v8/tools/heap-stats/trace-file-reader-template.html

<!-- Copyright 2018 the V8 project authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file. -->
<style>
#fileReader {
  width: 100%;
  height: 100px;
  line-height: 100px;
  text-align: center;
  border: solid 1px #000000;
  border-radius: 5px;
  cursor: pointer;
  transition: all 0.5s ease-in-out;
}

#fileReader.done {
    height: 20px;
    line-height: 20px;
}

#fileReader:hover {
  background-color: #e0edfe ;
}

.loading #fileReader {
  cursor: wait;
}

#fileReader > input {
  display: none;
}


#loader {
  display: none;
}

.loading #loader {
  display: block;
  position: fixed;
  top: 0px;
  left: 0px;
  width: 100%;
  height: 100%;
  background-color: rgba(255, 255, 255, 0.5);
}

#spinner {
  position: absolute;
  width: 100px;
  height: 100px;
  top: 40%;
  left: 50%;
  margin-left: -50px;
  border: 30px solid #000;
  border-top: 30px solid #36E;
  border-radius: 50%;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
 0% {
    transform: rotate(0deg);
 }
 100% {
    transform: rotate(360deg);
 }
}
</style>

<section id="fileReaderSection">
  <div id="fileReader" tabindex=1 >
    <span id="label">
      Drag and drop a trace file into this area, or click to choose from disk.
     </span>
    <input id="file" type="file" name="file" />
  </div>
  <div id="loader">
    <div id="spinner"></div>
  </div>
</section>