/* tanso.center — carbon observation archive
   Decommissioned carbon-monitoring observatory aesthetic.
   Jewel-tones on carbon black, blur-to-focus, instrument typography.
*/

:root {
    --carbon-void: #0D0D12;
    --carbon-surface: #111118;
    --carbon-hover: #1A1A24;
    --carbon-border: #2A2A35;
    --jewel-ruby: #E0457B;
    --jewel-amethyst: #7B4FA2;
    --jewel-emerald: #2A8B8B;
    --jewel-topaz: #D4A843;
    --jewel-sapphire: #3366CC;
    --carbon-jade: #8AA8A1;
    --text-silver: #C8C8D0;
    --text-graphite: #5E5E6E;
    --white: #FFFFFF;

    --font-mono: 'Share Tech Mono', 'Space Mono', monospace;
    --font-display: 'Oxanium', 'Inter', sans-serif;
    --font-num: 'Space Mono', 'Share Tech Mono', monospace;
    --ease-precise: cubic-bezier(0.25, 0.1, 0.25, 1.0);
}

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

html, body {
    background: var(--carbon-void);
    color: var(--text-silver);
    font-family: var(--font-mono);
    font-size: clamp(0.8rem, 1vw, 1rem);
    letter-spacing: 0.06em;
    line-height: 1.65;
    overflow-x: hidden;
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    position: relative;
}

/* ====================  GRAIN OVERLAY  ==================== */

.grain-svg {
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
}

.grain-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0;
    transition: opacity 800ms var(--ease-precise);
    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='4' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.78  0 0 0 0 0.78  0 0 0 0 0.81  0 0 0 1 0'/></filter><rect width='240' height='240' filter='url(%23n)' opacity='1'/></svg>");
    background-size: 240px 240px;
    mix-blend-mode: overlay;
}

.grain-overlay.visible {
    opacity: 0.04;
}

/* ====================  LEFT NAV STRIP  ==================== */

.nav-strip {
    position: fixed;
    top: 0;
    left: 0;
    width: 48px;
    height: 100vh;
    z-index: 100;
    pointer-events: none;
}

.nav-rail {
    position: absolute;
    top: 12vh;
    bottom: 12vh;
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    background: var(--carbon-border);
}

.nav-dot {
    position: absolute;
    left: 50%;
    top: 12vh;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--jewel-ruby);
    transform: translate(-50%, 0);
    transition: top 240ms var(--ease-precise), background 400ms var(--ease-precise);
    box-shadow: 0 0 8px currentColor;
    color: var(--jewel-ruby);
}

.nav-letters {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    list-style: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3rem;
}

.nav-letter {
    font-family: var(--font-mono);
    font-size: 0.625rem;
    color: var(--text-graphite);
    letter-spacing: 0.16em;
    transition: color 400ms var(--ease-precise), transform 400ms var(--ease-precise);
}

.nav-letter.active {
    color: var(--accent, var(--jewel-ruby));
    transform: scale(1.15);
}

/* ====================  ZONE 1 — OBSERVATORY HEADER  ==================== */

.observatory {
    position: relative;
    width: 100%;
    min-height: 100vh;
    background: var(--carbon-void);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem 3rem;
    overflow: hidden;
}

.domain-id {
    position: absolute;
    top: 1.6rem;
    left: 4rem;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-graphite);
    letter-spacing: 0.12em;
    opacity: 0;
    transition: opacity 700ms var(--ease-precise);
}

.domain-id.visible { opacity: 1; }

.fullerene-stage {
    width: min(60vmin, 540px);
    aspect-ratio: 1 / 1;
    perspective: 800px;
}

.fullerene {
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    animation: fullereneSpin 60s linear infinite;
}

.fullerene-edges line {
    stroke: var(--jewel-amethyst);
    stroke-width: 1;
    fill: none;
    stroke-dasharray: 1;
    stroke-dashoffset: 1;
    opacity: 0;
    transition: opacity 600ms var(--ease-precise), stroke-dashoffset 800ms var(--ease-precise);
}

.fullerene-edges line.drawn {
    opacity: 0.8;
    stroke-dashoffset: 0;
}

.fullerene-nodes circle {
    fill: var(--jewel-ruby);
    opacity: 0;
    transition: opacity 400ms var(--ease-precise);
}

.fullerene-nodes circle.visible {
    opacity: 1;
}

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

.status-line {
    margin-top: 2.4rem;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--carbon-jade);
    letter-spacing: 0.14em;
    opacity: 0;
    transition: opacity 800ms var(--ease-precise);
    text-align: center;
}

.status-line.visible { opacity: 1; }

.scroll-chevron {
    position: absolute;
    bottom: 2.4rem;
    left: 50%;
    transform: translateX(-50%);
    color: var(--text-graphite);
    opacity: 0;
    animation: chevronPulse 2.4s var(--ease-precise) infinite;
    animation-delay: 4s;
}

@keyframes chevronPulse {
    0%, 100% { opacity: 0.2; transform: translate(-50%, 0); }
    50%      { opacity: 0.7; transform: translate(-50%, 6px); }
}

/* ====================  ZONE 2 — SPECIMENS  ==================== */

.specimens {
    position: relative;
    background: var(--carbon-void);
    padding: 6rem 3rem 6rem 6rem;
}

.grid-section {
    max-width: 1480px;
    margin: 0 auto;
}

.zone-header {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 1rem 2rem;
    padding-bottom: 1.6rem;
    border-bottom: 1px solid var(--carbon-border);
    margin-bottom: 2.4rem;
}

.zone-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--jewel-ruby);
    letter-spacing: 0.16em;
    text-transform: uppercase;
}

.zone-title {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(1.6rem, 3.4vw, 2.8rem);
    color: var(--text-silver);
    letter-spacing: 0.02em;
}

.zone-meta {
    margin-left: auto;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--carbon-jade);
    letter-spacing: 0.12em;
}

/* ----------------  SPECIMEN GRID  ---------------- */

.specimen-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    grid-auto-rows: minmax(260px, auto);
    gap: clamp(1.2rem, 2vw, 2rem);
}

.span-2-cols { grid-column: span 2; }
.span-2-rows { grid-row: span 2; }

@media (max-width: 720px) {
    .span-2-cols, .span-2-rows {
        grid-column: span 1;
        grid-row: span 1;
    }
}

/* ----------------  CARD  ---------------- */

.card {
    position: relative;
    background: var(--carbon-surface);
    border: 1px solid var(--carbon-border);
    padding: 1.6rem 1.6rem 1.4rem;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    overflow: hidden;
    filter: blur(12px);
    opacity: 0.3;
    transform: translateY(8px);
    transition:
        background 400ms var(--ease-precise),
        border-color 400ms var(--ease-precise),
        filter 600ms var(--ease-precise),
        opacity 600ms var(--ease-precise),
        transform 600ms var(--ease-precise);
}

.card.in-view {
    filter: blur(0);
    opacity: 1;
    transform: translateY(0);
}

.card::before {
    /* graphene texture, very faint */
    content: "";
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='36' height='31.18' viewBox='0 0 36 31.18'><path d='M9 0 L27 0 L36 15.59 L27 31.18 L9 31.18 L0 15.59 Z' fill='none' stroke='%232A2A35' stroke-width='0.6'/></svg>");
    background-size: 36px 31.18px;
    opacity: 0.25;
    pointer-events: none;
    transition: opacity 400ms var(--ease-precise);
}

.card:hover {
    background: var(--carbon-hover);
}

.card:hover::before {
    opacity: 0.45;
}

/* corner tick-marks */
.corner {
    position: absolute;
    width: 8px;
    height: 8px;
    pointer-events: none;
    transition: width 400ms var(--ease-precise), height 400ms var(--ease-precise), opacity 400ms var(--ease-precise);
    opacity: 0.55;
}
.corner.tl { top: 0; left: 0; border-top: 1px solid var(--accent, var(--text-graphite)); border-left: 1px solid var(--accent, var(--text-graphite)); }
.corner.tr { top: 0; right: 0; border-top: 1px solid var(--accent, var(--text-graphite)); border-right: 1px solid var(--accent, var(--text-graphite)); }
.corner.bl { bottom: 0; left: 0; border-bottom: 1px solid var(--accent, var(--text-graphite)); border-left: 1px solid var(--accent, var(--text-graphite)); }
.corner.br { bottom: 0; right: 0; border-bottom: 1px solid var(--accent, var(--text-graphite)); border-right: 1px solid var(--accent, var(--text-graphite)); }

.card:hover .corner {
    width: 16px;
    height: 16px;
    opacity: 0.95;
}

/* jewel accent assignment */
.jewel-ruby      { --accent: var(--jewel-ruby); }
.jewel-amethyst  { --accent: var(--jewel-amethyst); }
.jewel-emerald   { --accent: var(--jewel-emerald); }
.jewel-topaz     { --accent: var(--jewel-topaz); }
.jewel-sapphire  { --accent: var(--jewel-sapphire); }
.jewel-jade      { --accent: var(--carbon-jade); }

.card:hover {
    border-color: color-mix(in srgb, var(--accent) 60%, transparent);
}

.reading-no {
    position: absolute;
    top: 0.85rem;
    right: 1.1rem;
    font-family: var(--font-mono);
    font-size: 0.625rem;
    color: var(--text-graphite);
    letter-spacing: 0.14em;
    z-index: 2;
}

.card-title {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(1.4rem, 2.4vw, 2.0rem);
    color: var(--accent);
    letter-spacing: 0.02em;
    line-height: 1.1;
    text-transform: lowercase;
    z-index: 2;
}

.rule {
    border: 0;
    height: 1px;
    background: color-mix(in srgb, var(--accent) 22%, transparent);
    margin: 0.2rem 0 0.4rem;
    z-index: 2;
}

.card-body {
    color: var(--text-silver);
    font-size: 0.82rem;
    line-height: 1.6;
    z-index: 2;
}

.caption {
    font-size: 0.7rem;
    color: var(--text-graphite);
    letter-spacing: 0.14em;
    z-index: 2;
}

/* readout */
.card-readout {
    display: flex;
    align-items: baseline;
    gap: 0.6rem;
    z-index: 2;
    margin: 0.3rem 0;
}

.big-num {
    font-family: var(--font-num);
    font-size: clamp(1.8rem, 4vw, 3rem);
    color: rgba(255, 255, 255, 0.92);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
    line-height: 1;
}

.big-unit {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--carbon-jade);
    letter-spacing: 0.14em;
}

/* meta rows */
.card-meta {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    margin-top: auto;
    z-index: 2;
}

.meta-row {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: 1rem;
    border-top: 1px dotted var(--carbon-border);
    padding-top: 0.35rem;
    font-size: 0.74rem;
}

.meta-k {
    color: var(--text-graphite);
    text-transform: uppercase;
    letter-spacing: 0.14em;
}

.meta-v {
    color: var(--text-silver);
    letter-spacing: 0.06em;
}

.meta-v.num {
    font-family: var(--font-num);
    font-variant-numeric: tabular-nums;
    color: rgba(255, 255, 255, 0.92);
}

/* visuals */
.card-visual {
    width: 100%;
    z-index: 2;
    margin-top: auto;
}
.card-visual.tall { min-height: 180px; }
.card-visual.wide { width: 100%; }

.card-visual svg {
    width: 100%;
    height: auto;
    display: block;
}

/* spinning structures */
.fullerene-spin {
    transform-origin: center;
    transform-box: fill-box;
    animation: spinXY 60s linear infinite;
}

.lattice-rotor {
    transform-origin: center;
    transform-box: fill-box;
    animation: spinY 80s linear infinite;
}

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

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

/* radial arc */
.radial-arc {
    width: 100%;
    max-width: 160px;
    margin: 0 auto;
    display: block;
}

.arc-fill {
    transition: stroke-dashoffset 1200ms var(--ease-precise);
}

/* log list */
.log-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.34rem;
    z-index: 2;
    margin-top: 0.3rem;
}

.log-list li {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.74rem;
    border-bottom: 1px dotted var(--carbon-border);
    padding-bottom: 0.3rem;
}

.log-time {
    color: var(--carbon-jade);
    font-family: var(--font-mono);
    letter-spacing: 0.08em;
}

.log-val {
    color: rgba(255, 255, 255, 0.92);
    font-family: var(--font-num);
    font-variant-numeric: tabular-nums;
}

/* econfig */
.econfig {
    font-family: var(--font-num);
    color: var(--white);
    font-size: 1.4rem;
    letter-spacing: 0.04em;
    margin: 0.3rem 0;
    z-index: 2;
}

/* ====================  ZONE 3 — ARCHIVE FOOTER  ==================== */

.archive-footer {
    position: relative;
    background: var(--carbon-void);
    padding: 6rem 3rem 4rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.4rem;
}

.end-line {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-graphite);
    letter-spacing: 0.14em;
}

.footer-fullerene {
    width: 200px;
    height: 200px;
    opacity: 0.4;
}

.footer-fullerene svg {
    width: 100%;
    height: 100%;
}

.footer-rule {
    border: 0;
    height: 1px;
    width: 200px;
    background: var(--carbon-border);
}

.brand {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: 0.875rem;
    color: var(--carbon-jade);
    letter-spacing: 0.14em;
}

/* ====================  RESPONSIVE TWEAKS  ==================== */

@media (max-width: 960px) {
    .specimens { padding: 4rem 1.2rem 4rem 4rem; }
    .nav-letters { gap: 2rem; }
}

@media (max-width: 560px) {
    .nav-strip { width: 36px; }
    .specimens { padding: 3rem 1rem 3rem 3rem; }
    .domain-id { left: 3rem; }
    .zone-meta { margin-left: 0; }
    .card { padding: 1.2rem 1.2rem 1.1rem; }
}

/* prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
    .fullerene, .fullerene-spin, .lattice-rotor { animation: none; }
    .scroll-chevron { animation: none; opacity: 0.4; }
}