/* layer-2.id — Isometric Architectural Cartography */

:root {
    --deep-brown: #2d2419;
    --deep-indigo: #1e2a4a;
    --parchment-cream: #faf7f0;
    --warm-ecru: #f4eee2;
    --muted-taupe: #c4b8a3;
    --aged-amber: #c4983c;
    --oxidized-copper: #5a8a7a;
    --walnut: #8b7355;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background: var(--parchment-cream);
    color: var(--deep-brown);
    font-family: 'Libre Baskerville', serif;
    font-size: 16px;
    line-height: 1.7;
    overflow-x: hidden;
}

/* Depth Container */
.depth-container {
    position: relative;
}

/* Strata */
.stratum {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    transition: filter 0.6s ease, opacity 0.6s ease;
}

.stratum-content {
    max-width: 900px;
    width: 90%;
    margin: 0 auto;
    padding: 4rem 2rem;
    position: relative;
    z-index: 2;
}

/* Stratum V — Bedrock */
.stratum-v {
    background: var(--deep-indigo);
    min-height: 60vh;
}

.stratum-v .grid-pattern {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(196, 184, 163, 0.08) 1px, transparent 1px),
        linear-gradient(90deg, rgba(196, 184, 163, 0.08) 1px, transparent 1px);
    background-size: 40px 40px;
}

.bedrock-text {
    color: var(--muted-taupe);
    font-family: 'DM Sans', sans-serif;
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-align: center;
    opacity: 0.6;
}

/* Stratum IV — Data Landscape */
.stratum-iv {
    background: var(--warm-ecru);
    min-height: 100vh;
}

.isometric-landscape {
    margin-bottom: 3rem;
}

.iso-svg {
    width: 100%;
    height: auto;
    max-height: 50vh;
}

.domain-title {
    font-family: 'Cormorant Garamond', serif;
    font-weight: 600;
    font-size: clamp(2.2rem, 5.5vw, 5rem);
    letter-spacing: 0.01em;
    line-height: 1.12;
    color: var(--deep-indigo);
    text-align: center;
    margin-bottom: 0.5rem;
}

.tagline {
    font-family: 'DM Sans', sans-serif;
    font-weight: 500;
    font-size: 0.9rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--walnut);
    text-align: center;
    opacity: 0.8;
}

/* Stratum III — Information */
.stratum-iii {
    background: var(--parchment-cream);
    border-top: 1px solid var(--muted-taupe);
}

.section-heading {
    font-family: 'Cormorant Garamond', serif;
    font-weight: 600;
    font-size: clamp(1.8rem, 4vw, 3.2rem);
    color: var(--deep-indigo);
    margin-bottom: 3rem;
    letter-spacing: 0.01em;
    line-height: 1.12;
}

.info-blocks {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2.5rem;
}

.info-block {
    padding: 2rem;
    border: 1px solid var(--muted-taupe);
    background: var(--warm-ecru);
    position: relative;
}

.block-number {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 0.2em;
    color: var(--aged-amber);
    margin-bottom: 1rem;
}

.info-block h3 {
    font-family: 'Cormorant Garamond', serif;
    font-weight: 600;
    font-size: 1.4rem;
    color: var(--deep-indigo);
    margin-bottom: 0.75rem;
}

.info-block p {
    font-size: 0.92rem;
    color: var(--walnut);
    line-height: 1.7;
}

/* Stratum II — Interaction */
.stratum-ii {
    background: var(--warm-ecru);
    border-top: 1px solid var(--muted-taupe);
}

.cross-section {
    margin-bottom: 2rem;
}

.cross-svg {
    width: 100%;
    height: auto;
    max-height: 400px;
}

.stratum-caption {
    font-family: 'Libre Baskerville', serif;
    font-style: italic;
    font-size: 1.05rem;
    color: var(--walnut);
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

/* Stratum I — Surface */
.stratum-i {
    background: var(--parchment-cream);
    border-top: 1px solid var(--muted-taupe);
}

.surface-element {
    text-align: center;
}

.copper-mark {
    display: block;
    font-size: 2.5rem;
    color: var(--oxidized-copper);
    margin-bottom: 1.5rem;
}

.surface-heading {
    font-family: 'Cormorant Garamond', serif;
    font-weight: 600;
    font-size: clamp(1.8rem, 4vw, 3rem);
    color: var(--deep-indigo);
    margin-bottom: 1.5rem;
    letter-spacing: 0.01em;
    line-height: 1.12;
}

.surface-text {
    font-size: 1rem;
    color: var(--walnut);
    max-width: 550px;
    margin: 0 auto 2.5rem;
}

.depth-indicator {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.depth-line {
    display: block;
    width: 60px;
    height: 1px;
    background: var(--muted-taupe);
}

.depth-label {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.72rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--muted-taupe);
}

/* Scroll Indicator */
.scroll-indicator {
    position: fixed;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.indicator-track {
    width: 2px;
    height: 120px;
    background: var(--muted-taupe);
    position: relative;
    opacity: 0.5;
}

.indicator-fill {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0%;
    background: var(--aged-amber);
    transition: height 0.3s ease;
}

.indicator-labels {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 120px;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.6rem;
    color: var(--muted-taupe);
    letter-spacing: 0.1em;
}

/* Animations */
.stratum.in-view .domain-title,
.stratum.in-view .section-heading,
.stratum.in-view .surface-heading {
    animation: fadeUp 0.8s ease forwards;
}

.stratum.in-view .info-block {
    animation: fadeUp 0.8s ease forwards;
}

.stratum.in-view .info-block:nth-child(2) { animation-delay: 0.15s; }
.stratum.in-view .info-block:nth-child(3) { animation-delay: 0.3s; }

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

/* Initial states for animation */
.domain-title,
.section-heading,
.surface-heading,
.info-block {
    opacity: 0;
}

.stratum.in-view .domain-title,
.stratum.in-view .section-heading,
.stratum.in-view .surface-heading,
.stratum.in-view .info-block {
    opacity: 1;
}

/* Depth blur effect for non-active strata */
.stratum.depth-blur {
    filter: blur(2px);
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .scroll-indicator {
        right: 1rem;
    }
    .stratum-content {
        padding: 3rem 1.5rem;
    }
    .info-blocks {
        grid-template-columns: 1fr;
    }
}