pre {
  background-color: #f2f4f5;
  padding: 5px;
  border-radius: 4px;
  position: relative;
  overflow: auto;
  display: block;
}
code {
  overflow: auto;
  position: relative;
}
.core-next-editor-bar {
  position: absolute;
  top: 0;
  right: 0;
}
.core-next-edit-code {
  width: 100%;
}
:root {
  --theme-color: #409eff;
}
h2 {
  padding-left: 16px;
  margin: 12px 0;
  border: 0;
  font-weight: 700;
  color: var(--theme-color);
  font-size: 20px;
  position: relative;
}
h2:before {
  position: absolute;
  content: '';
  width: 4px;
  background: var(--theme-color);
  top: 10%;
  left: 2px;
  bottom: 10%;
  border-radius: 5px;
  transition: 0.4s;
}
h3 {
  padding-bottom: 10px;
  margin: 12px 0;
  position: relative;
}
h3:hover:before {
  width: 50px;
}
h3:before {
  width: 40px;
  height: 3px;
  top: auto;
  left: 0;
  bottom: 3px;
  transition: 0.4s;
  position: absolute;
  content: '';
  background: var(--theme-color);
  border-radius: 5px;
  box-shadow: 0 1px 3px rgba(26, 26, 26, 0.1);
}