/* ===== RESET & BASE ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --deep-burgundy: #5c1a2a;
    --burgundy-glow: #8b2942;
    --parchment-cream: #e8d5c4;
    --dark-oak: #1a1410;
    --charcoal-study: #2a2320;
    --tarnished-brass: #a0875c;
    --terminal-phosphor: #7a9c6b;
}

html {
    scroll-behavior: smooth;
}

body {
    background: var(--dark-oak);
    color: var(--parchment-cream);
    font-family: 'Source Sans 3', sans-serif;
    font-weight: 400;
    font-size: clamp(1rem, 1.1vw, 1.15rem);
    line-height: 1.72;
    overflow-x: hidden;
}

.svg-filters {
    position: absolute;
    width: 0;
    height: 0;
    pointer-events: none;
}

/* ===== NOISE OVERLAY ===== */
.noise-overlay {
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.05'/%3E%3C/svg%3E");
    background-repeat: repeat;
    pointer-events: none;
    z-index: 0;
}

/* ===== TERMINAL NAV ===== */
.terminal-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 0.75rem 1.5rem;
    background: rgba(26, 20, 16, 0.95);
    border-bottom: 1px solid var(--deep-burgundy);
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    color: var(--burgundy-glow);
    text-shadow: 0 0 4px rgba(139, 41, 66, 0.4);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.nav-cursor {
    display: inline-block;
    width: 8px;
    height: 1.1em;
    background: var(--burgundy-glow);
    animation: blink 1.2s step-end infinite;
    vertical-align: middle;
}

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

/* ===== TERMINAL HEADER ===== */
.terminal-header {
    position: relative;
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--dark-oak);
    overflow: hidden;
}

.terminal-content {
    position: relative;
    z-index: 1;
    text-align: center;
}

.terminal-prompt {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.9rem;
    color: var(--burgundy-glow);
    text-shadow: 0 0 4px rgba(139, 41, 66, 0.4);
    letter-spacing: 0.05em;
    margin-bottom: 2rem;
}

.prompt-text {
    display: inline-block;
    overflow: hidden;
    white-space: nowrap;
    border-right: 2px solid var(--burgundy-glow);
    width: 0;
    animation: typewriter 2s steps(38) 0.4s forwards, blink-caret 0.8s step-end 0.4s 3;
}

@keyframes typewriter {
    to { width: 38ch; }
}

@keyframes blink-caret {
    0%, 100% { border-color: var(--burgundy-glow); }
    50% { border-color: transparent; }
}

.site-title {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    font-size: clamp(2rem, 4.5vw, 4rem);
    letter-spacing: 0.18em;
    font-variant: small-caps;
    color: var(--parchment-cream);
    opacity: 0;
    transform: scale(0.9);
    animation: title-reveal 0.8s ease-out 2.6s forwards;
}

@keyframes title-reveal {
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.site-subtitle {
    font-family: 'Source Sans 3', sans-serif;
    font-weight: 300;
    font-size: 1.1rem;
    color: var(--tarnished-brass);
    letter-spacing: 0.06em;
    margin-top: 0.75rem;
    opacity: 0;
    animation: fade-in 0.6s ease-out 3.2s forwards;
}

@keyframes fade-in {
    to { opacity: 1; }
}

/* Prompt fades after typing */
.prompt-faded .prompt-text {
    opacity: 0.4;
    border-color: transparent;
    transition: opacity 0.5s;
}

/* Scroll chevron */
.scroll-chevron {
    position: absolute;
    bottom: 2.5rem;
    z-index: 1;
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--tarnished-brass);
    border-bottom: 2px solid var(--tarnished-brass);
    transform: rotate(45deg);
    opacity: 0;
    animation: chevron-pulse 2s ease-in-out 3.5s infinite, fade-in 0.5s ease-out 3.5s forwards;
}

@keyframes chevron-pulse {
    0%, 100% { transform: rotate(45deg) translateY(0); opacity: 0.6; }
    50% { transform: rotate(45deg) translateY(6px); opacity: 1; }
}

/* ===== BRASS RULE ===== */
.brass-rule {
    position: relative;
    z-index: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--tarnished-brass) 20%, var(--tarnished-brass) 80%, transparent);
    margin: 0 2rem;
}

/* ===== CARD GRID WORKSHOP ===== */
.card-grid-workshop {
    position: relative;
    background: var(--charcoal-study);
    padding: 4rem 2rem;
    min-height: 100vh;
}

.grid-container {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    max-width: 1200px;
    margin: 2rem auto;
    perspective: 1200px;
}

/* ===== PUZZLE CARDS ===== */
.puzzle-card {
    position: relative;
    cursor: pointer;
    opacity: 0;
    transform: rotateX(-8deg);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* Card depth layers */
.card-foreground {
    z-index: 3;
    transform: rotateX(-8deg) rotate(-0.5deg);
}
.card-foreground.visible {
    transform: rotateX(0deg) rotate(-0.5deg);
}

.card-mid {
    z-index: 2;
}

.card-note {
    z-index: 1;
    opacity: 0;
}
.card-note.visible {
    opacity: 0.85;
    transform: rotateX(0deg);
}

/* Feature cards span 2 columns */
.card-feature {
    grid-column: span 2;
}

/* Card inner - flip container */
.card-inner {
    position: relative;
    width: 100%;
    min-height: 240px;
    transition: transform 0.5s ease;
    transform-style: preserve-3d;
}

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

.card-front, .card-back {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    background: var(--charcoal-study);
    border-left: 2px solid var(--deep-burgundy);
    border-radius: 2px;
    padding: 1.5rem;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.4),
        0 8px 24px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

/* Make front flow naturally */
.card-front {
    position: relative;
}

.card-back {
    transform: rotateY(180deg);
    background: var(--dark-oak);
    border-left-color: var(--tarnished-brass);
}

/* Card hover */
.puzzle-card:hover .card-front {
    border-left-width: 4px;
    transform: translateY(-4px);
    box-shadow:
        0 4px 8px rgba(0, 0, 0, 0.5),
        0 12px 32px rgba(0, 0, 0, 0.3);
    transition: all 0.25s ease;
}

/* Card typography */
.card-title {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    font-size: clamp(1.2rem, 2vw, 1.5rem);
    letter-spacing: 0.02em;
    color: var(--parchment-cream);
    margin-bottom: 0.5rem;
}

.card-desc {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.95rem;
    line-height: 1.72;
    color: var(--parchment-cream);
    margin-bottom: 0.75rem;
}

.card-tag {
    display: inline-block;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: var(--burgundy-glow);
    text-shadow: 0 0 4px rgba(139, 41, 66, 0.4);
    padding: 0.15rem 0.5rem;
    border: 1px solid var(--deep-burgundy);
    border-radius: 2px;
    margin-right: 0.35rem;
    margin-top: 0.25rem;
}

/* Card back styles */
.back-title {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--tarnished-brass);
    margin-bottom: 0.75rem;
    letter-spacing: 0.02em;
}

.back-class {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.8rem;
    color: var(--burgundy-glow);
    text-shadow: 0 0 4px rgba(139, 41, 66, 0.4);
    margin-bottom: 0.75rem;
}

.back-note {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.9rem;
    line-height: 1.65;
    color: var(--parchment-cream);
    margin-bottom: 1rem;
}

/* Difficulty bar */
.difficulty-bar {
    display: flex;
    gap: 4px;
}

.diff-block {
    width: 14px;
    height: 14px;
    border: 1px solid var(--deep-burgundy);
    background: transparent;
}

.diff-block.filled {
    background: var(--deep-burgundy);
}

/* ===== FEATURE CARD LAYOUT ===== */
.card-feature .card-front {
    display: flex;
    gap: 1.5rem;
    align-items: stretch;
}

.card-feature .card-back {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.card-art {
    flex: 0 0 40%;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
}

.card-text {
    flex: 1;
}

/* ===== CSS ART: INTERLOCKING PIECES ===== */
.art-interlocking {
    position: relative;
    width: 140px;
    height: 140px;
}

.interlock-piece {
    position: absolute;
    background: var(--deep-burgundy);
}

.piece-1 {
    width: 60px;
    height: 60px;
    top: 0;
    left: 0;
    clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 70%, 70% 100%, 0 100%);
}

.piece-2 {
    width: 60px;
    height: 60px;
    top: 0;
    right: 10px;
    background: var(--parchment-cream);
    clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%, 0 30%, 30% 30%);
}

.piece-3 {
    width: 60px;
    height: 60px;
    bottom: 10px;
    left: 0;
    background: var(--tarnished-brass);
    clip-path: polygon(0 0, 70% 0, 70% 30%, 100% 30%, 100% 100%, 0 100%);
}

.piece-4 {
    width: 60px;
    height: 60px;
    bottom: 10px;
    right: 10px;
    background: var(--burgundy-glow);
    clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%, 0 30%);
}

.puzzle-card:hover .interlock-piece {
    transition: transform 0.4s ease;
}
.puzzle-card:hover .piece-1 { transform: translate(-4px, -4px); }
.puzzle-card:hover .piece-2 { transform: translate(4px, -4px); }
.puzzle-card:hover .piece-3 { transform: translate(-4px, 4px); }
.puzzle-card:hover .piece-4 { transform: translate(4px, 4px); }

/* ===== CSS ART: CONCENTRIC SQUARES ===== */
.card-art-small {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100px;
    margin-bottom: 0.75rem;
}

.art-concentric {
    position: relative;
    width: 80px;
    height: 80px;
}

.concentric-sq {
    position: absolute;
    border: 2px solid var(--deep-burgundy);
    transition: transform 0.4s ease;
}

.sq-1 {
    inset: 0;
}
.sq-2 {
    inset: 12px;
    border-color: var(--tarnished-brass);
}
.sq-3 {
    inset: 24px;
    border-color: var(--burgundy-glow);
}

.puzzle-card:hover .sq-1 { transform: rotate(5deg); }
.puzzle-card:hover .sq-2 { transform: rotate(-8deg); }
.puzzle-card:hover .sq-3 { transform: rotate(12deg); }

/* ===== CSS ART: MAZE LINES ===== */
.art-maze {
    position: relative;
    width: 100%;
    height: 80px;
}

.maze-line {
    position: absolute;
    height: 2px;
    background: var(--deep-burgundy);
}

.ml-1 { top: 10px; left: 0; width: 60%; }
.ml-2 { top: 25px; left: 20%; width: 80%; }
.ml-3 { top: 40px; left: 0; width: 45%; }
.ml-4 { top: 55px; left: 30%; width: 70%; }
.ml-5 { top: 70px; left: 10%; width: 50%; }

/* ===== CSS ART: GRID PATTERN ===== */
.art-grid-pattern {
    display: grid;
    grid-template-columns: repeat(4, 28px);
    grid-template-rows: repeat(4, 28px);
    gap: 4px;
}

.grid-cell {
    background: var(--deep-burgundy);
    opacity: 0.3;
    transition: opacity 0.3s ease;
    animation: cell-pulse 3s ease-in-out infinite;
    animation-delay: calc((var(--row) * 4 + var(--col)) * 0.15s);
}

@keyframes cell-pulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.9; }
}

/* ===== CSS ART: INTERLOCKING SMALL ===== */
.art-interlocking-small {
    position: relative;
    width: 80px;
    height: 60px;
}

.interlock-sm-piece {
    position: absolute;
    background: var(--deep-burgundy);
}

.p-1 {
    width: 45px;
    height: 40px;
    top: 0;
    left: 0;
    clip-path: polygon(0 0, 80% 0, 80% 50%, 100% 50%, 100% 100%, 0 100%);
}

.p-2 {
    width: 45px;
    height: 40px;
    bottom: 0;
    right: 0;
    background: var(--tarnished-brass);
    clip-path: polygon(0 0, 100% 0, 100% 100%, 20% 100%, 20% 50%, 0 50%);
}

/* ===== CLASSIFICATION TERMINAL ===== */
.classification-terminal {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: var(--dark-oak);
    padding: 4rem 2rem;
}

.terminal-stats {
    position: relative;
    z-index: 1;
    max-width: 700px;
    margin: 0 auto;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
}

.stat-line {
    margin-bottom: 1rem;
    color: var(--parchment-cream);
}

.stat-prompt {
    color: var(--terminal-phosphor);
    margin-right: 0.5rem;
}

.stat-value {
    color: var(--burgundy-glow);
    text-shadow: 0 0 4px rgba(139, 41, 66, 0.4);
}

.terminal-cursor-block {
    display: inline-block;
    width: 10px;
    height: 1.1em;
    background: var(--burgundy-glow);
    vertical-align: middle;
    animation: blink 1.2s step-end infinite;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 700px) {
    .card-feature {
        grid-column: span 1;
    }

    .card-feature .card-front {
        flex-direction: column;
    }

    .card-art {
        min-height: 120px;
    }

    .grid-container {
        grid-template-columns: 1fr;
    }

    .terminal-nav {
        font-size: 0.75rem;
    }
}