:root {
    --terminal-green: #0a0a0a;
    --terminal-dim: #040f02;
    --terminal-bg: #dfded7;
    --terminal-selection: #020203;
    --font-stack: "SF Mono", ui-monospace, "Courier New", Courier, "Noto Mono", "Roboto Mono", monospace;
}

/* --- Reset & Base Styles --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--terminal-bg);
    color: var(--terminal-green);
    font-family: var(--font-stack);
    line-height: 1.6;
    padding: 1.5rem;
    min-height: 100vh;
}

/* --- Accessibility & Focus --- */
*:focus-visible {
    outline: 2px dashed var(--terminal-green);
    outline-offset: 4px;
}

.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--terminal-green);
    color: var(--terminal-bg);
    padding: 0.5rem;
    z-index: 100;
}
.skip-link:focus {
    top: 0;
}

/* --- Layout Container --- */
.terminal-container {
    max-width: 800px;
    margin: 0 auto;
    border: 1px solid var(--terminal-green);
    padding: 1.5rem;
    box-shadow: 0 0 15px rgba(8, 26, 4, 0.15);
    border-radius: 4px;
}

/* --- Header & Navigation Bar --- */
.terminal-header {
    margin-bottom: 2rem;
}

.nav-banner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    border-bottom: 1px solid var(--terminal-dim);
    padding-bottom: 1.5rem;
    margin-bottom: 1.5rem;
}

/* Accessible Nav Wrapper */
.terminal-nav {
    width: auto;
}

/* Navigation list behaves as a row by default */
.nav-list {
    display: flex;
    flex-direction: row;
    list-style: none;
    gap: 1rem;
}

.nav-list li {
    width: auto;
}

/* Buttons styled as terminal block options */
.nav-btn {
    display: block;
    text-align: center;
    background: transparent;
    color: var(--terminal-green);
    border: 1px solid var(--terminal-green);
    font-family: var(--font-stack);
    font-size: 0.95rem;
    padding: 0.5rem 1rem;
    text-decoration: none;
    cursor: pointer;
    white-space: nowrap;
}

.nav-btn:hover,
.nav-btn:focus {
    background-color: var(--terminal-selection);
    color: var(--terminal-bg);
}

.nav-btn[aria-current="page"] {
    background-color: var(--terminal-green);
    color: var(--terminal-bg);
    font-weight: bold;
}

/* --- Responsive Navigation (Stacking rule) --- */
@media (max-width: 560px) {
    .nav-banner {
        flex-direction: column;
        align-items: flex-start; /* Keeps text aligned left like a real terminal */
    }

    .terminal-nav {
        width: 100%; /* Force nav to take full width */
    }

    .nav-list {
        flex-direction: column; /* Stack buttons vertically */
        width: 100%;
        gap: 0.75rem;
    }

    .nav-btn {
        text-align: left; /* Align text left on mobile terminal stacks */
        width: 100%; /* Full block buttons for easier thumb tapping */
    }
}

/* --- Typography --- */
h1,
h2,
h3 {
    line-height: 1.2;
    margin-bottom: 1rem;
    font-weight: bold;
}

h1 {
    font-size: calc(1.3rem + 0.8vw);
}
h2 {
    font-size: calc(1.2rem + 0.5vw);
    margin-top: 2rem;
}

p {
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

/* --- Links --- */
a {
    color: var(--terminal-green);
    text-decoration: underline;
    text-underline-offset: 4px;
}

a:hover {
    background-color: var(--terminal-selection);
    color: var(--terminal-bg);
}

/* --- Sections & Grid --- */
.content-section {
    border: 1px dashed var(--terminal-dim);
    padding: 1.25rem;
    margin-bottom: 1.5rem;
}

.system-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.card {
    border: 1px solid var(--terminal-dim);
    padding: 1rem;
}

.article-card {
    border: 1px dotted var(--terminal-dim);
    margin-bottom: 1rem;
    padding: 0.5rem;
}


.terminal-footer {
    margin-top: 3rem;
    padding-top: 1rem;
    border-top: 1px solid var(--terminal-dim);
    font-size: 0.85rem;
    color: var(--terminal-dim);
}

.terminal-footer p {
    display: inline-flex;
    align-items: center;
    margin: 0;
}

.footer-inline-icon {
    width: 2em;
    height: 2em;
    vertical-align: middle;
}


/* Selection Color */
::-selection {
    background: var(--terminal-selection);
    color: var(--terminal-green);
}


/* Footnotes. Fix from covering left border  */
div.footnote ol {
    padding-left: 2rem;
    padding-top: 1rem;
}

/* Do not overflow with individual footnotes... */
div.footnote li {
    word-break: break-word;
}

/* Footnote-ref. Fix from blending into text */
a.footnote-ref {
    margin-left: 0.25em;
    padding-left: 0.05em;
    display: inline-block;
}