/* =====================================================================
   transactology.net — Bauhaus summit observatory
   Stacked geological sections with grain overlay & jewel-tone palette
   ===================================================================== */

:root {
    --c-obsidian: #1C1917;       /* Volcanic Obsidian (primary BG) */
    --c-granite: #292524;        /* Granite Dusk (secondary BG) */
    --c-malachite: #1E3A3A;      /* Deep Malachite (band 1) */
    --c-garnet: #3A1E2A;          /* Crushed Garnet (band 2) */
    --c-sapphire: #1E2A3A;        /* Midnight Sapphire (band 3) */
    --c-amber: #C2956B;           /* Tiger's Eye (accent) */
    --c-amber-deep: #8B6F4E;      /* Smoky Topaz (muted accent) */
    --c-parchment: #E8DCC8;       /* Aged Vellum (heading text) */
    --c-stone: #C8BFB0;           /* Limestone (body text) */
    --c-rose: #8B4F6E;            /* Rhodolite (rules / borders) */

    --font-serif: 'EB Garamond', 'Georgia', serif;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;

    --ease-tectonic: cubic-bezier(0.25, 0.1, 0.25, 1);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    background-color: var(--c-obsidian);
    color: var(--c-stone);
    font-family: var(--font-sans);
    font-weight: 400;
    line-height: 1.75;
    letter-spacing: 0.005em;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

body {
    min-height: 100vh;
}

main {
    position: relative;
    z-index: 1;
}

/* ----------------------------- Grain overlay ----------------------------- */
.grain-svg {
    position: absolute;
    width: 0;
    height: 0;
    pointer-events: none;
}

.grain-overlay {
    position: fixed;
    inset: 0;
    z-index: 9999;
    pointer-events: none;
    filter: url(#grain);
    mix-blend-mode: overlay;
    opacity: 0.035;
    background-color: rgba(232, 220, 200, 0.12);
}

@media (max-width: 768px) {
    .grain-overlay { opacity: 0.025; }
}

/* ----------------------------- Strata indicator ----------------------------- */
.strata-indicator {
    position: fixed;
    top: 50%;
    right: 28px;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 16px;
    z-index: 50;
}

.strata-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    border: 1px solid rgba(139, 111, 78, 0.35);
    background-color: transparent;
    transition: background-color 0.6s var(--ease-tectonic),
                border-color 0.6s var(--ease-tectonic),
                transform 0.6s var(--ease-tectonic);
    display: block;
    text-decoration: none;
}

.strata-dot.active {
    background-color: var(--c-amber);
    border-color: var(--c-amber);
    transform: scale(1.15);
}

.strata-dot:hover {
    border-color: var(--c-amber);
}

@media (max-width: 768px) {
    .strata-indicator {
        top: auto;
        bottom: 18px;
        right: 50%;
        transform: translateX(50%);
        flex-direction: row;
    }
}

/* ----------------------------- Reveal animation ----------------------------- */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

.reveal:nth-child(2).revealed { transition-delay: 200ms; }
.reveal:nth-child(3).revealed { transition-delay: 400ms; }
.reveal:nth-child(4).revealed { transition-delay: 600ms; }
.reveal:nth-child(5).revealed { transition-delay: 800ms; }
.reveal:nth-child(6).revealed { transition-delay: 1000ms; }
.reveal:nth-child(7).revealed { transition-delay: 1200ms; }
.reveal:nth-child(8).revealed { transition-delay: 1400ms; }

/* ----------------------------- Section base ----------------------------- */
.section {
    position: relative;
    width: 100%;
    overflow: hidden;
}

.section-label {
    display: inline-block;
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.85rem;
    letter-spacing: 0.02em;
    color: var(--c-amber);
    margin-bottom: 1.4rem;
}

/* Mountain silhouettes */
.ridge-silhouette {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 110px;
    pointer-events: none;
    z-index: 2;
}

.ridge-silhouette--summit {
    background-color: var(--c-granite);
    /* gentle rolling peaks */
    clip-path: polygon(
        0% 100%, 0% 70%,
        12% 55%, 22% 68%,
        34% 40%, 46% 60%,
        58% 48%, 70% 65%,
        82% 50%, 92% 62%,
        100% 55%, 100% 100%
    );
}

.ridge-silhouette--ridge {
    background-color: var(--c-malachite);
    /* sharper alpine peaks */
    clip-path: polygon(
        0% 100%, 0% 60%,
        7% 35%, 14% 55%,
        21% 22%, 28% 50%,
        36% 18%, 44% 48%,
        52% 28%, 60% 12%,
        68% 42%, 76% 25%,
        85% 50%, 92% 30%,
        100% 45%, 100% 100%
    );
}

.ridge-silhouette--strata {
    background-color: var(--c-obsidian);
    /* mesa-like plateaus */
    clip-path: polygon(
        0% 100%, 0% 60%,
        18% 60%, 22% 35%,
        46% 35%, 50% 55%,
        74% 55%, 78% 30%,
        100% 30%, 100% 100%
    );
}

.ridge-silhouette--treeline {
    background-color: var(--c-obsidian);
    height: 80px;
    clip-path: polygon(
        0% 100%, 0% 70%,
        10% 50%, 20% 65%,
        30% 45%, 42% 60%,
        54% 40%, 66% 55%,
        78% 35%, 88% 60%,
        100% 50%, 100% 100%
    );
}

/* ============================ Section 1 -- Summit ============================ */
.section--summit {
    background-color: var(--c-obsidian);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: clamp(2rem, 6vh, 5rem) 1.5rem;
}

.summit-frame {
    text-align: center;
    max-width: 90vw;
    position: relative;
    z-index: 3;
}

.summit-meta {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-bottom: clamp(2rem, 6vh, 4rem);
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 400;
    font-size: 0.85rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--c-amber-deep);
}

.summit-meta__divider {
    display: inline-block;
    width: 32px;
    height: 1px;
    background-color: var(--c-rose);
}

.summit-wordmark {
    font-family: var(--font-serif);
    font-weight: 600;
    font-size: clamp(2.8rem, 5vw, 4.2rem);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--c-parchment);
    line-height: 1.1;
    margin: 0 0 clamp(1.5rem, 3vh, 2.5rem) 0;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 1.2s var(--ease-tectonic), transform 1.2s var(--ease-tectonic);
}

.summit-wordmark.is-loaded {
    opacity: 1;
    transform: translateY(0);
}

.summit-rule {
    height: 1px;
    width: 0;
    max-width: 60vw;
    margin: 0 auto clamp(1.5rem, 3vh, 2.5rem) auto;
    background-color: var(--c-rose);
    transition: width 0.8s var(--ease-tectonic);
}

.summit-rule.is-drawn {
    width: 60vw;
}

.summit-tagline {
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 400;
    font-size: clamp(1rem, 1.4vw, 1.15rem);
    color: var(--c-amber);
    letter-spacing: 0.02em;
    line-height: 1.5;
    margin: 0 auto;
    max-width: 36rem;
    opacity: 0;
    transition: opacity 1s var(--ease-tectonic) 200ms;
}

.summit-tagline.is-faded-in {
    opacity: 1;
}

.summit-coords {
    margin-top: clamp(2.5rem, 8vh, 5rem);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.2rem;
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.85rem;
    letter-spacing: 0.06em;
    color: var(--c-amber-deep);
}

.summit-coords__sep {
    display: inline-block;
    width: 1px;
    height: 12px;
    background-color: var(--c-amber-deep);
    opacity: 0.5;
}

/* ============================ Section 2 -- Ridge Line ============================ */
.section--ridge {
    background-color: var(--c-granite);
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: clamp(4rem, 12vh, 8rem) clamp(1.5rem, 6vw, 5rem);
}

.ridge-grid {
    display: grid;
    grid-template-columns: 1fr 1.618fr;
    gap: clamp(2rem, 5vw, 5rem);
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    position: relative;
}

.ridge-left {
    position: relative;
    padding-right: clamp(1rem, 3vw, 2.5rem);
}

.ridge-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(2.4rem, 4.5vw, 3.6rem);
    line-height: 1.15;
    letter-spacing: 0.01em;
    color: var(--c-parchment);
    margin: 0;
}

.ridge-circle {
    display: block;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 1px solid var(--c-amber);
    margin-top: 2.5rem;
}

.ridge-right {
    position: relative;
    padding-left: clamp(1rem, 3vw, 2.5rem);
    border-left: 1px solid rgba(139, 79, 110, 0.25);
}

.ridge-right p {
    font-size: clamp(0.95rem, 1.1vw, 1.125rem);
    line-height: 1.75;
    letter-spacing: 0.005em;
    color: var(--c-stone);
    margin: 0 0 1.6rem 0;
}

.ridge-rect {
    display: block;
    width: 48px;
    height: 2px;
    background-color: var(--c-rose);
    margin: 2rem 0;
}

@media (max-width: 768px) {
    .ridge-grid {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
    .ridge-right {
        padding-left: 0;
        border-left: none;
        border-top: 1px solid rgba(139, 79, 110, 0.25);
        padding-top: 2rem;
    }
}

/* ============================ Section 3 -- Strata ============================ */
.section--strata {
    background-color: var(--c-obsidian);
    min-height: 100vh;
}

.stratum {
    position: relative;
    min-height: 33vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(3rem, 7vh, 5.5rem) clamp(1.5rem, 5vw, 4rem);
    overflow: hidden;
    box-shadow: 0 1px 0 0 rgba(139, 111, 78, 0.25);
    transition: filter 1.2s var(--ease-tectonic);
    filter: brightness(0.8);
}

.stratum.is-active {
    filter: brightness(1);
}

.stratum--malachite { background-color: var(--c-malachite); }
.stratum--garnet    { background-color: var(--c-garnet); }
.stratum--sapphire  { background-color: var(--c-sapphire); }

.contour-field {
    position: absolute;
    inset: 0;
    pointer-events: none;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    animation: contour-drift 30s var(--ease-tectonic) infinite alternate;
}

@keyframes contour-drift {
    from { transform: rotate(0deg); }
    to   { transform: rotate(2deg); }
}

.contour {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 0.5px solid rgba(194, 149, 107, 0.10);
    border-radius: 50%;
    pointer-events: none;
}

.contour-field .contour:nth-child(1) { width: 200px;  height: 140px; }
.contour-field .contour:nth-child(2) { width: 320px;  height: 220px; transform: translate(-48%, -52%); }
.contour-field .contour:nth-child(3) { width: 460px;  height: 320px; transform: translate(-52%, -48%); }
.contour-field .contour:nth-child(4) { width: 620px;  height: 420px; transform: translate(-49%, -51%); }
.contour-field .contour:nth-child(5) { width: 800px;  height: 540px; transform: translate(-51%, -49%); }
.contour-field .contour:nth-child(6) { width: 1000px; height: 670px; transform: translate(-50%, -50%); }
.contour-field .contour:nth-child(7) { width: 1240px; height: 820px; transform: translate(-49%, -50%); }
.contour-field .contour:nth-child(8) { width: 1500px; height: 990px; transform: translate(-50%, -49%); }
.contour-field .contour:nth-child(9) { width: 1800px; height: 1180px; transform: translate(-50%, -50%); }

.stratum-card {
    position: relative;
    z-index: 2;
    max-width: 680px;
    margin-inline: auto;
    text-align: left;
}

.stratum-label {
    display: inline-block;
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.85rem;
    letter-spacing: 0.06em;
    color: var(--c-amber);
    text-transform: uppercase;
    margin-bottom: 1.2rem;
}

.stratum-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(1.8rem, 3.2vw, 2.4rem);
    line-height: 1.2;
    letter-spacing: 0.01em;
    color: var(--c-parchment);
    margin: 0 0 1.4rem 0;
}

.stratum-card p {
    font-size: clamp(0.95rem, 1.1vw, 1.05rem);
    line-height: 1.75;
    color: var(--c-stone);
    margin: 0 0 1.2rem 0;
}

.stratum-card p:last-child {
    margin-bottom: 0;
}

/* ============================ Section 4 -- Treeline ============================ */
.section--treeline {
    background-color: var(--c-granite);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: clamp(3rem, 8vh, 6rem) 0 clamp(4rem, 10vh, 7rem) 0;
    position: relative;
}

.treeline-header {
    display: flex;
    align-items: baseline;
    gap: 1.2rem;
    padding: 0 clamp(1.5rem, 5vw, 4rem);
    margin-bottom: 2rem;
    color: var(--c-amber);
}

.treeline-italic {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: clamp(1.4rem, 2.5vw, 2rem);
    color: var(--c-parchment);
}

.treeline-instruction {
    font-family: var(--font-sans);
    font-weight: 300;
    font-size: 0.8rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--c-amber-deep);
    margin-left: auto;
}

.traverse-track {
    display: flex;
    overflow-x: auto;
    overflow-y: hidden;
    scroll-snap-type: x mandatory;
    scroll-behavior: smooth;
    gap: 0;
    padding: 1.5rem clamp(1.5rem, 5vw, 4rem);
    scrollbar-width: thin;
    scrollbar-color: var(--c-amber-deep) transparent;
}

.traverse-track::-webkit-scrollbar { height: 4px; }
.traverse-track::-webkit-scrollbar-track { background: transparent; }
.traverse-track::-webkit-scrollbar-thumb { background-color: var(--c-amber-deep); border-radius: 2px; }

.traverse-panel {
    flex: 0 0 85vw;
    scroll-snap-align: center;
    margin-right: 2vw;
    position: relative;
    background-color: var(--c-obsidian);
    padding: clamp(2rem, 5vh, 4rem) clamp(1.8rem, 4vw, 3.5rem);
    overflow: hidden;
    min-height: 56vh;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    box-shadow: inset 0 0 0 1px rgba(139, 111, 78, 0.18);
}

.traverse-panel--alt {
    background-color: var(--c-sapphire);
}

.traverse-panel--circle.traverse-panel--alt {
    background-color: var(--c-malachite);
}

.bauhaus-shape {
    position: absolute;
    pointer-events: none;
    opacity: 0.10;
}

.bauhaus-circle {
    width: 60vh;
    height: 60vh;
    max-width: 520px;
    max-height: 520px;
    border-radius: 50%;
    background-color: var(--c-amber);
    top: -10%;
    right: -8%;
}

.bauhaus-circle--small {
    width: 40vh;
    height: 40vh;
    max-width: 360px;
    max-height: 360px;
    background-color: var(--c-rose);
    top: 8%;
    right: 12%;
}

.bauhaus-rect {
    width: 65%;
    height: 36vh;
    max-height: 360px;
    background-color: var(--c-rose);
    top: 12%;
    left: -8%;
    transform: rotate(-6deg);
}

.bauhaus-rect--tall {
    width: 32%;
    height: 80%;
    background-color: var(--c-amber);
    top: 5%;
    right: -4%;
    left: auto;
    transform: rotate(4deg);
}

.bauhaus-triangle {
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 0 0 50vh 50vh;
    border-color: transparent transparent rgba(30, 58, 58, 0.55) transparent;
    bottom: 0;
    right: 0;
    background: transparent;
    opacity: 1;
    /* small watermark triangle in corner using clip-path on a colored block */
}

/* override bauhaus-triangle to use clip-path approach for crisp rendering */
.traverse-panel--triangle .bauhaus-triangle {
    width: 70%;
    height: 70%;
    border: none;
    background-color: var(--c-malachite);
    opacity: 0.35;
    clip-path: polygon(100% 0%, 100% 100%, 0% 100%);
    top: auto;
    bottom: 0;
    right: 0;
    left: auto;
}

.traverse-num {
    position: relative;
    z-index: 2;
    font-family: var(--font-serif);
    font-weight: 400;
    font-size: 0.85rem;
    letter-spacing: 0.18em;
    color: var(--c-amber);
    margin-bottom: 1.4rem;
}

.traverse-title {
    position: relative;
    z-index: 2;
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    line-height: 1.2;
    letter-spacing: 0.01em;
    color: var(--c-parchment);
    margin: 0 0 1rem 0;
    max-width: 30rem;
}

.traverse-panel p {
    position: relative;
    z-index: 2;
    font-size: clamp(0.95rem, 1.1vw, 1.05rem);
    line-height: 1.7;
    color: var(--c-stone);
    max-width: 36rem;
    margin: 0 0 1.4rem 0;
}

.traverse-foot {
    position: relative;
    z-index: 2;
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 0.85rem;
    letter-spacing: 0.02em;
    color: var(--c-amber-deep);
    display: block;
    border-top: 1px solid rgba(139, 79, 110, 0.25);
    padding-top: 0.8rem;
}

.traverse-dots {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 14px;
    margin-top: 1.5rem;
    padding: 0 clamp(1.5rem, 5vw, 4rem);
}

.traverse-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    border: 1px solid rgba(139, 111, 78, 0.35);
    background-color: transparent;
    transition: background-color 0.5s var(--ease-tectonic),
                border-color 0.5s var(--ease-tectonic);
}

.traverse-dot.active {
    background-color: var(--c-amber);
    border-color: var(--c-amber);
}

@media (max-width: 768px) {
    .traverse-panel {
        flex: 0 0 88vw;
        min-height: 70vh;
    }
}

/* ============================ Section 5 -- Bedrock ============================ */
.section--bedrock {
    background-color: var(--c-obsidian);
    padding: clamp(3rem, 8vh, 6rem) 1.5rem clamp(4rem, 12vh, 8rem) 1.5rem;
}

.bedrock-frame {
    max-width: 640px;
    margin: 0 auto;
    position: relative;
}

.bedrock-frame::before {
    content: '';
    position: absolute;
    top: 0.4em;
    left: -2.5rem;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 1px solid var(--c-amber);
}

.bedrock-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(2rem, 3.6vw, 2.8rem);
    line-height: 1.15;
    letter-spacing: 0.01em;
    color: var(--c-parchment);
    margin: 0 0 2.2rem 0;
}

.bedrock-frame p {
    font-size: clamp(0.95rem, 1.1vw, 1.125rem);
    line-height: 1.85;
    color: var(--c-stone);
    margin: 0 0 1.6rem 0;
}

.bedrock-quote {
    margin: 2.4rem 0;
    padding-inline-start: 2rem;
    border-left: 2px solid var(--c-rose);
    font-family: var(--font-serif);
    font-style: italic;
    font-size: clamp(1.05rem, 1.4vw, 1.25rem);
    line-height: 1.6;
    color: var(--c-amber);
}

.colophon {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(139, 111, 78, 0.25);
    text-align: center;
}

.colophon-name {
    font-family: var(--font-serif);
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--c-parchment);
    margin: 0 0 1rem 0;
}

.colophon-rule {
    width: 48px;
    height: 1px;
    background-color: var(--c-rose);
    margin: 0 auto 1rem auto;
}

.colophon-meta {
    font-family: var(--font-sans);
    font-weight: 300;
    font-size: 0.85rem;
    letter-spacing: 0.04em;
    color: var(--c-amber-deep);
    margin: 0;
}

@media (max-width: 768px) {
    .bedrock-frame::before {
        left: 0;
        top: -2.5rem;
    }
    .strata-indicator { gap: 12px; }
}

/* ============================ Selection ============================ */
::selection {
    background: rgba(194, 149, 107, 0.35);
    color: var(--c-parchment);
}