* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-color: #008080;
}

p {
  display: block;
  margin-block-start: 1em;
  margin-block-end: 1em;
  margin-inline-start: 0px;
  margin-inline-end: 0px;
}

#app {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  justify-content: center;
  align-items: center;
}
#app .app_inner form {
  width: 240px;
  max-width: 100%;
}
#app .app_inner form .row.mb {
  padding-bottom: 1em;
}
#app .app_inner form .row.submit {
  display: flex;
  justify-content: center;
}
#app .app_inner form .row.submit button:not(:last-child) {
  margin-right: 6px;
}
#app .app_inner form .row.source pre {
  margin: 0;
  overflow: auto;
}
#app .app_inner form .row input[type=text] {
  width: 100%;
}

#popup {
  display: none;
  z-index: 2;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}