:root {
  --textColor: black;
  --backgroundColor: white;
  --borderColor: gainsboro;
}

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

html,
body {
  height: 100%;
  overflow: hidden;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  display: flex;
  flex-direction: column;
  position: relative;
  font-family: Pretendard, serif;
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: .0125em;
  line-height: 1.5;
  word-break: keep-all;
  color: black;
  background-color: white;
  cursor: default;
}

a {
  text-decoration: none;
  color: inherit;
  cursor: pointer;
}

.header,
.footer {
  flex: 0 0 auto;
  position: relative;
  padding: 1rem;
  text-align: center;
}

.header {
  border-bottom: 1px solid var(--borderColor);
}

.footer {
  border-top: 1px solid var(--borderColor);
}

.main {
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  position: relative;
  overflow: hidden;
}

@media screen and (min-width: 900px) {
  .main {
    flex-direction: row;
  }
}

.main > * {
  display: flex;
  flex-direction: column;
  flex: 1 1 0;
  position: relative;
  height: 100%;
  overflow-x: hidden;
  overflow-y: auto;
}

.main > *:not(:last-child) {
  border-bottom: 1px solid gainsboro;
}

@media screen and (min-width: 900px) {
  .main > *:not(:last-child) {
    border-bottom: 0;
    border-right: 1px solid gainsboro;
  }
}

.article {
  display: flex;
  flex-direction: column;
}

.article-header {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 50%;
  padding: 1rem;
  text-align: center;
  border-bottom: 1px solid var(--borderColor);
}

.article-main {
  display: flex;
  flex-direction: column;
  flex: 0 0 50%;
  overflow-y: auto;
}

.title {
  font-size: 1rem;
  font-weight: inherit;
}

.content {
  font-size: 1rem;
  line-height: 1.625;
}

.content > *:not(:last-child) {
  margin-bottom: 1.5rem;
}

.content code {
  display: inline-block;
  position: relative;
  top: -.125em;
  padding: .125em .375em;
  font-size: .875rem;
  border-radius: .25rem;
  color: white;
  background-color: black;
}

.content pre {
  padding: .5rem;
  border-radius: .25rem;
  overflow: auto;
  filter: grayscale(100%);
}

.content pre:hover {
  filter: grayscale(0%);
}

.content pre code {
  padding: 0;
  background-color: transparent;
}

.search {
  border-bottom: 1px solid var(--borderColor);
}

.search-input {
  appearance: none;
  display: block;
  width: 100%;
  padding: 1rem;
  font: inherit;
  text-align: center;
  border: 0;
  border-radius: 0;
  outline: 0;
}

.list {
  list-style: none;
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  overflow-x: hidden;
  overflow-y: auto;
  text-align: center;
}

.list-item {
  display: flex;
  align-items: stretch;
}

.list-item:not(:last-child) {
  border-bottom: 1px solid var(--borderColor);
}

.list-item a {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  padding: 1rem;
  overflow: hidden;
}

.list-item a:hover span::before,
.list-item.is-active a span::before {
  content: "<";
}

.list-item a:hover span::after,
.list-item.is-active a span::after {
  content: ">";
}

.list-item.is-active {
  flex: 0 0 calc(100% + 1px);
  font-size: 3rem;
}

@media screen and (min-width: 900px) {
  .list-item.is-active {
    font-size: 6rem;
  }
}

.code {
  display: flex;
  flex: 1 1 auto;
  position: relative;
  overflow: hidden;
}

.code > * {
  flex: 1 1 0;
  overflow: hidden;
}

.CodeMirror {
  height: 100%;
}

.code-iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

.energy {
  color: black;
  text-shadow: 0 0 1em lime;
  animation: energy 1s infinite alternate;
}

@keyframes energy {
  0% {
    text-shadow: 0 0 .5em lime, 0 0 .5em lime, 0 0 .5em lime;
  }
  100% {
    text-shadow: 0 0 1.5em lime, 0 0 1.5em lime, 0 0 1.5em lime;
  }
}