/* hwaklyul.com — the architecture of chance
 * Probability-themed observatory.
 * Palette: deep ink, parchment, signal red, indigo, soft mist.
 */

:root {
    --ink: #0d1117;
    --ink-2: #141a24;
    --paper: #f4efe6;
    --paper-2: #ebe4d4;
    --line: #1f2632;
    --mist: #c8c2b3;
    --indigo: #3b4f8a;
    --indigo-2: #6b7ab2;
    --signal: #d44a3c;
    --signal-2: #e07a52;
    --gold: #c79a3a;
    --shadow: rgba(13, 17, 23, 0.18);
}

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

html, body {
    background: var(--paper);
    color: var(--ink);
    font-family: 'Fraunces', 'Noto Serif KR', Georgia, serif;
    font-feature-settings: "ss01", "ss02";
    line-height: 1.5;
    overflow-x: hidden;
}

body {
    background:
        radial-gradient(circle at 15% 0%, rgba(59, 79, 138, 0.08), transparent 45%),
        radial-gradient(circle at 88% 110%, rgba(212, 74, 60, 0.06), transparent 50%),
        var(--paper);
    min-height: 100vh;
    position: relative;
}

#grain {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.06;
    mix-blend-mode: multiply;
}

/* ----- header ----- */

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 2rem;
    padding: 1.1rem 2.5rem;
    background: rgba(244, 239, 230, 0.82);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(13, 17, 23, 0.08);
}

.brand {
    display: flex;
    align-items: baseline;
    gap: 0.6rem;
}

.brand-mark {
    font-family: 'Noto Serif KR', serif;
    font-weight: 900;
    font-size: 1.7rem;
    color: var(--signal);
    line-height: 1;
    transform: translateY(0.12em);
}

.brand-word {
    font-family: 'Fraunces', serif;
    font-weight: 600;
    font-size: 1.1rem;
    letter-spacing: 0.02em;
    color: var(--ink);
}

.site-nav {
    justify-self: center;
    display: flex;
    gap: 1.6rem;
}

.site-nav a {
    color: var(--ink);
    text-decoration: none;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    padding-bottom: 2px;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s ease, color 0.3s ease;
}

.site-nav a:hover {
    border-color: var(--signal);
    color: var(--signal);
}

.meta-readout {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    line-height: 1;
    font-family: 'JetBrains Mono', monospace;
}

.readout-label {
    font-size: 0.62rem;
    letter-spacing: 0.18em;
    color: var(--mist);
    margin-bottom: 0.25rem;
    text-transform: uppercase;
}

.readout-value {
    font-size: 1.05rem;
    color: var(--signal);
    font-variant-numeric: tabular-nums;
    font-weight: 600;
}

/* ----- hero ----- */

.hero {
    position: relative;
    padding: 5.5rem 2.5rem 4rem;
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 3rem;
    min-height: 88vh;
    align-items: center;
    overflow: hidden;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(13, 17, 23, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(13, 17, 23, 0.045) 1px, transparent 1px);
    background-size: 64px 64px;
    pointer-events: none;
    mask-image: linear-gradient(to bottom, black 30%, transparent 100%);
    -webkit-mask-image: linear-gradient(to bottom, black 30%, transparent 100%);
}

.hero-inner {
    position: relative;
    z-index: 2;
    max-width: 720px;
}

.kicker {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.82rem;
    letter-spacing: 0.2em;
    text-transform: lowercase;
    color: var(--indigo);
    margin-bottom: 1.8rem;
    padding-left: 1.6rem;
    position: relative;
}

.kicker::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 1.1rem;
    height: 1px;
    background: var(--indigo);
}

.hero-title {
    font-family: 'Fraunces', serif;
    font-weight: 300;
    font-size: clamp(3.2rem, 8.5vw, 7.5rem);
    line-height: 0.96;
    letter-spacing: -0.025em;
    color: var(--ink);
    margin-bottom: 2.4rem;
}

.hero-title .line {
    display: block;
    transform: translateY(20px);
    opacity: 0;
    animation: rise 1s cubic-bezier(0.2, 0.7, 0.2, 1) forwards;
}

.hero-title .line:nth-child(2) {
    animation-delay: 0.18s;
    margin-left: 1.2em;
    font-style: italic;
    font-weight: 300;
}

.hero-title .line:nth-child(3) {
    animation-delay: 0.34s;
    font-weight: 800;
}

.hero-title .outlined {
    color: transparent;
    -webkit-text-stroke: 1px var(--ink);
}

@keyframes rise {
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.hero-lede {
    font-size: 1.18rem;
    max-width: 30em;
    color: var(--ink-2);
    line-height: 1.6;
    margin-bottom: 3rem;
    opacity: 0;
    animation: rise 0.9s 0.5s ease forwards;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.4rem;
    max-width: 38rem;
    opacity: 0;
    animation: rise 0.9s 0.7s ease forwards;
}

.stat {
    border-top: 1px solid rgba(13, 17, 23, 0.18);
    padding-top: 0.8rem;
}

.stat-num {
    display: block;
    font-family: 'Fraunces', serif;
    font-weight: 600;
    font-size: 2.2rem;
    line-height: 1;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
    margin-bottom: 0.35rem;
}

.stat-label {
    display: block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    color: var(--mist);
    text-transform: lowercase;
}

.hero-aside {
    position: relative;
    z-index: 2;
}

.bell {
    width: 100%;
    height: 220px;
    display: block;
}

.bell path {
    fill: rgba(59, 79, 138, 0.14);
    stroke: var(--indigo);
    stroke-width: 1.2;
    stroke-linejoin: round;
}

.bell .bell-axis {
    stroke: rgba(13, 17, 23, 0.2);
    stroke-dasharray: 2 4;
    stroke-width: 1;
}

.aside-caption {
    margin-top: 0.6rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 0.12em;
    color: var(--mist);
    text-align: right;
}

/* ----- generic section ----- */

.section-head {
    max-width: 920px;
    margin: 0 auto 2.6rem;
    padding: 0 2.5rem;
}

.section-tag {
    display: inline-block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    color: var(--signal);
    margin-bottom: 1rem;
    text-transform: lowercase;
}

.section-head h2 {
    font-family: 'Fraunces', serif;
    font-weight: 300;
    font-size: clamp(2.2rem, 4.6vw, 3.6rem);
    line-height: 1.05;
    letter-spacing: -0.018em;
    color: var(--ink);
    margin-bottom: 1rem;
    max-width: 18em;
}

.section-head h2 em {
    font-style: italic;
    color: var(--signal);
    font-weight: 400;
}

.section-sub {
    font-size: 1.05rem;
    color: var(--ink-2);
    max-width: 42em;
}

/* ----- field section ----- */

.field {
    position: relative;
    padding: 5rem 0 6rem;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
}

#particleField {
    display: block;
    width: 100%;
    height: 540px;
    background: linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 100%);
    cursor: crosshair;
}

.field-controls {
    display: flex;
    gap: 0.7rem;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 1.5rem;
    padding: 0 2.5rem;
}

.ctl {
    background: var(--paper-2);
    border: 1px solid rgba(13, 17, 23, 0.18);
    color: var(--ink);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
    letter-spacing: 0.06em;
    padding: 0.65rem 1.1rem;
    cursor: pointer;
    transition: background 0.25s ease, color 0.25s ease, border-color 0.25s ease, transform 0.2s ease;
    text-transform: lowercase;
}

.ctl:hover {
    background: var(--ink);
    color: var(--paper);
    border-color: var(--ink);
    transform: translateY(-1px);
}

.ctl.ghost {
    background: transparent;
}

.ctl:active {
    transform: translateY(0);
}

/* ----- dice ----- */

.dice {
    padding: 6rem 0 6rem;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
    background:
        linear-gradient(180deg, rgba(244, 239, 230, 0) 0%, rgba(235, 228, 212, 0.6) 100%);
}

.dice-stage {
    max-width: 920px;
    margin: 0 auto;
    padding: 0 2.5rem;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 3rem;
    align-items: center;
}

.dice-cube {
    width: 200px;
    height: 200px;
    margin: 1rem auto;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 1.4s cubic-bezier(0.4, 0.1, 0.2, 1);
    transform: rotateX(-25deg) rotateY(35deg);
}

.face {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--paper) 0%, var(--paper-2) 100%);
    border: 1px solid rgba(13, 17, 23, 0.25);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: inset 0 0 24px rgba(13, 17, 23, 0.08);
}

.face span {
    font-family: 'Fraunces', serif;
    font-weight: 600;
    font-size: 4.6rem;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.face.f1 { transform: rotateY(0deg) translateZ(100px); }
.face.f2 { transform: rotateY(90deg) translateZ(100px); }
.face.f3 { transform: rotateY(180deg) translateZ(100px); }
.face.f4 { transform: rotateY(-90deg) translateZ(100px); }
.face.f5 { transform: rotateX(90deg) translateZ(100px); }
.face.f6 { transform: rotateX(-90deg) translateZ(100px); }

.dice-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem;
    align-items: center;
}

.dice-sum {
    display: flex;
    flex-direction: column;
    margin-left: auto;
    line-height: 1.1;
    font-family: 'JetBrains Mono', monospace;
}

.dice-sum span {
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    color: var(--mist);
    text-transform: lowercase;
}

.dice-sum strong {
    font-family: 'Fraunces', serif;
    font-size: 1.7rem;
    color: var(--signal);
    font-variant-numeric: tabular-nums;
}

.histogram {
    max-width: 920px;
    margin: 3rem auto 0;
    padding: 0 2.5rem;
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 0.9rem;
    align-items: end;
    height: 220px;
}

.bar {
    position: relative;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: center;
    border-bottom: 1px solid rgba(13, 17, 23, 0.18);
}

.bar-fill {
    width: 100%;
    height: 4px;
    background: linear-gradient(180deg, var(--signal) 0%, var(--signal-2) 100%);
    transition: height 0.5s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.bar-num {
    position: absolute;
    bottom: -2rem;
    font-family: 'Fraunces', serif;
    font-size: 1.1rem;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.bar-pct {
    position: absolute;
    top: -1.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    color: var(--mist);
    font-variant-numeric: tabular-nums;
}

/* ----- bayes ----- */

.bayes {
    padding: 6rem 0;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
}

.bayes-board {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 2.5rem;
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 3rem;
    align-items: start;
}

.bayes-controls {
    display: flex;
    flex-direction: column;
    gap: 1.6rem;
    padding: 1.5rem;
    background: var(--ink);
    color: var(--paper);
    border-radius: 2px;
}

.slider-block {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.4rem 1rem;
    align-items: center;
}

.slider-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
    letter-spacing: 0.06em;
    color: var(--mist);
    grid-column: 1 / -1;
    text-transform: lowercase;
}

.slider-block input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 2px;
    background: rgba(244, 239, 230, 0.3);
    outline: none;
}

.slider-block input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    background: var(--signal);
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.slider-block input[type="range"]::-moz-range-thumb {
    width: 14px;
    height: 14px;
    background: var(--signal);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

.slider-block input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.3);
}

.slider-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    color: var(--signal-2);
    font-variant-numeric: tabular-nums;
}

.bayes-output {
    display: flex;
    flex-direction: column;
    gap: 1.4rem;
}

.bayes-formula {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    font-family: 'Fraunces', serif;
}

.frac {
    display: inline-flex;
    flex-direction: column;
    text-align: center;
    line-height: 1.1;
    font-size: 0.92rem;
    color: var(--ink-2);
}

.frac .num {
    border-bottom: 1px solid var(--ink);
    padding: 0.2rem 0.5rem;
}

.frac .den {
    padding: 0.2rem 0.5rem;
}

.equals {
    font-size: 1.6rem;
    color: var(--mist);
}

.result {
    font-family: 'Fraunces', serif;
    font-size: clamp(2.2rem, 4vw, 3.4rem);
    font-weight: 600;
    color: var(--signal);
    font-variant-numeric: tabular-nums;
}

.posterior-curve {
    width: 100%;
    height: 200px;
    background: var(--paper-2);
    border: 1px solid rgba(13, 17, 23, 0.12);
}

.posterior-curve path {
    fill: rgba(59, 79, 138, 0.18);
    stroke: var(--indigo);
    stroke-width: 1.4;
}

.posterior-curve .post-mark {
    stroke: var(--signal);
    stroke-width: 1.2;
    stroke-dasharray: 3 3;
}

.bayes-note {
    font-style: italic;
    font-size: 1rem;
    color: var(--ink-2);
    border-left: 2px solid var(--signal);
    padding-left: 1rem;
    transition: color 0.3s ease;
}

/* ----- walk ----- */

.walk {
    padding: 6rem 0 5rem;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
    background: linear-gradient(180deg, rgba(244, 239, 230, 0) 0%, rgba(13, 17, 23, 0.04) 100%);
}

#walkCanvas {
    display: block;
    width: 100%;
    height: 480px;
    background: #fbf8f1;
    border-top: 1px solid rgba(13, 17, 23, 0.1);
    border-bottom: 1px solid rgba(13, 17, 23, 0.1);
}

.walk-controls {
    display: flex;
    gap: 0.7rem;
    justify-content: center;
    margin-top: 1.5rem;
    padding: 0 2.5rem;
}

/* ----- ledger ----- */

.ledger {
    padding: 6rem 0;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
}

.ledger-list {
    max-width: 920px;
    margin: 0 auto;
    padding: 0 2.5rem;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0;
    counter-reset: ledger;
}

.ledger-list li {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 1.4rem;
    padding: 2.2rem 0;
    border-top: 1px solid rgba(13, 17, 23, 0.12);
    transition: background 0.4s ease, padding 0.4s ease;
}

.ledger-list li:last-child {
    border-bottom: 1px solid rgba(13, 17, 23, 0.12);
}

.ledger-list li:hover {
    background: rgba(13, 17, 23, 0.04);
    padding-left: 1rem;
    padding-right: 1rem;
}

.ledger-num {
    font-family: 'Fraunces', serif;
    font-style: italic;
    font-weight: 400;
    font-size: 2.4rem;
    color: var(--signal);
    line-height: 1;
}

.ledger-list h3 {
    font-family: 'Fraunces', serif;
    font-weight: 500;
    font-size: 1.55rem;
    color: var(--ink);
    margin-bottom: 0.5rem;
    letter-spacing: -0.01em;
}

.ledger-list p {
    color: var(--ink-2);
    max-width: 38em;
    font-size: 1.02rem;
}

/* ----- closing ----- */

.closing {
    padding: 8rem 2.5rem 6rem;
    text-align: center;
    border-top: 1px solid rgba(13, 17, 23, 0.08);
    background: var(--ink);
    color: var(--paper);
}

.closing-glyph {
    font-family: 'Fraunces', serif;
    font-size: 7rem;
    color: var(--signal);
    line-height: 1;
    margin-bottom: 1.4rem;
    font-weight: 300;
}

.closing-line {
    font-family: 'Fraunces', serif;
    font-style: italic;
    font-weight: 300;
    font-size: clamp(1.6rem, 3vw, 2.4rem);
    max-width: 30em;
    margin: 0 auto 1.5rem;
    line-height: 1.3;
}

.closing-sig {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.78rem;
    letter-spacing: 0.16em;
    color: var(--mist);
    text-transform: lowercase;
}

/* ----- footer ----- */

.site-foot {
    background: var(--ink);
    color: var(--mist);
    padding: 1.4rem 2.5rem;
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.72rem;
    letter-spacing: 0.08em;
}

.site-foot .dot {
    color: var(--signal);
}

/* ----- responsive ----- */

@media (max-width: 960px) {
    .site-header {
        grid-template-columns: 1fr 1fr;
        gap: 0.6rem 1rem;
        padding: 1rem 1.4rem;
    }
    .site-nav {
        display: none;
    }
    .meta-readout {
        align-items: flex-end;
    }
    .hero {
        grid-template-columns: 1fr;
        padding: 4rem 1.4rem 3rem;
    }
    .hero-aside {
        order: 2;
    }
    .hero-title .line:nth-child(2) {
        margin-left: 0.6em;
    }
    .section-head, .dice-stage, .bayes-board, .ledger-list, .histogram, .field-controls, .walk-controls {
        padding-left: 1.4rem;
        padding-right: 1.4rem;
    }
    .dice-stage {
        grid-template-columns: 1fr;
    }
    .bayes-board {
        grid-template-columns: 1fr;
    }
    .hero-stats {
        grid-template-columns: 1fr;
    }
}