.content-area{
    display: flex;
    justify-content: center;
    width: 100%;
    min-height: calc(100vh - 154px);
    margin: 0;
}

.left-content {
    width: 350px;
    min-height: calc(100vh - 174px);
    background-color: #ffffff;
    margin: 20px 40px 20px 0;
    display: flex;
    flex-direction: column;
}

.course-menu-header {
    height: 35px;
    background-color: #ff9933;
    font-size: 20px;
    padding: 3px 25px;
    font-weight: bold;
    border-top-left-radius: 15px;
    border-top-right-radius: 15px;
}

.odd {
    text-decoration: none;
    height: 70px;
    display: flex;
    background-color: #ffcc99;
    align-items: center;
    border-bottom: 3px solid #ff9933;
}

.even {
    text-decoration: none;
    height: 70px;
    display: flex;
    background-color: #ffffff;
    align-items: center;
    border-bottom: 3px solid #ff9933;
}

.main-content {
    width: 1200px;
}

.main-section {
    width: 1200px;
    height: 35px;
    background-color: #ff9933;
    font-size: 20px;
    padding: 3px 15px;
    font-weight: bold;
    margin-top: 20px;
    border-left: 15px solid #ff6600;
    border-radius: 15px;
}

.exp-area{
    background-color: #ffffff;
    padding: 20px 40px;
    border-radius: 20px;
    border: 2px dashed #cccccc;
}

.lesson-category{
    position: relative;
    color: #000000;
    background: #FF9933;
    box-shadow: 0px 0px 0px 5px #FF9933;
    border: dashed 2px white;
    width: 240px;
    padding: 5px 20px;
    list-style: none;
}

.lesson-category:after{
  position: absolute;
  content: '';
  left: -7px;
  top: -7px;
  border-width: 0 0 15px 15px;
  border-style: solid;
  border-color: #fff #fff #ff6600;
  box-shadow: 1px 1px 1px rgba(0, 0, 0, 0.15);
}

.lesson-list-style{
    padding: 16px 10px;
    display: flex;
    justify-content:space-between;
    border-bottom: 2px dashed #aaaaaa;
    background-color:#ffffff;
}

.lesson-name-style{
    font-size: 16px;
    line-height: 24px;
    height: 24px;
    vertical-align: middle;
    color: #000000;
    text-decoration: none;
}

.lesson-name-style:hover{
    text-decoration: underline;
}

.record-star{
    width: 24px;
    height: 24px;
}

.course-img {
    width: 40px;
    margin-left: 15px;
}

.link-text{
    color: #000000;
    font-weight: bold;
    text-decoration: none;
    margin-left: 10px;
}