:root {
    --ink: #101014;
    --paper: #F3EAD8;
    --indigo: #20204A;
    --red: #B64935;
    --chalk: #9BC7D4;
    --tea: #B8C7A3;
    --gold: #C2A45D;
    --graphite: #5B5A55;
    --serif-jp: 'Noto Serif JP', serif;
    --chapter: 'Cormorant Garamond', serif;
    --caption: 'DM Sans', sans-serif;
    --object: 'Fraunces', serif;
}

* { box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    background: var(--ink);
}

body {
    margin: 0;
    color: var(--paper);
    font-family: var(--caption);
    background: var(--ink);
    overflow-x: hidden;
}

.grain {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 30;
    opacity: .28;
    background-image:
        radial-gradient(circle at 18% 24%, rgba(243, 234, 216, .08) 0 1px, transparent 1px),
        radial-gradient(circle at 78% 62%, rgba(155, 199, 212, .07) 0 1px, transparent 1px),
        linear-gradient(115deg, transparent 0 48%, rgba(243, 234, 216, .035) 49%, transparent 51% 100%);
    background-size: 17px 19px, 23px 29px, 100% 100%;
    mix-blend-mode: screen;
}

.cursor-orbit {
    position: fixed;
    width: 42px;
    height: 42px;
    border: 1px solid rgba(182, 73, 53, .55);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    z-index: 28;
    pointer-events: none;
    opacity: .55;
    transition: width .35s ease, height .35s ease, opacity .35s ease;
}

.proof-index {
    position: fixed;
    left: 24px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 25;
    display: flex;
    flex-direction: column;
    gap: 18px;
    font-family: var(--serif-jp);
    writing-mode: vertical-rl;
    letter-spacing: .28em;
    color: rgba(243, 234, 216, .42);
}

.proof-index span {
    cursor: pointer;
    transition: color .5s ease, transform .5s ease;
}

.proof-index span.active {
    color: var(--red);
    transform: translateX(5px);
}

.house { position: relative; }

.chamber {
    min-height: 100vh;
    position: relative;
    overflow: hidden;
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    grid-template-rows: repeat(11, 1fr);
    padding: clamp(28px, 5vw, 72px);
    isolation: isolate;
}

.chamber::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(243, 234, 216, .04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(243, 234, 216, .035) 1px, transparent 1px);
    background-size: calc(100vw / 7) calc(100vh / 11);
    opacity: .52;
    z-index: -2;
}

.chamber::after {
    content: "";
    position: absolute;
    inset: -20%;
    background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%), rgba(155, 199, 212, .16), transparent 22rem);
    z-index: -1;
    transition: opacity .4s ease;
}

h1, h2, p { margin: 0; }

h2 {
    font-family: var(--chapter);
    font-size: clamp(3.8rem, 9vw, 10rem);
    font-weight: 500;
    line-height: .82;
    letter-spacing: -.05em;
}

p {
    font-size: clamp(1rem, 1.4vw, 1.22rem);
    line-height: 1.8;
}

.kicker, small {
    font-family: var(--caption);
    text-transform: uppercase;
    letter-spacing: .26em;
    font-size: .72rem;
    color: var(--gold);
}

.axiom {
    background:
        radial-gradient(circle at 68% 28%, rgba(32, 32, 74, .72), transparent 38%),
        linear-gradient(155deg, #101014 0%, #101014 54%, #20204A 140%);
}

.paper-strip {
    position: absolute;
    left: -7vw;
    top: -3vh;
    width: 54vw;
    height: 16vh;
    background: linear-gradient(90deg, rgba(243, 234, 216, .94), rgba(243, 234, 216, .58));
    transform: rotate(-18deg);
    box-shadow: 0 24px 60px rgba(0,0,0,.38), inset 0 -1px 0 rgba(91, 90, 85, .22);
}

.doorway {
    grid-column: 2 / span 3;
    grid-row: 3 / span 6;
    position: relative;
    transform: translateX(-4vw);
}

.red-line {
    position: absolute;
    display: block;
    background: var(--red);
    box-shadow: 0 0 18px rgba(182, 73, 53, .24);
    transform-origin: left center;
}

.red-line.top, .red-line.bottom { height: 1px; width: 88%; left: 0; }
.red-line.left, .red-line.right { width: 1px; height: 88%; top: 0; }
.red-line.top { top: 0; }
.red-line.bottom { bottom: 0; }
.red-line.left { left: 0; }
.red-line.right { right: 12%; }

.wordmark {
    position: absolute;
    left: 28px;
    top: 26px;
    font-family: var(--serif-jp);
    font-size: clamp(2rem, 5vw, 5.8rem);
    letter-spacing: .18em;
    writing-mode: vertical-rl;
    color: var(--paper);
    text-shadow: 0 0 30px rgba(243, 234, 216, .12);
    transition: transform 1.1s cubic-bezier(.2,.7,.2,1), writing-mode .1s linear, letter-spacing 1s ease;
}

.axiom.seen .wordmark {
    writing-mode: horizontal-tb;
    transform: translate(46px, 56px) rotate(-2deg);
    letter-spacing: .08em;
}

.axiom-copy {
    grid-column: 5 / span 2;
    grid-row: 5 / span 4;
    display: flex;
    flex-direction: column;
    gap: 22px;
    color: rgba(243, 234, 216, .86);
}

.axiom-diagram {
    grid-column: 4 / span 4;
    grid-row: 2 / span 4;
    width: 100%;
    opacity: .42;
}

.draw-svg { overflow: visible; }
.draw-svg path, .draw-svg circle {
    fill: none;
    stroke: currentColor;
    stroke-width: 1.2;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-dasharray: 900;
    stroke-dashoffset: 900;
    transition: stroke-dashoffset 1.8s cubic-bezier(.2,.8,.2,1);
}
.draw-svg.drawn path, .draw-svg.drawn circle { stroke-dashoffset: 0; }

.lemma {
    background: linear-gradient(108deg, var(--paper), #eadfc8 56%, var(--tea));
    color: var(--ink);
}

.lemma::before { background-image: linear-gradient(rgba(91, 90, 85, .1) 1px, transparent 1px), linear-gradient(90deg, rgba(91, 90, 85, .09) 1px, transparent 1px); }

.vertical-note {
    grid-column: 7;
    grid-row: 2 / span 8;
    justify-self: center;
    writing-mode: vertical-rl;
    font-family: var(--serif-jp);
    letter-spacing: .34em;
    color: var(--red);
}

.fold-stage {
    grid-column: 2 / span 5;
    grid-row: 2 / span 8;
    position: relative;
    perspective: 1200px;
}

.fold-panel {
    position: absolute;
    width: min(430px, 42vw);
    min-height: 320px;
    padding: 34px;
    background:
        linear-gradient(135deg, rgba(255,255,255,.34), transparent 38%),
        rgba(243, 234, 216, .76);
    border: 1px solid rgba(91, 90, 85, .24);
    box-shadow: 0 25px 70px rgba(16,16,20,.17), inset -22px 0 36px rgba(194, 164, 93, .10);
    backdrop-filter: blur(2px);
    transform-origin: left center;
    transition: transform 1.2s cubic-bezier(.2,.8,.2,1);
}

.fold-panel p { color: rgba(16, 16, 20, .76); }
.fold-panel h2 { font-size: clamp(3rem, 6vw, 6.8rem); margin: 16px 0 22px; }

.panel-one { left: 2%; top: 5%; transform: rotate(-3deg) rotateY(0); z-index: 3; }
.panel-two { left: 29%; top: 22%; transform: rotate(2deg) rotateY(0); z-index: 2; }
.panel-three { left: 49%; top: 43%; transform: rotate(-1deg) rotateY(0); z-index: 1; }
.lemma.seen .panel-one { transform: rotate(-4deg) rotateY(-18deg) translateX(-18px); }
.lemma.seen .panel-two { transform: rotate(3deg) rotateY(-28deg) translateX(10px); }
.lemma.seen .panel-three { transform: rotate(-2deg) rotateY(-12deg) translateX(28px); }

.pin {
    position: absolute;
    width: 11px;
    height: 11px;
    right: 24px;
    top: 23px;
    border-radius: 50%;
    background: var(--red);
    box-shadow: 0 0 0 5px rgba(182,73,53,.12);
}

.proof-tree {
    grid-column: 1 / span 7;
    grid-row: 7 / span 4;
    width: 88%;
    justify-self: center;
    color: rgba(182, 73, 53, .54);
}

.contradiction {
    background: radial-gradient(circle at 45% 54%, #050507 0 12%, #101014 34%, #20204A 100%);
}

.well {
    grid-column: 2 / span 4;
    grid-row: 2 / span 8;
    position: relative;
    display: grid;
    place-items: center;
}

.void {
    width: min(58vw, 650px);
    aspect-ratio: 1;
    border-radius: 50%;
    background: radial-gradient(circle, #020203 0 38%, rgba(16,16,20,.5) 39% 48%, transparent 49%);
    border: 1px solid rgba(155, 199, 212, .18);
    box-shadow: inset 0 0 70px rgba(0,0,0,.95), 0 0 90px rgba(32, 32, 74, .8);
}

.orbit {
    position: absolute;
    width: min(50vw, 560px);
    aspect-ratio: 1;
    border: 1px solid rgba(155, 199, 212, .28);
    border-radius: 50%;
    animation: turn 20s linear infinite;
}
.orbit-b { width: min(41vw, 460px); animation-duration: 15s; animation-direction: reverse; border-color: rgba(182,73,53,.38); }
.orbit-c { width: min(30vw, 340px); animation-duration: 24s; transform: rotate(35deg); border-color: rgba(194,164,93,.38); }
.orbit span {
    position: absolute;
    left: 50%;
    top: -14px;
    transform: translateX(-50%);
    padding: 6px 12px;
    color: var(--paper);
    background: var(--ink);
    border: 1px solid rgba(243,234,216,.2);
    font-family: var(--chapter);
    font-size: 1.2rem;
}

@keyframes turn { to { transform: rotate(360deg); } }

.erasure {
    position: absolute;
    width: 180px;
    height: 22px;
    border-radius: 50%;
    background: rgba(243, 234, 216, .16);
    filter: blur(6px);
}
.e1 { transform: rotate(-18deg) translate(120px, 80px); }
.e2 { transform: rotate(24deg) translate(-140px, -105px); }

.contradiction-text {
    grid-column: 5 / span 2;
    grid-row: 4 / span 4;
    display: flex;
    flex-direction: column;
    gap: 22px;
}

.seal {
    position: absolute;
    right: 8vw;
    bottom: 8vh;
    width: 112px;
    height: 112px;
    display: grid;
    place-items: center;
    border: 3px double var(--red);
    color: var(--red);
    font-family: var(--serif-jp);
    font-size: 4rem;
    transform: rotate(10deg);
    opacity: .78;
}

.stair {
    background: linear-gradient(130deg, var(--paper) 0 46%, #d9dcbf 100%);
    color: var(--ink);
}
.stair::before { background-image: linear-gradient(rgba(91,90,85,.11) 1px, transparent 1px), linear-gradient(90deg, rgba(91,90,85,.1) 1px, transparent 1px); }

.stair-copy {
    grid-column: 1 / span 3;
    grid-row: 2 / span 4;
    display: flex;
    flex-direction: column;
    gap: 20px;
    z-index: 4;
}

.risers {
    grid-column: 2 / span 6;
    grid-row: 4 / span 6;
    position: relative;
    z-index: 3;
}

.riser {
    position: absolute;
    left: calc(var(--i) * 8%);
    top: calc(var(--i) * 15%);
    width: 72%;
    min-height: 82px;
    padding: 18px 32px;
    background: rgba(243,234,216,.64);
    border-top: 1px solid rgba(16,16,20,.28);
    border-bottom: 1px solid rgba(182,73,53,.28);
    box-shadow: 0 18px 34px rgba(16,16,20,.12);
    transform: rotate(-13deg) translateX(-70px);
    opacity: .45;
    transition: transform .9s cubic-bezier(.2,.8,.2,1), opacity .9s ease;
}
.riser:nth-child(1) { --i: 0; }
.riser:nth-child(2) { --i: 1; }
.riser:nth-child(3) { --i: 2; }
.riser:nth-child(4) { --i: 3; }
.riser:nth-child(5) { --i: 4; }
.stair.seen .riser { transform: rotate(-13deg) translateX(0); opacity: 1; transition-delay: calc(var(--i) * .12s); }
.riser span {
    font-family: var(--object);
    font-size: clamp(2rem, 5vw, 5.2rem);
    color: rgba(182, 73, 53, .88);
    line-height: .8;
}
.riser p { display: inline-block; margin-left: 24px; color: rgba(16,16,20,.72); }
.stair-arcs { grid-column: 1 / span 7; grid-row: 4 / span 7; width: 92%; color: rgba(32,32,74,.35); z-index: 1; }

.lantern {
    background: radial-gradient(circle at 54% 46%, rgba(194,164,93,.22), transparent 28%), linear-gradient(150deg, #101014 0%, #20204A 80%);
}

.lantern-wrap {
    grid-column: 2 / span 4;
    grid-row: 2 / span 8;
    position: relative;
    display: grid;
    place-items: center;
}

.lantern-core {
    position: absolute;
    width: 168px;
    height: 168px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    font-family: var(--object);
    font-size: 8rem;
    color: var(--ink);
    background: radial-gradient(circle, #F3EAD8 0, #C2A45D 66%, rgba(194,164,93,.12) 68%);
    box-shadow: 0 0 90px rgba(194,164,93,.55), 0 0 180px rgba(155,199,212,.18);
    z-index: 3;
}

.lantern-svg {
    width: min(62vw, 620px);
    color: rgba(243,234,216,.72);
    filter: drop-shadow(0 0 24px rgba(155,199,212,.2));
    animation: breathe 6s ease-in-out infinite;
}

@keyframes breathe { 50% { transform: scale(1.035) rotate(1deg); } }

.card {
    position: absolute;
    padding: 12px 18px;
    border: 1px solid rgba(243,234,216,.28);
    background: rgba(16,16,20,.52);
    color: rgba(243,234,216,.76);
    font-family: var(--chapter);
    font-size: 1.35rem;
    transform: rotate(var(--r));
}
.c-a { --r: -4deg; left: 2%; top: 18%; }
.c-b { --r: 3deg; right: 3%; top: 28%; }
.c-c { --r: -2deg; left: 23%; bottom: 11%; }

.lantern-copy {
    grid-column: 5 / span 2;
    grid-row: 5 / span 4;
    display: flex;
    flex-direction: column;
    gap: 22px;
}

.premise-button {
    position: fixed;
    right: 28px;
    bottom: 24px;
    z-index: 26;
    border: 1px solid rgba(182,73,53,.74);
    background: rgba(16,16,20,.62);
    color: var(--paper);
    padding: 13px 18px;
    font-family: var(--caption);
    text-transform: uppercase;
    letter-spacing: .18em;
    font-size: .68rem;
    cursor: pointer;
    backdrop-filter: blur(8px);
    transition: transform .35s ease, background .35s ease;
}
.premise-button:hover { transform: translateY(-3px); background: rgba(182,73,53,.5); }

@media (max-width: 820px) {
    .chamber { display: flex; flex-direction: column; gap: 34px; padding: 80px 28px; }
    .proof-index { display: none; }
    .doorway, .axiom-copy, .fold-stage, .well, .contradiction-text, .stair-copy, .risers, .lantern-wrap, .lantern-copy { grid-column: auto; grid-row: auto; }
    .doorway { min-height: 420px; transform: none; }
    .fold-stage { min-height: 650px; }
    .fold-panel { width: 82vw; }
    .panel-two { left: 7%; top: 30%; }
    .panel-three { left: 2%; top: 58%; }
    .well { min-height: 520px; }
    .contradiction-text, .lantern-copy { max-width: 560px; }
    .risers { min-height: 540px; }
    .riser { width: 92%; }
    .riser p { display: block; margin: 10px 0 0; }
    .premise-button { left: 18px; right: 18px; }
}