html {
    box-sizing: border-box;
    background-color: var(--colorfondo);
}

:root {
    --colorfondo: #e6e6fe;
    --colorprincipal: #00008b;
    --colorsecundario: #3838b3;
    --colorfondo2: #f7f7ff;
    --negro: black;
    --blanco: white;
}

* {
    box-sizing: border-box;
}

body {
    background-color: var(--colorfondo);
    font-family: Arial, Helvetica, sans-serif;
    color: var(--colorprincipal);
    margin: 0px;
    width: 80vw;
    margin: auto;
}

header {
    background-color: var(--colorprincipal);
    color: var(--blanco);
    height: 150px;
    display: grid;
    grid-template-columns: 5fr 4fr;
    justify-items: center;
    align-items: center;
}

header>div {
    display: none;
}

header ul {
    list-style: none;
    margin: 0px;
    padding: 0px;
}

header ul li {
    display: inline-block;
}

header ul li a {
    color: inherit;
    text-decoration: none;
    display: block;
    margin: 15px;
    font-size: 1.3em;
}

header form {
    width: 80%;
}

header form input {
    width: 75%;
    border: 0px;
    color: var(--colorprincipal);
    padding: 4px;
    border-radius: 4px;
    margin-left: 45px;
}

header form button {
    background-color: var(--colorprincipal);
    border: 0px;
    color: var(--blanco);
    font-size: 1.2em;
    margin-left: 10px;
}

main {
    background-color: var(--blanco);
    display: grid;
    grid-template-columns: 8fr 2fr;
}

main section {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    margin: 10px;
    gap: 20px;
    background-color: var(--colorfondo2);
}

main section article {
    padding: 10px;
}

main section article img {
    width: 100%;
}

main section article div {
    display: grid;
    grid-template-columns: 7fr 3fr;
    justify-items: center;
    align-items: center;
}

main section article p {
    font-size: 0.9em;
    text-align: justify;
}

main section article div a {
    background-color: var(--colorprincipal);
    color: var(--blanco);
    padding: 10px;
    border-radius: 3px;
    text-decoration: none;
}

main aside {
    background-color: var(--colorsecundario);
    color: var(--blanco);
}

main aside ul {
    list-style: none;
    margin-left: 6px;
    padding: 0px;
}

main aside ul li a {
    color: inherit;
    text-decoration: none;
    margin-top: 7px;
    display: block;
}

main aside ul li a:hover {
    color: var(--negro);
}


footer {
    background-color: var(--negro);
    color: var(--blanco);
    padding: 40px;
}


footer p {
    margin: 0px;
    text-align: center;
}

footer ul {
    list-style: none;
    padding: 0px;
    margin: 0px;
    text-align: center;
}

footer ul li {
    display: inline-block;
}


footer ul li a {
    color: inherit;
    text-decoration: none;
    display: block;
    margin: 15px;
    font-size: 1.3em;
}

@media (max-width: 850px) {
    body {
        width: 80vw;
    }

    header {
        height: auto;
        display: grid;
        grid-template-columns: 1fr;
        justify-items: left;
        align-items: center;
    }

    header>div {
        display: block;
        margin: 7px;
        font-size: 1.5em;
    }

    header nav,
    header form {
        display: none;
    }


    header nav {
        width: 100%;
    }

    header ul li {
        display: block;
        width: 100%;
        font-size: 1em;
    }

    header ul li a {
        border-bottom: 1px solid var(--colorsecundario);
        width: 100%;
        font-size: 1em;
        margin: 0px;
        margin-top: 8px;
        padding-left: 15px;
    }


    header form {
        margin: 25px;
    }

    header form input {
        margin: 0px;
    }

    main {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto;
        grid-template-areas: "categorias"
            "articulos";
    }

    main section {
        grid-template-columns: 1fr;
        grid-area: articulos;
    }

    main section article {
        border-bottom: 10px solid var(--blanco);
        padding-bottom: 15px;
    }

    main aside{
        grid-area: categorias;
    }

    main aside h3{
        text-align: right;
        margin-right: 15px;
    }

    main aside ul{
        display: none;
    }
}