html, body {
  overflow: auto;
}

body {
  background: #ebebeb;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 14px;
  text-align: left;
  max-width: 60%;
  margin: auto;
}

header {
  display: flex;
  margin-top: 36px;
  height: 64px;
  justify-content: center;
  text-align: center;
}

header #title {
  color: #4b005a;
  text-decoration: none;
  margin: 0px;
  width: 100%;
  font-size: 50px;
  font-weight: bold;
}

footer {
  margin-top: 20px;
  text-align: center;
}

#error_box {
  color: red;
  visibility: hidden;
}

.hidden {
  display: none;
}

.header_btn {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-left: 10px;
}