/* ============================================================
   tanso.wiki — Crystallographic Atlas of Carbon
   Dark-academia × isometric × crystalline
   ============================================================ */

:root {
    /* Carbon spectrum palette */
    --anthracite: #0D0D0D;
    --charcoal: #1A1816;
    --bituminous: #2A2622;
    --bone: #E8E4DD;
    --graphite: #B8B0A4;
    --burgundy: #6B2D3E;
    --lichen: #7A8B6F;
    --amber: #C4A882;
    --diamond: #4A6670;

    /* Typography */
    --font-display: "Space Grotesk", "Inter", system-ui, sans-serif;
    --font-body: "IBM Plex Sans", "Inter", sans-serif;
    --font-mono: "IBM Plex Mono", "Courier New", monospace;
    --font-serif: "Cormorant Garamond", "Lora", Georgia, serif;

    /* Phase tokens (driven by IntersectionObserver) */
    --phase-bg: var(--anthracite);
    --phase-fg: var(--bone);
    --phase-accent: var(--diamond);
    --phase-warmth: 0;

    /* Hex clip-path (pointy-top) */
    --hex-clip: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
}

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

html, body {
    background: var(--anthracite);
    color: var(--bone);
    font-family: var(--font-body);
    font-size: 17px;
    line-height: 1.65;
    overflow-x: hidden;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    min-height: 100vh;
    background:
        radial-gradient(ellipse at 30% 0%, rgba(107, 45, 62, 0.14) 0%, transparent 55%),
        radial-gradient(ellipse at 80% 100%, rgba(74, 102, 112, 0.12) 0%, transparent 55%),
        var(--anthracite);
    transition: background-color 0.6s ease;
}

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

/* ------------------------------------------------------------
   Charcoal grain overlay (turbulence noise via SVG)
   ------------------------------------------------------------ */
.grain-overlay {
    position: fixed;
    inset: 0;
    z-index: 1;
    pointer-events: none;
    opacity: 0.55;
    mix-blend-mode: overlay;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='220' height='220'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='4' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.05  0 0 0 0 0.05  0 0 0 0 0.05  0 0 0 0.4 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
    background-size: 220px 220px;
}

/* ------------------------------------------------------------
   Crystallographic axis navigation
   ------------------------------------------------------------ */
.axis-nav {
    position: fixed;
    left: 36px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 50;
    pointer-events: none;
}

.axis-line {
    position: absolute;
    left: 5px;
    top: 0;
    bottom: 0;
    width: 1px;
    background: linear-gradient(
        to bottom,
        transparent 0%,
        var(--diamond) 12%,
        var(--diamond) 88%,
        transparent 100%
    );
    opacity: 0.5;
}

.axis-markers {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 56px;
    pointer-events: auto;
}

.axis-marker {
    position: relative;
    display: flex;
    align-items: center;
    gap: 18px;
    cursor: pointer;
    color: var(--graphite);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    transition: color 0.3s ease;
}

.marker-dot {
    width: 11px;
    height: 11px;
    border: 1px solid var(--diamond);
    background: var(--anthracite);
    transform: rotate(45deg);
    transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

.marker-label {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--graphite);
    transition: color 0.3s ease;
    min-width: 36px;
}

.marker-label sub, .marker-label sup {
    font-size: 8px;
}

.marker-name {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.18em;
    color: rgba(184, 176, 164, 0.45);
    transition: color 0.3s ease, letter-spacing 0.3s ease;
}

.axis-marker.is-active .marker-dot {
    background: var(--amber);
    border-color: var(--amber);
    box-shadow: 0 0 14px rgba(196, 168, 130, 0.55);
}

.axis-marker.is-active .marker-label,
.axis-marker.is-active .marker-name {
    color: var(--bone);
}

.axis-marker:hover {
    color: var(--bone);
}

.axis-marker:hover .marker-dot {
    border-color: var(--amber);
}

/* ------------------------------------------------------------
   Masthead
   ------------------------------------------------------------ */
.masthead {
    position: fixed;
    top: 28px;
    right: 36px;
    z-index: 50;
    text-align: right;
    pointer-events: none;
}

.masthead-inner {
    display: inline-flex;
    align-items: baseline;
    gap: 14px;
    margin-bottom: 8px;
}

.masthead-mark {
    font-family: "Cormorant Garamond", "Lora", serif;
    font-size: 28px;
    font-weight: 300;
    color: var(--amber);
    line-height: 1;
}

.masthead-title {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 16px;
    letter-spacing: 0.06em;
    color: var(--bone);
}

.masthead-meta {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.meta-line {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--lichen);
}

.meta-line:nth-child(2) {
    color: var(--graphite);
    opacity: 0.65;
}

/* ------------------------------------------------------------
   Phase sections
   ------------------------------------------------------------ */
.allotrope-stack {
    position: relative;
    z-index: 5;
}

.phase {
    position: relative;
    min-height: 100vh;
    padding: 12vh 8vw 12vh 12vw;
    overflow: hidden;
    transition: background-color 1s ease, color 1s ease;
}

.phase-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.phase-inner {
    position: relative;
    z-index: 2;
    max-width: 1280px;
    margin: 0 auto;
}

.phase-epigraph {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-bottom: 36px;
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 300;
    font-size: 19px;
    color: var(--amber);
    letter-spacing: 0.01em;
    max-width: 720px;
}

.epigraph-rule {
    flex-shrink: 0;
    width: 64px;
    height: 1px;
    background: var(--amber);
    opacity: 0.5;
}

.phase-heading-block {
    margin-bottom: 80px;
    max-width: 820px;
}

.phase-formula {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--lichen);
    margin-bottom: 22px;
}

.phase-heading {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: clamp(56px, 9vw, 128px);
    letter-spacing: 0.02em;
    line-height: 1.04;
    color: var(--bone);
    margin-bottom: 28px;
}

.phase-heading--xl {
    font-size: clamp(72px, 14vw, 220px);
    font-weight: 300;
    letter-spacing: -0.02em;
}

.phase-lede {
    font-family: var(--font-body);
    font-size: 19px;
    line-height: 1.65;
    color: var(--graphite);
    max-width: 640px;
}

/* ============================================================
   SECTION 1 · ATMOSPHERE
   ============================================================ */
.phase--atmosphere {
    background: radial-gradient(ellipse at 50% 30%, rgba(122, 139, 111, 0.06) 0%, transparent 60%), var(--anthracite);
}

.atmosphere-haze {
    position: absolute;
    inset: -50px;
    background:
        radial-gradient(circle at 20% 30%, rgba(196, 168, 130, 0.05) 0%, transparent 30%),
        radial-gradient(circle at 80% 70%, rgba(74, 102, 112, 0.06) 0%, transparent 35%),
        radial-gradient(circle at 50% 90%, rgba(107, 45, 62, 0.05) 0%, transparent 40%);
    filter: blur(50px);
    animation: hazeDrift 28s ease-in-out infinite alternate;
}

@keyframes hazeDrift {
    0%   { transform: translate(0, 0) scale(1); }
    100% { transform: translate(-30px, 20px) scale(1.05); }
}

.orbital-bg {
    position: absolute;
    width: 110%;
    height: 110%;
    top: -5%;
    left: -5%;
    opacity: 0.12;
}

.orbital-group ellipse {
    fill: none;
    stroke: var(--burgundy);
    stroke-width: 1;
    transform-origin: 500px 500px;
    animation: orbitalSpin 60s linear infinite;
}

@keyframes orbitalSpin {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

/* Floating hex cards */
.hex-field {
    position: relative;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
    margin-top: 60px;
}

.hex-card {
    position: relative;
    width: 100%;
    aspect-ratio: 1 / 1.1547;
    clip-path: var(--hex-clip);
    background: linear-gradient(135deg, rgba(42, 38, 34, 0.85), rgba(26, 24, 22, 0.92));
    cursor: default;
    transition: transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1), filter 0.4s ease;
    animation: hexDrift 16s ease-in-out infinite alternate;
    animation-delay: calc(var(--drift) * -3.7s);
}

.hex-card::before {
    content: "";
    position: absolute;
    inset: 1px;
    clip-path: var(--hex-clip);
    background: linear-gradient(135deg, var(--bituminous) 0%, var(--charcoal) 100%);
    z-index: 1;
}

.hex-card-inner {
    position: relative;
    z-index: 2;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 18% 16%;
    text-align: center;
}

.hex-card-eyebrow {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--lichen);
    margin-bottom: 12px;
}

.hex-card-title {
    font-family: var(--font-display);
    font-size: clamp(30px, 3.4vw, 46px);
    font-weight: 500;
    color: var(--bone);
    letter-spacing: 0.02em;
    margin-bottom: 10px;
    line-height: 1;
}

.hex-card-title sup {
    font-size: 0.55em;
    color: var(--amber);
}

.hex-card-body {
    font-family: var(--font-body);
    font-size: 13px;
    line-height: 1.5;
    color: var(--graphite);
    margin-bottom: 12px;
}

.hex-card-meta {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--amber);
    opacity: 0.7;
}

.hex-card:hover {
    transform: translateY(-6px) scale(1.02);
    filter: brightness(1.18);
}

@keyframes hexDrift {
    0%   { transform: translateY(0) translateX(0); }
    50%  { transform: translateY(-12px) translateX(6px); }
    100% { transform: translateY(8px) translateX(-4px); }
}

/* ============================================================
   SECTION 2 · GRAPHITE
   ============================================================ */
.phase--graphite {
    background: linear-gradient(180deg, var(--anthracite) 0%, var(--charcoal) 50%, var(--anthracite) 100%);
}

.phase-bg--graphite {
    perspective: 1200px;
}

.graphite-layer {
    position: absolute;
    left: -10%;
    width: 130%;
    height: 240px;
    background-image:
        repeating-linear-gradient(
            90deg,
            transparent 0,
            transparent 38px,
            rgba(184, 176, 164, 0.05) 38px,
            rgba(184, 176, 164, 0.05) 39px,
            transparent 39px,
            transparent 78px
        ),
        linear-gradient(180deg, transparent 0%, rgba(74, 102, 112, 0.06) 50%, transparent 100%);
    border-top: 1px solid rgba(74, 102, 112, 0.18);
    border-bottom: 1px solid rgba(74, 102, 112, 0.12);
    transform-origin: center;
    will-change: transform;
}

.graphite-layer--1 { top: 18%; }
.graphite-layer--2 { top: 46%; opacity: 0.85; height: 180px; }
.graphite-layer--3 { top: 72%; opacity: 0.7; height: 160px; }

/* Hex grid */
.hex-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    column-gap: 24px;
    row-gap: 14px;
    margin-top: 40px;
    max-width: 1100px;
}

.hex-cell {
    position: relative;
    width: 100%;
    aspect-ratio: 1 / 1.1547;
    clip-path: var(--hex-clip);
    background: linear-gradient(160deg, var(--bituminous) 0%, var(--charcoal) 100%);
    transition: transform 0.5s cubic-bezier(0.22, 0.7, 0.2, 1), filter 0.4s ease;
}

.hex-cell--row2 {
    transform: translateY(50%);
}

.hex-cell::before {
    content: "";
    position: absolute;
    inset: 0;
    clip-path: var(--hex-clip);
    border: 1px solid transparent;
    background:
        linear-gradient(var(--bituminous), var(--bituminous)) padding-box,
        linear-gradient(135deg, rgba(196, 168, 130, 0) 0%, rgba(196, 168, 130, 0) 100%) border-box;
    transition: background 0.3s ease;
    pointer-events: none;
}

.hex-cell-inner {
    position: relative;
    z-index: 2;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 14% 14%;
    text-align: center;
}

.hex-eyebrow {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--lichen);
    margin-bottom: 10px;
}

.hex-title {
    font-family: var(--font-display);
    font-size: clamp(26px, 3vw, 38px);
    font-weight: 500;
    color: var(--bone);
    letter-spacing: 0.02em;
    margin-bottom: 10px;
    line-height: 1.1;
}

.hex-body {
    font-family: var(--font-body);
    font-size: 12.5px;
    line-height: 1.5;
    color: var(--graphite);
    margin-bottom: 10px;
}

.hex-meta {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--amber);
    opacity: 0.75;
}

/* Covalent-bond hover: highlight adjacent siblings */
.hex-cell:hover {
    filter: brightness(1.18);
    transform: translateY(0) scale(1.03);
    z-index: 5;
}

.hex-cell--row2:hover {
    transform: translateY(50%) scale(1.03);
}

.hex-cell:hover::before {
    background:
        linear-gradient(var(--bituminous), var(--bituminous)) padding-box,
        linear-gradient(135deg, var(--amber) 0%, var(--burgundy) 100%) border-box;
    border: 1px solid var(--amber);
}

/* Adjacent edge illumination */
.hex-cell:hover + .hex-cell::before,
.hex-cell:has(+ .hex-cell:hover)::before {
    background:
        linear-gradient(var(--bituminous), var(--bituminous)) padding-box,
        linear-gradient(135deg, rgba(196, 168, 130, 0.5) 0%, rgba(196, 168, 130, 0.2) 100%) border-box;
    border: 1px solid rgba(196, 168, 130, 0.5);
}

/* ============================================================
   SECTION 3 · DIAMOND
   ============================================================ */
.phase--diamond {
    background: linear-gradient(180deg, var(--anthracite) 0%, #14171a 100%);
    color: var(--bone);
}

.phase-bg--diamond {
    background:
        radial-gradient(circle at 70% 40%, rgba(74, 102, 112, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 20% 80%, rgba(196, 168, 130, 0.05) 0%, transparent 50%);
}

.diamond-lattice {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0.18;
}

.lattice-tetra polygon,
.lattice-tetra line {
    fill: none;
    stroke: var(--amber);
    stroke-width: 1;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.lattice-tetra-group {
    transform-origin: 400px 400px;
    animation: latticeRotate 90s linear infinite;
}

@keyframes latticeRotate {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

/* Iso grid */
.iso-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: rgba(74, 102, 112, 0.25);
    border: 1px solid rgba(74, 102, 112, 0.4);
    margin-top: 40px;
}

.iso-cell {
    position: relative;
    background: var(--charcoal);
    aspect-ratio: 1 / 0.85;
    transition: background 0.4s ease;
}

.iso-cell-frame {
    position: relative;
    height: 100%;
    padding: 36px 32px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    border: 1px solid transparent;
    transition: border-color 0.3s ease, background 0.3s ease;
}

.iso-cell:hover .iso-cell-frame {
    border-color: var(--diamond);
    background: linear-gradient(135deg, rgba(74, 102, 112, 0.08) 0%, rgba(196, 168, 130, 0.04) 100%);
}

.iso-cell::before {
    content: "";
    position: absolute;
    top: 8px;
    left: 8px;
    width: 8px;
    height: 8px;
    border-top: 1px solid var(--diamond);
    border-left: 1px solid var(--diamond);
    opacity: 0.55;
}

.iso-cell::after {
    content: "";
    position: absolute;
    bottom: 8px;
    right: 8px;
    width: 8px;
    height: 8px;
    border-bottom: 1px solid var(--diamond);
    border-right: 1px solid var(--diamond);
    opacity: 0.55;
}

.iso-eyebrow {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--diamond);
    margin-bottom: 16px;
}

.iso-title {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: clamp(36px, 4.5vw, 64px);
    letter-spacing: 0.01em;
    color: var(--bone);
    line-height: 1;
    margin-bottom: 14px;
}

.iso-body {
    font-family: var(--font-body);
    font-size: 14px;
    line-height: 1.55;
    color: var(--graphite);
    margin-bottom: 16px;
    flex-grow: 1;
}

.iso-meta {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--amber);
}

/* ============================================================
   SECTION 4 · FULLERENE
   ============================================================ */
.phase--fullerene {
    background:
        radial-gradient(ellipse at 50% 50%, rgba(107, 45, 62, 0.12) 0%, transparent 55%),
        var(--anthracite);
    min-height: 110vh;
}

.fullerene-sphere {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 80vh;
    height: 80vh;
    transform: translate(-50%, -50%);
    opacity: 0.18;
    pointer-events: none;
}

.fullerene-rotor circle,
.fullerene-rotor polygon,
.fullerene-rotor line {
    fill: none;
    stroke: var(--diamond);
    stroke-width: 1;
}

.fullerene-rotor polygon:nth-child(2) { stroke: var(--amber); opacity: 0.7; }
.fullerene-rotor polygon:nth-child(3) { stroke: var(--burgundy); opacity: 0.6; }

.fullerene-rotor {
    transform-origin: center;
    animation: fullereneSpin 120s linear infinite;
}

@keyframes fullereneSpin {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

/* Radial grid */
.radial-grid {
    position: relative;
    width: min(720px, 90%);
    aspect-ratio: 1 / 1;
    margin: 60px auto 0;
}

.radial-cell {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 220px;
    height: 220px;
    margin: -110px 0 0 -110px;
    clip-path: var(--hex-clip);
    background: linear-gradient(160deg, var(--bituminous) 0%, var(--charcoal) 100%);
    transform: rotate(var(--angle)) translateY(-260px) rotate(calc(-1 * var(--angle)));
    transition: filter 0.5s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.radial-cell::before {
    content: "";
    position: absolute;
    inset: 1px;
    clip-path: var(--hex-clip);
    background: linear-gradient(160deg, var(--bituminous) 0%, var(--charcoal) 100%);
    border: 1px solid rgba(196, 168, 130, 0.18);
    z-index: 1;
}

.radial-cell-inner {
    position: relative;
    z-index: 2;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20% 18%;
    text-align: center;
}

.radial-eyebrow {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--lichen);
    margin-bottom: 8px;
}

.radial-title {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: clamp(26px, 2.6vw, 36px);
    color: var(--amber);
    letter-spacing: 0.02em;
    margin-bottom: 8px;
    line-height: 1;
}

.radial-body {
    font-family: var(--font-body);
    font-size: 12px;
    line-height: 1.45;
    color: var(--graphite);
}

.radial-cell:hover {
    filter: brightness(1.25);
    transform: rotate(var(--angle)) translateY(-275px) rotate(calc(-1 * var(--angle))) scale(1.05);
}

/* ============================================================
   SECTION 5 · GRAPHENE
   ============================================================ */
.phase--graphene {
    background: linear-gradient(180deg, var(--anthracite) 0%, #050505 100%);
    min-height: 130vh;
    padding-bottom: 14vh;
}

.phase-bg--graphene {
    background: radial-gradient(ellipse at 50% 60%, rgba(74, 102, 112, 0.08) 0%, transparent 60%);
}

.graphene-sheet {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0.25;
}

.graphene-tess polygon {
    fill: none;
    stroke: var(--diamond);
    stroke-width: 0.6;
    stroke-linejoin: round;
}

.phase-inner--graphene {
    text-align: left;
}

.phase-heading-block--graphene {
    margin-bottom: 100px;
}

.graphene-statement {
    max-width: 820px;
    margin-bottom: 100px;
}

.graphene-line {
    font-family: var(--font-serif);
    font-weight: 300;
    font-style: italic;
    font-size: clamp(20px, 1.9vw, 26px);
    line-height: 1.55;
    color: var(--graphite);
    margin-bottom: 24px;
    opacity: 0;
    transform: translateY(14px);
    transition: opacity 1s ease, transform 1s ease;
}

.graphene-line--4 {
    color: var(--amber);
    font-size: clamp(28px, 3vw, 42px);
    font-style: italic;
    margin-top: 36px;
}

.phase--graphene.is-visible .graphene-line {
    opacity: 1;
    transform: translateY(0);
}

.phase--graphene.is-visible .graphene-line--1 { transition-delay: 0.05s; }
.phase--graphene.is-visible .graphene-line--2 { transition-delay: 0.35s; }
.phase--graphene.is-visible .graphene-line--3 { transition-delay: 0.65s; }
.phase--graphene.is-visible .graphene-line--4 { transition-delay: 0.95s; }

.graphene-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    border-top: 1px solid rgba(74, 102, 112, 0.4);
    border-bottom: 1px solid rgba(74, 102, 112, 0.4);
    padding: 36px 0;
    margin-bottom: 80px;
}

.graphene-stat {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.g-stat-num {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(36px, 4vw, 64px);
    color: var(--bone);
    letter-spacing: 0.01em;
    line-height: 1;
}

.g-stat-label {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--lichen);
}

/* ------------------------------------------------------------
   Phase footer
   ------------------------------------------------------------ */
.phase-footer {
    margin-top: 80px;
    padding-top: 60px;
    border-top: 1px solid rgba(74, 102, 112, 0.25);
    text-align: center;
}

.footer-rule {
    display: inline-block;
    width: 80px;
    height: 1px;
    background: var(--amber);
    opacity: 0.5;
    margin-bottom: 20px;
}

.footer-line {
    font-family: var(--font-serif);
    font-weight: 300;
    font-style: italic;
    font-size: 18px;
    color: var(--graphite);
    margin-bottom: 6px;
}

.footer-line--small {
    font-family: var(--font-mono);
    font-style: normal;
    font-size: 10px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--lichen);
    opacity: 0.7;
}

/* ============================================================
   Phase entry animations (clip-path reveal + opacity)
   ============================================================ */
.phase {
    opacity: 1;
}

.hex-card,
.hex-cell,
.iso-cell,
.radial-cell {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.9s ease, transform 0.9s cubic-bezier(0.2, 0.7, 0.2, 1), filter 0.4s ease;
}

.phase.is-visible .hex-card,
.phase.is-visible .hex-cell,
.phase.is-visible .iso-cell,
.phase.is-visible .radial-cell {
    opacity: 1;
    transform: translateY(0);
}

.phase.is-visible .hex-cell--row2 {
    transform: translateY(50%);
}

.phase.is-visible .radial-cell {
    transform: rotate(var(--angle)) translateY(-260px) rotate(calc(-1 * var(--angle)));
}

/* Stagger by index */
.phase.is-visible .hex-card:nth-child(1),
.phase.is-visible .hex-cell:nth-child(1),
.phase.is-visible .iso-cell:nth-child(1),
.phase.is-visible .radial-cell:nth-child(1) { transition-delay: 0.05s; }
.phase.is-visible .hex-card:nth-child(2),
.phase.is-visible .hex-cell:nth-child(2),
.phase.is-visible .iso-cell:nth-child(2),
.phase.is-visible .radial-cell:nth-child(2) { transition-delay: 0.17s; }
.phase.is-visible .hex-card:nth-child(3),
.phase.is-visible .hex-cell:nth-child(3),
.phase.is-visible .iso-cell:nth-child(3),
.phase.is-visible .radial-cell:nth-child(3) { transition-delay: 0.29s; }
.phase.is-visible .hex-card:nth-child(4),
.phase.is-visible .hex-cell:nth-child(4),
.phase.is-visible .iso-cell:nth-child(4),
.phase.is-visible .radial-cell:nth-child(4) { transition-delay: 0.41s; }
.phase.is-visible .hex-cell:nth-child(5),
.phase.is-visible .iso-cell:nth-child(5),
.phase.is-visible .radial-cell:nth-child(5) { transition-delay: 0.53s; }
.phase.is-visible .hex-cell:nth-child(6),
.phase.is-visible .iso-cell:nth-child(6),
.phase.is-visible .radial-cell:nth-child(6) { transition-delay: 0.65s; }

/* Even rows reveal right-to-left */
.phase.is-visible .hex-cell--row2 {
    animation-direction: reverse;
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 980px) {
    .axis-nav { display: none; }
    .masthead { right: 20px; top: 18px; }
    .meta-line { font-size: 9px; }
    .phase { padding: 14vh 6vw; }
    .hex-field { grid-template-columns: repeat(2, 1fr); }
    .hex-grid { grid-template-columns: repeat(2, 1fr); }
    .iso-grid { grid-template-columns: 1fr; }
    .radial-grid { width: 480px; aspect-ratio: 1 / 1; }
    .radial-cell { transform: rotate(var(--angle)) translateY(-180px) rotate(calc(-1 * var(--angle))); width: 180px; height: 180px; margin: -90px 0 0 -90px; }
    .phase.is-visible .radial-cell { transform: rotate(var(--angle)) translateY(-180px) rotate(calc(-1 * var(--angle))); }
    .graphene-stats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
    .hex-field { grid-template-columns: 1fr; }
    .hex-grid { grid-template-columns: 1fr; }
    .hex-cell--row2 { transform: translateY(0); }
    .phase.is-visible .hex-cell--row2 { transform: translateY(0); }
    .radial-grid { width: 320px; }
    .radial-cell { width: 130px; height: 130px; margin: -65px 0 0 -65px; transform: rotate(var(--angle)) translateY(-110px) rotate(calc(-1 * var(--angle))); }
    .phase.is-visible .radial-cell { transform: rotate(var(--angle)) translateY(-110px) rotate(calc(-1 * var(--angle))); }
}