:root {
    --primary-color: #004080;
    --accent-color: #006dcc;
    --background-color: #ffffff;
    --text-color: #333333;
    --max-width: 1000px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

img {
    max-width: 100%;
    height: auto;
}

.site-header {
    background-color: var(--primary-color);
    color: #ffffff;
    padding: 1rem;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
}

.site-header .logo {
    max-height: 60px;
    width: auto;
}

.site-nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 0;
    padding: 0;
}

.site-nav a {
    color: #ffffff;
    text-decoration: none;
    font-weight: 500;
}

.site-nav a:hover,
.site-nav a:focus {
    text-decoration: underline;
}

.content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1rem;
    flex-grow: 1;
    width: 100%;
}

.content h1,
.content h2,
.content h3 {
    color: var(--primary-color);
}

h1 {
    text-align: center;
}

.content a {
    color: var(--accent-color);
    text-decoration: none;
}

.content a:hover,
.content a:focus {
    text-decoration: underline;
}

blockquote {
    border-left: 4px solid var(--accent-color);
    padding-left: 1rem;
    margin: 1rem 0;
    background: #f0f4ff;
}

/* Listing shown on "index" folder pages. */
.index-list {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0;
}

.index-list li {
    border-bottom: 1px solid #e1e4e8;
}

.index-list a {
    display: block;
    padding: 0.75rem 0.5rem;
    font-size: 1.1rem;
}

.site-footer {
    background: var(--primary-color);
    color: #ffffff;
    text-align: center;
    padding: 1rem;
}

.site-footer address {
    font-style: normal;
}

@media (max-width: 600px) {
    .site-nav ul {
        flex-direction: column;
        align-items: center;
    }

    .site-header {
        justify-content: center;
    }
}