body {
    margin-top: 0;
    margin-bottom: 0;
    margin-left: auto;
    margin-right: auto;
}

.header{
    width: 100%;
    height: 100px;
    background-color: blueviolet;
}

.header-image{
    width: 100%;
    height: 600px;
    background-color: cadetblue;
}

.main-area {
    padding: 20px;
    margin-left: 15%;
    margin-right: 15%;
    height: 100%;
    background-color: chocolate;
}

@media (max-width: 800px) {
    .main-area {
        padding: 10px;
        margin-left: 0;
        margin-right: 0;
        height: 100%;
        background-color: chocolate;
    }
}

.title-area{
    width: 100%;
    height: 80px;
    margin-top: 10px;
    margin-bottom: 5px;
    background-color: blue;
}
.subtitle-area{
    width: 100%;
    height: 50px;
    margin-bottom: 10px;
    background-color: aqua;
}

.selection-area{
    width: 80%;
    padding-left: 10%;
    padding-right: 10%;
    padding-top: 5px;
    padding-bottom: 5px;
    background-color: blueviolet;
    margin: 0 auto;
}

.content-area{ 
    display: inline-block;
    width: 300px; 
    height: 500px; 
    background-color: #f1f1f1; 
    float: left;
    margin: 10px;
    padding: 10px;
}
@media (max-width: 800px) {
    .content-area{
        width: 200px;
        height: 300px;
    }
}

.content-image{
    width: 100%;
    height: 300px;
    background-color: brown;
}
@media (max-width: 800px) {
    .content-image{
        height: 200px;
    }
}
    
.content-text{
    margin-top: 10px;
    width: 100%;
    height: 180px;
    background-color: cadetblue;
}
@media (max-width: 800px) {
    .content-text{
        height: 80px;
    }
}
    
.footer{
    width: 100%;
    height: 100px;
    background-color: forestgreen;
}

.end-of-block{
    clear: both;
}