@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;600;700&family=Space+Mono:wght@400;700&display=swap');

/* The home page's system (index.html), shared by every page under guides/. */
:root {
    color-scheme: dark;
    --bg: #0d1117;
    --text: #c9d1d9;
    --text-80: rgba(200, 209, 217, 0.8);
    --text-60: rgba(200, 209, 217, 0.6);
    --label: rgba(200, 200, 220, 0.6);
    --accent: #8b7ec8;
    --accent-bright: #f0f0f4;
    --accent-soft: rgba(139, 126, 200, 0.10);
    --border: rgba(200, 200, 220, 0.12);
    --control-border: rgba(200, 200, 220, 0.45);
    --grid-color: rgba(200, 200, 220, 0.04);
    --glass-bg: rgba(13, 17, 23, 0.6);
    --glass-border: rgba(200, 200, 220, 0.1);
    --font-sans: 'Space Grotesk', sans-serif;
    --font-mono: 'Space Mono', monospace;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    padding: 4rem 1rem;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    font-family: var(--font-sans);
    color: var(--text);
    background-color: var(--bg);
    background-image:
        linear-gradient(var(--grid-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
    background-size: 18px 18px;
}

:focus-visible {
    outline: 2px solid var(--accent-bright);
    outline-offset: 2px;
}

/* .container is the index's card, .card a guide's. */
.container,
.card {
    width: 100%;
    max-width: 880px;
    padding: 2.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    box-shadow: 0 0 40px rgba(0, 0, 0, 0.3);
}

.card {
    max-width: 640px;
}

.meta-label {
    display: block;
    margin-bottom: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--label);
}

h1 {
    margin: 0 0 1rem;
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--accent-bright);
}

.intro,
.card > p {
    margin: 0 0 2.5rem;
    font-size: 1.05rem;
    line-height: 1.5;
    color: var(--text-80);
}

/* Index: guide cells tile with 1px gaps over a border fill, like the home tool grid. */
.guides-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr));
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}

.guide-link {
    display: block;
    padding: 1.25rem;
    background: var(--glass-bg);
    text-decoration: none;
    transition: all 0.2s;
}

.guide-link:hover {
    background: rgba(22, 27, 34, 0.7);
    box-shadow: inset 0 0 0 1px rgba(139, 126, 200, 0.2);
}

.guide-link h2 {
    margin: 0 0 0.5rem;
    font-size: 1.15rem;
    line-height: 1.2;
    color: var(--accent);
}

.guide-link p {
    margin: 0;
    font-size: 0.85rem;
    line-height: 1.4;
    color: var(--text-60);
}

/* Guide: the call to action, as the error pages' .home-link. */
.btn {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 0.75rem 2rem;
    border: 1px solid var(--accent);
    background: var(--accent-soft);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--accent-bright);
    transition: all 0.2s ease;
}

.btn:hover {
    background: rgba(139, 126, 200, 0.5);
    box-shadow: 0 0 20px var(--accent-soft);
}

.links {
    margin-top: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.links a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 0 1.2rem;
    border: 1px solid rgba(139, 126, 200, 0.7);
    background: rgba(139, 126, 200, 0.06);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--accent);
    transition: all 0.2s ease;
}

.links a:hover {
    background: rgba(139, 126, 200, 0.12);
    border-color: var(--accent);
}

.features {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.features h3 {
    margin: 0 0 1rem;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--label);
}

.features ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}

.features li {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 1rem;
    padding: 1rem 1.25rem;
    background: var(--glass-bg);
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text-80);
}

.features strong {
    flex: 0 0 10rem;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--accent);
}

.features li span {
    flex: 1 1 14rem;
}

.footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-60);
}

.footer-actions {
    display: flex;
    gap: 0.5rem;
}

.footer-btn {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 0 1.2rem;
    border: 1px solid var(--control-border);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--accent);
}

.footer-btn:hover {
    background: var(--accent-soft);
}

@media (max-width: 1023px) {
    body {
        padding: 1.5rem 0.75rem;
    }

    .container,
    .card {
        padding: 1.5rem;
    }

    h1 {
        font-size: 2.2rem;
    }
}