@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@100;400;700&family=Poppins:wght@100;400;800&display=swap');

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Poppins', 'Noto Sans JP', sans-serif;
}

:root {
  --main-letter-color: #efeff1
}

html {
  scroll-behavior: smooth;
}

a {
  text-decoration: none;
  cursor: pointer;
  color: var(--main-letter-color);
}

a:hover {
  color: gray;
}

ul {
  list-style: none;
}

li {
  color: var(--main-letter-color);
  font-size: 14px;
}

h1,h2,h3,h4,p,summary {
  color: var(--main-letter-color);
}

p {
  font-size: 14px;
}

summary {
  color: var(--main-letter-color);
  cursor: pointer;
}

summary:hover {
  color: gray;
}

body {
  position: relative;
  background-color: #252525;
}

header {
  height: 80px;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 12px;
  position: fixed;
  top: 0;
  left: 0;
  background-color: #252525;
}

header .logo h1 {
  font-size: 28px;
  letter-spacing: 1px;
  line-height: 1;
}

header .logo h1 b {
  color: orange;
}

header .logo h1 span {
  margin-left: 12px;
  font-size: 15px;
}

footer {
  height: 120px;
  width: 100%;
  background-color: #252525;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 12px;
}

main {
  height: calc(100vh - 120px);
  margin: 0 auto;
  padding-top: 80px;
  display: flex;
  justify-content: space-between;
  max-width: 1280px;
}

main nav {
  width: 240px;
  padding: 6px 6px 6px 30px;
  overflow-y: scroll;
}

main nav::-webkit-scrollbar {
  width: 10px;
}

main nav::-webkit-scrollbar-track {
  background-color: transparent;
}

main nav::-webkit-scrollbar-thumb {
  border-radius: 5px;
  background-color: orange;
}

main nav h2::before {
  content: "> ";
}

main nav h2 {
  font-size: 20px;
  font-weight: 400;
  border-bottom: dotted 1px var(--main-letter-color);
  margin-bottom: 6px;
}

main nav ol {
  margin-bottom:6px;
}

main nav ul {
  list-style: disc;
  margin-bottom:6px;
}

main .container {
  width: 100%;
  overflow-y: scroll;
  padding: 6px;
}

main .container::-webkit-scrollbar {
  width: 10px;
}

main .container::-webkit-scrollbar-track {
  background-color: transparent;
}

main .container::-webkit-scrollbar-thumb {
  border-radius: 5px;
  background-color: orange;
}

main .container section h2 {
  font-size: 24px;
  font-weight: 400;
}

main .container section h2::first-letter {
  font-size: 32px;
  font-weight: 800;
}

main .container section h2 span {
  margin-left: 12px;
  font-size: 20px;
}

main .container section .detail {
  margin: 12px 0;
  padding: 4px 12px;
  border-left: solid 8px var(--main-letter-color);
  border-bottom: dotted 1px var(--main-letter-color);
}

main .container section .detail h3 {
  letter-spacing: 1px;
  font-weight: 400;
}

main .container section .detail h3 span {
  margin-left: 12px;
  font-size: 14px;
  color: orange;
}

main .container section .detail h3 span.working-computer {
  color: greenyellow;
  font-weight: 800;
}

main .container section .detail p.hint {
  color: orange;
}

main .container section .detail p.hint::before {
  content: "💡Hint : ";
  font-weight: 800;
}

main .container section .detail img {
  width: 75%;
}

main .container section .detail details {
  margin-top: 6px;
}

main .container section .detail details summary {
  font-size: 14px;
}

main .overlay {
  display: none;
  position: absolute;
  top: 80px;
  left: 0;
  width: 100%;
  height: calc(100% - 80px);
  background-color: rgba(0, 0, 0, 0.8);
}

main .overlay.enable {
  display: block;
  animation: overlay-enable .25s ease;
}

@keyframes overlay-enable {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

main .overlay.enable .inner {
  position: relative;
  display: flex;
  width: 100%;
  height: 100%;
}

main .overlay.enable .inner a#exit {
  position: absolute;
  top: 0;
  right: 0;
  color: var(--main-letter-color);
  cursor: pointer;
  width: 64px;
  height: 64px;
  font-size: 64px;
}

main .overlay.enable .inner a#exit:hover {
  color: gray;
}

main .overlay.enable .inner section.guide {
  display: none;
  justify-content: center;
  align-items: center;
  background-color: #252525;
  width: 100%;
  margin: 72px;
  padding: 12px;
  overflow-y: scroll;
}

main .overlay.enable .inner section.guide::-webkit-scrollbar {
  width: 10px;
}

main .overlay.enable .inner section.guide::-webkit-scrollbar-track {
  background-color: transparent;
}

main .overlay.enable .inner section.guide::-webkit-scrollbar-thumb {
  border-radius: 5px;
  background-color: orange;
}

main .overlay.enable .inner section.guide.enable {
  display: block;
}

main .overlay.enable .inner section.guide h3 {
  border-bottom: solid 1px #252525;
}