/* ============================================
   riron.org -- Design Language Stylesheet
   Deconstructed blackboard lecture aesthetic
   Isometric broken-grid with axiom numbering
   ============================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
    --void-black: #0A0A0F;
    --chalk-white: #E8E4DC;
    --theorem-red: #C7342D;
    --proof-blue: #2D5F8A;
    --axiom-gold: #B8943E;
    --grid-gray: #1E1E28;
    --margin-slate: #6B6B7B;

    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'Literata', serif;
    --font-mono: 'JetBrains Mono', monospace;

    --skew-angle: -3deg;
    --cut-angle: 7deg;
}

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

html {
    scroll-behavior: smooth;
    background-color: var(--void-black);
}

body {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.4vw, 1.15rem);
    font-weight: 400;
    line-height: 1.72;
    color: var(--chalk-white);
    background-color: var(--void-black);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ---------- Isometric Grid Background Substrate ---------- */
#grid-substrate {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 0.15;
    background:
        repeating-linear-gradient(
            30deg,
            transparent,
            transparent 59px,
            var(--grid-gray) 59px,
            var(--grid-gray) 60px
        ),
        repeating-linear-gradient(
            -30deg,
            transparent,
            transparent 59px,
            var(--grid-gray) 59px,
            var(--grid-gray) 60px
        ),
        repeating-linear-gradient(
            90deg,
            transparent,
            transparent 59px,
            var(--grid-gray) 59px,
            var(--grid-gray) 60px
        );
}

/* ---------- Site Header (No Hero) ---------- */
#site-header {
    position: relative;
    z-index: 10;
    padding: 2rem 2.5rem;
}

.domain-name {
    font-family: var(--font-display);
    font-size: clamp(0.75rem, 1.2vw, 0.9rem);
    font-weight: 500;
    letter-spacing: 0.02em;
    color: var(--margin-slate);
    display: inline-flex;
    align-items: baseline;
    gap: 0.75em;
}

.domain-text {
    color: var(--chalk-white);
}

.domain-kanji {
    font-size: 0.85em;
    color: var(--margin-slate);
    opacity: 0.6;
}

/* ---------- Main Treatise Container ---------- */
#treatise {
    position: relative;
    z-index: 5;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ---------- Treatise Sections ---------- */
.treatise-section {
    position: relative;
    padding: 4rem 0;
    transform: skewY(var(--skew-angle));
    clip-path: polygon(
        0% 3%,
        100% 0%,
        100% 97%,
        0% 100%
    );
}

.section-inner {
    transform: skewY(calc(var(--skew-angle) * -1));
    display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    gap: 2rem;
    align-items: start;
}

/* ---------- Axiom Column (Left) ---------- */
.axiom-column {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 0.5rem;
}

.axiom-marker {
    position: sticky;
    top: 2rem;
    z-index: 20;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.axiom-circle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--theorem-red);
    background: var(--void-black);
    transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

.axiom-circle .axiom-num {
    font-family: var(--font-mono);
    font-size: clamp(0.65rem, 1vw, 0.75rem);
    font-weight: 400;
    color: var(--theorem-red);
    letter-spacing: 0.02em;
    transition: color 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}

/* Active axiom marker */
.axiom-marker.active .axiom-circle {
    background: var(--theorem-red);
}

.axiom-marker.active .axiom-num {
    color: var(--chalk-white);
}

/* Proof line extending from active marker */
.axiom-proof-line {
    position: absolute;
    top: 24px;
    left: 50%;
    width: 0;
    height: 1px;
    background-color: var(--theorem-red);
    opacity: 0;
    transition: width 0.6s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.4s ease;
    transform-origin: left center;
    z-index: 15;
    pointer-events: none;
}

.axiom-marker.active ~ .axiom-proof-line {
    width: calc(100vw - 50%);
    opacity: 0.08;
}

/* ---------- Content Column (Center) ---------- */
.content-column {
    position: relative;
}

.content-block {
    position: relative;
    padding: 2.5rem;
    background: rgba(30, 30, 40, 0.3);
    transition: transform 0.25s ease-out, box-shadow 0.25s ease-out;
}

.content-block:hover {
    transform: translateY(-2px);
    box-shadow: 4px 4px 0px var(--proof-blue);
}

/* Section headings */
.section-heading {
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 4vw, 3.5rem);
    font-weight: 700;
    letter-spacing: 0.02em;
    color: var(--chalk-white);
    margin-bottom: 1.5rem;
    line-height: 1.15;
}

/* Body text */
.body-text {
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.4vw, 1.15rem);
    font-weight: 400;
    line-height: 1.72;
    color: var(--chalk-white);
    margin-bottom: 1.5em;
}

.body-text:last-child {
    margin-bottom: 0;
}

.body-text.notation {
    color: var(--margin-slate);
    font-size: 0.95em;
    padding-left: 1.5em;
    border-left: 2px solid var(--grid-gray);
}

.body-text code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    color: var(--axiom-gold);
    background: rgba(30, 30, 40, 0.5);
    padding: 0.15em 0.35em;
    border-radius: 0;
}

/* ---------- Corner Crop Marks ---------- */
.corner-marks {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.corner-mark {
    position: absolute;
    width: 12px;
    height: 12px;
}

.corner-mark::before,
.corner-mark::after {
    content: '';
    position: absolute;
    background-color: var(--axiom-gold);
}

/* Top-left */
.corner-mark.tl {
    top: -1px;
    left: -1px;
}
.corner-mark.tl::before {
    top: 0;
    left: 0;
    width: 12px;
    height: 1px;
}
.corner-mark.tl::after {
    top: 0;
    left: 0;
    width: 1px;
    height: 12px;
}

/* Top-right */
.corner-mark.tr {
    top: -1px;
    right: -1px;
}
.corner-mark.tr::before {
    top: 0;
    right: 0;
    width: 12px;
    height: 1px;
}
.corner-mark.tr::after {
    top: 0;
    right: 0;
    width: 1px;
    height: 12px;
}

/* Bottom-left */
.corner-mark.bl {
    bottom: -1px;
    left: -1px;
}
.corner-mark.bl::before {
    bottom: 0;
    left: 0;
    width: 12px;
    height: 1px;
}
.corner-mark.bl::after {
    bottom: 0;
    left: 0;
    width: 1px;
    height: 12px;
}

/* Bottom-right */
.corner-mark.br {
    bottom: -1px;
    right: -1px;
}
.corner-mark.br::before {
    bottom: 0;
    right: 0;
    width: 12px;
    height: 1px;
}
.corner-mark.br::after {
    bottom: 0;
    right: 0;
    width: 1px;
    height: 12px;
}

/* ---------- Slash-Through Strike Motifs ---------- */
.slash-through {
    position: relative;
    display: inline;
}

.slash-through::after {
    content: '';
    position: absolute;
    top: 0;
    left: -2px;
    right: -2px;
    bottom: 0;
    background: linear-gradient(
        7deg,
        transparent 45%,
        var(--theorem-red) 45%,
        var(--theorem-red) 47%,
        transparent 47%
    );
    pointer-events: none;
}

/* ---------- SVG Diagrams ---------- */
.diagram-container {
    margin-top: 2.5rem;
    display: flex;
    justify-content: center;
}

.iso-diagram {
    width: 100%;
    max-width: 400px;
    height: auto;
}

/* Stroke-dashoffset animation for path drawing */
.diagram-lines path,
.diagram-lines line,
.diagram-lines circle {
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
    transition: stroke-dashoffset 1.5s ease-in-out;
}

.diagram-lines.drawn path,
.diagram-lines.drawn line,
.diagram-lines.drawn circle {
    stroke-dashoffset: 0;
}

/* Reverse when scrolling back */
.diagram-lines.undrawn path,
.diagram-lines.undrawn line,
.diagram-lines.undrawn circle {
    stroke-dashoffset: 1000;
}

/* ---------- Corollary Column (Right) ---------- */
.corollary-column {
    padding-top: 3rem;
}

.corollary-annotation {
    opacity: 0;
    transform: translateX(20px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.corollary-annotation.visible {
    opacity: 1;
    transform: translateX(0);
}

.corollary-text {
    font-family: var(--font-body);
    font-size: 0.85em;
    font-weight: 400;
    font-style: italic;
    line-height: 1.6;
    color: var(--proof-blue);
    padding-left: 1em;
    border-left: 1px solid var(--proof-blue);
}

/* ---------- Diagonal Section Gaps ---------- */
.section-gap {
    position: relative;
    height: 20px;
    overflow: visible;
    z-index: 2;
}

.section-gap::before {
    content: '';
    position: absolute;
    top: 0;
    left: -5%;
    width: 110%;
    height: 100%;
    background:
        repeating-linear-gradient(
            30deg,
            transparent,
            transparent 29px,
            var(--grid-gray) 29px,
            var(--grid-gray) 30px
        ),
        repeating-linear-gradient(
            -30deg,
            transparent,
            transparent 29px,
            var(--grid-gray) 29px,
            var(--grid-gray) 30px
        );
    opacity: 1;
}

.gap-rule {
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: var(--axiom-gold);
    transform: translateY(-50%);
    z-index: 3;
}

/* ---------- Footer Colophon ---------- */
#colophon {
    position: relative;
    z-index: 5;
    padding: 4rem 2.5rem 3rem;
    margin-top: 4rem;
}

.colophon-inner {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    max-width: 1400px;
    margin: 0 auto;
    border-top: 1px solid var(--grid-gray);
    padding-top: 2rem;
}

.colophon-mark {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--axiom-gold);
    letter-spacing: 0.1em;
}

.colophon-domain {
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--margin-slate);
    letter-spacing: 0.02em;
}

/* ---------- Counter Animation for Axiom Numbers ---------- */
.axiom-num {
    display: inline-block;
}

.axiom-num.counting {
    animation: none;
}

/* ---------- Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
    .treatise-section {
        transform: none;
        clip-path: none;
    }

    .section-inner {
        transform: none;
    }

    .diagram-lines path,
    .diagram-lines line,
    .diagram-lines circle {
        stroke-dashoffset: 0;
        transition: none;
    }

    .corollary-annotation {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .content-block {
        transition: none;
    }

    .axiom-circle {
        transition: none;
    }

    .axiom-proof-line {
        transition: none;
    }
}

/* ---------- Responsive: Tablet ---------- */
@media (max-width: 1024px) {
    .section-inner {
        grid-template-columns: 60px 1fr;
        gap: 1.5rem;
    }

    .corollary-column {
        grid-column: 2;
        padding-top: 1rem;
    }

    .corollary-annotation {
        opacity: 1;
        transform: none;
    }

    .content-block {
        padding: 2rem;
    }
}

/* ---------- Responsive: Mobile ---------- */
@media (max-width: 640px) {
    .treatise-section {
        transform: none;
        clip-path: none;
        padding: 2rem 0;
    }

    .section-inner {
        transform: none;
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .axiom-column {
        flex-direction: row;
        gap: 1rem;
        padding-bottom: 0.5rem;
    }

    .axiom-marker {
        position: relative;
        top: auto;
    }

    .axiom-proof-line {
        display: none;
    }

    .content-block {
        padding: 1.5rem;
    }

    .corollary-column {
        grid-column: 1;
    }

    #site-header {
        padding: 1.5rem;
    }

    #treatise {
        padding: 0 1rem;
    }

    .iso-diagram {
        max-width: 300px;
    }

    .section-heading {
        font-size: clamp(1.4rem, 6vw, 2rem);
    }
}