/* =============================================
   ronri.day - Isometric Proof Architecture
   ============================================= */

/* --- CSS Custom Properties --- */
:root {
    /* Colors */
    --deep-ink: #0F1923;
    --chalk-white: #E8ECF1;
    --logic-gold: #C9A227;
    --slate-blue: #3D5A80;
    --warm-gray: #8B9DAF;
    --ember-red: #A43820;
    --pale-sage: #B8C5AA;
    --slate-left: #2E4A6B;
    --slate-right: #4D6A90;
    --inference-line: #4A5568;

    /* Isometric */
    --iso-angle: 30deg;
    --grid-unit: 2.4rem;
    --iso-depth: 0.8rem;

    /* Typography */
    --font-display: 'IBM Plex Mono', monospace;
    --font-body: 'Noto Serif JP', serif;
    --font-accent: 'Space Grotesk', sans-serif;
}

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    background-color: var(--deep-ink);
    color: var(--chalk-white);
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.8vw, 1.25rem);
    font-weight: 400;
    line-height: 1.85;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Isometric Grid Background --- */
#iso-grid-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='56' height='96' viewBox='0 0 56 96'%3E%3Cpath d='M28 0 L56 48 L28 96 L0 48 Z' fill='none' stroke='%23E8ECF1' stroke-width='0.5' opacity='0.06'/%3E%3C/svg%3E");
    background-size: 56px 96px;
}

/* --- SVG Inference Line Overlay --- */
#inference-lines {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10;
    pointer-events: none;
}

/* --- Turnstile Scroll Indicator --- */
#turnstile-indicator {
    position: fixed;
    right: 1.5rem;
    top: 10%;
    z-index: 100;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--logic-gold);
    transition: top 0.15s ease-out;
    text-shadow: 0 0 12px rgba(201, 162, 39, 0.4);
    pointer-events: none;
}

/* --- Main Proof Tree --- */
#proof-tree {
    position: relative;
    z-index: 5;
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem 8rem;
}

/* --- Proof Node (generic) --- */
.proof-node {
    position: relative;
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.proof-node.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Watermark Symbol --- */
.watermark-symbol {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotate(5deg);
    font-family: var(--font-display);
    font-size: 20vw;
    font-weight: 300;
    color: var(--chalk-white);
    opacity: 0.03;
    pointer-events: none;
    z-index: 0;
    animation: watermark-rotate 720s linear infinite;
    line-height: 1;
}

@keyframes watermark-rotate {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to   { transform: translate(-50%, -50%) rotate(360deg); }
}

/* --- Isometric Tile --- */
.iso-tile {
    position: relative;
    perspective: 1200px;
    transform-style: preserve-3d;
    margin: 0 auto;
}

/* Top face */
.iso-face.iso-top {
    position: relative;
    background: rgba(61, 90, 128, 0.85);
    border: 1px solid rgba(232, 236, 241, 0.1);
    padding: 2.5rem 3rem;
    z-index: 2;
    transform: translateZ(0);
    transition: background-color 0.4s ease;
}

/* Left face (pseudo-element for depth) */
.iso-face.iso-left {
    position: absolute;
    bottom: calc(-1 * var(--iso-depth));
    left: 0;
    width: 100%;
    height: var(--iso-depth);
    background: var(--slate-left);
    transform: skewX(-45deg);
    transform-origin: top left;
    z-index: 1;
}

/* Right face */
.iso-face.iso-right {
    position: absolute;
    top: 0;
    right: calc(-1 * var(--iso-depth));
    width: var(--iso-depth);
    height: 100%;
    background: var(--slate-right);
    transform: skewY(-45deg);
    transform-origin: top left;
    z-index: 1;
}

/* --- Tile assembly animation --- */
.iso-tile .iso-face {
    opacity: 0;
    transition: opacity 0.6s cubic-bezier(0.34, 1.56, 0.64, 1),
                transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.iso-tile .iso-face.iso-top {
    transform: translateY(-20px);
}

.iso-tile .iso-face.iso-left {
    transform: skewX(-45deg) translateY(20px);
}

.iso-tile .iso-face.iso-right {
    transform: skewY(-45deg) translateX(20px);
}

.proof-node.visible .iso-tile .iso-face {
    opacity: 1;
}

.proof-node.visible .iso-tile .iso-face.iso-top {
    transform: translateY(0) translateZ(0);
}

.proof-node.visible .iso-tile .iso-face.iso-left {
    transform: skewX(-45deg) translateY(0);
}

.proof-node.visible .iso-tile .iso-face.iso-right {
    transform: skewY(-45deg) translateX(0);
}

/* --- Tile Content --- */
.tile-content {
    position: relative;
    z-index: 3;
}

/* --- Node Headings --- */
.node-heading {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.8rem);
    font-weight: 500;
    letter-spacing: 0.04em;
    color: var(--chalk-white);
    margin-bottom: 1.2rem;
    font-feature-settings: "tnum" 1;
}

/* --- Node Body --- */
.node-body {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.8vw, 1.25rem);
    font-weight: 400;
    line-height: 1.85;
    color: var(--chalk-white);
    margin-bottom: 1rem;
    max-width: 60ch;
}

.node-body em {
    font-style: italic;
    color: var(--logic-gold);
}

/* --- Notation Aside --- */
.notation-aside {
    margin-top: 1.5rem;
    padding: 1rem 1.5rem;
    border-left: 2px solid var(--logic-gold);
    background: rgba(15, 25, 35, 0.5);
}

.notation {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 300;
    letter-spacing: 0.08em;
    color: var(--logic-gold);
}

/* =============================================
   NODE-SPECIFIC STYLES
   ============================================= */

/* --- Axiom Node --- */
#axiom-node {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 4rem;
}

.axiom-tile {
    width: 100%;
    max-width: 700px;
}

.axiom-tile .iso-face.iso-top {
    background: rgba(61, 90, 128, 0.6);
    padding: 4rem 3rem;
    text-align: center;
}

.axiom-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

/* Kanji container for radical decomposition */
.kanji-container {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    position: relative;
}

.kanji {
    font-family: var(--font-body);
    font-size: clamp(3rem, 8vw, 7rem);
    font-weight: 500;
    text-rendering: geometricPrecision;
    color: var(--chalk-white);
    display: inline-flex;
    position: relative;
}

.radical {
    display: inline-block;
    transition: transform 2s cubic-bezier(0.34, 1.56, 0.64, 1),
                opacity 1.5s ease;
}

/* Radical decomposition animation */
.kanji-container.decomposing .kanji-ron .radical-gon {
    transform: translate(-40px, -20px) rotate(-15deg);
    opacity: 0.5;
}

.kanji-container.decomposing .kanji-ron .radical-rin {
    transform: translate(40px, 20px) rotate(10deg);
    opacity: 0.5;
}

.kanji-container.decomposing .kanji-ri .radical-ou {
    transform: translate(-30px, 25px) rotate(12deg);
    opacity: 0.5;
}

.kanji-container.decomposing .kanji-ri .radical-sato {
    transform: translate(35px, -15px) rotate(-8deg);
    opacity: 0.5;
}

/* Composed kanji (shown after decomposition) */
.kanji-composed {
    font-family: var(--font-body);
    font-size: clamp(3rem, 8vw, 7rem);
    font-weight: 500;
    text-rendering: geometricPrecision;
    color: var(--chalk-white);
    letter-spacing: 0.1em;
    opacity: 0;
    transition: opacity 1s ease;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
}

.kanji-composed.revealed {
    opacity: 1;
}

.composed-char {
    display: inline-block;
}

.axiom-subtitle {
    font-family: var(--font-accent);
    font-size: 0.75rem;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--warm-gray);
    margin-top: 0.5rem;
}

/* --- Derivation Node A (conjunction pair) --- */
#derivation-a {
    margin-bottom: 2rem;
}

.conjunction-pair {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 0;
    flex-wrap: wrap;
}

.conjunction-line {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    position: relative;
}

.conjunction-line::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background: rgba(232, 236, 241, 0.6);
}

.connective-symbol {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--logic-gold);
    background: var(--deep-ink);
    padding: 0.2rem 0.5rem;
    position: relative;
    z-index: 2;
}

.deriv-tile-left,
.deriv-tile-right {
    flex: 1;
    min-width: 280px;
    max-width: 500px;
}

/* --- Derivation Node B (wide) --- */
.deriv-tile-wide {
    max-width: 900px;
}

/* --- Lemma Node --- */
.lemma-node {
    max-width: 700px;
    margin-left: 0;
    margin-right: auto;
    padding-left: 2rem;
}

.lemma-tile .iso-face.iso-top {
    border-left: 3px solid var(--pale-sage);
    background: rgba(61, 90, 128, 0.7);
}

.lemma-tile .iso-face.iso-left {
    background: #253D55;
}

.falsum-symbol {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 300;
    color: var(--ember-red);
    text-align: center;
    margin-top: 1.5rem;
    opacity: 0;
    transition: opacity 0.4s ease;
}

/* Reductio flash animation */
@keyframes reductio-flash {
    0%   { background-color: rgba(61, 90, 128, 0.7); }
    25%  { background-color: rgba(164, 56, 32, 0.85); }
    45%  { background-color: rgba(164, 56, 32, 0.85); }
    100% { background-color: rgba(61, 90, 128, 0.7); }
}

.lemma-node.reductio .lemma-tile .iso-face.iso-top {
    animation: reductio-flash 0.75s ease-out forwards;
}

.lemma-node.reductio .falsum-symbol {
    animation: falsum-appear 0.75s ease-out forwards;
}

@keyframes falsum-appear {
    0%   { opacity: 0; }
    30%  { opacity: 1; }
    60%  { opacity: 1; }
    100% { opacity: 0; }
}

/* --- Conclusion Node --- */
#conclusion-node {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 4rem;
}

.conclusion-tile {
    max-width: 800px;
    width: 100%;
}

.conclusion-tile .iso-face.iso-top {
    text-align: center;
    padding: 4rem 3rem;
    background: rgba(61, 90, 128, 0.9);
}

.conclusion-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.conclusion-domain {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 6vw, 5rem);
    font-weight: 500;
    letter-spacing: 0.04em;
    color: var(--chalk-white);
}

.conclusion-qed {
    font-family: var(--font-display);
    font-size: 3rem;
    color: var(--logic-gold);
    line-height: 1;
}

.conclusion-text {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.8vw, 1.25rem);
    font-style: italic;
    color: var(--warm-gray);
    letter-spacing: 0.03em;
}

/* --- Inference Connectors --- */
.inference-connector {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 80px;
    position: relative;
}

.inference-connector::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    width: 1px;
    height: 100%;
    background: var(--inference-line);
    transform: translateX(-50%);
}

.inference-connector-dashed::before {
    background: none;
    border-left: 1px dashed var(--pale-sage);
}

.rule-label {
    font-family: var(--font-accent);
    font-size: 0.75rem;
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--warm-gray);
    background: var(--deep-ink);
    padding: 0.2rem 0.8rem;
    position: relative;
    z-index: 2;
}

/* --- Inference Connector Animations --- */
.inference-connector::before {
    transform-origin: top center;
    transform: translateX(-50%) scaleY(0);
    transition: transform 0.8s ease-out;
}

.inference-connector.visible::before {
    transform: translateX(-50%) scaleY(1);
}

.inference-connector .rule-label {
    opacity: 0;
    transition: opacity 0.5s ease 0.4s;
}

.inference-connector.visible .rule-label {
    opacity: 1;
}

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

@media (max-width: 768px) {
    #proof-tree {
        padding: 2rem 1rem 6rem;
    }

    .conjunction-pair {
        flex-direction: column;
        align-items: center;
    }

    .conjunction-line {
        width: 1px;
        height: 60px;
        flex-direction: column;
    }

    .conjunction-line::before {
        width: 1px;
        height: 100%;
        top: 0;
        left: 50%;
    }

    .deriv-tile-left,
    .deriv-tile-right {
        max-width: 100%;
        min-width: auto;
    }

    .lemma-node {
        padding-left: 0;
        max-width: 100%;
    }

    .iso-face.iso-top {
        padding: 1.5rem 1.5rem;
    }

    .axiom-tile .iso-face.iso-top {
        padding: 3rem 1.5rem;
    }

    .conclusion-tile .iso-face.iso-top {
        padding: 3rem 1.5rem;
    }

    #turnstile-indicator {
        right: 0.75rem;
        font-size: 1.2rem;
    }

    .watermark-symbol {
        font-size: 30vw;
    }
}

@media (max-width: 480px) {
    .node-heading {
        font-size: clamp(1.2rem, 5vw, 1.8rem);
    }

    .kanji, .kanji-composed {
        font-size: clamp(2.5rem, 12vw, 4rem);
    }

    .conclusion-domain {
        font-size: clamp(2rem, 8vw, 3rem);
    }
}

/* --- Selection Color --- */
::selection {
    background: var(--logic-gold);
    color: var(--deep-ink);
}

/* --- Scrollbar Styling --- */
::-webkit-scrollbar {
    width: 4px;
}

::-webkit-scrollbar-track {
    background: var(--deep-ink);
}

::-webkit-scrollbar-thumb {
    background: var(--slate-blue);
    border-radius: 2px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--logic-gold);
}