html {
    background-image: url(images/background.jpg);
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
}
#backToTop {
    color: white;
    font-family: verdana;
    border: none;
    position: fixed;
    border-radius: 14px;
    bottom: 10px;
    max-width: 150px;
    width: 100%;
    font-size: 12px;
    background-color: rgb(255, 59, 48, 0.5);
    backdrop-filter: blur(50px);
    padding: 10px;
    z-index: 4;
    float: right;
    right: 46%;
    left: 46%;
}
#backToTop:hover {
    background-color: rgb(255, 59, 48);
}
.header {
    background-color: rgba(255, 255, 255, .15);
    backdrop-filter: blur(15px);
    width: 1000px;
    border-radius: 14px;
    margin: 0 auto;
    margin-top: 30px;
    position: sticky;
    top: 0;
    z-index: 1;
    box-shadow: 0 0 1rem 0 rgba(0, 0, 0, .2);
}
.banner img {
    border-radius: 14px 14px 0 0;
    margin: 0px;
    background-color: rgba(0, 0, 0, 0.7);
}
.nav {
    margin: 0 auto;
    width: 1000px;
}
.nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border-radius: 0 0 14px 14px;
}
.nav li {
    float: left;
    font-family: Arial;
    display: inline;
}
.nav li a {
    color: white;
    display: inline-block;
    text-align: center;
    text-decoration: none;
    width: 200px;
    padding: 14px 0px;
}
.nav li a:hover:not(.active) {
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    color: rgb(255, 59, 48);
}
.nav .active {
    background-color: gainsboro;
}
.content {
    box-shadow: 0 0 1rem 0 rgba(51, 31, 31, 0.2); 
    background-color: black;
    backdrop-filter: blur(5px);
    width: 1000px;
    border-radius: 14px;
    margin: 0 auto;
    clear: both;
    color: white;
}
.content h2 {
    overflow: auto;
    font-family: verdana;
    padding: 30px 30px 0 30px;
    font-size: 24px;
    color: white;
}
.introduction {
    box-shadow: 0 0 1rem 0 rgba(51, 31, 31, 0.2); 
    background-color: black;
    backdrop-filter: blur(5px);
    width: 1000px;
    border-radius: 14px;
    margin: 0 auto;
    clear: both;
    color: white;
}
.introduction h2 {
    overflow: auto;
    font-family: verdana;
    padding: 30px 30px 0 30px;
    font-size: 24px;
    color: white;
}
.introduction p {
    overflow: auto;
    font-family: verdana;
    padding: 20px 30px;
    font-size: 18px;
    color: white;
}
.footer {
    box-shadow: 0 0 1rem 0 rgba(51, 31, 31, 0.2); 
    background-color: black;
    backdrop-filter: blur(5px);
    width: 1000px;
    border-radius: 14px;
    margin: 0 auto;
    clear: both;
    color: white;
    margin-bottom: 50px;
}
.footer p {
    overflow: auto;
    font-family: verdana;
    padding: 20px 30px;
    font-size: 18px;
    color: white;
    text-align: center;
}