rgba(0, 0, 0, .4);
  display: block;
  height: 8px;
  opacity: 0;
  top: anchor(top);
  transition: opacity 500ms;
  z-index: 1;

  &:where(.force-on) {
    opacity: 1;
  }

  @container scroll-state(scrollable: top) {
    opacity: 1;
  }
}