/* ==========================================================================
   yesang.xyz — a generative phase-portrait of expectation
   Palette: Abyssal #070a14 · Deep Inference #0f1a2e · Isocontour #22406a
            Credible #4a7ab5 · Sample #89b6e8 · Prior #dfe8f4
            Surprise #f6cc6d · Tail-Risk #c24b5e · Slate #7a8fa9
   ========================================================================== */

:root {
    --c-abyss: #070a14;
    --c-deep: #0f1a2e;
    --c-iso: #22406a;
    --c-ci: #4a7ab5;
    --c-sample: #89b6e8;
    --c-prior: #dfe8f4;
    --c-surprise: #f6cc6d;
    --c-tail: #c24b5e;
    --c-slate: #7a8fa9;

    --f-display: "Fraunces", "Playfair Display", Georgia, serif;
    --f-body: "Newsreader", "Cormorant Garamond", Georgia, serif;
    --f-mono: "JetBrains Mono", "Space Mono", ui-monospace, monospace;
    --f-label: "Space Mono", "JetBrains Mono", ui-monospace, monospace;

    --ease-entrance: cubic-bezier(0.22, 1, 0.36, 1);
    --ease-cursor: cubic-bezier(0.4, 0, 0.2, 1);

    --soft: 0;
    --scroll-progress: 0;
    --evidence-progress: 0;
}

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

html, body {
    background: var(--c-abyss);
    color: var(--c-prior);
    font-family: var(--f-body);
    font-size: 16px;
    line-height: 1.58;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    cursor: none;
}

body {
    position: relative;
    min-height: 100vh;
    font-variation-settings: "opsz" 14;
}

/* ================= Planes (parallax layers) ================= */

.plane {
    position: fixed;
    inset: 0;
    pointer-events: none;
    will-change: transform;
}

.plane svg {
    width: 100%;
    height: 100%;
    display: block;
}

.plane--field {
    z-index: 1;
    opacity: 0.88;
}

.plane--traj {
    z-index: 2;
    opacity: 0.92;
    mix-blend-mode: screen;
}

.plane--ripple {
    z-index: 6;
    opacity: 0.9;
    mix-blend-mode: screen;
}

/* The annotation plane sits above the field and below HUD */
.annotation {
    position: relative;
    z-index: 4;
}

/* Abyssal base texture layer for subtle depth */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 10%, rgba(34, 64, 106, 0.18), transparent 55%),
        radial-gradient(ellipse at 80% 90%, rgba(15, 26, 46, 0.6), transparent 60%),
        var(--c-abyss);
    z-index: 0;
    pointer-events: none;
}

/* ================= HUD (fixed frame) ================= */

.hud {
    position: fixed;
    inset: 0;
    z-index: 20;
    pointer-events: none;
    font-family: var(--f-mono);
    color: var(--c-slate);
    font-size: 0.72rem;
    letter-spacing: 0.06em;
    font-feature-settings: "tnum" 1;
}

.hud__bracket {
    position: absolute;
    font-family: var(--f-mono);
    font-size: 1.2rem;
    color: var(--c-ci);
    line-height: 1;
}
.hud__bracket--tl { top: 14px; left: 14px; }
.hud__bracket--tr { top: 14px; right: 14px; }
.hud__bracket--bl { bottom: 14px; left: 14px; }
.hud__bracket--br { bottom: 14px; right: 14px; }

.hud__entropy {
    position: absolute;
    top: 20px;
    left: 48px;
    color: var(--c-sample);
    font-weight: 400;
    letter-spacing: 0.08em;
}

.hud__clock {
    position: absolute;
    top: 20px;
    right: 48px;
    color: var(--c-slate);
    letter-spacing: 0.08em;
}

.hud__ident {
    position: absolute;
    bottom: 22px;
    right: 48px;
    color: var(--c-iso);
    letter-spacing: 0.14em;
    text-transform: lowercase;
}

.hud__graticule {
    position: absolute;
    top: 50%;
    right: 18px;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 44px;
}

.hud__tick {
    position: relative;
    width: 22px;
    border-top: 1px solid var(--c-iso);
}

.hud__tick span {
    position: absolute;
    right: 28px;
    top: -0.55rem;
    font-size: 0.6rem;
    color: var(--c-iso);
    letter-spacing: 0.08em;
}

/* ================= Custom cursor + ghost ================= */

.cursor {
    position: fixed;
    top: 0;
    left: 0;
    border-radius: 50%;
    pointer-events: none;
    z-index: 30;
    transform: translate3d(-100px, -100px, 0);
    mix-blend-mode: screen;
    will-change: transform;
}

.cursor--live {
    width: 10px;
    height: 10px;
    background: transparent;
    border: 1px solid var(--c-sample);
    box-shadow: 0 0 12px rgba(137, 182, 232, 0.45), inset 0 0 4px rgba(137, 182, 232, 0.35);
}

.cursor--ghost {
    width: 6px;
    height: 6px;
    background: transparent;
    border: 1px solid var(--c-ci);
    opacity: 0.55;
}

/* ================= Sections (shared) ================= */

.section {
    position: relative;
    width: 100%;
    padding: 12vh 8vw;
    z-index: 4;
}

.section__header {
    display: grid;
    grid-template-columns: 3rem 1fr auto;
    align-items: baseline;
    gap: 1.4rem;
    margin-bottom: 6vh;
    padding-top: 2vh;
    border-top: 1px solid rgba(34, 64, 106, 0.55);
}

.section__header--inset {
    border-top: none;
    padding-top: 0;
    margin-bottom: 3vh;
}

.section__index {
    font-family: var(--f-mono);
    font-size: 0.82rem;
    color: var(--c-ci);
    letter-spacing: 0.16em;
    padding-top: 0.8rem;
}

.section__title {
    font-family: var(--f-display);
    font-variation-settings: "opsz" 48, "SOFT" calc(var(--soft) * 1), "wght" 400;
    font-size: clamp(2.4rem, 4.5vw, 4rem);
    font-weight: 400;
    color: var(--c-prior);
    letter-spacing: -0.015em;
    line-height: 1;
    transition: font-variation-settings 0.4s linear;
}

.section__sub {
    font-family: var(--f-mono);
    font-size: 0.78rem;
    color: var(--c-slate);
    letter-spacing: 0.1em;
    padding-bottom: 0.2rem;
}

/* ================= Section I — PRIOR ================= */

.section--prior {
    min-height: 100vh;
    padding: 0;
    display: flex;
    align-items: stretch;
    justify-content: stretch;
}

.prior-grid {
    position: relative;
    width: 100%;
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    padding: 10vh 8vw;
    gap: 2vw;
}

.prior-hangul {
    grid-column: 1 / 2;
    grid-row: 1 / 2;
    display: flex;
    align-items: flex-end;
    justify-content: flex-start;
    position: relative;
}

.prior-hangul__text {
    font-family: var(--f-display);
    font-variation-settings: "opsz" 144, "SOFT" calc(var(--soft) * 1), "wght" 300, "wdth" 100;
    font-size: clamp(5rem, 13vw, 11rem);
    color: var(--c-prior);
    letter-spacing: -0.035em;
    line-height: 0.88;
    transition: font-variation-settings 0.5s linear;
}

.prior-caret {
    display: inline-block;
    margin-left: 0.4rem;
    font-family: var(--f-mono);
    font-size: 2.4rem;
    color: var(--c-surprise);
    animation: caretBlink 1.1s steps(2, end) infinite;
    transform: translateY(-0.3em);
}

@keyframes caretBlink {
    0%, 50% { opacity: 1; }
    50.01%, 100% { opacity: 0; }
}

.prior-gloss {
    grid-column: 2 / 3;
    grid-row: 2 / 3;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: flex-end;
    text-align: right;
    font-family: var(--f-display);
    font-variation-settings: "opsz" 24, "SOFT" 60, "wght" 350;
    font-size: clamp(1.2rem, 2vw, 1.8rem);
    line-height: 1.2;
    color: var(--c-prior);
    font-style: italic;
    letter-spacing: -0.01em;
}

.prior-gloss__line {
    display: block;
}

.prior-meta {
    grid-column: 1 / 2;
    grid-row: 2 / 3;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    gap: 0.4rem;
    font-family: var(--f-mono);
    font-size: 0.76rem;
    color: var(--c-slate);
    letter-spacing: 0.08em;
}

.prior-meta__row {
    display: flex;
    gap: 1rem;
}

.prior-meta__row .k {
    color: var(--c-iso);
    width: 5rem;
    text-transform: uppercase;
    letter-spacing: 0.14em;
}

.prior-meta__row .v {
    color: var(--c-sample);
    font-feature-settings: "tnum" 1;
}

.prior-scrollhint {
    grid-column: 2 / 3;
    grid-row: 1 / 2;
    display: flex;
    gap: 0.6rem;
    align-items: flex-start;
    justify-content: flex-end;
    font-family: var(--f-label);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.22em;
    color: var(--c-slate);
}

.prior-scrollhint__arrow {
    display: inline-block;
    color: var(--c-ci);
    animation: hintDrift 2.6s ease-in-out infinite;
}

@keyframes hintDrift {
    0%, 100% { transform: translateY(0); opacity: 0.6; }
    50% { transform: translateY(6px); opacity: 1; }
}

/* ================= Section II — LIKELIHOOD ================= */

.section--likelihood {
    min-height: 120vh;
    padding-bottom: 14vh;
}

.likelihood-grid {
    display: grid;
    grid-template-columns: repeat(14, 1fr);
    gap: 1.2rem 1.4rem;
    align-items: start;
}

.margin {
    font-family: var(--f-mono);
    font-size: 0.78rem;
    color: var(--c-slate);
    padding: 0.8rem 0.6rem;
    border-left: 1px solid var(--c-iso);
    letter-spacing: 0.06em;
}

.margin--a { grid-column: 1 / 6; margin-top: 0; }
.margin--b { grid-column: 1 / 6; margin-top: 6vh; }
.margin--c { grid-column: 1 / 6; margin-top: 4vh; }

.margin__row {
    display: flex;
    justify-content: space-between;
    padding: 0.22rem 0;
    border-bottom: 1px dotted rgba(34, 64, 106, 0.65);
}

.margin__row .k {
    color: var(--c-iso);
    text-transform: uppercase;
    letter-spacing: 0.14em;
}

.margin__row .v {
    color: var(--c-sample);
    font-feature-settings: "tnum" 1;
}

.margin__label {
    color: var(--c-slate);
    text-transform: uppercase;
    letter-spacing: 0.18em;
    font-size: 0.66rem;
    margin-bottom: 0.4rem;
}

.margin__dist {
    width: 100%;
    height: 48px;
    display: block;
}

.margin__dist-curve {
    stroke-dasharray: 200;
    stroke-dashoffset: 0;
    animation: curveBreathe 7s ease-in-out infinite;
}

@keyframes curveBreathe {
    0%, 100% { opacity: 0.55; transform: translateY(0); }
    50% { opacity: 1; transform: translateY(-1px); }
}

.margin__cap {
    font-size: 0.66rem;
    color: var(--c-iso);
    margin-top: 0.3rem;
    letter-spacing: 0.1em;
}

.margin__bar {
    height: 18px;
    display: flex;
    align-items: center;
    margin: 0.4rem 0;
}

.ci {
    position: relative;
    height: 1px;
    background: var(--c-iso);
    flex: 1;
}

.ci::before, .ci::after {
    content: "";
    position: absolute;
    top: -4px;
    width: 1px;
    height: 9px;
    background: var(--c-ci);
}
.ci::before { left: 22%; }
.ci::after { right: 22%; }

.ci__median {
    position: absolute;
    left: 50%;
    top: -5px;
    width: 2px;
    height: 11px;
    background: var(--c-sample);
    transform: translateX(-50%);
}

.prose {
    font-family: var(--f-body);
    font-variation-settings: "opsz" 14;
    font-size: 1.05rem;
    line-height: 1.62;
    color: var(--c-prior);
    max-width: 62ch;
}

.prose p + p {
    margin-top: 1.1em;
}

.prose em {
    font-style: italic;
    color: var(--c-sample);
}

.prose--a { grid-column: 6 / 14; }
.prose--b { grid-column: 6 / 14; margin-top: 5vh; }
.prose--c { grid-column: 6 / 14; margin-top: 3vh; }

/* inline micro-distributions */
.yd-mu {
    display: inline-flex;
    align-items: baseline;
    gap: 0.22em;
    color: var(--c-sample);
    white-space: nowrap;
}

.yd-mu svg {
    height: 1.1em;
    width: auto;
    vertical-align: -0.14em;
    display: inline-block;
    opacity: 0.9;
}

/* ================= Section III — EVIDENCE (horizontal scroll) ================= */

.section--evidence {
    position: relative;
    padding: 0;
    height: 420vh;
}

.evidence-sticky {
    position: sticky;
    top: 0;
    height: 100vh;
    overflow: hidden;
    padding: 10vh 8vw 6vh;
    background: linear-gradient(180deg, transparent 0%, rgba(15, 26, 46, 0.35) 50%, transparent 100%);
}

.evidence-rail {
    position: relative;
    width: 100%;
    height: calc(100vh - 26vh);
    overflow: hidden;
}

.evidence-strip {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    display: flex;
    gap: 3vw;
    padding: 0 4vw;
    will-change: transform;
    transform: translateX(0);
}

.ev-panel {
    flex: 0 0 33vw;
    max-width: 33vw;
    background: rgba(15, 26, 46, 0.45);
    border: 1px solid var(--c-iso);
    border-top: 1px solid var(--c-ci);
    padding: 1.6rem 1.4rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-self: center;
    min-height: 56vh;
    position: relative;
    opacity: 0.35;
    transform: translateY(8px);
    transition: opacity 0.8s var(--ease-entrance), transform 0.8s var(--ease-entrance);
}

.ev-panel.is-active {
    opacity: 1;
    transform: translateY(0);
}

.ev-panel--surprise {
    border-top-color: var(--c-surprise);
}

.ev-panel__num {
    font-family: var(--f-mono);
    font-size: 0.72rem;
    color: var(--c-ci);
    letter-spacing: 0.2em;
}

.ev-panel__formula {
    font-family: var(--f-mono);
    font-size: 0.9rem;
    color: var(--c-prior);
    letter-spacing: 0.06em;
}

.ev-panel__formula--hot {
    color: var(--c-surprise);
}

.ev-panel__pair {
    width: 100%;
    height: 90px;
    border-top: 1px solid rgba(34, 64, 106, 0.6);
    border-bottom: 1px solid rgba(34, 64, 106, 0.6);
    padding: 0.4rem 0;
}

.ev-panel__note {
    font-family: var(--f-body);
    font-size: 0.95rem;
    color: var(--c-prior);
    line-height: 1.5;
}

.evidence-progress {
    position: absolute;
    bottom: 3vh;
    left: 8vw;
    right: 8vw;
    display: flex;
    align-items: center;
    gap: 1rem;
    font-family: var(--f-mono);
    font-size: 0.72rem;
    color: var(--c-slate);
    letter-spacing: 0.1em;
}

.evidence-progress__bar {
    flex: 1;
    height: 1px;
    background: var(--c-iso);
    position: relative;
}

.evidence-progress__fill {
    position: absolute;
    top: -1px;
    left: 0;
    height: 3px;
    background: var(--c-sample);
    width: 0%;
    box-shadow: 0 0 6px rgba(137, 182, 232, 0.6);
}

/* ================= Section IV — POSTERIOR (hex lattice) ================= */

.section--posterior {
    min-height: 140vh;
    padding-bottom: 16vh;
}

.hex-wrap {
    width: 100%;
    max-width: 1100px;
    margin: 2vh auto 4vh;
    padding: 0 2vw;
}

.hex-lattice {
    width: 100%;
    height: auto;
    display: block;
}

.hex-cell {
    transition: transform 0.6s var(--ease-entrance), opacity 0.6s var(--ease-entrance);
    transform-origin: center;
    transform-box: fill-box;
}

.hex-cell__poly {
    fill: rgba(15, 26, 46, 0.55);
    stroke: var(--c-iso);
    stroke-width: 1;
    transition: stroke 0.4s linear, fill 0.4s linear;
}

.hex-cell.is-hover .hex-cell__poly {
    stroke: var(--c-sample);
    fill: rgba(34, 64, 106, 0.45);
}

.hex-cell.is-ripple .hex-cell__poly {
    stroke: var(--c-ci);
}

.hex-cell__label {
    font-family: var(--f-mono);
    font-size: 9px;
    fill: var(--c-slate);
    letter-spacing: 0.1em;
    text-anchor: middle;
    pointer-events: none;
}

.hex-cell__title {
    font-family: var(--f-display);
    font-variation-settings: "opsz" 24, "SOFT" 40, "wght" 400, "ital" 1;
    font-size: 13px;
    fill: var(--c-prior);
    text-anchor: middle;
    pointer-events: none;
}

.posterior-caption {
    max-width: 48rem;
    margin: 0 auto;
    padding: 4vh 2vw 0;
    text-align: center;
    font-family: var(--f-body);
    font-size: 1rem;
    color: var(--c-slate);
    font-style: italic;
    line-height: 1.55;
}

/* ================= Section V — SURPRISE ================= */

.section--surprise {
    min-height: 120vh;
    padding: 20vh 8vw;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--c-abyss);
    transition: background 1.2s linear;
}

.section--surprise.is-black {
    background: #000;
}

.surprise-inner {
    max-width: 40rem;
    width: 100%;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3.2rem;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 1.2s linear, transform 1.2s var(--ease-entrance);
}

.surprise-inner.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.surprise-line {
    font-family: var(--f-display);
    font-variation-settings: "opsz" 48, "SOFT" 60, "wght" 350, "ital" 1;
    font-size: clamp(1.6rem, 3vw, 2.4rem);
    line-height: 1.3;
    color: var(--c-prior);
    letter-spacing: -0.01em;
}

.surprise-btn {
    background: transparent;
    border: 1px solid var(--c-surprise);
    color: var(--c-surprise);
    padding: 0.9rem 1.6rem;
    font-family: var(--f-mono);
    font-size: 0.82rem;
    letter-spacing: 0.24em;
    text-transform: lowercase;
    cursor: none;
    transition: background 0.35s linear, color 0.35s linear, border-color 0.35s linear;
    display: inline-flex;
    gap: 0.6rem;
}

.surprise-btn:hover {
    background: var(--c-surprise);
    color: var(--c-abyss);
    border-color: var(--c-surprise);
}

.surprise-btn__brackets {
    color: inherit;
}

.surprise-foot {
    font-family: var(--f-mono);
    font-size: 0.7rem;
    color: var(--c-iso);
    letter-spacing: 0.12em;
    display: flex;
    gap: 0.8rem;
    font-feature-settings: "tnum" 1;
}

.surprise-foot__sep {
    color: var(--c-deep);
}

.surprise-foot__item {
    color: var(--c-slate);
}

/* ================= Field / trajectory SVG styling ================= */

#field-svg path {
    fill: none;
    stroke: var(--c-iso);
    stroke-width: 0.6;
    opacity: 0.55;
    vector-effect: non-scaling-stroke;
}

#traj-svg path {
    fill: none;
    stroke: var(--c-sample);
    stroke-width: 0.6;
    opacity: 0.26;
    vector-effect: non-scaling-stroke;
}

#ripple-svg circle {
    fill: none;
    stroke: var(--c-ci);
    stroke-width: 1;
    vector-effect: non-scaling-stroke;
}

/* ================= Narrow viewport fallback ================= */

@media (max-width: 720px) {
    .section { padding: 8vh 6vw; }

    .prior-grid {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto auto;
        padding: 8vh 6vw;
    }
    .prior-hangul { grid-column: 1 / 2; grid-row: 1 / 2; }
    .prior-gloss { grid-column: 1 / 2; grid-row: 2 / 3; align-items: flex-start; text-align: left; }
    .prior-meta { grid-column: 1 / 2; grid-row: 3 / 4; }
    .prior-scrollhint { grid-column: 1 / 2; grid-row: 4 / 5; justify-content: flex-start; }

    .likelihood-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .margin--a, .margin--b, .margin--c,
    .prose--a, .prose--b, .prose--c {
        grid-column: 1 / 2;
        margin-top: 0;
    }
    .margin { border-left: none; border-top: 1px solid var(--c-iso); padding: 0.8rem 0; }

    .section--evidence { height: auto; }
    .evidence-sticky { position: relative; height: auto; padding: 6vh 6vw; }
    .evidence-rail { height: auto; overflow: visible; }
    .evidence-strip {
        position: relative;
        transform: none !important;
        flex-direction: column;
        gap: 2rem;
        padding: 0;
    }
    .ev-panel { flex: 0 0 auto; max-width: 100%; min-height: auto; opacity: 1; transform: none; }
    .evidence-progress { display: none; }

    .hud__graticule { display: none; }
    .hud__entropy { left: 44px; font-size: 0.64rem; }
    .hud__clock { right: 44px; font-size: 0.64rem; }
}

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

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
    }
    .prior-caret { animation: none; opacity: 1; }
    .prior-scrollhint__arrow { animation: none; }
    .margin__dist-curve { animation: none; }
}