:root {
    --bleuRoyal: rgb(30, 55, 90);
    --bleuClair: rgb(200, 225, 255);
    --bleuCiel: rgb(0, 171, 228);
    --blanc: rgb(255, 255, 255);
    --noir: rgb(0, 0, 0);
}

* {
    font-family: "Kanit";
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bleuClair);
    color: var(--bleuRoyal);
}

header,
section:nth-child(even),
footer:nth-child(even) {
    background-color: var(--bleuRoyal);
    color: var(--bleuClair);
}

h1 {
    font-size: 5em;
    text-align: center;
    padding: 0.25em;
}

nav {
    display: flex;
    justify-content: center;
}

nav a {
    color: var(--bleuClair);
    text-decoration: none;
    width: 8em;
    text-align: center;
    border: 1px solid var(--bleuClair);
    border-radius: 1em 1em 0 0;
}

nav a:hover,
button:hover {
    text-decoration: underline;
}

section {
    padding: 5em;
    display: flex;
    justify-content: space-around;
    align-items: center;
}

button {
    background-color: var(--bleuCiel);
    color: var(--blanc);
    font-size: 2em;
    width: 8em;
    height: 5em;
    border-radius: 1em;
}

ul {
    margin-left: 2em;
}

footer {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 1em;
}

@media (orientation: landscape) {
    section {
        flex-direction: row;
    }

    button {
        margin-left: 2em;
    }
}

@media (orientation: portrait) {
    section {
        flex-direction: column;
    }

    button {
        margin-top: 2em;
    }
}