.button {
  display: inline-block;
  margin: 0.2rem 0;
  padding: 0.9rem;
  color: #fff;
  background-color: #e3695f;
  border-radius: 0.2rem;
  font-size: 1.4rem;
  text-align: center;
  text-decoration: none;
}

.width-1 {
  width: 10% !important;
}

.width-2 {
  width: 20% !important;
}

.width-3 {
  width: 30% !important;
}

.width-4 {
  width: 40% !important;
}

.width-5 {
  width: 50% !important;
}

.width-6 {
  width: 60% !important;
}

.width-7 {
  width: 70% !important;
}

.width-8 {
  width: 80% !important;
}

.width-9 {
  width: 90% !important;
}

.width-10 {
  width: 100% !important;
}

.luminous {
  display: inline-block;
}
.luminous .img {
  display: block;
  width: 100%;
  margin-right: 1rem;
  border: solid 1px #ccc;
}

@media screen and (max-width: 480px) {
  .luminous {
    margin-top: 0.8rem;
    margin-bottom: 0.8rem;
  }
}
.red-pen {
  color: #e3695f;
  font-weight: bold;
}

.inline-command {
  display: inline-block;
  margin: 0.3rem 0.2rem;
  padding: 0.5rem;
  background: #eee;
  font-size: 1.1rem;
}

.terminal {
  display: inline-block;
  margin: 0.3rem 0.2rem;
  padding: 0.5rem;
  background: #000;
  color: #fff;
  font-size: 1.1rem;
}

.command {
  display: inline-block;
  margin: 0.8rem 0.1rem 0.8rem 0.9rem;
  padding: 0.5rem;
  border-left: solid 0.4rem #888;
  font-size: 1.1rem;
}

body {
  padding: 2rem;
  color: #333;
  font-family: Open Sans, Helvetica, Arial, sans-serif;
}
body a {
  color: inherit;
}
body a:hover {
  text-decoration: none;
}

.base {
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

@media screen and (max-width: 480px) {
  body {
    padding: 0.8rem;
  }

  .base {
    font-size: 0.95rem;
  }
}
.nav {
  position: sticky;
  top: 2rem;
  width: 14%;
  margin-right: 1rem;
  padding: 2rem;
  user-select: none;
}

.nav__icon {
  display: block;
  width: 30%;
  min-width: 45px;
  margin-left: 1.4rem;
  border: solid 1px #eee;
  border-radius: 50%;
}

.nav__list {
  margin: 2rem 0;
  padding: 0;
  list-style: none;
}

.nav__item {
  display: inline-block;
  margin: 0.5rem 0.4rem;
  padding: 0.6rem 1rem;
  color: inherit;
  font: 1.5rem Open Sans, Helvetica, Arial, sans-serif;
  border-radius: 100vh;
  text-decoration: none;
}
.nav__item:hover {
  background: #eee;
}
.nav__item.active {
  font-weight: bold;
}

.nav-sp {
  display: none;
}

@media screen and (max-width: 480px) {
  .nav {
    display: none;
  }

  .nav-sp {
    display: block;
    position: relative;
  }

  .nav-sp__hide {
    display: none;
  }

  #nav-sp-open {
    display: inline-block;
    width: 30px;
    height: 22px;
    vertical-align: middle;
    position: fixed;
    top: 1.2rem;
    left: 1.2rem;
  }

  #nav-sp-open span,
#nav-sp-open span::before,
#nav-sp-open span::after {
    display: block;
    width: 25px;
    height: 3px;
    background: #333;
    border-radius: 3px;
    position: absolute;
    content: "";
    cursor: pointer;
  }

  #nav-sp-open span::before {
    bottom: -8px;
  }

  #nav-sp-open span::after {
    bottom: -16px;
  }

  #nav-sp-close {
    display: none;
    width: 100%;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
    opacity: 0;
    transition: 0.3s ease-in-out;
    z-index: 99;
  }

  .nav-sp__content {
    width: 80%;
    max-width: 330px;
    height: 100%;
    background: #fff;
    position: fixed;
    top: 0;
    left: 0;
    overflow: auto;
    opacity: 0.95;
    transition: 0.3s ease-in-out;
    z-index: 9999;
    transform: translateX(-105%);
    -webkit-transform: translateX(-105%);
  }
  .nav-sp__content .nav-sp__list {
    margin: 2rem;
    padding: 0;
    list-style-type: none;
  }
  .nav-sp__content .nav-sp__item {
    display: block;
    margin-bottom: 3rem;
    padding-bottom: 0.3rem;
    border-bottom: 0.1rem solid #333;
    font-size: 1.5rem;
  }
  .nav-sp__content .nav-sp__item a {
    text-decoration: none;
    color: #333;
    font-weight: bold;
  }
  .nav-sp__content .nav-sp__title {
    /* extend main__title */
    font: 3rem Open Sans, Helvetica, Arial, sans-serif;
    font-weight: bold;
    text-align: center;
  }
  .nav-sp__content .nav-sp__logo {
    /* extend main__mv */
    display: block;
    width: 50%;
    margin: 1rem auto;
    border-radius: 50%;
    box-shadow: 0.1rem 0.1rem 1rem #ccc;
    user-select: none;
  }

  #nav-sp-checkbox:checked ~ #nav-sp-close {
    display: block;
    opacity: 0.5;
  }

  #nav-sp-checkbox:checked ~ .nav-sp__content {
    transform: translateX(0%);
    -webkit-transform: translateX(0%);
    box-shadow: 6px 0 25px rgba(0, 0, 0, 0.15);
  }
}
.main {
  width: 50%;
  padding: 2rem;
  box-shadow: 0.01rem 0.01rem 0.2rem #ccc;
}

.main__mv {
  display: block;
  width: 50%;
  margin: 0 auto;
  border-radius: 50%;
  box-shadow: 0.1rem 0.1rem 1rem #ccc;
  user-select: none;
}

.main__title, .main__subtitle {
  font: 3rem Open Sans, Helvetica, Arial, sans-serif;
  font-weight: bold;
}

.main__subtitle {
  font-size: 1.6rem;
}

.main__content, .main__date {
  width: 80%;
  margin: 4rem 0 1rem 0.5rem;
}

.main__h1, .main__h2 {
  border-left: solid 0.5rem #333;
  padding: 0.2rem 0.4rem;
}
.main__h1 a, .main__h2 a {
  display: inline-block;
  position: relative;
  color: inherit;
  text-decoration: none;
}
.main__h1 a::after, .main__h2 a::after {
  position: absolute;
  bottom: -4px;
  left: 0;
  content: "";
  width: 100%;
  height: 2px;
  background: #333;
  transform: scale(0, 1);
  transform-origin: right top;
  transition: transform 0.3s;
}
.main__h1 a:hover::after, .main__h2 a:hover::after {
  transform-origin: left top;
  transform: scale(1, 1);
}
.main__h1:not(:first-child), .main__h2:not(:first-child) {
  margin-top: 4rem;
}

.main__h1__content {
  margin-left: 0.9rem;
}

.main__h2 {
  margin-top: 2rem;
  margin-left: 0.9rem;
}

.main__h2__content {
  margin-left: 1.8rem;
}

.main__p, .main__annotation-text, .main__date {
  line-height: 1.5rem;
}

.footer {
  margin-top: 2rem;
  text-align: right;
}

@media screen and (max-width: 480px) {
  .main {
    width: 100%;
    padding: 2rem;
    box-shadow: 0.01rem 0.01rem 0.2rem #ccc;
    overflow: scroll;
  }

  .main__title, .main__subtitle {
    font-size: 2.8rem;
  }

  .main__subtitle {
    font-size: 1.4rem;
  }

  .main__content, .main__date {
    width: calc(100% - 0.5rem);
  }

  .main__h1__content,
.main__h2,
.main__h2__content {
    margin-left: 0;
  }
}
.main__intro {
  display: flex;
}

.main__intro-q {
  width: 15%;
  margin-right: 0.5rem;
  padding: 0.6rem;
}

.main__intro-a {
  width: 85%;
  padding: 0.6rem;
}

.main__intro-flex-wrap {
  display: flex;
  align-items: flex-start;
  flex-direction: column;
}

.main__intro-flex-wrap div:not(:first-of-type) {
  margin-top: 2rem;
}

.main__intro-h {
  margin: 0;
  padding: 0;
}

.main__intro-h ~ * {
  margin-left: 1.4rem;
}

@media screen and (max-width: 480px) {
  .main__intro-q {
    padding: 0.6rem 0;
  }

  .main__intro-a {
    padding: 0.6rem 0;
  }

  .main__intro-h ~ * {
    margin-left: 0;
  }
}
.main__cat-btns {
  display: flex;
  flex-wrap: wrap;
}

.main__cat-btn {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 25%;
  margin: 0.3rem 0.3rem;
  padding: 0.9rem 0.3rem;
  text-align: center;
  font-size: 1rem;
  text-decoration: none;
  border-radius: 0.2rem;
  box-shadow: 0.01rem 0.01rem 0.2rem #aaa;
  cursor: pointer;
  user-select: none;
}
.main__cat-btn.active, .main__cat-btn:hover {
  background-color: #e3695f;
  color: #fff;
  font-weight: bold;
}

.main__cat-wrap {
  display: none;
}
.main__cat-wrap .main__h1::after, .main__cat-wrap .main__h2::after {
  content: "";
  display: inline-block;
  width: 1rem;
  height: 1rem;
  margin-left: 0.4rem;
  background-image: url("img/link.svg");
  background-size: cover;
}

@media screen and (max-width: 480px) {
  .main__cat-btn {
    font-size: 0.9rem;
    line-height: 1.3rem;
  }
}
.main__date {
  margin-top: -1rem;
  margin-bottom: 0;
}

.main__ol,
.main__ul {
  padding: 0;
  padding-left: 1.1rem;
}
.main__ol li,
.main__ul li {
  margin: 0.4rem 0;
}

.main__annotation {
  margin: 2rem 0;
  padding: 1rem;
  border: solid 2px #27a7c6;
  border-radius: 1rem;
  position: relative;
}

.main__annotation-i {
  display: inline-block;
  min-width: 2rem;
  min-height: 2rem;
  line-height: 2rem;
  text-align: center;
  font-family: serif;
  background: #27a7c6;
  color: #fff;
  border-radius: 50vh;
  position: absolute;
  top: -1rem;
}

.main__annotation-text {
  margin: 0 auto 0 2rem;
}

.main__imgs {
  display: flex;
  align-items: flex-start;
}
.main__imgs .luminous {
  margin-right: 1rem;
}
.main__imgs .img {
  display: inline-block;
}