:root {
    --x-dark-background: #1E1D1A;
    --x-background: #292825;
    --x-light-background: #3B3A36;
    --x-card-background: #434139;
    --x-primary-color: #ffc848;
    --x-bubble-color: #1e1e1d;
    --x-font-color: #ededed;
}

@font-face {
    font-family: "Doto";
    src: url("../fonts/doto/Doto-Regular.ttf") format("truetype");
}

@font-face {
    font-family: "Lexend";
    src: url("../fonts/lexend/Lexend-Regular.ttf") format("truetype");
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--x-background);
    color: var(--x-font-color);
}

body, p {
    font-family: "Lexend", Arial, sans-serif;
}
h1 {
    font-size: 2em;
}

h2, .subtitle {
    font-size: 1.5em;
}

h3 {
    font-size: 1.25em;
}

h1, h2, .subtitle {
    font-family: "Doto", Arial, sans-serif;
}

h2, h3 {
    color: var(--x-primary-color);
}

a {
    color: var(--x-primary-color);
}

a:hover {
    color: var(--x-font-color);
}

header {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 50px;
    background-color: var(--x-dark-background);
}

nav {
    width: 100%;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: none;
    flex-direction: column;
    align-items: center;
    position: absolute;
    top: 50px;
    left: 0;
    width: 100%;
    background-color: var(--x-dark-background);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

nav ul li {
    padding: 10px;
    width: 100%;
    text-align: center;
    border-top: 1px solid #ddd;
}

nav a {
    text-decoration: none;
}

nav ul.active {
    display: flex;
}

section:nth-child(odd) {
    background-color: var(--x-light-background);
    padding: 1.5em 0;
}

button {
    border: none;
    cursor: pointer;
}

footer {
    text-align: center;
    padding: 0.5rem;
    background-color: var(--x-dark-background);
    color: var(--x-font-color);
}

@media (min-width: 768px) {

    h1 {
        font-size: 3em;
    }

    h2, .subtitle {
        font-size: 1.75em;
    }

    h3 {
        font-size: 1.25em;
    }

    header {
        justify-content: center;
    }

    nav {
        width: auto;
        text-align: center;
    }

    nav ul.active {
        display: inline-block;
    }

    nav ul {
        display: inline-block;
        position: static;
        background: transparent;
        box-shadow: none;
    }

    nav ul li {
        display: inline;
        border-top: none;
    }
}