:root {
  /* Typography source note: Inter** from Google Fonts for refined body copy. */
  --graphite: #07080D;
  --carrara: #F2EFEA;
  --vein: #A9A3A0;
  --cyan: #00F5FF;
  --magenta: #FF2BD6;
  --lime: #B8FF1A;
  --violet: #351C75;
  --pencil: #4A4650;
  --display: "Bebas Neue", Impact, sans-serif;
  --body: "Inter", Arial, sans-serif;
  --hand: "Caveat", cursive;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  color: var(--carrara);
  background:
    radial-gradient(circle at 82% 12%, rgba(53, 28, 117, .46), transparent 34rem),
    radial-gradient(circle at 12% 74%, rgba(255, 43, 214, .15), transparent 28rem),
    linear-gradient(135deg, #07080D 0%, #101019 48%, #07080D 100%);
  font-family: var(--body);
}

body::before { content: "Inter* Inter**"; display: none; }

body.ignited .neon-rail,
body.ignited .neon-seam { filter: brightness(1.8) drop-shadow(0 0 24px currentColor); }

.stage-grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .36;
  z-index: 2;
  background-image:
    linear-gradient(rgba(242, 239, 234, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 239, 234, .025) 1px, transparent 1px);
  background-size: 44px 44px, 44px 44px;
  mix-blend-mode: screen;
}

.cursor-spark {
  position: fixed;
  left: 0;
  top: 0;
  width: 13px;
  height: 13px;
  border: 1px solid var(--lime);
  border-radius: 50%;
  pointer-events: none;
  z-index: 30;
  opacity: .75;
  transform: translate3d(-50px, -50px, 0);
  box-shadow: 0 0 18px var(--lime), inset 0 0 8px var(--cyan);
}

.blueprint { position: relative; isolation: isolate; }

.chapter {
  position: relative;
  min-height: 100vh;
  overflow: hidden;
  display: grid;
  place-items: center;
  padding: clamp(2rem, 5vw, 6rem);
}

.marble-slab {
  position: absolute;
  z-index: -1;
  background:
    linear-gradient(112deg, rgba(242,239,234,.95), rgba(169,163,160,.45) 36%, rgba(242,239,234,.86) 62%, rgba(74,70,80,.32)),
    repeating-linear-gradient(128deg, transparent 0 28px, rgba(74,70,80,.12) 29px 31px, transparent 34px 72px),
    radial-gradient(circle at 20% 20%, rgba(255,255,255,.65), transparent 18rem);
  box-shadow: 0 2rem 7rem rgba(0, 0, 0, .5), inset 0 0 2px rgba(255,255,255,.75);
}

.marble-slab::before,
.marble-slab::after {
  content: "";
  position: absolute;
  inset: -12%;
  background:
    linear-gradient(27deg, transparent 16%, rgba(74,70,80,.22) 16.4%, transparent 17.2%),
    linear-gradient(151deg, transparent 38%, rgba(53,28,117,.18) 38.5%, transparent 39.6%),
    linear-gradient(94deg, transparent 65%, rgba(169,163,160,.35) 65.5%, transparent 66.2%);
  opacity: .72;
}

.marble-slab::after { transform: rotate(180deg) scale(1.08); opacity: .42; }

.slab-hero {
  width: 110vw;
  height: 68vh;
  left: -22vw;
  top: 20vh;
  clip-path: polygon(0 30%, 100% 0, 88% 73%, 8% 100%);
  transform: rotate(-7deg);
}

.slab-a { width: 90vw; height: 82vh; right: -23vw; top: 11vh; clip-path: polygon(14% 0, 100% 8%, 82% 100%, 0 81%); transform: rotate(5deg); }
.slab-b { width: 104vw; height: 80vh; left: -35vw; top: 9vh; clip-path: polygon(0 0, 92% 17%, 100% 79%, 18% 100%); transform: rotate(-4deg); }
.slab-c { width: 94vw; height: 82vh; right: -18vw; top: 10vh; clip-path: polygon(8% 11%, 100% 0, 86% 88%, 0 100%); transform: rotate(8deg); }

.neon-rail {
  position: fixed;
  width: 150vw;
  height: 2px;
  left: -25vw;
  top: 50vh;
  pointer-events: none;
  z-index: 5;
  opacity: .75;
  transform-origin: center;
}

.rail-cyan { color: var(--cyan); background: var(--cyan); transform: rotate(-14deg); box-shadow: 0 0 18px var(--cyan); }
.rail-magenta { color: var(--magenta); background: var(--magenta); top: 55vh; transform: rotate(-14deg); box-shadow: 0 0 18px var(--magenta); opacity: .35; }

.hero-copy { width: min(1100px, 92vw); transform: rotate(-6deg); z-index: 3; }
.tag-left { margin-left: .4rem; }

.wordmark {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(5rem, 18vw, 17rem);
  line-height: .78;
  letter-spacing: -.045em;
  color: var(--graphite);
  text-shadow: 0 0 1px var(--carrara), 0 0 22px rgba(0,245,255,.18);
  filter: drop-shadow(0 1rem 0 rgba(53, 28, 117, .22));
}

.wordmark .engine {
  color: transparent;
  -webkit-text-stroke: 2px var(--graphite);
  text-shadow: 0 0 16px rgba(255,43,214,.32);
}

.wordmark .rivet {
  display: inline-block;
  color: var(--magenta);
  font-style: normal;
  animation: rivetDrift 4.8s ease-in-out infinite;
  text-shadow: 0 0 16px var(--magenta), 0 0 28px var(--cyan);
}

.calibration,
.eyebrow,
.chapter-label,
.scroll-pin {
  font-family: var(--display);
  letter-spacing: .16em;
  text-transform: uppercase;
}

.calibration { color: var(--cyan); font-size: clamp(.9rem, 1.7vw, 1.35rem); text-shadow: 0 0 12px rgba(0,245,255,.55); }
.handnote { font-family: var(--hand); color: var(--pencil); font-size: clamp(1.6rem, 3vw, 2.7rem); margin: .2rem 0; }
.hero-note { color: var(--violet); margin-left: 18vw; transform: rotate(5deg); }

.stroke-field { position: absolute; inset: 17% 4% auto; height: 42vh; z-index: 2; transform: rotate(-6deg); }
.pencil-trace { width: 100%; height: 100%; overflow: visible; }
.pencil-trace path,
.diagram-cluster path,
.diagram-cluster circle,
.mechanical-underlay path,
.mechanical-underlay circle,
.spring-doodle path {
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.pencil-trace path { color: var(--pencil); stroke-width: 3; stroke-dasharray: 1500; stroke-dashoffset: 1500; animation: drawStroke 3s ease forwards .4s; }
.pencil-trace path + path { color: var(--magenta); stroke-width: 1.5; animation-delay: .95s; opacity: .8; }

.mechanical-underlay { position: absolute; right: clamp(-5rem, 3vw, 5rem); bottom: 4vh; width: min(42vw, 520px); color: rgba(0,245,255,.62); z-index: 1; transform: rotate(12deg); }
.mechanical-underlay svg { width: 100%; filter: drop-shadow(0 0 14px rgba(0,245,255,.45)); }
.mechanical-underlay path, .mechanical-underlay circle { stroke-width: 2; }
.gear-zig { stroke: var(--magenta); }

.scroll-pin {
  position: absolute;
  right: 8vw;
  bottom: 10vh;
  border: 1px solid var(--cyan);
  background: rgba(7,8,13,.72);
  color: var(--carrara);
  padding: .8rem 1rem;
  transform: rotate(-6deg);
  box-shadow: 0 0 24px rgba(0,245,255,.25);
  cursor: pointer;
}

.diagonal-strip {
  width: min(540px, 82vw);
  padding: clamp(1.5rem, 4vw, 3rem);
  background: rgba(7, 8, 13, .76);
  border: 1px solid rgba(242,239,234,.2);
  box-shadow: 0 1rem 4rem rgba(0,0,0,.42);
  backdrop-filter: blur(10px);
}

.strip-left { justify-self: start; margin-left: 7vw; transform: rotate(-5deg); }
.strip-right { justify-self: end; margin-right: 6vw; transform: rotate(5deg); }

.eyebrow { color: var(--lime); font-size: 1rem; margin: 0 0 .7rem; }
h2 { margin: 0 0 1rem; font-family: var(--display); font-size: clamp(3rem, 8vw, 7rem); line-height: .82; letter-spacing: -.018em; }
p { font-size: clamp(1rem, 1.5vw, 1.18rem); line-height: 1.6; }

.chapter-label {
  position: absolute;
  top: 13vh;
  left: 5vw;
  color: var(--magenta);
  font-size: clamp(2rem, 5vw, 5rem);
  transform: rotate(-84deg);
  transform-origin: left top;
  opacity: .84;
  text-shadow: 0 0 18px rgba(255,43,214,.45);
}

.diagram-cluster { position: absolute; right: 10vw; top: 22vh; width: min(33vw, 360px); color: var(--graphite); padding: 1.3rem; }
.diagram-cluster svg { width: 100%; filter: drop-shadow(0 0 15px rgba(255,43,214,.25)); }
.diagram-cluster path, .diagram-cluster circle { stroke-width: 3; }
.note-a { position: absolute; right: 21vw; bottom: 18vh; color: var(--cyan); transform: rotate(4deg); }

.ticks { position: absolute; width: 230px; height: 70px; background: repeating-linear-gradient(90deg, var(--pencil) 0 2px, transparent 2px 18px); opacity: .55; }
.ticks-a { right: 11vw; bottom: 11vh; transform: rotate(-13deg); }

.neon-seam { position: absolute; width: 120vw; height: 3px; left: -10vw; z-index: 1; transform: rotate(-19deg); }
.seam-one { top: 34vh; background: var(--cyan); color: var(--cyan); box-shadow: 0 0 22px var(--cyan); }
.seam-two { top: 63vh; background: var(--magenta); color: var(--magenta); box-shadow: 0 0 22px var(--magenta); opacity: .68; }

.parts-cloud { position: absolute; inset: 0; pointer-events: none; }
.part { position: absolute; display: block; pointer-events: auto; }
.screw { left: 18vw; top: 27vh; width: 34px; height: 34px; border-radius: 50%; border: 3px solid var(--cyan); box-shadow: inset 0 0 0 8px var(--graphite), 0 0 18px var(--cyan); }
.screw::after { content: ""; position: absolute; left: 5px; right: 5px; top: 14px; height: 3px; background: var(--cyan); transform: rotate(26deg); }
.bearing { left: 66vw; top: 66vh; width: 44px; height: 44px; border-radius: 50%; background: radial-gradient(circle at 30% 25%, #fff, var(--carrara) 32%, var(--vein) 60%, var(--pencil)); box-shadow: 0 0 22px var(--lime); }
.shard { width: 0; height: 0; filter: drop-shadow(0 0 14px rgba(255,43,214,.45)); }
.shard-one { left: 31vw; top: 62vh; border-left: 46px solid transparent; border-right: 12px solid transparent; border-bottom: 92px solid rgba(242,239,234,.86); transform: rotate(30deg); }
.shard-two { left: 78vw; top: 24vh; border-left: 18px solid transparent; border-right: 54px solid transparent; border-bottom: 78px solid rgba(169,163,160,.9); transform: rotate(-25deg); }
.spring-doodle { position: absolute; width: min(40vw, 420px); left: 12vw; bottom: 17vh; color: var(--lime); transform: rotate(6deg); }
.spring-doodle path { stroke-width: 4; filter: drop-shadow(0 0 12px rgba(184,255,26,.45)); }

.artifact-card {
  width: min(690px, 86vw);
  padding: clamp(1.5rem, 4vw, 3.6rem);
  background: linear-gradient(145deg, rgba(242,239,234,.91), rgba(169,163,160,.72));
  color: var(--graphite);
  border: 1px solid rgba(255,255,255,.7);
  clip-path: polygon(5% 0, 100% 7%, 92% 100%, 0 87%);
  transform: rotate(-4deg);
  box-shadow: 0 2rem 6rem rgba(0,0,0,.45), 0 0 35px rgba(0,245,255,.18);
}
.artifact-card h2 { color: var(--graphite); }
.artifact-card .calibration { color: var(--violet); text-shadow: none; }
.artifact-rule { display: flex; gap: .8rem; margin-top: 2rem; transform: rotate(2deg); }
.artifact-rule span { height: 4px; flex: 1; background: var(--magenta); box-shadow: 0 0 13px var(--magenta); }
.artifact-rule span:nth-child(2) { background: var(--cyan); box-shadow: 0 0 13px var(--cyan); }
.artifact-rule span:nth-child(3) { background: var(--lime); box-shadow: 0 0 13px var(--lime); }
.vertical-word { position: absolute; right: 4vw; top: 13vh; font-family: var(--display); font-size: clamp(5rem, 12vw, 13rem); writing-mode: vertical-rl; color: transparent; -webkit-text-stroke: 1px var(--cyan); opacity: .65; }
.note-b { position: absolute; left: 11vw; bottom: 12vh; color: var(--lime); transform: rotate(-7deg); }

.floating { transition: transform .42s ease, filter .42s ease, box-shadow .42s ease; animation: floatSoft 6s ease-in-out infinite; }
.floating:hover { transform: translateY(-8px) rotate(var(--hover-rotate, 2deg)); filter: drop-shadow(0 0 20px rgba(0,245,255,.62)); }
.floating::after {
  content: attr(data-note);
  position: absolute;
  left: 70%;
  top: -1.7rem;
  min-width: max-content;
  font-family: var(--hand);
  font-size: 1.55rem;
  color: var(--magenta);
  opacity: 0;
  transform: translateY(6px) rotate(-7deg);
  transition: opacity .35s ease, transform .35s ease;
}
.floating:hover::after { opacity: 1; transform: translateY(0) rotate(-7deg); }

@keyframes drawStroke { to { stroke-dashoffset: 0; } }
@keyframes rivetDrift { 0%, 100% { transform: translate(0, 0); } 42% { transform: translate(14px, -10px); } 56% { transform: translate(-3px, 2px); } }
@keyframes floatSoft { 0%, 100% { translate: 0 0; } 50% { translate: 0 -7px; } }

@media (max-width: 760px) {
  .chapter { padding: 2rem 1rem; }
  .hero-copy { transform: rotate(-4deg); }
  .wordmark { font-size: clamp(4.5rem, 24vw, 8rem); }
  .mechanical-underlay { width: 78vw; opacity: .45; right: -25vw; }
  .strip-left, .strip-right { margin: 0; transform: rotate(-2deg); }
  .diagram-cluster, .spring-doodle { opacity: .55; width: 70vw; }
  .chapter-label { font-size: 2.8rem; }
  .cursor-spark { display: none; }
}