*{
    margin: 0;
    padding: 0;
    
}

body {
    background: #3F724C;
    font-family:sans-serif
}

.contenedor {
    width: 85%;
    max-width: 1000px;
    margin: auto;
    overflow: hidden;
}

header {
    background: #3F724C;
    margin: 0px 0;
    z-index: 100;
}

header img {
    width: 100%;
    height: auto;
    text-align: center;
}

.main {
    width:100%;
    height:90%;
    background:#fff;
    padding: 10px;
    float: left;
    box-sizing:border-box;
}

.main img {
    width: 30%;
    height: auto;
}

@media screen and (max-width:400px){
    .contenedor {
        width: 100%;
    }
}
@media all and (max-width: 600px){
    div{
        width:100%;
        height:auto;
        margin-left:10px;
    }
}
a.menu {
    display:inline-block;
    padding:0px 12px;
    margin:0px 8px;
}
@media all and (max-width: 1200px) {
    a.menu {
        display: inline-block;
        padding:0px 6px;
        margin:0px 4px;
    }
}
@media all and (max-width: 840px) {
    a.menu{
        margin:0px;
        padding:0px;
        padding-left:5%;
        display:block;
        float:none;
        text-align:left;
    }
}
@media all and (max-width: 520px) {
    a.menu{
        padding-left:20%;
    }
}