body {
  color: #444;
  font-family: 'Open Sans', sans-serif;
}

nav {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 999;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav .logo {
  margin: 10px 30px;
  width: 80px;
  height: 80px;
}

nav .logo img {
  width: 100%;
  height: 100%;
}

nav ul {
  display: flex;
  padding: 5px;
  margin: 0 20px;
  list-style: none;
}

nav ul li {
  padding: 0 10px;
  margin: 0 10px;
  font-size: 20px;
}

nav ul li a {
  color: #413e66;
}

#intro {
  width: 100%;
  height: 100vh;
  position: relative;
  background: #f5f8fd url('../img/intro-bg.jpg') center top no-repeat;
  background-size: cover;
}

#intro .intro-info h2 {
  color: #413e66;
  margin-bottom: 40px;
  font-size: 48px;
  font-weight: bold;
}

#intro .intro-info h2 span {
  color: #1bb1dc;
}
#intro .btn-study {
  color: #fff;
  background: #1bb1dc;
  transition: all 0.3s ease;
}
#intro .btn-study:hover {
  color: #1bb1dc;
  background: #fff;
  border: 1px solid #1bb1dc;
}

#about .about-content {
  padding-top: 40px;
}

#about .about-content h2 {
  color: #413e66;
  font-weight: bold;
}

#about .about-content ul {
  list-style: circle;
  padding: 0;
}

#about .about-content ul li {
  margin-bottom: 10px;
}

#about .about-img {
  /* position: relative; */
  margin: 30px;
}

#about .about-img img {
  width: 100%;
  /* border: 8px solid #fff; */
}

.section-header h3 {
  position: relative;
  font-size: 36px;
  color: #413e66;
  font-weight: bold;
}

.course .course-img {
  /* position: relative; */
  display: block;
  margin-bottom: 20px;
  /* border-radius: 5px; */
  transition: all 0.3s ease;
}

.course .course-img img {
  width: 100%;
  min-height: 200px;
  max-height: 250px;
  border: solid 1px #413e66;
  border-radius: 20px;
}

.course .course-img:hover {
  transform: scale(1.1);
}

.course {
  margin: 20px 0;
}

.course .course-title {
  display: block;
  height: 58px;
  color: #0a98c0;
  text-decoration: none;
}

.course .course-details {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid #ebebeb;
}

.course .course-free {
  color: green;
}

.course .course-paid {
  color: red;
}

.more-button {
  padding: 10px 30px;
  background-color: #413e66;
  color: #fff;
  border: 1px solid transparent;
  border-radius: 40px;
  transition: all 0.3s ease;
}

.more-button:hover {
  background-color: #fff;
  color: #413e66;
  text-decoration: none;
  border: 1px solid #413e66;
}

#footer {
  margin-top: 30px;
  background: #f5f8fd;
  padding: 25px 0;
  font-size: 14px;
}

#footer .copyright {
  text-align: center;
  color: #535074;
  font-size: 15px;
}