styles.css

:root {
    --color-brand-primary: #a1603b;
    --color-brand-contrast: #fff;
    --color-medium-gray: #898989;
    --color-light-gray: #ccc;
    --color-background: #E5E5E5;
    --font-body: 'Segoe UI', Arial, Helvetica, sans-serif;
}

header {
    background-color: var(--color-brand-primary);
}

html,
body {
    margin: 0;
    padding: 0;
    font-family: var(--font-body);
    background-color: var(--color-background);
}

nav ul {
    margin: 0;
    padding: 0;
}

nav > ul > li {
    display: inline-block;
    list-style: none;
    margin: 0 1.5em 0 1.5em;
    vertical-align: middle;
}

nav > ul > li:first-child {
    margin: 0.5em;
    padding: 0;
}

nav ul li a,
nav ul li a:active,
nav ul li a:hover,
nav ul li a:visited {
    color: var(--color-brand-contrast);
    text-decoration: none;
    text-transform: uppercase;
    font-weight: 600;
    font-size: 1.25em;
}

h1 {
    color: var(--color-brand-primary);
}

article{
    padding: 2em;
}

#calculator {
    box-shadow: 2px 2px 8px rgba(0, 0, 0, 0.2);
    border: solid 1px var(--color-medium-gray);
    border-radius: 1em;
    padding: 1.5em;
    width: 90%;
    max-width: 325px;
    background-color: var(--color-brand-contrast);
    margin-top: 2em;
}

#calculator h2 {
    margin: .5em 0 0.5em 0;


}

#calculator input {
    padding: 5px;
    border-radius: 3px;
    border: solid 1px var(--color-medium-gray);
    width: 150px;
}

footer {
    margin: 3em 0;
    padding: 1em;
    background-color: var(--color-light-gray);
}

footer address {
    font-style: normal;
}

footer address h2,
footer address p {
    margin: 0;

}

footer address h2 {
    font-size: 1.25em;
}

.logo-container {
    display: none;
}

@media (min-width: 960px) {
    main {
        display: flex;
        flex-direction: row-reverse;
    }
    article, aside {
        display: block;
        flex-basis: 0;
        flex-shrink: 1;
        padding: 0.75rem;
    }
    article {
        flex: 4;
        padding-right: 6em;
    }
    aside {
        flex: 1;
    }

    footer {
        padding-left: 20%;
    }
    
    .logo-container {
        display: block;
        text-align: center;
        padding-top: 2em;
    }

    .logo-container img {
        max-width: 120px;
    }
}