ui/src/assets/widgets/linear_progress.scss

// Copyright (C) 2025 The Android Open Source Project
//
// 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.

.pf-linear-progress {
  // Make the progress bar 1px high but -1px margin which makes it render over
  // the top of the element above it to save space.
  height: 1px;
  margin-bottom: -1px;
  z-index: 10;
  position: relative;
  overflow: hidden;
}

.pf-linear-progress--anim {
  &:before {
    content: "";
    position: absolute;
    background-color: var(--pf-color-accent);
    top: 0;
    left: 0;
    bottom: 0;
    will-change: left, right;
    animation: indeterminate 2.1s cubic-bezier(0.65, 0.815, 0.735, 0.395)
      infinite;
  }

  &:after {
    content: "";
    position: absolute;
    background-color: var(--pf-color-accent);
    top: 0;
    left: 0;
    bottom: 0;
    will-change: left, right;
    animation: indeterminate-short 2.1s cubic-bezier(0.165, 0.84, 0.44, 1)
      infinite;
    animation-delay: 1.15s;
  }
}

@keyframes indeterminate {
  0% {
    left: -35%;
    right: 100%;
  }
  60% {
    left: 100%;
    right: -90%;
  }
  100% {
    left: 100%;
    right: -90%;
  }
}

@keyframes indeterminate-short {
  0% {
    left: -35%;
    right: 100%;
  }
  60% {
    left: 100%;
    right: -90%;
  }
  100% {
    left: 100%;
    right: -90%;
  }
}