/* lower.quest — vertical contemplative descent
   coastal-blend palette, japanese-minimal, monospace-led
   ============================================================ */

:root {
    /* Palette */
    --paper-shell: #F2F0E9;
    --ink-deep: #1B2733;
    --slate-tide: #5B7A8C;
    --fog-glass: #9FB7BD;
    --sea-glass: #D8DDD0;
    --driftwood-mint: #C2D4D2;
    --kelp-amber: #E8C9A0;
    --gunmetal: #3D4F5C;

    /* Type */
    --font-body: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
    --font-label: 'Space Mono', ui-monospace, monospace;
    --font-display: 'IBM Plex Mono', ui-monospace, monospace;
    --font-italic: 'Cormorant Garamond', Georgia, serif;

    /* Layout */
    --gutter-left: 96px;
    --gutter-right: 64px;
    --column-width: 56ch;
    --column-offset: clamp(140px, 22vw, 280px);
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--paper-shell);
    color: var(--ink-deep);
    font-family: var(--font-body);
    font-size: 14.5px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

body {
    min-height: 100vh;
    position: relative;
    transition: background-color 1200ms ease-out;
}

/* When deep into descent, body cools subtly */
body.depth-mid { background: #ECECE6; }
body.depth-low { background: #E2E6E5; }
body.depth-bottom { background: var(--gunmetal); color: var(--paper-shell); }

/* ============================================================
   Paper-grain and pencil-scuff overlays (mixed-media texture)
   ============================================================ */

.paper-grain {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    opacity: 0.03;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(27,39,51,0.45) 0px, transparent 1px),
        radial-gradient(circle at 70% 60%, rgba(27,39,51,0.35) 0px, transparent 1px),
        radial-gradient(circle at 40% 80%, rgba(27,39,51,0.4) 0px, transparent 1px),
        radial-gradient(circle at 85% 15%, rgba(27,39,51,0.3) 0px, transparent 1px);
    background-size: 7px 7px, 11px 11px, 13px 13px, 9px 9px;
    mix-blend-mode: multiply;
}

.pencil-scuff {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 2;
    opacity: 0.008;
    background-image:
        repeating-linear-gradient(98deg, rgba(27,39,51,0.5) 0px, rgba(27,39,51,0.5) 1px, transparent 2px, transparent 220px),
        repeating-linear-gradient(174deg, rgba(27,39,51,0.4) 0px, rgba(27,39,51,0.4) 1px, transparent 3px, transparent 380px);
}

/* ============================================================
   Depth ruler (fixed left edge)
   ============================================================ */

.depth-ruler {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: var(--gutter-left);
    z-index: 10;
    font-family: var(--font-body);
    font-size: 10px;
    color: var(--slate-tide);
    pointer-events: none;
    padding: 32px 0 32px 24px;
    display: flex;
    flex-direction: column;
}

.ruler-track {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    border-left: 1px solid rgba(91,122,140,0.35);
    padding-left: 12px;
}

.ruler-tick {
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.04em;
    opacity: 0.55;
    position: relative;
    transition: opacity 600ms ease-out, color 600ms ease-out;
}

.ruler-tick::before {
    content: "";
    position: absolute;
    left: -13px;
    top: 50%;
    width: 10px;
    height: 1px;
    background: rgba(91,122,140,0.5);
}

body.depth-bottom .depth-ruler { color: rgba(242,240,233,0.65); }
body.depth-bottom .ruler-track { border-left-color: rgba(242,240,233,0.3); }
body.depth-bottom .ruler-tick::before { background: rgba(242,240,233,0.4); }

.ruler-current {
    position: absolute;
    top: 0;
    left: 24px;
    width: calc(var(--gutter-left) - 36px);
    transition: top 60ms linear;
    will-change: top;
}

.ruler-marker {
    display: block;
    width: 18px;
    height: 1px;
    background: var(--kelp-amber);
    margin-left: -6px;
}

.ruler-readout {
    display: block;
    font-family: var(--font-label);
    font-size: 11px;
    letter-spacing: 0.04em;
    color: var(--kelp-amber);
    margin-top: 4px;
    font-variant-numeric: tabular-nums;
    text-transform: lowercase;
}

/* ============================================================
   Top-right minimal nav rail
   ============================================================ */

.nav-rail {
    position: fixed;
    top: 32px;
    right: var(--gutter-right);
    z-index: 12;
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: flex-end;
    font-family: var(--font-label);
    font-size: 11px;
    letter-spacing: 0.04em;
}

.nav-link {
    color: var(--slate-tide);
    text-decoration: none;
    text-transform: lowercase;
    transition: color 800ms ease-out, opacity 800ms ease-out;
    opacity: 0.75;
}

.nav-link:hover {
    color: var(--driftwood-mint);
    opacity: 1;
}

body.depth-bottom .nav-link { color: rgba(242,240,233,0.65); }
body.depth-bottom .nav-link:hover { color: var(--kelp-amber); }

/* ============================================================
   Top-right corner glyph (morphs per band)
   ============================================================ */

.corner-glyph {
    position: fixed;
    top: 88px;
    right: var(--gutter-right);
    z-index: 11;
    width: 60px;
    height: 60px;
    pointer-events: none;
    color: var(--slate-tide);
    transition: color 800ms ease-out, opacity 800ms ease-out;
    opacity: 0.7;
}

.corner-glyph svg {
    width: 100%;
    height: 100%;
    display: block;
    fill: none;
    stroke: currentColor;
    stroke-width: 1;
    stroke-linecap: round;
    stroke-linejoin: round;
}

body.depth-mid .corner-glyph { color: var(--driftwood-mint); }
body.depth-low .corner-glyph { color: var(--fog-glass); }
body.depth-bottom .corner-glyph { color: var(--kelp-amber); opacity: 0.85; }

/* ============================================================
   Bottom-left fixed wordmark
   ============================================================ */

.wordmark {
    position: fixed;
    bottom: 24px;
    left: 24px;
    z-index: 12;
    font-family: var(--font-label);
    font-size: 11px;
    letter-spacing: 0.04em;
    color: var(--slate-tide);
    text-transform: lowercase;
    opacity: 0.8;
    pointer-events: none;
    transition: color 800ms ease-out;
}

body.depth-bottom .wordmark { color: var(--paper-shell); opacity: 0.9; }

/* ============================================================
   Scroll progress vertical fill (right edge)
   ============================================================ */

.scroll-progress {
    position: fixed;
    top: 0;
    right: 0;
    width: 1px;
    height: 0%;
    background: var(--kelp-amber);
    opacity: 0.35;
    z-index: 9;
    transition: opacity 600ms ease-out;
    will-change: height;
}

/* ============================================================
   Main descent
   ============================================================ */

.descent {
    position: relative;
    padding: 0;
    margin: 0;
    z-index: 5;
}

/* ============================================================
   Bands (depth strata)
   ============================================================ */

.band {
    position: relative;
    min-height: 110vh;
    padding: 20vh var(--gutter-right) 16vh calc(var(--gutter-left) + var(--column-offset));
    transition: background-color 1500ms ease-out;
}

.band--surface { min-height: 100vh; padding-top: 18vh; }
.band--photic { min-height: 110vh; }
.band--mesopelagic { min-height: 120vh; background: linear-gradient(180deg, transparent 0%, rgba(159,183,189,0.08) 100%); }
.band--bathyal { min-height: 130vh; background: linear-gradient(180deg, rgba(159,183,189,0.08) 0%, rgba(216,221,208,0.18) 100%); }
.band--abyssal { min-height: 130vh; background: linear-gradient(180deg, rgba(216,221,208,0.18) 0%, rgba(159,183,189,0.28) 100%); }
.band--hadal { min-height: 120vh; background: linear-gradient(180deg, rgba(159,183,189,0.28) 0%, rgba(91,122,140,0.18) 100%); }
.band--seabed {
    min-height: 110vh;
    background: var(--gunmetal);
    color: var(--paper-shell);
    padding-top: 18vh;
}

/* ============================================================
   Band-rule (hairline horizontal divider that draws on enter)
   ============================================================ */

.band-rule {
    position: absolute;
    top: 12vh;
    left: var(--gutter-left);
    right: var(--gutter-right);
    height: 1px;
    pointer-events: none;
}

.band-rule svg {
    width: 100%;
    height: 1px;
    display: block;
    overflow: visible;
}

.band-rule line {
    stroke: var(--slate-tide);
    stroke-width: 1;
    opacity: 0.5;
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
    transition: stroke-dashoffset 700ms ease-out;
}

.band-rule--inverted line {
    stroke: var(--paper-shell);
    opacity: 0.4;
}

.band.in-view .band-rule line {
    stroke-dashoffset: 0;
}

/* ============================================================
   Band-meta (index + label + range, top-left of band content)
   ============================================================ */

.band-meta {
    display: flex;
    gap: 24px;
    align-items: baseline;
    margin-bottom: 36px;
    font-family: var(--font-label);
    font-size: 11px;
    letter-spacing: 0.04em;
    color: var(--slate-tide);
    text-transform: lowercase;
    opacity: 0;
    transform: translateY(6px);
    transition: opacity 800ms ease-out, transform 800ms ease-out;
}

.band.in-view .band-meta {
    opacity: 1;
    transform: translateY(0);
}

.band-index {
    font-variant-numeric: tabular-nums;
    color: var(--kelp-amber);
}

.band-label {
    font-weight: 700;
    color: var(--ink-deep);
    letter-spacing: 0.06em;
}

.band-range {
    font-variant-numeric: tabular-nums;
    opacity: 0.7;
}

.band-meta--inverted .band-label { color: var(--paper-shell); }
.band-meta--inverted { color: rgba(242,240,233,0.7); }

/* ============================================================
   Band content
   ============================================================ */

.band-content {
    max-width: var(--column-width);
    position: relative;
}

.band-content > * {
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 900ms ease-out, transform 900ms ease-out;
}

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

.band.in-view .band-content > *:nth-child(1) { transition-delay: 100ms; }
.band.in-view .band-content > *:nth-child(2) { transition-delay: 200ms; }
.band.in-view .band-content > *:nth-child(3) { transition-delay: 300ms; }
.band.in-view .band-content > *:nth-child(4) { transition-delay: 400ms; }
.band.in-view .band-content > *:nth-child(5) { transition-delay: 500ms; }
.band.in-view .band-content > *:nth-child(6) { transition-delay: 600ms; }

/* ============================================================
   Display numerals (per-band header)
   ============================================================ */

.display-numeral {
    font-family: var(--font-display);
    font-weight: 200;
    font-size: clamp(36px, 6vw, 64px);
    letter-spacing: 0.02em;
    line-height: 1;
    margin: 0 0 28px;
    color: var(--ink-deep);
    font-variant-numeric: tabular-nums;
}

.display-numeral--horizon {
    font-size: clamp(32px, 5vw, 56px);
    color: var(--paper-shell);
    letter-spacing: 0.08em;
    text-transform: lowercase;
}

.band-content--inverted .display-numeral { color: var(--paper-shell); }

/* ============================================================
   Lead, body copy, field-notes
   ============================================================ */

.lead {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.65;
    color: var(--ink-deep);
    margin: 0 0 28px;
    max-width: 50ch;
}

.body-copy {
    font-family: var(--font-body);
    font-size: 14.5px;
    line-height: 1.7;
    color: var(--ink-deep);
    margin: 0 0 22px;
    max-width: 56ch;
}

.band-content--inverted .body-copy,
.band-content--inverted .lead {
    color: var(--paper-shell);
}

.field-note {
    font-family: var(--font-italic);
    font-style: italic;
    font-size: 19px;
    line-height: 1.7;
    color: var(--gunmetal);
    margin: 32px 0 32px;
    padding-left: 16px;
    border-left: 1px solid var(--kelp-amber);
    max-width: 48ch;
}

.band-content--inverted .field-note {
    color: var(--paper-shell);
}

/* ============================================================
   Annotations (kelp-amber margin notes)
   ============================================================ */

.annotation {
    font-family: var(--font-body);
    font-size: 10px;
    color: var(--slate-tide);
    letter-spacing: 0.05em;
    margin: 0 0 24px;
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
    font-variant-numeric: tabular-nums;
}

.ann {
    display: inline-block;
    color: var(--kelp-amber);
    opacity: 0.95;
}

.ann--accent {
    color: var(--kelp-amber);
    border-bottom: 1px dotted var(--kelp-amber);
}

.band-content--inverted .annotation { color: rgba(242,240,233,0.6); }

/* ============================================================
   Contour-host (procedural bathymetric contours)
   ============================================================ */

.contour-host {
    position: absolute;
    right: -6vw;
    top: 30%;
    width: 38vw;
    max-width: 480px;
    height: 60%;
    pointer-events: none;
    opacity: 0;
    transition: opacity 1400ms ease-out;
}

.band.in-view .contour-host {
    opacity: 0.85;
    transition-delay: 700ms;
}

.contour-host svg {
    width: 100%;
    height: 100%;
    display: block;
    overflow: visible;
}

.contour-host svg path {
    fill: none;
    stroke: var(--slate-tide);
    stroke-width: 0.6;
    opacity: 0.5;
    stroke-dasharray: 4000;
    stroke-dashoffset: 4000;
    transition: stroke-dashoffset 2400ms ease-out;
}

.band.in-view .contour-host svg path {
    stroke-dashoffset: 0;
}

.contour-host--inverted svg path {
    stroke: var(--driftwood-mint);
    opacity: 0.45;
}

/* ============================================================
   Closing line (deepest band)
   ============================================================ */

.closing {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(20px, 2.4vw, 28px);
    letter-spacing: 0.03em;
    line-height: 1.5;
    color: var(--paper-shell);
    margin: 48px 0 24px;
    max-width: 48ch;
}

.counter {
    font-family: var(--font-display);
    font-weight: 200;
    color: var(--kelp-amber);
    font-variant-numeric: tabular-nums;
    padding: 0 6px;
    letter-spacing: 0.04em;
}

.closing-sub {
    font-family: var(--font-italic);
    font-style: italic;
    font-size: 17px;
    color: rgba(242,240,233,0.7);
    margin: 24px 0;
    max-width: 48ch;
}

/* ============================================================
   More indicator (breathing chevron)
   ============================================================ */

.more-indicator {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--slate-tide);
    z-index: 11;
    pointer-events: none;
    animation: breathe 4s ease-in-out infinite;
    transition: opacity 800ms ease-out;
}

.more-indicator.is-hidden {
    opacity: 0;
}

body.depth-bottom .more-indicator {
    opacity: 0;
}

@keyframes breathe {
    0%, 100% { opacity: 0.25; }
    50% { opacity: 0.65; }
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 900px) {
    :root {
        --gutter-left: 64px;
        --gutter-right: 32px;
        --column-offset: 24px;
    }
    .band {
        padding-left: calc(var(--gutter-left) + 12px);
    }
    .corner-glyph {
        top: 64px;
        right: 24px;
        width: 44px;
        height: 44px;
    }
    .nav-rail {
        top: 24px;
        right: 24px;
    }
    .contour-host {
        right: -10vw;
        width: 60vw;
        opacity: 0.4;
    }
    .band.in-view .contour-host { opacity: 0.4; }
    .display-numeral { font-size: clamp(32px, 9vw, 48px); }
    .lead { font-size: 15px; }
    .field-note { font-size: 17px; }
}

@media (max-width: 560px) {
    .band {
        padding-right: 20px;
        padding-left: 56px;
    }
    .nav-rail {
        gap: 6px;
    }
    .nav-link {
        font-size: 10px;
    }
    .depth-ruler {
        width: 48px;
        padding-left: 12px;
    }
    .ruler-track {
        padding-left: 8px;
    }
    .ruler-tick { font-size: 9px; }
}

/* ============================================================
   Reduced motion
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
    .band-rule line,
    .contour-host svg path {
        stroke-dashoffset: 0;
        transition: none;
    }
    .band-content > *,
    .band-meta {
        opacity: 1;
        transform: none;
        transition: none;
    }
    .more-indicator {
        animation: none;
        opacity: 0.5;
    }
}