:root {
  /* fonts from Google Fonts */
  --paper-white: #F6F2EA;
  --rice-paper: #E8E0D2;
  --soft-ash: #B8B3AA;
  --graphite: #5E5A53;
  --sumi: #171512;
  --seal: #2B211B;
  --mist: #D7D1C7;
  --progress: 0;
  --display: "Roboto Flex", "Inter", "Roboto", system-ui, sans-serif;
  --serif: "Noto Serif JP", Georgia, serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--sumi);
  background: var(--paper-white);
  font-family: var(--display);
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

.paper-grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 20;
  opacity: 0.33;
  background:
    radial-gradient(circle at 12% 18%, rgba(23, 21, 18, 0.035) 0 1px, transparent 1.8px),
    radial-gradient(circle at 76% 64%, rgba(94, 90, 83, 0.035) 0 1px, transparent 2px),
    linear-gradient(115deg, rgba(232, 224, 210, 0.35), rgba(246, 242, 234, 0.1) 38%, rgba(215, 209, 199, 0.32));
  background-size: 38px 38px, 51px 51px, 100% 100%;
  mix-blend-mode: multiply;
}

.scroll-meter {
  position: fixed;
  top: 0;
  right: 0;
  width: 2px;
  height: calc(var(--progress) * 100vh);
  background: var(--seal);
  z-index: 30;
  opacity: 0.45;
  transition: height 0.08s linear;
}

.vertical-index {
  position: fixed;
  left: 2.2vw;
  top: 50%;
  transform: translateY(-50%);
  z-index: 25;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.index-mark {
  width: 24px;
  height: 24px;
  border: 1px solid rgba(94, 90, 83, 0.35);
  color: var(--graphite);
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: 11px;
  background: rgba(246, 242, 234, 0.48);
  transition: border-color 0.8s ease, background 0.8s ease, color 0.8s ease, transform 0.8s ease;
}

.index-mark.is-active {
  border-color: var(--seal);
  background: var(--seal);
  color: var(--rice-paper);
  transform: translateX(5px);
}

.site-stage {
  position: relative;
}

.chamber {
  min-height: 100vh;
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(90deg, rgba(215, 209, 199, 0.22), transparent 18%, transparent 78%, rgba(232, 224, 210, 0.34)),
    var(--paper-white);
  isolation: isolate;
}

.chamber::before,
.chamber::after {
  content: "";
  position: absolute;
  pointer-events: none;
  z-index: -1;
}

.chamber::before {
  width: 1px;
  height: 76vh;
  left: 17vw;
  top: 12vh;
  background: linear-gradient(to bottom, transparent, rgba(184, 179, 170, 0.72) 16%, transparent 47%, rgba(184, 179, 170, 0.55) 64%, transparent);
}

.chamber::after {
  width: 54vw;
  height: 1px;
  right: 7vw;
  bottom: 18vh;
  background: linear-gradient(to right, transparent, rgba(184, 179, 170, 0.68), transparent 88%);
}

.kicker {
  display: block;
  font-family: var(--mono);
  color: var(--graphite);
  font-size: 10px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  margin-bottom: 18px;
}

.reveal-copy {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 1.5s ease, transform 1.5s ease;
}

.chamber.is-visible .reveal-copy {
  opacity: 1;
  transform: translateY(0);
}

.rail-note {
  position: absolute;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--mono);
  letter-spacing: 0.16em;
  font-size: 11px;
  color: var(--graphite);
  margin: 0;
}

.rail-note-left {
  left: 8vw;
  top: 12vh;
}

.rail-note-right {
  right: 9vw;
  top: 10vh;
}

.pause-chamber {
  background: radial-gradient(circle at 63% 72%, rgba(215, 209, 199, 0.42), transparent 22%), var(--paper-white);
}

.domain-mark {
  position: absolute;
  right: 8vw;
  top: 9vh;
  margin: 0;
  writing-mode: vertical-rl;
  font-family: var(--display);
  font-variation-settings: "wdth" 38, "wght" 620, "opsz" 96;
  font-size: clamp(42px, 5.4vw, 88px);
  line-height: 0.82;
  letter-spacing: -0.07em;
  color: var(--sumi);
}

.fragment-grid {
  position: absolute;
  width: 42vw;
  height: 36vh;
  left: 18vw;
  top: 15vh;
  opacity: 0.5;
  background-image:
    linear-gradient(to right, rgba(184, 179, 170, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(184, 179, 170, 0.42) 1px, transparent 1px);
  background-size: 64px 100%, 100% 46px;
  mask-image: linear-gradient(115deg, transparent 0 15%, #000 28% 64%, transparent 84%);
  clip-path: inset(0 100% 0 0);
  transition: clip-path 2.2s ease 0.2s;
}

.pause-chamber.is-visible .fragment-grid {
  clip-path: inset(0 0 0 0);
}

.opening-gate {
  position: absolute;
  left: 22vw;
  bottom: 12vh;
  width: 54vw;
  height: 30vh;
  display: flex;
  align-items: flex-end;
  filter: drop-shadow(0 14px 22px rgba(43, 33, 27, 0.08));
}

.gate-post {
  display: block;
  width: 13vw;
  background: var(--sumi);
  border-radius: 1px;
  transform-origin: bottom;
  transform: scaleY(0.04);
  transition: transform 2s cubic-bezier(.21,.72,.16,1);
}

.gate-post-tall {
  height: 28vh;
}

.gate-post-short {
  height: 18vh;
}

.gate-void {
  width: 17vw;
  height: 4.8vh;
  background: var(--rice-paper);
  border-top: 1px solid rgba(94, 90, 83, 0.2);
  border-bottom: 1px solid rgba(94, 90, 83, 0.2);
  opacity: 0;
  transition: opacity 1.2s ease 1s;
}

.pause-chamber.is-visible .gate-post {
  transform: scaleY(1);
}

.pause-chamber.is-visible .gate-void {
  opacity: 1;
}

.brush-rectangle {
  position: absolute;
  left: 15vw;
  top: 45vh;
  width: 31vw;
  height: 13vh;
  border: 2px solid var(--sumi);
  border-right-color: transparent;
  clip-path: inset(0 100% 0 0);
  transition: clip-path 1.8s ease 0.55s;
}

.pause-chamber.is-visible .brush-rectangle {
  clip-path: inset(0 0 0 0);
}

.transfer-dot {
  position: absolute;
  width: 11px;
  height: 11px;
  background: var(--seal);
  border-radius: 50%;
  left: 7%;
  top: calc(50% - 5px);
  box-shadow: 0 0 16px rgba(43, 33, 27, 0.22);
}

.opening-copy {
  position: absolute;
  left: 52vw;
  top: 42vh;
  width: 20vw;
  min-width: 260px;
  font-family: var(--serif);
  font-size: clamp(18px, 2vw, 30px);
  line-height: 1.55;
  color: var(--seal);
}

.ledger-chamber {
  background: linear-gradient(180deg, var(--paper-white), var(--rice-paper));
}

.ledger-field {
  position: absolute;
  inset: 7vh 9vw 9vh 19vw;
}

.ledger-line {
  position: absolute;
  background: var(--soft-ash);
  opacity: 0.58;
  transform-origin: left center;
  transform: scaleX(0);
  transition: transform 1.7s ease;
}

.ledger-line::after {
  content: "";
  position: absolute;
  width: 1px;
  height: 68px;
  right: 23%;
  top: -34px;
  background: rgba(184, 179, 170, 0.7);
}

.line-one { width: 48vw; height: 1px; top: 14%; left: 0; transition-delay: 0.1s; }
.line-two { width: 61vw; height: 1px; top: 32%; left: 8vw; transition-delay: 0.3s; }
.line-three { width: 34vw; height: 1px; top: 51%; left: 3vw; transition-delay: 0.5s; }
.line-four { width: 52vw; height: 1px; top: 70%; left: 12vw; transition-delay: 0.7s; }
.line-five { width: 23vw; height: 1px; top: 86%; left: 27vw; transition-delay: 0.9s; }

.ledger-chamber.is-visible .ledger-line {
  transform: scaleX(1);
}

.ledger-marginalia {
  position: absolute;
  left: 12vw;
  top: 22vh;
  display: grid;
  gap: 10vh;
  font-family: var(--mono);
  letter-spacing: 0.2em;
  color: var(--graphite);
  font-size: 11px;
}

.ledger-marginalia span {
  opacity: 0;
  transform: translateX(-14px);
  transition: opacity 1.2s ease, transform 1.2s ease;
}

.ledger-chamber.is-visible .ledger-marginalia span {
  opacity: 1;
  transform: translateX(0);
}

.ledger-chamber.is-visible .ledger-marginalia span:nth-child(2) { transition-delay: 0.25s; }
.ledger-chamber.is-visible .ledger-marginalia span:nth-child(3) { transition-delay: 0.5s; }
.ledger-chamber.is-visible .ledger-marginalia span:nth-child(4) { transition-delay: 0.75s; }

.ledger-text {
  position: absolute;
  right: 12vw;
  bottom: 19vh;
  width: min(38vw, 520px);
}

h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(38px, 6vw, 86px);
  line-height: 1.05;
  margin: 0 0 28px;
  color: var(--sumi);
}

.ledger-text p,
.record-copy p,
.quiet-receipt p,
.fold-panel p {
  font-family: var(--serif);
  font-size: clamp(16px, 1.4vw, 22px);
  line-height: 1.85;
  color: var(--graphite);
  margin: 0;
}

.coordinate-stack {
  position: absolute;
  right: 28vw;
  top: 15vh;
  display: grid;
  grid-template-columns: repeat(2, 9px);
  gap: 35px 74px;
}

.coordinate-stack i {
  width: 9px;
  height: 9px;
  border: 1px solid var(--graphite);
}

.record-chamber {
  background: linear-gradient(90deg, var(--rice-paper), var(--paper-white) 42%, var(--paper-white));
}

.split-record {
  position: absolute;
  left: 11vw;
  top: 20vh;
  width: 66vw;
  height: 52vh;
}

.record-svg {
  width: 100%;
  height: 100%;
  overflow: visible;
}

.ink-stone {
  fill: none;
  stroke: var(--sumi);
  stroke-width: 2.2;
  opacity: 0.95;
  stroke-dasharray: 940;
  stroke-dashoffset: 940;
  transition: stroke-dashoffset 2.4s ease, fill 2s ease 1s;
}

.stone-right {
  stroke: var(--seal);
  stroke-width: 1.6;
}

.record-chamber.is-visible .ink-stone {
  stroke-dashoffset: 0;
  fill: rgba(23, 21, 18, 0.025);
}

.bent-path {
  fill: none;
  stroke: var(--graphite);
  stroke-width: 1;
  stroke-dasharray: 370;
  stroke-dashoffset: 370;
  transition: stroke-dashoffset 2s ease 0.8s;
}

.record-chamber.is-visible .bent-path {
  stroke-dashoffset: 0;
}

.path-dot {
  fill: var(--seal);
  opacity: 0;
  transition: opacity 1s ease 1.6s;
}

.record-chamber.is-visible .path-dot {
  opacity: 1;
}

.record-copy {
  position: absolute;
  right: 10vw;
  bottom: 11vh;
  width: min(35vw, 470px);
}

.ceremony-chamber {
  background: var(--paper-white);
}

.fold-screen {
  position: absolute;
  left: 12vw;
  top: 17vh;
  width: 74vw;
  height: 62vh;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  perspective: 1400px;
}

.fold-panel {
  position: relative;
  padding: 42px 24px 34px;
  border-left: 1px solid rgba(184, 179, 170, 0.75);
  border-top: 1px solid rgba(184, 179, 170, 0.45);
  background: linear-gradient(90deg, rgba(215, 209, 199, 0.36), rgba(246, 242, 234, 0.82));
  transform: rotateY(-9deg) translateY(24px);
  transform-origin: left center;
  opacity: 0;
  transition: transform 1.3s cubic-bezier(.21,.72,.16,1), opacity 1.3s ease;
}

.ceremony-chamber.is-visible .fold-panel {
  transform: rotateY(0deg) translateY(0);
  opacity: 1;
}

.ceremony-chamber.is-visible .fold-panel:nth-child(2) { transition-delay: 0.16s; }
.ceremony-chamber.is-visible .fold-panel:nth-child(3) { transition-delay: 0.32s; }
.ceremony-chamber.is-visible .fold-panel:nth-child(4) { transition-delay: 0.48s; }
.ceremony-chamber.is-visible .fold-panel:nth-child(5) { transition-delay: 0.64s; }

.fold-number {
  font-family: var(--mono);
  color: var(--graphite);
  font-size: 10px;
  letter-spacing: 0.24em;
}

.fold-panel h3 {
  writing-mode: vertical-rl;
  font-family: var(--display);
  font-variation-settings: "wdth" 42, "wght" 330, "opsz" 72;
  font-size: clamp(28px, 4vw, 54px);
  letter-spacing: 0.02em;
  line-height: 1;
  height: 250px;
  margin: 28px 0 34px;
  color: var(--sumi);
}

.fold-panel p {
  font-size: 15px;
  line-height: 1.7;
}

.ceremony-copy {
  position: absolute;
  right: 9vw;
  bottom: 7vh;
}

.receipt-chamber {
  background: radial-gradient(circle at 75% 57%, rgba(43, 33, 27, 0.08), transparent 14%), var(--rice-paper);
}

.receipt-grid {
  position: absolute;
  inset: 8vh 8vw;
  background-image:
    linear-gradient(to right, rgba(184, 179, 170, 0.36) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(184, 179, 170, 0.28) 1px, transparent 1px);
  background-size: 82px 100%, 100% 58px;
  mask-image: radial-gradient(circle at 72% 54%, #000 0 16%, transparent 44%), linear-gradient(to bottom, transparent, #000 22%, #000 64%, transparent);
  opacity: 0.55;
}

.quiet-receipt {
  position: absolute;
  left: 16vw;
  top: 22vh;
  width: min(37vw, 520px);
}

.final-seal {
  position: absolute;
  right: 19vw;
  bottom: 24vh;
  width: 118px;
  height: 118px;
  border: 2px solid var(--seal);
  display: grid;
  place-items: center;
  opacity: 0;
  transform: scale(1.28) rotate(2deg);
  transition: opacity 0.45s ease 0.65s, transform 0.7s cubic-bezier(.14,.9,.32,1.05) 0.65s;
}

.receipt-chamber.is-visible .final-seal {
  opacity: 1;
  transform: scale(1) rotate(0deg);
}

.seal-gate {
  width: 74px;
  height: 62px;
  display: flex;
  align-items: flex-end;
}

.seal-gate span {
  width: 24px;
  background: var(--seal);
}

.seal-gate span:first-child { height: 58px; }
.seal-gate span:last-child { height: 40px; }
.seal-gate b {
  display: block;
  width: 26px;
  height: 12px;
  border-top: 1px solid var(--seal);
  border-bottom: 1px solid var(--seal);
  background: var(--rice-paper);
}

.receipt-domain {
  position: absolute;
  right: 8vw;
  top: 12vh;
  margin: 0;
  writing-mode: vertical-rl;
  font-family: var(--mono);
  letter-spacing: 0.22em;
  color: var(--graphite);
  font-size: 12px;
}

@keyframes breatheGrid {
  0%, 100% { opacity: 0.42; }
  50% { opacity: 0.72; }
}

.ledger-field,
.receipt-grid {
  animation: breatheGrid 6s ease-in-out infinite;
}

@media (max-width: 820px) {
  .domain-mark {
    right: 6vw;
    font-size: 46px;
  }

  .opening-copy,
  .ledger-text,
  .record-copy,
  .quiet-receipt {
    left: 18vw;
    right: auto;
    width: 68vw;
    min-width: 0;
  }

  .opening-gate {
    left: 15vw;
    width: 72vw;
  }

  .brush-rectangle {
    left: 16vw;
    width: 50vw;
  }

  .fold-screen {
    grid-template-columns: 1fr;
    height: auto;
    top: 10vh;
  }

  .fold-panel {
    min-height: 15vh;
    padding: 20px;
  }

  .fold-panel h3 {
    writing-mode: horizontal-tb;
    height: auto;
    margin: 14px 0;
  }
}