html, body, h1, h2, h3, ul {
  margin: 0;
  padding: 0;
}

body {
  font-family: "Raleway", sans-serif;
  font-weight: 400;
  font-size: 1.1em;
  font-style: normal;
  background: lightblue;
}

h1 {
  font-weight: 600;
}

h2 {
  font-weight: 500;
}

section {
  padding: 12px 24px;
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: #ddd;
  &:hover {
    color: rgba(218, 165, 32, 0.9);
  }
}

ul {
  list-style: none;
}

/****** begin header ******/
header {
  display: flex;
  align-items: center;
  background: indigo;
  background: linear-gradient(indigo 15%, rgba(0,0,0,0) 100%);
  height: 20vh;
  width: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 10;
  > a {
    margin-left: 24px;
    :hover {
      color: #ddd;
    }
  }
}


nav {
  margin-left: auto;
  ul {
    display: flex;
    padding-inline-start: 0;
    li {
      margin-right: 24px;
      margin-bottom: 8px;
    }
  }
}

@media (max-width: 600px) {
  nav ul {
    display: block;
  }
}

@media (max-width: 368px) {
  nav {
    display: none;
  }
}

/********** section - about **********/
#about {
  padding-top: 24vh;
  min-height: 74vh;
  color: #222;
  box-shadow: inset 0 -3px 6px rgba(76, 0, 130, 0.4);
  h2 {
    color: indigo;
  }
  img {
    float: left;
    max-width: 164px;
    margin: 24px 24px 24px 0;
  }
}

/************* section - books ************/
#books {
  background: rgba(218, 165, 32, 0.6);
  position: relative;
  width: 100%;
  height: 80vh;
  overflow: hidden;
  padding: 0;
  padding-top: 20vh;
  text-align: end;
  box-shadow: 0 3px 6px rgba(76, 0, 130, 0.4);
  > h2 {
    color: indigo;
    text-shadow: #ddd -2px 2px 2px;
    position: absolute;
    right: 48px;
    top: 22vvh;
    z-index: 1;
  }
  img {
    height: 70vh;
    position: absolute;
    left: 24px;
    bottom: 36px;
  }
  ul li {
    position: absolute;
    top: 0;
    left: 100vw;
    height: 100%;
    width: 100%;
    display: flex;
    transition: transform .2s ease-out;
    .description  {
      max-width: 512px;
      position: absolute;
      top: 54%;
      transform: translateY(-50%);
      right: 24px;
      padding: 36px;
      margin-left: 48px;
      color: #222;
      background: #ddd;
      opacity: 0.7;
      text-shadow: white -2px 2px 2px;
      a {
        color: indigo;
        &:hover {
          color: goldenrod;
        }
      }
    }
  }
}

#book1 {
  left: 0 !important;
}

@media (max-width: 368px) {
  #books ul li .description  {
    padding: 18px;
  }
}

@media (max-width: 512px) {
  #books ul li a img {
    left: 0px;
    width: 100vw;
    height: auto;
  }
}

#arrow {
  position: absolute;
  bottom: 48px;
  right: 48px;
  color: indigo;
  opacity: .8;
  font-size: 52px;
  text-shadow: #ddd -2px 2px 2px;
  cursor: pointer;
  &:hover {
    opacity: 1;
  }
}

/********** section - lessons **********/
#lessons {
  min-height: 80vh;
  padding-top: 20vh;
  padding-bottom: 48px;  
  background-color: rgba(24, 158, 113, 0.637);
  box-shadow: 0 3px 6px rgba(76, 0, 130, 0.4);
}

#lessons h2 {
  color: #ddd;
  margin-bottom: 18px;
}

#lessons h3 {
  color: indigo;
  font-weight: 350;
}

#lessons a {
  color: indigo;
}

#lessons a:hover {
  color: #ddd;
}

#accessories, #packages {
  display: flex;
  position: relative;
  margin-top: -32px;
  margin-bottom: 24px;
}

#expand-accessories,
#expand-packages {
  color: indigo;
  font-size: 44px;
  font-weight: 100;
  cursor: pointer;
  z-index: 2;
}

#accessories ul,
#packages ul {
  position: absolute;
  left: 0;
  top: 10px;
  width: 100%;
  height: 18vh;
  margin-right: auto;
  margin-left: auto;
  background: #ddd;
  opacity: .7;
  display: none;
  justify-content: space-evenly;
}

#accessories ul li,
#packages ul li {
  align-content: center;
}

#expand-accessories:hover + ul,
#expand-packages:hover + ul {
  display: flex;
}

/********** section - music **********/
#music {
  min-height: 60vh;
  padding-top: 20vh;
  padding-bottom: 36px;
  a {
    color: indigo;
  }
  a:hover {
    color: goldenrod;
  }
  iframe {
    width: 240px;
    height: 180px;
  }
}

/************ footer ************/
footer {
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding: 12px 24px;
  color: darkslateblue;
  background: indigo;
  background: linear-gradient(rgba(0,0,0,0) 0%, indigo 85%);
  img {
    width: 42px; 
  }
  a {
    color: darkslateblue;
  }
}

#ucsign {
    position: fixed;
    top: 120px;
    right: -30px;
    width: 300px;
    transform: rotate(50deg);
}