/* ==========================================================================
   longitude.day -- a parallax meridian journey
   ========================================================================== */

:root {
    --c-midnight: #0c1445;
    --c-twilight: #1a2a5e;
    --c-dawn:     #3a1a4a;
    --c-equator:  #1a3a3a;
    --c-meridian: #c9a84c;
    --c-text:     #d8d0e0;
    --c-time:     #ffffff;
    --c-subtle:   #2a2a5a;

    --font-display: 'Cormorant Garamond', 'Times New Roman', serif;
    --font-body:    'Jost', 'Inter', system-ui, sans-serif;
    --font-mono:    'Inconsolata', 'Courier New', monospace;
}

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

html, body {
    height: 100%;
    overflow: hidden;
    background: var(--c-midnight);
    color: var(--c-text);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    position: relative;
}

/* --------------------------------------------------------------------------
   Fixed meridian line (vertical spine)
   -------------------------------------------------------------------------- */
.meridian-line {
    position: fixed;
    left: 50%;
    top: 0;
    width: 1px;
    height: 100vh;
    background: linear-gradient(
        180deg,
        transparent 0%,
        rgba(201, 168, 76, 0.05) 8%,
        rgba(201, 168, 76, 0.30) 50%,
        rgba(201, 168, 76, 0.05) 92%,
        transparent 100%
    );
    z-index: 10;
    pointer-events: none;
    transform: translateX(-0.5px);
}

/* --------------------------------------------------------------------------
   Fixed horizon line
   -------------------------------------------------------------------------- */
.horizon-line {
    position: fixed;
    top: 50vh;
    left: 0;
    width: 100vw;
    height: 1px;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(201, 168, 76, 0.05) 10%,
        rgba(201, 168, 76, 0.18) 50%,
        rgba(201, 168, 76, 0.05) 90%,
        transparent 100%
    );
    z-index: 9;
    pointer-events: none;
}

/* Crosshair dot at intersection */
.horizon-line::after {
    content: '';
    position: absolute;
    top: -2px;
    left: 50%;
    width: 5px;
    height: 5px;
    background: var(--c-meridian);
    border-radius: 50%;
    transform: translateX(-50%);
    box-shadow: 0 0 8px rgba(201, 168, 76, 0.6);
    opacity: 0.7;
}

/* --------------------------------------------------------------------------
   SVG tick overlay (positioned along the meridian)
   -------------------------------------------------------------------------- */
.tick-overlay {
    position: fixed;
    left: 50%;
    top: 0;
    width: 80px;
    height: 100vh;
    transform: translateX(-50%);
    z-index: 11;
    pointer-events: none;
    overflow: visible;
}

.tick-overlay line {
    stroke: var(--c-meridian);
    stroke-width: 1;
    opacity: 0.5;
}

.tick-overlay line.major {
    opacity: 0.85;
}

.tick-overlay text {
    fill: var(--c-meridian);
    font-family: var(--font-mono);
    font-size: 9px;
    letter-spacing: 0.08em;
    opacity: 0.7;
}

/* --------------------------------------------------------------------------
   Coordinate readout (top-right)
   -------------------------------------------------------------------------- */
.coordinate-readout {
    position: fixed;
    top: 1.75rem;
    right: 1.75rem;
    z-index: 20;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--c-meridian);
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 0.25rem;
    pointer-events: none;
    opacity: 0.85;
}

.coord-label {
    opacity: 0.55;
    font-size: 0.62rem;
}

.coord-value {
    color: var(--c-time);
    font-size: 0.78rem;
    letter-spacing: 0.2em;
}

/* --------------------------------------------------------------------------
   Section indicator (top-left)
   -------------------------------------------------------------------------- */
.section-indicator {
    position: fixed;
    top: 1.75rem;
    left: 1.75rem;
    z-index: 20;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--c-meridian);
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    pointer-events: none;
    opacity: 0.85;
}

.indicator-label {
    opacity: 0.55;
    font-size: 0.62rem;
}

.indicator-value {
    color: var(--c-time);
    font-size: 0.78rem;
    letter-spacing: 0.2em;
    transition: opacity 0.6s ease;
}

/* --------------------------------------------------------------------------
   Scroll container (snap)
   -------------------------------------------------------------------------- */
.scroll-container {
    height: 100vh;
    overflow-y: scroll;
    overflow-x: hidden;
    scroll-snap-type: y mandatory;
    scroll-behavior: smooth;
    scrollbar-width: none;
    -ms-overflow-style: none;
    background: var(--c-midnight);
    transition: background-color 1.2s ease;
}

.scroll-container::-webkit-scrollbar {
    display: none;
}

/* --------------------------------------------------------------------------
   Zone (section) shared
   -------------------------------------------------------------------------- */
.zone {
    min-height: 100vh;
    scroll-snap-align: start;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    position: relative;
    text-align: center;
}

.zone-inner,
.hero-inner,
.colophon-inner {
    max-width: 38rem;
    width: 100%;
    position: relative;
    z-index: 2;
}

/* --------------------------------------------------------------------------
   Zone-specific gradients
   -------------------------------------------------------------------------- */
.zone-hero {
    background: radial-gradient(
        ellipse at center,
        #14205e 0%,
        var(--c-midnight) 55%,
        #050a26 100%
    );
}

.zone-polar {
    background: linear-gradient(
        180deg,
        #060a26 0%,
        var(--c-midnight) 50%,
        #14205e 100%
    );
}

.zone-twilight {
    background: linear-gradient(
        180deg,
        var(--c-midnight) 0%,
        var(--c-twilight) 50%,
        #2a3a7e 100%
    );
}

.zone-dawn {
    background: linear-gradient(
        180deg,
        #1f2a5e 0%,
        var(--c-dawn) 55%,
        #2a1530 100%
    );
}

.zone-subtle {
    background: linear-gradient(
        180deg,
        var(--c-dawn) 0%,
        var(--c-subtle) 55%,
        #1a2a5a 100%
    );
}

.zone-equator {
    background: linear-gradient(
        180deg,
        #1a2a5a 0%,
        var(--c-equator) 55%,
        #0c2424 100%
    );
}

.zone-twilight.zone-south {
    background: linear-gradient(
        180deg,
        #0c2424 0%,
        var(--c-twilight) 55%,
        #16204a 100%
    );
}

.zone-polar.zone-antarctic {
    background: linear-gradient(
        180deg,
        #16204a 0%,
        var(--c-midnight) 50%,
        #050a26 100%
    );
}

.zone-colophon {
    background: linear-gradient(
        180deg,
        #050a26 0%,
        var(--c-midnight) 100%
    );
}

/* --------------------------------------------------------------------------
   Hero (Prime Meridian)
   -------------------------------------------------------------------------- */
.star-field {
    position: absolute;
    inset: 0;
    overflow: hidden;
    z-index: 1;
    pointer-events: none;
}

.star {
    position: absolute;
    width: 1px;
    height: 1px;
    background: #ffffff;
    border-radius: 50%;
    animation: twinkle 4s ease-in-out infinite;
}

.star.large {
    width: 2px;
    height: 2px;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.10; }
    50%      { opacity: 0.45; }
}

.hero-inner {
    text-align: center;
    padding: 0 2rem;
}

.hero-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--c-meridian);
    opacity: 0.75;
    margin-bottom: 2.5rem;
}

.hero-title {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(2.5rem, 7vw, 5.25rem);
    line-height: 1;
    letter-spacing: 0.01em;
    color: var(--c-time);
    margin-bottom: 1.25rem;
}

.hero-coord {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    letter-spacing: 0.28em;
    color: var(--c-meridian);
    opacity: 0.85;
    margin-bottom: 2rem;
}

.hero-tagline {
    font-family: var(--font-display);
    font-style: italic;
    font-weight: 300;
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--c-text);
    max-width: 28rem;
    margin: 0 auto 4.5rem;
    opacity: 0.85;
}

.scroll-cue {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.32em;
    color: var(--c-meridian);
    opacity: 0.7;
    animation: floatDown 2.4s ease-in-out infinite;
}

.scroll-cue-arrow {
    display: block;
    width: 1px;
    height: 36px;
    background: linear-gradient(180deg, var(--c-meridian), transparent);
}

@keyframes floatDown {
    0%, 100% { transform: translateY(0); opacity: 0.55; }
    50%      { transform: translateY(6px); opacity: 0.9; }
}

/* --------------------------------------------------------------------------
   Zone content
   -------------------------------------------------------------------------- */
.zone-time {
    font-family: var(--font-mono);
    font-size: 1.3rem;
    letter-spacing: 0.22em;
    color: var(--c-time);
    margin-bottom: 1.75rem;
    font-variant-numeric: tabular-nums;
}

.zone-name {
    font-family: var(--font-display);
    font-weight: 300;
    font-size: clamp(2rem, 5vw, 4rem);
    line-height: 1.05;
    letter-spacing: 0.005em;
    color: var(--c-time);
    margin-bottom: 1rem;
}

.zone-coord {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.24em;
    color: var(--c-meridian);
    opacity: 0.8;
    margin-bottom: 2rem;
    text-transform: uppercase;
}

.zone-blurb {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--c-text);
    max-width: 32rem;
    margin: 0 auto 2.75rem;
    opacity: 0.92;
}

.zone-meta {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2.25rem;
    flex-wrap: wrap;
    border-top: 1px solid rgba(201, 168, 76, 0.18);
    padding-top: 1.5rem;
    max-width: 28rem;
    margin: 0 auto;
}

.zone-meta li {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    align-items: center;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.meta-key {
    color: var(--c-meridian);
    opacity: 0.7;
    font-size: 0.62rem;
}

.meta-val {
    color: var(--c-text);
    font-size: 0.78rem;
    letter-spacing: 0.16em;
}

/* --------------------------------------------------------------------------
   Colophon
   -------------------------------------------------------------------------- */
.colophon-mark {
    font-family: var(--font-display);
    color: var(--c-meridian);
    font-size: 1.5rem;
    margin-bottom: 1.75rem;
    opacity: 0.7;
    letter-spacing: 0.5em;
}

.colophon-title {
    font-family: var(--font-display);
    font-weight: 300;
    font-style: italic;
    font-size: clamp(1.5rem, 3.5vw, 2.5rem);
    line-height: 1.35;
    color: var(--c-time);
    margin-bottom: 1.75rem;
    max-width: 30rem;
    margin-left: auto;
    margin-right: auto;
}

.colophon-body {
    font-family: var(--font-body);
    font-size: 0.95rem;
    line-height: 1.75;
    color: var(--c-text);
    max-width: 32rem;
    margin: 0 auto 2.5rem;
    opacity: 0.9;
}

.colophon-coord {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    letter-spacing: 0.22em;
    color: var(--c-meridian);
    margin-bottom: 1.75rem;
    font-variant-numeric: tabular-nums;
}

.colophon-credit {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--c-text);
    opacity: 0.5;
}

/* --------------------------------------------------------------------------
   Reveal animation (used by JS for in-view sections)
   -------------------------------------------------------------------------- */
.zone-inner,
.hero-inner,
.colophon-inner {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 1.2s ease, transform 1.2s ease;
}

.zone.is-visible .zone-inner,
.zone.is-visible .hero-inner,
.zone.is-visible .colophon-inner {
    opacity: 1;
    transform: translateY(0);
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 640px) {
    .coordinate-readout,
    .section-indicator {
        top: 1rem;
        font-size: 0.62rem;
    }
    .coordinate-readout {
        right: 1rem;
    }
    .section-indicator {
        left: 1rem;
    }
    .coord-value,
    .indicator-value {
        font-size: 0.68rem;
    }
    .tick-overlay {
        width: 64px;
    }
    .zone {
        padding: 4rem 1.5rem;
    }
    .zone-meta {
        gap: 1.5rem;
    }
}

@media (max-width: 420px) {
    .tick-overlay text {
        display: none;
    }
}