style.css

*{
    margin: 0 auto;
    box-sizing: border-box;
}
body{
    width: 70vw;
    font-family: "raleway";
}
.top-header{
    display: flex;
    justify-content: right;
    margin: 0 auto;
}
#logo{
    width: 110px;
}
.indentite{
    width: 100%;
}
h1{
    font-size: 2.5em;
    text-align: center;
}
.section_header, .section_footer{
    display: flex;
    justify-content: space-around;
    width: 70vw;
    margin: auto;
}
.nav_header{
    display: flex;
}
.nav_header li{
    list-style-type: none;
    font-size: 1.2em;
    margin: 20px;
    padding-top: 30px;
}
.nav_header a{
    display: inline-block;
    position: relative;
    display: inline-block;
    text-decoration: none;
    height: 50px;
    color: #145DA0;
}
.nav_header a:hover::after{
    content: "";
    position: absolute;
    bottom: 0;
    right: 50%;
    text-decoration: underline;
    width: 2px;
    border: 4px solid;
    border-radius: 45%;
}

#baniere{
    width: 600px;
}
.video_container{
    display: inline-block;
    width: 40%;
}
.video_header{
    width: 100%;
}
.contenu_footer{
    display: flex;
}