/* ==========================================
   mechanic.stream - Dark Academia Codex
   ========================================== */

/* --- Google Fonts are loaded in HTML --- */

/* --- CSS Custom Properties --- */
:root {
    --bg-primary: #1a1520;
    --bg-card-front: #252030;
    --bg-card-back: #2a2218;
    --text-primary: #e8d4b0;
    --text-secondary: #c4b89a;
    --accent-ruby: #9b2335;
    --accent-sapphire: #264e78;
    --accent-emerald: #2d6b4f;
    --accent-amethyst: #5c3d6e;
    --metallic-brass: #c4963a;
    --dusty-bronze: #8a7d6b;

    --font-display: 'Cormorant Garamond', serif;
    --font-body: 'Libre Baskerville', serif;
    --font-annotation: 'Recursive', monospace;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: clamp(0.95rem, 1.2vw, 1.1rem);
    line-height: 1.75;
    overflow-x: hidden;
    min-height: 100vh;
}

/* --- Candle Flicker Effect --- */
#candle-flicker {
    position: fixed;
    top: 0;
    right: 0;
    width: 60vw;
    height: 60vh;
    background: radial-gradient(ellipse at 80% 20%, rgba(196, 150, 58, 0.04) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
    animation: flicker 3s ease-in-out infinite alternate;
}

@keyframes flicker {
    0% { opacity: 0.02; }
    25% { opacity: 0.06; }
    50% { opacity: 0.03; }
    75% { opacity: 0.05; }
    100% { opacity: 0.02; }
}

/* --- Mountain Background --- */
#mountain-bg {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 40vh;
    pointer-events: none;
    z-index: 0;
}

.mountain-layer {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.mountain-far {
    background: 
        linear-gradient(135deg, transparent 40%, #1e1a28 40%, #1e1a28 42%, transparent 42%),
        linear-gradient(160deg, transparent 55%, #1e1a28 55%, #1e1a28 57%, transparent 57%),
        linear-gradient(145deg, transparent 65%, #1e1a28 65%, #1e1a28 67%, transparent 67%);
    opacity: 0.3;
}

.mountain-mid {
    background:
        linear-gradient(140deg, transparent 50%, #201c2a 50%, #201c2a 53%, transparent 53%),
        linear-gradient(155deg, transparent 60%, #201c2a 60%, #201c2a 63%, transparent 63%);
    opacity: 0.2;
}

.mountain-near {
    background:
        linear-gradient(150deg, transparent 70%, #252030 70%, #252030 74%, transparent 74%);
    opacity: 0.15;
    background:
        linear-gradient(150deg, transparent 70%, #2a2838 70%, #2a2838 74%, transparent 74%);
}

/* --- Opening Overlay --- */
#opening-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.8s ease;
}

#opening-overlay.fade-out {
    opacity: 0;
    pointer-events: none;
}

#opening-overlay.hidden {
    display: none;
}

#opening-arch {
    width: min(500px, 80vw);
    height: auto;
    margin-bottom: 1rem;
}

.arch-draw {
    stroke-dasharray: 1200;
    stroke-dashoffset: 1200;
    animation: drawArch 1.2s ease-out 0.3s forwards;
}

.trefoil-draw {
    stroke-dasharray: 200;
    stroke-dashoffset: 200;
    animation: drawArch 0.6s ease-out 1s forwards;
}

@keyframes drawArch {
    to { stroke-dashoffset: 0; }
}

#opening-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.08em;
    font-feature-settings: 'liga' 1, 'onum' 1;
    min-height: 1.2em;
}

#opening-title span {
    display: inline-block;
    opacity: 0;
    transform: translateY(8px);
}

#opening-title span.visible {
    animation: letterIn 0.3s ease-out forwards;
}

@keyframes letterIn {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#opening-subtitle {
    font-family: var(--font-annotation);
    font-variation-settings: 'MONO' 1, 'CASL' 0.5, 'wght' 400, 'slnt' 0, 'CRSV' 0;
    font-size: 0.9rem;
    color: var(--accent-sapphire);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    opacity: 0;
    margin-top: 0.5rem;
    transition: opacity 0.6s ease;
}

#opening-subtitle.visible {
    opacity: 1;
}

/* --- Fixed Header --- */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(to bottom, var(--bg-primary) 0%, rgba(26, 21, 32, 0.95) 80%, transparent 100%);
    opacity: 0;
    transition: opacity 0.5s ease;
}

#header.visible {
    opacity: 1;
}

#gothic-arch {
    position: absolute;
    top: 0;
    width: 300px;
    height: 60px;
    opacity: 0.4;
}

#header-content {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    z-index: 1;
}

#gear-emblem svg {
    display: block;
}

.rotating-gear {
    animation: rotateGear 30s linear infinite;
    transform-origin: 30px 30px;
}

@keyframes rotateGear {
    to { transform: translate(30px, 30px) rotate(360deg); }
}

#site-title {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.06em;
    font-feature-settings: 'liga' 1, 'onum' 1;
}

#site-subtitle {
    font-family: var(--font-annotation);
    font-variation-settings: 'MONO' 1, 'CASL' 0.5;
    font-size: 0.7rem;
    color: var(--accent-sapphire);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: none;
}

/* --- Sidebar Navigation --- */
#sidebar {
    position: fixed;
    top: 60px;
    left: 0;
    width: 200px;
    height: calc(100vh - 60px);
    z-index: 50;
    display: flex;
    align-items: center;
    opacity: 0;
    transition: opacity 0.5s ease;
}

#sidebar.visible {
    opacity: 1;
}

.sidebar-inner {
    padding: 2rem 1.5rem;
    border-right: 1px solid rgba(196, 150, 58, 0.15);
    width: 100%;
}

.toc-heading {
    font-family: var(--font-annotation);
    font-variation-settings: 'MONO' 1, 'CASL' 0.5;
    font-size: 0.7rem;
    color: var(--dusty-bronze);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin-bottom: 1.5rem;
}

#sidebar ul {
    list-style: none;
}

#sidebar li {
    margin-bottom: 1.2rem;
}

#sidebar a {
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-style: italic;
    color: var(--text-secondary);
    text-decoration: none;
    display: block;
    transition: color 0.3s ease;
    line-height: 1.4;
}

#sidebar a:hover {
    color: var(--metallic-brass);
}

#sidebar a.active {
    color: var(--metallic-brass);
}

.roman {
    font-style: normal;
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--metallic-brass);
    margin-right: 0.3rem;
}

/* --- Main Content --- */
#main-content {
    margin-left: 200px;
    padding: 80px 2rem 4rem 2rem;
    position: relative;
    z-index: 1;
    max-width: 1200px;
}

/* --- Codex Sections --- */
.codex-section {
    margin-bottom: 5rem;
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
    position: relative;
}

.section-arch {
    width: min(300px, 80%);
    height: auto;
    margin-bottom: 0.5rem;
    opacity: 0.5;
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 3vw, 2.5rem);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.04em;
    font-feature-settings: 'liga' 1, 'onum' 1;
}

.chapter-num {
    color: var(--metallic-brass);
    margin-right: 0.3em;
}

.section-desc {
    font-family: var(--font-body);
    font-style: italic;
    font-size: 0.9rem;
    color: var(--dusty-bronze);
    margin-top: 0.3rem;
}

/* --- Ornamental Divider --- */
.ornamental-divider {
    text-align: center;
    margin-bottom: 2.5rem;
}

.ornamental-divider svg {
    width: min(400px, 90%);
    height: auto;
}

/* --- Card Grid --- */
.card-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(280px, 1fr));
    gap: 2rem;
    grid-auto-flow: dense;
}

/* --- Cards --- */
.card {
    perspective: 1200px;
    cursor: pointer;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.card.card-visible {
    opacity: 1;
    transform: translateY(0) rotateX(2deg) rotateY(1deg);
}

.card-wide {
    grid-column: span 2;
}

.card-inner {
    position: relative;
    width: 100%;
    min-height: 320px;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.card.flipped .card-inner {
    transform: rotateY(180deg);
}

.card-front,
.card-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 4px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.card-front {
    background: var(--bg-card-front);
    border: 1px solid rgba(92, 61, 110, 0.3);
    box-shadow: 0 4px 20px rgba(92, 61, 110, 0.15);
}

.card-back {
    background: var(--bg-card-back);
    border: 1px solid rgba(196, 150, 58, 0.2);
    box-shadow: 0 4px 20px rgba(42, 34, 24, 0.4);
    transform: rotateY(180deg);
    justify-content: flex-start;
    padding-top: 2rem;
}

/* --- Card Illustrations --- */
.card-illustration {
    width: 100%;
    max-width: 200px;
    height: auto;
    margin-bottom: 1rem;
}

.card-wide .card-illustration {
    max-width: 360px;
}

.mechanism-svg {
    animation: pulseAttention 4s ease-in-out infinite;
}

@keyframes pulseAttention {
    0%, 100% { opacity: 0.85; }
    50% { opacity: 1; }
}

/* --- Card Typography --- */
.card-title {
    font-family: var(--font-display);
    font-size: clamp(1.1rem, 2vw, 1.4rem);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.04em;
    text-align: center;
    font-feature-settings: 'liga' 1, 'onum' 1;
}

.card-back-content {
    max-width: 100%;
}

.card-back-content p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: clamp(0.85rem, 1.1vw, 0.95rem);
}

.drop-cap {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    float: left;
    line-height: 0.8;
    margin-right: 0.15em;
    margin-top: 0.1em;
    color: var(--text-primary);
    background: radial-gradient(circle at center, rgba(155, 35, 53, 0.3) 0%, transparent 70%);
    padding: 0.05em 0.1em;
}

.annotation {
    font-family: var(--font-annotation);
    font-variation-settings: 'MONO' 1, 'CASL' 0.5, 'wght' 400, 'slnt' 0, 'CRSV' 0;
    font-size: 0.8rem !important;
    color: var(--dusty-bronze) !important;
    border-left: 2px solid var(--accent-sapphire);
    padding-left: 0.75rem;
    line-height: 1.6;
}

/* --- Footer --- */
#footer {
    position: relative;
    z-index: 1;
    margin-left: 200px;
    padding: 4rem 2rem 2rem;
    text-align: center;
}

.footer-mountains {
    position: absolute;
    bottom: 0;
    left: -200px;
    width: calc(100% + 200px);
    height: 200px;
    pointer-events: none;
}

.footer-mountains svg {
    width: 100%;
    height: 100%;
}

.footer-content {
    position: relative;
    z-index: 1;
}

.footer-text {
    font-family: var(--font-display);
    font-size: 1rem;
    color: var(--dusty-bronze);
    letter-spacing: 0.06em;
    opacity: 0.6;
}

.footer-motto {
    font-family: var(--font-body);
    font-style: italic;
    font-size: 0.8rem;
    color: var(--dusty-bronze);
    opacity: 0.4;
    margin-top: 0.3rem;
}

.footer-gear {
    margin-bottom: 0.5rem;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
    #sidebar {
        display: none;
    }
    #main-content,
    #footer {
        margin-left: 0;
    }
    .card-grid {
        grid-template-columns: repeat(2, minmax(250px, 1fr));
    }
    .footer-mountains {
        left: 0;
        width: 100%;
    }
}

@media (max-width: 768px) {
    .card-grid {
        grid-template-columns: 1fr;
    }
    .card-wide {
        grid-column: span 1;
    }
    #main-content {
        padding: 80px 1rem 3rem;
    }
    .card-inner {
        min-height: auto;
    }
    /* On mobile: tap to expand instead of flip */
    .card-front,
    .card-back {
        position: relative;
        backface-visibility: visible;
    }
    .card-back {
        transform: none;
        display: none;
        padding: 1.5rem;
    }
    .card.flipped .card-inner {
        transform: none;
    }
    .card.flipped .card-back {
        display: block;
    }
    .card-illustration {
        max-width: 180px;
    }
    .card-wide .card-illustration {
        max-width: 280px;
    }
}