* {
    margin: 0;
    padding: 0;
}
header {
    width: 100%;
    overflow: hidden;
    background: #C8FE2E;
    margin-bottom: 20px;
}

.encabezado {
    width: 90%;
    max-width: 1000px;
    margin: auto;
    overflow: hidden;
}
header .logo a {
    color: #ee1515;
    font-size: 50px;
    line-height: 60px;
    float: left;
    font-weight:bold; 
    text-decoration: none;
}
header nav {
    float: right;
    line-height: 60px;
    
}

header nav a {
    display: inline-block;
    color: #000;
    text-decoration: none;
    padding: 10px 20px;
    line-height: normal;
    font-size: 20px;
    font-weight: bold;
}
header nav a:hover {
    background: #FE1212;
    border-radius: 40px;
    color: #000;
}

@media screen and (max-width:900px) {
    header .logo a,
    header nav {
        width: 100%;
        text-align: center;
     }
}