* {
    margin: 0;
    padding: 0;
}

header {
    margin-top: 5em;
    margin-bottom: 4em;
}

header img {
    width: 55vw;
    height: auto;
}

nav ul li a {
    text-decoration: none;
    color: #ffffff;
    font-family: "roboto condensed", sans-serif;
    font-weight:550;
    font-size: 1.8em;
}

nav ul li{
    list-style: none;
}

nav ul li img {
    max-height: 5em;
    max-width: auto;
}

ul {
    padding: 0;
}

.materias{
    background-color: #f49648;
    width: 50vw;
    height: 50vw;
}

.evaluaciones{
    background-color: #3eb49c;
    width: 50vw;
    height: 50vw;
}

.foro{
    background-color: #00B1EB;
    width: 50vw;
    height: 50vw;
}

.agenda{
    background-color: #1D3D77;
    width: 50vw;
    height: 50vw;
}

/*Flex box*/

body{
    display: flex;
    flex-direction: column;
}

header{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-content: center;
    align-items: center;
}

nav ul{
    display: flex;
    flex-direction: row;
    flex-flow: wrap;
    justify-content: center;
    box-sizing: content-box;
}

.menu{
    max-width: 100%;
    max-height: auto;
}

.materias{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-content: center;
    align-items: center;
}

.evaluaciones{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-content: center;
    align-items: center;
}

.foro{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-content: center;
    align-items: center;
}

.agenda{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-content: center;
    align-items: center;
}