/* ==========================================================================
   layer2.wiki — Retro Encyclopedia Terminal / Library Catalog
   ========================================================================== */

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

:root {
    --deep-mahogany: #2A1818;
    --warm-brown: #3A2828;
    --catalog-cream: #F4EDE0;
    --amber-glow: #D4A040;
    --library-red: #8A3030;
    --faded-ink: #7A6A5A;
    --shelf-wood: #6A5040;
    --bg-edge: #E8DCC8;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Merriweather', Georgia, serif;
    font-size: clamp(0.95rem, 1.2vw, 1.1rem);
    line-height: 1.85;
    color: var(--warm-brown);
    background: radial-gradient(ellipse at center, var(--catalog-cream) 0%, var(--bg-edge) 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

/* --- Index Tabs Navigation --- */
#index-tabs {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--deep-mahogany);
    border-bottom: 3px solid var(--shelf-wood);
    transform: translateY(-100%);
    animation: slideTabsIn 0.5s ease-out forwards;
}

@keyframes slideTabsIn {
    to { transform: translateY(0); }
}

.tabs-container {
    display: flex;
    justify-content: center;
    gap: 0;
    padding: 0 1rem;
    max-width: 1200px;
    margin: 0 auto;
    overflow-x: auto;
}

.index-tab {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.8rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--catalog-cream);
    background: var(--warm-brown);
    border: none;
    border-top: none;
    border-radius: 0 0 6px 6px;
    padding: 0.6rem 1.2rem;
    cursor: pointer;
    transition: background 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    white-space: nowrap;
    opacity: 0;
    animation: fadeTabIn 0.3s ease-out forwards;
}

.index-tab:nth-child(1) { animation-delay: 0.05s; }
.index-tab:nth-child(2) { animation-delay: 0.1s; background: #5A2A2A; }
.index-tab:nth-child(3) { animation-delay: 0.15s; background: #4A4A2A; }
.index-tab:nth-child(4) { animation-delay: 0.2s; background: #2A3A4A; }
.index-tab:nth-child(5) { animation-delay: 0.25s; background: #3A4A3A; }
.index-tab:nth-child(6) { animation-delay: 0.3s; background: #4A2A4A; }
.index-tab:nth-child(7) { animation-delay: 0.35s; background: #3A3A2A; }

@keyframes fadeTabIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.index-tab:hover {
    box-shadow: 0 3px 10px rgba(212, 160, 64, 0.3);
    color: var(--amber-glow);
}

.index-tab.active {
    background: var(--shelf-wood);
    color: var(--catalog-cream);
    box-shadow: 0 3px 12px rgba(212, 160, 64, 0.25);
}

/* --- Hero / Title Section --- */
#hero {
    padding-top: 80px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

.hero-inner {
    opacity: 0;
    animation: heroFadeIn 1s ease-out 0.4s forwards;
}

@keyframes heroFadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

#site-title {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 900;
    font-size: clamp(2rem, 4vw, 3.5rem);
    letter-spacing: 0.01em;
    color: var(--deep-mahogany);
    text-shadow: 0 0 40px rgba(212, 160, 64, 0.3), 0 0 80px rgba(212, 160, 64, 0.1);
    margin-bottom: 0.5rem;
    position: relative;
}

#site-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--amber-glow), transparent);
}

.subtitle {
    font-family: 'Merriweather', Georgia, serif;
    font-weight: 300;
    font-size: clamp(0.9rem, 1.5vw, 1.15rem);
    color: var(--faded-ink);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    margin-top: 1.2rem;
}

.ornament {
    font-size: 1.5rem;
    color: var(--faded-ink);
    margin: 0.8rem 0;
    opacity: 0.5;
}

/* --- Marble Texture for Section Headers --- */
.marble-bg {
    background:
        radial-gradient(ellipse at 20% 30%, rgba(244, 237, 224, 0.8) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 70%, rgba(232, 220, 200, 0.6) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(122, 106, 90, 0.05) 0%, transparent 70%),
        var(--catalog-cream);
}

/* --- Card Catalog Grid --- */
#catalog-grid {
    padding: 2rem 1.5rem 4rem;
    max-width: 1200px;
    margin: 0 auto;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

@media (max-width: 900px) {
    .grid-container {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .grid-container {
        grid-template-columns: 1fr;
    }
}

/* --- Catalog Card --- */
.catalog-card {
    background: var(--catalog-cream);
    border-radius: 4px;
    box-shadow: 1px 2px 6px rgba(42, 24, 24, 0.12), 0 1px 3px rgba(42, 24, 24, 0.08);
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s ease;
    position: relative;
    opacity: 0;
    transform: translateY(-30px);
}

.catalog-card.visible {
    animation: bounceEnter 0.6s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes bounceEnter {
    0% {
        opacity: 0;
        transform: translateY(-30px);
    }
    60% {
        opacity: 1;
        transform: translateY(4px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

.catalog-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(42, 24, 24, 0.15), 0 0 15px rgba(212, 160, 64, 0.2);
}

.catalog-card.hidden-card {
    display: none;
}

.card-stripe {
    height: 5px;
    width: 100%;
}

.card-body {
    padding: 1.2rem 1.4rem 1.4rem;
}

.card-icon {
    margin-bottom: 0.8rem;
    opacity: 0.85;
}

.card-icon svg {
    display: block;
}

.card-title {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: clamp(1.05rem, 1.6vw, 1.25rem);
    color: var(--deep-mahogany);
    margin-bottom: 0.5rem;
    letter-spacing: 0.01em;
    line-height: 1.3;
}

.card-excerpt {
    font-family: 'Merriweather', Georgia, serif;
    font-weight: 400;
    font-size: 0.85rem;
    color: var(--warm-brown);
    line-height: 1.7;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 0.8rem;
}

.card-catalog-number {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.75rem;
    color: var(--faded-ink);
    letter-spacing: 0.08em;
}

/* --- Vintage Printer's Ornaments / Dividers --- */
.article-divider {
    text-align: center;
    color: var(--faded-ink);
    font-size: 1rem;
    letter-spacing: 0.5em;
    margin: 1.5rem 0;
    opacity: 0.6;
}

/* --- Reading Mode --- */
#reading-mode {
    max-width: 1100px;
    margin: 0 auto;
    padding: 6rem 1.5rem 4rem;
    display: grid;
    grid-template-columns: 1fr 260px;
    gap: 3rem;
    align-items: start;
}

#reading-mode.hidden {
    display: none;
}

@media (max-width: 800px) {
    #reading-mode {
        grid-template-columns: 1fr;
    }
    #cross-references {
        order: -1;
    }
}

.back-button {
    grid-column: 1 / -1;
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.85rem;
    color: var(--faded-ink);
    background: none;
    border: 1px solid var(--shelf-wood);
    border-radius: 3px;
    padding: 0.5rem 1rem;
    cursor: pointer;
    transition: color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    justify-self: start;
    margin-bottom: 1rem;
}

.back-button:hover {
    color: var(--amber-glow);
    border-color: var(--amber-glow);
    box-shadow: 0 0 10px rgba(212, 160, 64, 0.15);
}

.back-arrow {
    margin-right: 0.3rem;
}

/* --- Article Content --- */
#article-content {
    max-width: 60ch;
}

.article-header {
    margin-bottom: 2rem;
}

.article-catalog-number {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.8rem;
    color: var(--faded-ink);
    letter-spacing: 0.1em;
    display: block;
    margin-bottom: 0.5rem;
}

.article-title {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 900;
    font-size: clamp(1.8rem, 3.5vw, 2.8rem);
    color: var(--deep-mahogany);
    letter-spacing: 0.01em;
    line-height: 1.2;
    margin-bottom: 0.5rem;
}

.article-body {
    font-family: 'Merriweather', Georgia, serif;
    font-weight: 400;
    font-size: clamp(0.95rem, 1.2vw, 1.1rem);
    color: var(--warm-brown);
    line-height: 1.85;
}

.article-body p {
    margin-bottom: 1.4rem;
}

.article-body h2 {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: clamp(1.3rem, 2.2vw, 1.7rem);
    color: var(--deep-mahogany);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: 0.01em;
}

.article-body h3 {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: clamp(1.1rem, 1.6vw, 1.3rem);
    color: var(--deep-mahogany);
    margin-top: 2rem;
    margin-bottom: 0.8rem;
}

.article-body a,
.cross-ref-link {
    color: var(--deep-mahogany);
    text-decoration: none;
    border-bottom: 2px solid var(--amber-glow);
    transition: color 0.2s ease, border-color 0.2s ease;
}

.article-body a:hover,
.cross-ref-link:hover {
    color: var(--amber-glow);
}

.article-body blockquote {
    border-left: 3px solid var(--amber-glow);
    padding-left: 1.2rem;
    margin: 1.5rem 0;
    font-style: italic;
    color: var(--faded-ink);
}

.article-body ul, .article-body ol {
    padding-left: 1.5rem;
    margin-bottom: 1.4rem;
}

.article-body li {
    margin-bottom: 0.5rem;
}

.article-footer {
    margin-top: 3rem;
}

.article-meta {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.78rem;
    color: var(--faded-ink);
    text-align: center;
    letter-spacing: 0.05em;
}

/* --- Cross-Reference Sidebar --- */
#cross-references {
    position: sticky;
    top: 80px;
    background:
        radial-gradient(ellipse at 30% 20%, rgba(244, 237, 224, 0.9) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 80%, rgba(232, 220, 200, 0.7) 0%, transparent 60%),
        var(--catalog-cream);
    border: 1px solid var(--shelf-wood);
    border-radius: 4px;
    padding: 1.2rem;
    box-shadow: 1px 2px 8px rgba(42, 24, 24, 0.1);
}

.sidebar-title {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--deep-mahogany);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--shelf-wood);
    letter-spacing: 0.03em;
}

.sidebar-card {
    padding: 0.7rem 0;
    border-bottom: 1px solid rgba(106, 80, 64, 0.2);
    cursor: pointer;
    transition: background 0.2s ease;
}

.sidebar-card:last-child {
    border-bottom: none;
}

.sidebar-card:hover {
    background: rgba(212, 160, 64, 0.08);
}

.sidebar-card-title {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--deep-mahogany);
    margin-bottom: 0.2rem;
}

.sidebar-card-number {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.7rem;
    color: var(--faded-ink);
}

/* --- Footer --- */
#site-footer {
    text-align: center;
    padding: 3rem 1.5rem 2.5rem;
    border-top: 1px solid var(--shelf-wood);
    margin-top: 2rem;
}

.footer-ornament {
    color: var(--faded-ink);
    letter-spacing: 0.5em;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.footer-text {
    font-family: 'Playfair Display', Georgia, serif;
    font-weight: 700;
    font-size: 1rem;
    color: var(--deep-mahogany);
    margin-bottom: 0.3rem;
}

.footer-meta {
    font-family: 'Courier Prime', 'Courier New', monospace;
    font-size: 0.75rem;
    color: var(--faded-ink);
    letter-spacing: 0.08em;
}

/* --- Scrollbar Styling --- */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-edge);
}

::-webkit-scrollbar-thumb {
    background: var(--shelf-wood);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--faded-ink);
}

/* --- Selection --- */
::selection {
    background: rgba(212, 160, 64, 0.3);
    color: var(--deep-mahogany);
}

/* --- Transition for catalog/reading mode switch --- */
#catalog-grid {
    transition: opacity 0.4s ease;
}

#catalog-grid.fade-out {
    opacity: 0;
    pointer-events: none;
}