@import url(https://fonts.googleapis.com/css?family=Raleway);
body {
    font-family: Raleway, arial;
    margin: 0;
    background: yellow;
    height: 100vh;
    margin-top: 8rem;
}
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #3fa46a;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
}
header > a {
    margin: 1rem;
}
header > a > img {
    height: 3rem;
}
header ul { 
    display: flex;
    justify-content: flex-end;
    list-style: none;
    padding: 0;
    margin: 0;
}
header ul a { 
    display: block;
    margin: 1rem;
    padding: 1rem;
    color: white;
    text-decoration: initial;
}
header ul a:hover { 
    background-color: white;
    color: #3fa46a;
}
main {
    max-width: 800px;
    margin: 3rem auto;
}
footer {
    text-align: center;
}

.title-welcome {
    text-align: center;
    color: #3fa46a;
}

.logo-welcome {
    text-align: center;
}

.logo-welcome img {
    width: 20rem;
    margin: 4rem auto;
}