* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-deep: #0f0c08;
    --bg-dark: #1e1a14;
    --text-light: #f0ebe1;
    --text-warm: #e8dcc8;
    --text-muted: #e8e0d2;
    --accent-green: #7a8b6e;
    --accent-rust: #9e5a3c;
    --accent-sand: #b5a48a;
}

html {
    scroll-behavior: smooth;
    scroll-snap-type: y mandatory;
}

body {
    background-color: var(--bg-deep);
    color: var(--text-light);
    font-family: 'Commissioner', serif;
    overflow-x: hidden;
}

/* Folio Base */
.folio {
    width: 100vw;
    height: 100vh;
    position: relative;
    overflow: hidden;
    scroll-snap-align: start;
    display: flex;
    align-items: center;
    justify-content: center;
}

.folio:nth-child(odd) {
    background-color: var(--bg-deep);
}

.folio:nth-child(even) {
    background-color: var(--bg-dark);
}

.folio-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 2rem;
}

.folio-number {
    display: block;
    font-family: 'Commissioner', serif;
    font-weight: 300;
    font-size: 0.85rem;
    letter-spacing: 0.2em;
    color: var(--accent-sand);
    margin-bottom: 1.5rem;
    opacity: 0.7;
}

.folio-heading {
    font-family: 'Commissioner', serif;
    font-weight: 700;
    font-size: clamp(2rem, 5vw, 4.5rem);
    letter-spacing: -0.01em;
    line-height: 1.1;
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.folio-text {
    font-family: 'Commissioner', serif;
    font-weight: 300;
    font-size: clamp(1rem, 1.5vw, 1.2rem);
    line-height: 1.7;
    color: var(--text-warm);
    max-width: 600px;
    margin-bottom: 2rem;
}

/* Lambda Watermark */
.lambda-watermark {
    position: absolute;
    font-family: 'Commissioner', serif;
    font-weight: 700;
    font-size: 40vw;
    color: var(--bg-dark);
    opacity: 0.3;
    z-index: 1;
    user-select: none;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    line-height: 1;
}

.lambda-final {
    opacity: 0.15;
    font-size: 60vw;
}

/* Folio 1 */
.folio-1-content {
    text-align: center;
}

.site-title {
    font-family: 'Commissioner', serif;
    font-weight: 700;
    font-size: clamp(3rem, 8vw, 7rem);
    letter-spacing: -0.02em;
    line-height: 1;
    color: var(--text-light);
}

.site-title .dot {
    color: var(--accent-rust);
}

.tagline {
    font-family: 'Commissioner', serif;
    font-weight: 300;
    font-size: clamp(1rem, 2vw, 1.4rem);
    color: var(--accent-sand);
    margin-top: 1rem;
    letter-spacing: 0.05em;
}

.scroll-indicator {
    margin-top: 3rem;
    animation: float 2.5s ease-in-out infinite;
}

.scroll-dot {
    animation: scrollPulse 2.5s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

@keyframes scrollPulse {
    0%, 100% { cy: 10; opacity: 1; }
    50% { cy: 26; opacity: 0.4; }
}

/* Code Specimens */
.code-specimen {
    background: rgba(15, 12, 8, 0.6);
    border: 1px solid rgba(181, 164, 138, 0.2);
    border-radius: 4px;
    padding: 1.5rem 2rem;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.code-specimen pre {
    margin: 0;
}

.code-specimen code {
    font-family: 'Fira Code', monospace;
    font-size: clamp(0.85rem, 1.2vw, 1rem);
    color: var(--text-muted);
    line-height: 1.6;
}

/* SVG Diagrams */
.svg-diagram {
    margin: 2rem 0;
    display: flex;
    justify-content: center;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.svg-diagram.visible {
    opacity: 1;
    transform: translateY(0);
}

.svg-diagram svg {
    max-width: 100%;
    height: auto;
}

/* Card Flip */
.card-flip {
    perspective: 1000px;
    cursor: pointer;
    margin: 1.5rem 0;
}

.card-flip .card-front,
.card-flip .card-back {
    background: rgba(30, 26, 20, 0.8);
    border: 1px solid rgba(181, 164, 138, 0.2);
    border-radius: 4px;
    padding: 2rem;
    transition: transform 0.6s ease, opacity 0.6s ease;
    backface-visibility: hidden;
}

.card-flip .card-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform: rotateY(180deg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-flip[data-flipped="true"] .card-front {
    transform: rotateY(180deg);
}

.card-flip[data-flipped="true"] .card-back {
    transform: rotateY(0deg);
}

.card-hint {
    font-family: 'Commissioner', serif;
    font-size: 0.8rem;
    color: var(--accent-sand);
    opacity: 0.6;
    margin-top: 1rem;
    letter-spacing: 0.1em;
}

.card-explanation {
    font-family: 'Commissioner', serif;
    font-weight: 300;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-warm);
}

.card-explanation code {
    font-family: 'Fira Code', monospace;
    color: var(--accent-rust);
    font-size: 0.9em;
}

/* Folio 7 */
.folio-7-content {
    text-align: center;
}

.final-text {
    margin-left: auto;
    margin-right: auto;
}

.cta-links {
    display: flex;
    gap: 2rem;
    justify-content: center;
    margin: 2rem 0;
}

.cta-link {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--accent-rust);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    padding-bottom: 2px;
    transition: border-color 0.3s ease, color 0.3s ease;
}

.cta-link:hover {
    border-bottom-color: var(--accent-rust);
    color: var(--text-light);
}

.colophon {
    font-family: 'Commissioner', serif;
    font-weight: 300;
    font-size: 0.75rem;
    color: var(--accent-sand);
    opacity: 0.5;
    margin-top: 4rem;
    letter-spacing: 0.1em;
}

/* Folio reveal animation */
.folio-content {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease 0.2s, transform 0.8s ease 0.2s;
}

.folio.in-view .folio-content {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .folio-content {
        padding: 1.5rem;
    }

    .code-specimen {
        padding: 1rem 1.2rem;
    }

    .cta-links {
        flex-direction: column;
        gap: 1rem;
        align-items: center;
    }

    .lambda-watermark {
        font-size: 60vw;
    }
}