* {
  margin: 0;
  padding: 0;
}

*,
*::after,
*::before {
  box-sizing: inherit;
}

html {
  box-sizing: border-box;
  font-size: 93.75%;
}

body {
  font-family: "Open Sans", Arial, sans-serif;
  color: #4d4e53;
  line-height: 1.6;
  overflow: hidden;
  height: 100vh;
}

p {
  margin: 1rem;
}

code {
  background-color: #f7f7f7;
  border-radius: 0.3rem;
  display: block;
  line-height: 2;
  margin: 1.3rem auto;
  padding: 1rem;
}

pre {
  margin: 0;
}

span {
  color: #007936;
}

.nav-list {
  list-style: none;
}

.nav-list li:not(:last-child) {
  border-bottom: 0.1rem solid rgba(0, 22, 22, 0.4);
}

.nav-link {
  display: block;
  padding: 0.7rem 1.5rem;
  text-decoration: none;
  color: inherit;
  font-size: 1.1rem;
}

.nav-link:hover {
  background-color: rgba(0, 22, 22, 0.4);
  color: #fff;
  font-size: 1.1rem;
}

.main-section {
  margin-bottom: 2rem;
}

.section-header {
  font-size: 1.7rem;
}

.image {
  display: block;
  margin: 1.3rem auto;
  width: 50%;
}

.ul-main-doc li {
  margin: 1rem 0 0 2rem;
}

.pre {
  margin: 1.3rem 1rem;
}

.tag {
  background-color: #f7f7f7;
  color: black;
}

.element {
  color: black;
  font-style: italic;
}

.attribute {
  color: #d30638;
}

.doctype {
  color: #858585;
}

#container {
  display: flex;
  height: 100%;
}

#navbar {
  background-color: #f1f1f1;
  border-right: 2px solid rgba(0, 22, 22, 0.4);
  animation: moveInLeft 2.5s ease-out;

  flex: 1 0 20%;
}

#nav-header {
  height: 4.7rem;
  padding: 0.8rem 0;
  background-color: #8ebebc;
  text-align: center;
  color: #fff;
  font-size: 1.9rem;
}

#content {
  width: 95%;
  margin: 10px auto;
}

#main-doc {
  overflow: auto;
  opacity: 0;
  animation: isVisible 2.5s ease-in-out;
  animation-fill-mode: forwards;
}

#image {
  display: block;
  border: 0.1rem solid rgba(0, 0, 0, 0.2);
  border-radius: 0.3rem;
  margin: 1.3rem 0;
  padding: 1rem 52rem 4rem 1rem;
}

@keyframes moveInLeft {
  0% {
    opacity: 0;
    transform: translateX(-20rem);
  }
  100% {
    opacity: 1;
    transform: translate(0);
  }
}

@keyframes isVisible {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

@keyframes moveInTop {
  0% {
    opacity: 0;
    transform: translateY(-30rem);
  }
  100% {
    opacity: 1;
    transform: translate(0);
  }
}

@media only screen and (max-width: 1400px) {
  #nav-header {
    padding: 0.4rem 0;
    line-height: 1;
  }
}

@media only screen and (max-width: 900px) {
  #container {
    flex-direction: column;
  }

  #navbar {
    border-bottom: 2px solid rgba(0, 22, 22, 0.4);
    overflow: auto;
    flex: 1 0 40%;
    animation: moveInTop 2.5s ease-out;
  }

  #nav-header {
    padding: 1.3rem 0;
  }
}