/* ==========================================================================
   PPEBBL.com — A meditation on river-tumbled stones
   ========================================================================== */

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

:root {
    /* Palette — exact hex values from DESIGN.md */
    --slate:       #2d3436;  /* Riverbed Slate */
    --shallow:     #74b9ff;  /* Shallow Water  */
    --wet-stone:   #636e72;  /* Wet Stone      */
    --dry-pebble:  #dfe6e9;  /* Dry Pebble     */
    --agate:       #e17055;  /* Agate Blush    */
    --deep-pool:   #0c2461;  /* Deep Pool      */
    --lichen:      #6ab04c;  /* Lichen Green   */
    --sand-foam:   #ffeaa7;  /* Sand Foam      */
    --charcoal:    #3d3d3d;  /* secondary band shade */

    /* Typography */
    --font-display: 'DM Serif Display', Georgia, serif;
    --font-body:    'Nunito Sans', system-ui, sans-serif;
    --font-mono:    'Azeret Mono', ui-monospace, monospace;

    /* Curves */
    --ease-stone: cubic-bezier(0.22, 1, 0.36, 1);

    /* Layer geometry */
    --seam-angle: 6deg;
    --seam-h: 4px;
    --rail-w: 56px;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    font-size: 18px;
    line-height: 1.75;
    color: var(--dry-pebble);
    background: var(--slate);
    overflow-x: hidden;
    scroll-snap-type: y proximity;
    -webkit-font-smoothing: antialiased;
}

main { display: block; position: relative; }

img, svg { display: block; max-width: 100%; }

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

/* --------------------------------------------------------------------------
   Grain overlay — global tactile noise
   -------------------------------------------------------------------------- */
.grain-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 50;
    opacity: 0.05;
    mix-blend-mode: overlay;
    background-image:
        url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/><feColorMatrix type='matrix' values='0 0 0 0 0.18  0 0 0 0 0.20  0 0 0 0 0.21  0 0 0 0.7 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

/* --------------------------------------------------------------------------
   Bubble particle field — foreground depth layer
   -------------------------------------------------------------------------- */
.bubble-field {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 30;
    overflow: hidden;
}
.bubble {
    position: absolute;
    border-radius: 50%;
    background: rgba(116, 185, 255, 0.15);
    box-shadow: inset 0 0 4px rgba(255, 255, 255, 0.1);
    will-change: transform, opacity;
    animation-name: bubbleRise;
    animation-iteration-count: infinite;
    animation-timing-function: linear;
}
@keyframes bubbleRise {
    0%   { transform: translate3d(0, 0, 0) scale(0.9); opacity: 0; }
    8%   { opacity: 1; }
    50%  { transform: translate3d(8px, -50vh, 0) scale(1); }
    92%  { opacity: 1; }
    100% { transform: translate3d(-6px, -110vh, 0) scale(0.85); opacity: 0; }
}

/* --------------------------------------------------------------------------
   Click ripple stage
   -------------------------------------------------------------------------- */
.ripple-stage {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 40;
    overflow: hidden;
}
.click-ripple {
    position: absolute;
    width: 14px;
    height: 14px;
    border: 1px solid var(--shallow);
    border-radius: 50%;
    transform: translate(-50%, -50%) scale(1);
    opacity: 0.85;
    animation: clickRipple 1400ms var(--ease-stone) forwards;
}
.click-ripple.r2 { animation-delay: 120ms; opacity: 0.6; }
.click-ripple.r3 { animation-delay: 240ms; opacity: 0.4; }
@keyframes clickRipple {
    0%   { transform: translate(-50%, -50%) scale(0.4); opacity: 0.9; }
    100% { transform: translate(-50%, -50%) scale(28); opacity: 0; }
}

/* --------------------------------------------------------------------------
   Stratum rail — fixed left navigation
   -------------------------------------------------------------------------- */
.stratum-rail {
    position: fixed;
    top: 50%;
    left: 24px;
    transform: translateY(-50%);
    z-index: 60;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}
.stratum-rail ol {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.stratum-rail li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--wet-stone);
    cursor: pointer;
    transition: color 320ms var(--ease-stone);
}
.stratum-rail .rail-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: transparent;
    border: 1px solid var(--wet-stone);
    transition: background 320ms var(--ease-stone), border-color 320ms var(--ease-stone), transform 320ms var(--ease-stone);
}
.stratum-rail .rail-label {
    opacity: 0;
    transform: translateX(-6px);
    transition: opacity 320ms var(--ease-stone), transform 320ms var(--ease-stone);
}
.stratum-rail li:hover { color: var(--dry-pebble); }
.stratum-rail li:hover .rail-dot { border-color: var(--shallow); }
.stratum-rail li:hover .rail-label,
.stratum-rail li.active .rail-label {
    opacity: 1;
    transform: translateX(0);
}
.stratum-rail li.active .rail-dot {
    background: var(--shallow);
    border-color: var(--shallow);
    transform: scale(1.4);
}
.stratum-rail li.active { color: var(--dry-pebble); }

/* --------------------------------------------------------------------------
   Layer base
   -------------------------------------------------------------------------- */
.layer {
    position: relative;
    min-height: 100vh;
    padding: clamp(4rem, 9vh, 8rem) clamp(1.5rem, 8vw, 8rem) clamp(6rem, 12vh, 10rem) clamp(4rem, 12vw, 12rem);
    scroll-snap-align: start;
    overflow: hidden;
    isolation: isolate;
}

.layer-meta {
    display: inline-flex;
    align-items: baseline;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--wet-stone);
    margin-bottom: clamp(1.5rem, 3vh, 2.5rem);
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 900ms var(--ease-stone), transform 900ms var(--ease-stone);
}
.layer.in-view .layer-meta { opacity: 1; transform: translateY(0); }

.layer-meta .stratum-depth { color: var(--shallow); letter-spacing: 0.14em; }
.layer-meta.light { color: rgba(45, 52, 54, 0.6); }
.layer-meta.light .stratum-depth { color: var(--agate); }

.layer-title {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: clamp(2.5rem, 7vw, 7rem);
    line-height: 1.02;
    letter-spacing: -0.03em;
    color: var(--dry-pebble);
    max-width: 22ch;
    margin-bottom: clamp(1.4rem, 3vh, 2.4rem);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 1100ms var(--ease-stone) 80ms, transform 1100ms var(--ease-stone) 80ms;
}
.layer-title em {
    font-style: italic;
    color: var(--shallow);
    font-weight: 400;
}
.layer-title.light { color: var(--slate); }
.layer-title.light em { color: var(--agate); }
.layer-title.small { font-size: clamp(1.8rem, 4.2vw, 4rem); }
.layer.in-view .layer-title { opacity: 1; transform: translateY(0); }

.layer-lede {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1rem, 1.4vw, 1.2rem);
    line-height: 1.7;
    color: rgba(99, 110, 114, 0.95);
    max-width: 52ch;
    margin-bottom: clamp(2rem, 4vh, 3.5rem);
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 1100ms var(--ease-stone) 200ms, transform 1100ms var(--ease-stone) 200ms;
}
.layer.in-view .layer-lede { opacity: 1; transform: translateY(0); }

/* --------------------------------------------------------------------------
   Diagonal erosion seams between sections
   -------------------------------------------------------------------------- */
.diagonal-seam {
    position: absolute;
    left: -2vw;
    right: -2vw;
    bottom: -1px;
    height: 60px;
    pointer-events: none;
    z-index: 4;
}
.diagonal-seam::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(to bottom, transparent 0%, transparent 50%, var(--charcoal) 50%, var(--charcoal) 54%, transparent 54%);
    clip-path: polygon(0 0, 100% var(--seam-angle, 6%), 100% 100%, 0 100%);
}
.diagonal-seam::after {
    content: "";
    position: absolute;
    left: 0; right: 0; bottom: 0;
    height: 4px;
    background-image:
        url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='4'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix type='matrix' values='0 0 0 0 0.55  0 0 0 0 0.6  0 0 0 0 0.62  0 0 0 0.7 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
    opacity: 0.55;
    clip-path: polygon(0 0, 100% 60%, 100% 100%, 0 40%);
}
.diagonal-seam.alt::before { clip-path: polygon(0 var(--seam-angle, 6%), 100% 0, 100% 100%, 0 100%); }
.diagonal-seam.alt::after { clip-path: polygon(0 60%, 100% 0, 100% 40%, 0 100%); }

/* --------------------------------------------------------------------------
   LAYER 1 — Hero / Deep Pool
   -------------------------------------------------------------------------- */
.layer-hero {
    background: radial-gradient(120% 90% at 50% 60%, #122a6b 0%, var(--deep-pool) 55%, #06163f 100%);
    color: var(--dry-pebble);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-left: clamp(1rem, 8vw, 8rem);
    padding-right: clamp(1rem, 8vw, 8rem);
}

.hero-ripple-set {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    z-index: 1;
}
.hero-ripple {
    position: absolute;
    width: 10vmin;
    height: 10vmin;
    border: 1px solid rgba(116, 185, 255, 0.6);
    border-radius: 50%;
    opacity: 0;
    animation: heroRipple 6s var(--ease-stone) infinite;
    animation-delay: 1.5s;
}
.hero-ripple:nth-child(2) { animation-delay: 3.0s; border-color: rgba(116, 185, 255, 0.4); }
.hero-ripple:nth-child(3) { animation-delay: 4.5s; border-color: rgba(255, 234, 167, 0.25); }
@keyframes heroRipple {
    0%   { transform: scale(0.4); opacity: 0; }
    20%  { opacity: 0.9; }
    100% { transform: scale(22); opacity: 0; }
}

.hero-pebbles { position: absolute; inset: 0; pointer-events: none; z-index: 0; opacity: 0.25; }
.bg-pebble {
    position: absolute;
    background: radial-gradient(circle at 35% 30%, #74b9ff, #0c2461 75%);
    filter: blur(28px);
}
.bp1 { width: 50vmin; height: 38vmin; left: -10%; top: 10%;  border-radius: 60% 40% 55% 45% / 50% 60% 40% 50%; animation: drift 60s linear infinite; }
.bp2 { width: 38vmin; height: 30vmin; right: -8%; top: 55%;  border-radius: 55% 45% 60% 40% / 60% 50% 50% 40%; animation: drift 48s linear infinite reverse; }
.bp3 { width: 30vmin; height: 24vmin; left:  35%; bottom: -8%; border-radius: 50% 60% 40% 55% / 45% 55% 50% 60%; animation: drift 72s linear infinite; }
@keyframes drift {
    0%   { transform: rotate(0deg)   translate(0,0); }
    50%  { transform: rotate(180deg) translate(2vw, -1vw); }
    100% { transform: rotate(360deg) translate(0,0); }
}

.hero-content {
    position: relative;
    z-index: 5;
    max-width: 920px;
    width: 100%;
}
.meta-coord {
    display: block;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: rgba(116, 185, 255, 0.7);
    margin-bottom: clamp(2rem, 4vh, 4rem);
    opacity: 0;
    animation: fadeIn 1.6s var(--ease-stone) 0.8s forwards;
}

.wordmark {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: clamp(3.5rem, 14vw, 12rem);
    letter-spacing: -0.03em;
    line-height: 1;
    color: var(--dry-pebble);
    display: inline-flex;
    justify-content: center;
    margin-bottom: clamp(1.4rem, 3vh, 2.6rem);
}
.wordmark .ch {
    display: inline-block;
    opacity: 0;
    transform: translateY(28px);
    animation: charDrop 1100ms var(--ease-stone) forwards;
}
.wordmark .ch:nth-child(1) { animation-delay: 2.0s; }
.wordmark .ch:nth-child(2) { animation-delay: 2.12s; }
.wordmark .ch:nth-child(3) { animation-delay: 2.24s; }
.wordmark .ch:nth-child(4) { animation-delay: 2.36s; }
.wordmark .ch:nth-child(5) { animation-delay: 2.48s; }
.wordmark .ch:nth-child(6) { animation-delay: 2.60s; }
@keyframes charDrop {
    0%   { opacity: 0; transform: translateY(28px); }
    60%  { opacity: 1; transform: translateY(-3px); }
    100% { opacity: 1; transform: translateY(0); }
}

.hero-rule {
    width: clamp(180px, 28vw, 480px);
    height: 4px;
    margin: 0 auto clamp(1.4rem, 3vh, 2.2rem);
    overflow: visible;
}
#heroRulePath {
    stroke-dasharray: 600;
    stroke-dashoffset: 600;
    animation: drawRule 1600ms var(--ease-stone) 3.4s forwards;
}
@keyframes drawRule { to { stroke-dashoffset: 0; } }

.hero-sub {
    font-family: var(--font-body);
    font-weight: 300;
    font-size: clamp(1rem, 1.4vw, 1.2rem);
    line-height: 1.7;
    color: rgba(223, 230, 233, 0.78);
    max-width: 36ch;
    margin: 0 auto clamp(2.2rem, 5vh, 3.8rem);
    opacity: 0;
    animation: fadeIn 1.6s var(--ease-stone) 4.0s forwards;
}

.hero-scroll-hint {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: rgba(116, 185, 255, 0.55);
    opacity: 0;
    animation: fadeIn 1.6s var(--ease-stone) 4.6s forwards, scrollHintBob 3.8s ease-in-out infinite 5s;
}
@keyframes fadeIn { to { opacity: 1; } }
@keyframes scrollHintBob {
    0%, 100% { transform: translateY(0); opacity: 0.55; }
    50%      { transform: translateY(6px); opacity: 0.95; }
}

/* --------------------------------------------------------------------------
   LAYER 2 — Cairn / stacked architecture
   -------------------------------------------------------------------------- */
.layer-cairn {
    background:
        radial-gradient(50% 80% at 110% 0%, rgba(225, 112, 85, 0.07), transparent 70%),
        linear-gradient(180deg, #1d2326 0%, var(--slate) 100%);
}

.cairn-stack {
    position: relative;
    margin-top: clamp(2rem, 4vh, 3rem);
    display: flex;
    flex-direction: column;
    gap: clamp(1.2rem, 2.4vh, 2rem);
    perspective: 1400px;
}
.cairn-block {
    position: relative;
    background: linear-gradient(170deg, rgba(99, 110, 114, 0.16) 0%, rgba(45, 52, 54, 0.55) 100%);
    border: 1px solid rgba(223, 230, 233, 0.08);
    border-radius: clamp(16px, 3vw, 48px);
    padding: clamp(1.6rem, 3.4vw, 2.6rem) clamp(1.6rem, 4vw, 3.2rem);
    box-shadow:
        inset 0 1px 0 rgba(223, 230, 233, 0.04),
        0 30px 80px -40px rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(2px);
    will-change: transform;
    transition: transform 600ms var(--ease-stone), box-shadow 600ms var(--ease-stone);
    opacity: 0;
    transform: translateY(36px);
}
.layer.in-view .cairn-block { opacity: 1; transform: translateY(0); }
.layer.in-view .cb1 { transition: opacity 1100ms var(--ease-stone) 200ms, transform 1100ms var(--ease-stone) 200ms; }
.layer.in-view .cb2 { transition: opacity 1100ms var(--ease-stone) 360ms, transform 1100ms var(--ease-stone) 360ms; }
.layer.in-view .cb3 { transition: opacity 1100ms var(--ease-stone) 520ms, transform 1100ms var(--ease-stone) 520ms; }
.layer.in-view .cb4 { transition: opacity 1100ms var(--ease-stone) 680ms, transform 1100ms var(--ease-stone) 680ms; }

.cb1 { width: 78%; margin-left: 5vw;  margin-right: auto; }
.cb2 { width: 64%; margin-left: auto; margin-right: 5vw; }
.cb3 { width: 70%; margin-left: 8vw;  margin-right: auto; }
.cb4 { width: 56%; margin-left: auto; margin-right: 8vw; }

.block-label {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    color: var(--shallow);
    margin-bottom: 14px;
}
.block-text {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.3vw, 1.15rem);
    line-height: 1.75;
    color: rgba(223, 230, 233, 0.82);
    max-width: 56ch;
}

.contour-wrap {
    margin-top: 22px;
    height: 80px;
    overflow: hidden;
}
.contour-svg { width: 100%; height: 100%; }
.contour-path {
    fill: none;
    stroke: var(--wet-stone);
    stroke-width: 0.6;
    stroke-opacity: 0.5;
    stroke-dasharray: 1200;
    stroke-dashoffset: 1200;
    transition: stroke-dashoffset 2200ms var(--ease-stone);
}
.layer.in-view .contour-path { stroke-dashoffset: 0; }

.cairn-illustration {
    position: relative;
    margin-top: 20px;
    height: 110px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 0;
}
.cairn-illustration::before,
.cairn-illustration::after,
.cairn-illustration > .ill-stone {
    content: "";
    display: block;
    background: radial-gradient(circle at 35% 28%, var(--dry-pebble), var(--wet-stone) 65%, var(--slate));
    box-shadow: inset -4px -4px 8px rgba(0,0,0,0.3);
}
.cairn-illustration::before {
    width: 76px; height: 28px;
    border-radius: 60% 40% 55% 45% / 70% 70% 30% 30%;
    margin-bottom: -2px;
    transform: translateX(-3px);
    z-index: 1;
}
.cairn-illustration::after {
    width: 54px; height: 22px;
    border-radius: 55% 45% 60% 40% / 60% 70% 30% 40%;
    background: radial-gradient(circle at 35% 28%, var(--sand-foam), var(--agate) 70%, #6b2f20);
    margin-bottom: -1px;
    transform: translate(2px, -22px);
    z-index: 3;
}
.cairn-illustration .ill-stone {
    position: absolute;
    width: 64px; height: 24px;
    border-radius: 50% 60% 45% 55% / 65% 65% 35% 35%;
    background: radial-gradient(circle at 35% 28%, var(--shallow), var(--deep-pool) 75%);
    bottom: 22px;
    z-index: 2;
}

/* --------------------------------------------------------------------------
   LAYER 3 — Strata / sediment bands
   -------------------------------------------------------------------------- */
.layer-strata {
    background: linear-gradient(180deg, var(--dry-pebble) 0%, #c8d2d6 100%);
    color: var(--slate);
}
.layer-strata .layer-lede { color: rgba(45, 52, 54, 0.75); }

.strata-figure {
    position: relative;
    margin-top: clamp(2rem, 4vh, 3rem);
    border-radius: clamp(16px, 3vw, 32px);
    overflow: hidden;
    box-shadow: 0 30px 80px -40px rgba(0,0,0,0.4);
    border: 1px solid rgba(45, 52, 54, 0.12);
}
.strata-band {
    position: relative;
    height: clamp(46px, 7vh, 76px);
    display: flex;
    align-items: center;
    padding: 0 clamp(1rem, 2.4vw, 2rem);
    border-bottom: 0.5px solid rgba(0,0,0,0.18);
    transform: translateX(-30px);
    opacity: 0;
    transition: transform 1100ms var(--ease-stone), opacity 1100ms var(--ease-stone);
}
.layer.in-view .strata-band { transform: translateX(0); opacity: 1; }
.layer.in-view .strata-band.band-a { transition-delay: 100ms; }
.layer.in-view .strata-band.band-b { transition-delay: 200ms; }
.layer.in-view .strata-band.band-c { transition-delay: 300ms; }
.layer.in-view .strata-band.band-d { transition-delay: 400ms; }
.layer.in-view .strata-band.band-e { transition-delay: 500ms; }
.layer.in-view .strata-band.band-f { transition-delay: 600ms; }
.layer.in-view .strata-band.band-g { transition-delay: 700ms; }

.band-a { background: #c5cdd1; color: var(--slate); }
.band-b { background: #a4adb1; color: var(--slate); }
.band-c { background: var(--wet-stone); color: var(--dry-pebble); }
.band-d { background: var(--charcoal); color: var(--dry-pebble); }
.band-e {
    background:
        repeating-linear-gradient(90deg, rgba(225,112,85,0.18) 0 22px, transparent 22px 44px),
        var(--slate);
    color: var(--sand-foam);
}
.band-f { background: #1f2528; color: var(--dry-pebble); }
.band-g {
    background:
        radial-gradient(120% 140% at 30% 50%, rgba(116,185,255,0.12), transparent 60%),
        #0e1316;
    color: var(--shallow);
    height: clamp(64px, 9vh, 100px);
}

.band-tag {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
}

/* --------------------------------------------------------------------------
   LAYER 4 — Tidal split-screen
   -------------------------------------------------------------------------- */
.layer-tidal {
    background:
        radial-gradient(80% 60% at 0% 100%, rgba(106, 176, 76, 0.08), transparent 60%),
        radial-gradient(70% 60% at 100% 0%, rgba(225, 112, 85, 0.08), transparent 60%),
        var(--slate);
}

.tidal-split {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 12px 1fr;
    column-gap: 0;
    align-items: center;
    margin-top: clamp(1.5rem, 4vh, 3rem);
    min-height: 60vh;
    transition: column-gap 1400ms var(--ease-stone);
}
.layer.in-view .tidal-split { column-gap: 2vw; }

.tidal-pane {
    padding: clamp(1.4rem, 3vw, 2.4rem);
    opacity: 0;
    transition: opacity 1400ms var(--ease-stone) 300ms, transform 1400ms var(--ease-stone) 300ms;
}
.tidal-text  { transform: translateX(-50px); }
.tidal-visual { transform: translateX(50px); }
.layer.in-view .tidal-pane { opacity: 1; transform: translateX(0); }

.tidal-paragraph {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.3vw, 1.15rem);
    line-height: 1.8;
    color: rgba(223, 230, 233, 0.82);
    margin-bottom: 1.2rem;
    max-width: 50ch;
}
.tidal-cite {
    display: inline-block;
    margin-top: 0.6rem;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--shallow);
}

.tidal-divider {
    position: relative;
    width: 12px;
    height: 100%;
    min-height: 60vh;
    display: flex;
    align-items: stretch;
    justify-content: center;
}
.tidal-ripple-svg { width: 100%; height: 100%; }
.tidal-ripple-path {
    stroke-dasharray: 1400;
    stroke-dashoffset: 1400;
    transition: stroke-dashoffset 2600ms var(--ease-stone) 600ms;
    animation: ripplePulse 5s ease-in-out infinite;
}
.tidal-ripple-path.delay { transition-delay: 900ms; animation-delay: 1.4s; }
.layer.in-view .tidal-ripple-path { stroke-dashoffset: 0; }
@keyframes ripplePulse {
    0%, 100% { stroke-opacity: 1; }
    50%      { stroke-opacity: 0.35; }
}

.tidal-stone-cluster {
    position: relative;
    width: 100%;
    aspect-ratio: 5 / 4;
    max-width: 560px;
    margin-left: auto;
    margin-right: 0;
}
.tidal-stone-cluster .ripple-anchor {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 18px;
    height: 18px;
    border: 1px solid var(--shallow);
    border-radius: 50%;
    transform: translate(-50%, -50%) scale(1);
    animation: anchorRipple 4s var(--ease-stone) infinite;
}
@keyframes anchorRipple {
    0%   { transform: translate(-50%, -50%) scale(0.5); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(20); opacity: 0; }
}
.organic-pebble { position: absolute; transition: transform 700ms var(--ease-stone); }
.organic-pebble.big   { width: 70%;  left: 5%;  top: 18%; animation: stoneFloat 14s ease-in-out infinite; }
.organic-pebble.mid   { width: 45%;  right: 8%; top: 8%;  animation: stoneFloat 17s ease-in-out infinite -3s; }
.organic-pebble.small { width: 32%;  left: 32%; bottom: 6%; animation: stoneFloat 11s ease-in-out infinite -6s; }
@keyframes stoneFloat {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    50%      { transform: translate(6px, -8px) rotate(2deg); }
}

/* --------------------------------------------------------------------------
   LAYER 5 — Bento specimen grid
   -------------------------------------------------------------------------- */
.layer-specimen {
    background: linear-gradient(180deg, #c8d2d6 0%, var(--dry-pebble) 100%);
    color: var(--slate);
}
.layer-specimen .layer-lede { color: rgba(45, 52, 54, 0.75); }

.bento-grid {
    margin-top: clamp(2rem, 4vh, 3rem);
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: 180px 180px 180px;
    gap: clamp(10px, 1.4vw, 18px);
    grid-template-areas:
        "a a b c"
        "a a d c"
        "e f f g";
}
.bento {
    position: relative;
    background: rgba(255, 255, 255, 0.45);
    border: 1px solid rgba(45, 52, 54, 0.12);
    border-radius: clamp(14px, 2vw, 22px);
    padding: clamp(0.9rem, 1.6vw, 1.4rem);
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.12);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 600ms var(--ease-stone), box-shadow 600ms var(--ease-stone);
    opacity: 0;
    transform: translateY(20px);
}
.layer.in-view .bento { opacity: 1; transform: translateY(0); }
.layer.in-view .bento-a { transition: opacity 1000ms var(--ease-stone) 100ms, transform 1000ms var(--ease-stone) 100ms; }
.layer.in-view .bento-b { transition: opacity 1000ms var(--ease-stone) 200ms, transform 1000ms var(--ease-stone) 200ms; }
.layer.in-view .bento-c { transition: opacity 1000ms var(--ease-stone) 300ms, transform 1000ms var(--ease-stone) 300ms; }
.layer.in-view .bento-d { transition: opacity 1000ms var(--ease-stone) 400ms, transform 1000ms var(--ease-stone) 400ms; }
.layer.in-view .bento-e { transition: opacity 1000ms var(--ease-stone) 500ms, transform 1000ms var(--ease-stone) 500ms; }
.layer.in-view .bento-f { transition: opacity 1000ms var(--ease-stone) 600ms, transform 1000ms var(--ease-stone) 600ms; }
.layer.in-view .bento-g { transition: opacity 1000ms var(--ease-stone) 700ms, transform 1000ms var(--ease-stone) 700ms; }

.bento:hover {
    transform: translateY(-3px);
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.12), 0 12px 30px -10px rgba(0,0,0,0.2);
}

.bento-a { grid-area: a; background: linear-gradient(160deg, rgba(225, 112, 85, 0.14), rgba(255,234,167,0.18)); }
.bento-b { grid-area: b; }
.bento-c {
    grid-area: c;
    background: linear-gradient(170deg, var(--deep-pool), #1d3680);
    color: var(--dry-pebble);
    border-color: rgba(116, 185, 255, 0.25);
}
.bento-d { grid-area: d; background: linear-gradient(150deg, rgba(106, 176, 76, 0.12), rgba(255,255,255,0.5)); }
.bento-e { grid-area: e; }
.bento-f { grid-area: f; background: linear-gradient(150deg, rgba(99, 110, 114, 0.18), rgba(255,255,255,0.4)); }
.bento-g { grid-area: g; }

.bento-tag {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.24em;
    text-transform: uppercase;
    color: var(--wet-stone);
}
.bento-c .bento-tag { color: var(--shallow); }

.bento-word {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.6rem);
    line-height: 1;
    letter-spacing: -0.02em;
    color: var(--slate);
}
.bento-c .bento-word { color: var(--dry-pebble); }
.bento-word.large { font-size: clamp(2rem, 4.4vw, 3.4rem); }
.bento-word.small {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--wet-stone);
}

.bento-note {
    font-family: var(--font-body);
    font-size: 13px;
    line-height: 1.55;
    color: rgba(223, 230, 233, 0.82);
    max-width: 22ch;
}
.bento-a .bento-note,
.bento-f .bento-note { color: rgba(45, 52, 54, 0.7); }

.bento-pebble {
    width: 80%;
    margin-left: auto;
    margin-top: auto;
    filter: drop-shadow(0 6px 12px rgba(0,0,0,0.18));
}

.bento-swatch {
    width: 100%;
    height: 60%;
    border-radius: 12px;
    box-shadow: inset 0 2px 6px rgba(0,0,0,0.25);
}

/* --------------------------------------------------------------------------
   LAYER 6 — Erosion / time scale rows
   -------------------------------------------------------------------------- */
.layer-erosion {
    background:
        radial-gradient(60% 50% at 100% 0%, rgba(116, 185, 255, 0.06), transparent 60%),
        var(--slate);
}

.erosion-rows {
    margin-top: clamp(2rem, 4vh, 3rem);
    display: flex;
    flex-direction: column;
    gap: clamp(0.8rem, 1.6vh, 1.2rem);
    max-width: 1100px;
}
.erosion-row {
    display: grid;
    grid-template-columns: 80px 1fr 1.4fr;
    align-items: center;
    gap: clamp(1rem, 2.4vw, 2rem);
    padding: 0.8rem 0;
    border-bottom: 1px dashed rgba(99, 110, 114, 0.35);
}
.erosion-time {
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: 0.18em;
    color: var(--shallow);
}
.erosion-track {
    position: relative;
    height: 6px;
    background: rgba(99, 110, 114, 0.25);
    border-radius: 3px;
    overflow: hidden;
}
.erosion-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--deep-pool) 0%, var(--shallow) 60%, var(--sand-foam) 100%);
    border-radius: 3px;
    transition: width 2400ms var(--ease-stone);
}
.erosion-note {
    font-family: var(--font-body);
    font-style: italic;
    font-size: clamp(0.95rem, 1.2vw, 1.05rem);
    color: rgba(223, 230, 233, 0.7);
}

/* --------------------------------------------------------------------------
   LAYER 7 — Basin / footer
   -------------------------------------------------------------------------- */
.layer-basin {
    background:
        radial-gradient(80% 60% at 50% 100%, rgba(116,185,255,0.10), transparent 70%),
        linear-gradient(180deg, var(--slate) 0%, #0e1517 100%);
    text-align: center;
    padding-left: clamp(1rem, 6vw, 6rem);
    padding-right: clamp(1rem, 6vw, 6rem);
}
.basin-inner {
    max-width: 800px;
    margin: 0 auto;
}
.basin-cairn {
    position: relative;
    width: clamp(220px, 28vw, 320px);
    height: clamp(220px, 30vh, 320px);
    margin: 0 auto clamp(2rem, 4vh, 3rem);
}
.basin-cairn svg {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}
.basin-p1 { width: 100%; bottom: 0; }
.basin-p2 { width: 78%; bottom: 22%; }
.basin-p3 { width: 56%; bottom: 46%; }
.basin-p4 { width: 36%; bottom: 70%; }

.basin-h {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: clamp(1.8rem, 4vw, 3.2rem);
    line-height: 1.1;
    color: var(--dry-pebble);
    margin-bottom: 1.2rem;
    letter-spacing: -0.02em;
}
.basin-h em { font-style: italic; color: var(--shallow); }

.basin-text {
    font-size: clamp(1rem, 1.3vw, 1.1rem);
    color: rgba(223, 230, 233, 0.78);
    max-width: 50ch;
    margin: 0 auto 2rem;
}

.basin-meta {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--wet-stone);
}
.basin-meta-dot { color: rgba(116,185,255,0.5); }

.basin-rule {
    width: 80px;
    height: 1px;
    background: var(--wet-stone);
    margin: 2.5rem auto;
}

.basin-footer {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--wet-stone);
}
.basin-footer .footer-mark {
    font-family: var(--font-display);
    font-size: 14px;
    letter-spacing: 0.04em;
    color: var(--dry-pebble);
}

/* --------------------------------------------------------------------------
   Tilt-3d helper class
   -------------------------------------------------------------------------- */
.tilt-3d {
    transform-style: preserve-3d;
    transform: perspective(900px) rotateX(var(--rotX, 0deg)) rotateY(var(--rotY, 0deg));
}

/* --------------------------------------------------------------------------
   Selection / scrollbar
   -------------------------------------------------------------------------- */
::selection { background: var(--shallow); color: var(--deep-pool); }
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #1a1f22; }
::-webkit-scrollbar-thumb { background: var(--wet-stone); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--shallow); }

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
    .layer { padding-left: clamp(1.5rem, 8vw, 4rem); padding-right: clamp(1.5rem, 6vw, 4rem); }
    .stratum-rail { left: 12px; }
    .cb1, .cb2, .cb3, .cb4 { width: 92%; margin-left: auto; margin-right: auto; }
    .tidal-split {
        grid-template-columns: 1fr;
        grid-template-rows: auto 18px auto;
        column-gap: 0;
    }
    .tidal-divider {
        width: 100%;
        height: 18px;
        min-height: 18px;
        transform: rotate(90deg);
    }
    .tidal-ripple-svg { transform: rotate(0deg); }
    .bento-grid {
        grid-template-columns: repeat(2, 1fr);
        grid-template-rows: repeat(5, 160px);
        grid-template-areas:
            "a a"
            "b c"
            "d c"
            "e f"
            "g f";
    }
    .erosion-row {
        grid-template-columns: 60px 1fr;
        grid-template-rows: auto auto;
    }
    .erosion-note { grid-column: 1 / -1; }
}

@media (max-width: 560px) {
    .stratum-rail { display: none; }
    .layer { padding: 4rem 1.4rem 5rem; }
    .layer-title { font-size: clamp(2rem, 9vw, 3.4rem); }
    .basin-footer { justify-content: center; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
    .wordmark .ch { opacity: 1; transform: none; }
}