@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Noto+Serif+SC:wght@400;500;600;700&display=swap');

:root {
  --reader-bg: #07080b;
  --reader-panel: rgba(13, 15, 20, 0.94);
  --reader-ink: #e9e6de;
  --reader-soft: #a7a8ad;
  --reader-dim: #737780;
  --reader-line: rgba(255, 255, 255, 0.1);
  --reader-cyan: #7ad9e6;
  --reader-gold: #cfb66d;
  --reader-danger: #d66b72;
  --reader-serif: 'Noto Serif SC', 'Songti SC', serif;
  --reader-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --reader-size: 19px;
  --reader-measure: 720px;
}

* { box-sizing: border-box; }

html {
  color-scheme: dark;
  background: var(--reader-bg);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 50% -10%, rgba(122, 217, 230, 0.07), transparent 36rem),
    linear-gradient(180deg, #090b0f, var(--reader-bg) 56%, #050609);
  color: var(--reader-ink);
  font-family: var(--reader-serif);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  transition: background 700ms ease, filter 700ms ease;
}

.reader-atmosphere {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  opacity: 0.38;
  background:
    radial-gradient(circle at 16% 22%, rgba(122, 217, 230, 0.045), transparent 30rem),
    radial-gradient(circle at 82% 62%, rgba(207, 182, 109, 0.035), transparent 32rem),
    repeating-linear-gradient(0deg, rgba(255,255,255,0.008) 0, rgba(255,255,255,0.008) 1px, transparent 1px, transparent 4px);
  transition: opacity 700ms ease, filter 700ms ease;
}

.phenomena-layer {
  position: fixed;
  inset: 0;
  z-index: 45;
  pointer-events: none;
  overflow: hidden;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(circle at center, transparent 44%, rgba(0, 0, 0, 0.34) 100%);
  transition: background 700ms ease, opacity 700ms ease;
}

body.phenomenon-absence::after {
  background: radial-gradient(circle at center, transparent 30%, rgba(0, 0, 0, 0.58) 100%);
}

body.phenomenon-silence .reader-atmosphere {
  opacity: 0.08;
  filter: blur(1.8px);
}

body.phenomenon-silence::after {
  background: radial-gradient(circle at center, transparent 56%, rgba(0, 0, 0, 0.48) 100%);
}

body.theme-warm {
  --reader-bg: #11100e;
  --reader-panel: rgba(25, 22, 18, 0.96);
  --reader-ink: #eee6d6;
  --reader-soft: #b6aa96;
  --reader-dim: #837967;
  --reader-line: rgba(231, 213, 179, 0.13);
  --reader-cyan: #9dcbd0;
  --reader-gold: #d3ae67;
  background:
    radial-gradient(circle at 50% -10%, rgba(211, 174, 103, 0.07), transparent 36rem),
    linear-gradient(180deg, #15130f, #11100e 58%, #0c0b09);
}

::selection {
  color: #fff;
  background: rgba(122, 217, 230, 0.28);
}

button,
select,
a { font: inherit; }

a { color: inherit; }

button:focus-visible,
select:focus-visible,
a:focus-visible,
[tabindex='0']:focus-visible {
  outline: 2px solid var(--reader-cyan);
  outline-offset: 4px;
}

.reader-topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 66px;
  padding: 0 22px;
  border-bottom: 1px solid var(--reader-line);
  background: rgba(7, 8, 11, 0.84);
  backdrop-filter: blur(18px);
}

.theme-warm .reader-topbar {
  background: rgba(17, 16, 14, 0.86);
}

.reader-brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  width: fit-content;
  text-decoration: none;
}

.reader-brand strong {
  font-weight: 600;
  letter-spacing: 0.18em;
}

.reader-brand span {
  color: var(--reader-dim);
  font: 500 10px/1 var(--reader-mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.chapter-select {
  min-width: 190px;
  height: 36px;
  padding: 0 34px 0 12px;
  border: 1px solid var(--reader-line);
  border-radius: 0;
  background: var(--reader-panel);
  color: var(--reader-soft);
  font: 500 11px/1 var(--reader-mono);
  letter-spacing: 0.06em;
}

.reader-controls {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 8px;
}

.reader-control {
  min-width: 36px;
  height: 36px;
  padding: 0 10px;
  border: 1px solid var(--reader-line);
  background: transparent;
  color: var(--reader-soft);
  font: 500 11px/1 var(--reader-mono);
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease, background 160ms ease;
}

.reader-control:hover,
.reader-control.active {
  border-color: rgba(122, 217, 230, 0.55);
  background: rgba(122, 217, 230, 0.08);
  color: var(--reader-ink);
}

.reader-control.observer.active {
  color: var(--reader-cyan);
  box-shadow: inset 0 -2px var(--reader-cyan);
}

.reading-progress {
  position: fixed;
  top: 65px;
  left: 0;
  right: 0;
  z-index: 60;
  height: 2px;
  background: rgba(255, 255, 255, 0.035);
}

.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--reader-cyan), var(--reader-gold));
  box-shadow: 0 0 12px rgba(122, 217, 230, 0.35);
  transition: width 80ms linear;
}

.reader-layout {
  display: grid;
  grid-template-columns: minmax(150px, 210px) minmax(0, 1fr) minmax(210px, 270px);
  gap: clamp(28px, 4vw, 68px);
  width: min(1440px, calc(100% - 48px));
  margin: 0 auto;
  padding: 64px 0 120px;
  transition: grid-template-columns 360ms ease, gap 360ms ease;
}

body:not(.observer-mode) .reader-layout {
  grid-template-columns: minmax(150px, 210px) minmax(0, 1fr) 0;
  gap: clamp(30px, 5vw, 82px);
}

.chapter-rail,
.observation-panel {
  position: sticky;
  top: 104px;
  align-self: start;
  max-height: calc(100vh - 132px);
  overflow: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--reader-line) transparent;
}

.observation-panel {
  transition: opacity 280ms ease, transform 280ms ease, visibility 280ms;
}

body:not(.observer-mode) .observation-panel {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateX(18px);
}

.rail-label,
.panel-label {
  margin-bottom: 18px;
  color: var(--reader-dim);
  font: 500 10px/1.5 var(--reader-mono);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.chapter-list {
  display: grid;
  gap: 8px;
}

.chapter-link {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 8px;
  padding: 13px 12px;
  border-left: 1px solid var(--reader-line);
  color: var(--reader-dim);
  text-decoration: none;
  transition: color 160ms ease, border-color 160ms ease, background 160ms ease;
}

.chapter-link .number {
  font: 500 10px/1.6 var(--reader-mono);
}

.chapter-link .name {
  font-size: 14px;
  line-height: 1.45;
}

.chapter-link:hover,
.chapter-link.active {
  border-left-color: var(--reader-cyan);
  background: rgba(122, 217, 230, 0.05);
  color: var(--reader-ink);
}

.rail-status {
  margin-top: 30px;
  padding: 14px;
  border: 1px solid var(--reader-line);
  color: var(--reader-soft);
  font: 400 10px/1.7 var(--reader-mono);
}

.rail-status strong {
  display: block;
  margin-bottom: 4px;
  color: var(--reader-cyan);
  font-weight: 500;
}

.reader-article {
  min-width: 0;
}

.chapter-header {
  width: min(100%, var(--reader-measure));
  margin: 0 auto 60px;
  padding-bottom: 42px;
  border-bottom: 1px solid var(--reader-line);
}

.chapter-meta {
  margin: 0 0 22px;
  color: var(--reader-cyan);
  font: 500 10px/1 var(--reader-mono);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.chapter-title {
  margin: 0;
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.18;
  font-weight: 500;
  letter-spacing: -0.035em;
}

.chapter-hook {
  max-width: 620px;
  margin: 24px 0 0;
  color: var(--reader-soft);
  font-size: 17px;
  line-height: 1.9;
}

.reader-content {
  width: min(100%, var(--reader-measure));
  margin: 0 auto;
  font-size: var(--reader-size);
  line-height: 2.08;
  letter-spacing: 0.012em;
}

.reader-content > :first-child { margin-top: 0; }

.reader-content p {
  position: relative;
  margin: 0 0 1.58em;
  text-wrap: pretty;
}

.reader-content h2,
.reader-content h3 {
  margin: 3.4em 0 1.4em;
  color: var(--reader-ink);
  font-weight: 600;
}

.reader-content h2 { font-size: 1.42em; }
.reader-content h3 { font-size: 1.18em; }

.reader-content hr {
  width: 90px;
  margin: 4.5em auto;
  border: 0;
  border-top: 1px solid var(--reader-line);
}

.reader-content blockquote {
  margin: 2.2em 0;
  padding: 1.1em 1.35em;
  border-left: 2px solid var(--reader-gold);
  background: rgba(207, 182, 109, 0.045);
  color: #ddd7c8;
}

.reader-content blockquote p {
  margin: 0.4em 0;
}

.reader-content code {
  padding: 0.12em 0.36em;
  border: 1px solid var(--reader-line);
  background: rgba(255, 255, 255, 0.035);
  color: var(--reader-cyan);
  font: 0.78em/1.5 var(--reader-mono);
}

.reader-content pre {
  overflow: auto;
  margin: 2em 0;
  padding: 18px;
  border: 1px solid var(--reader-line);
  background: rgba(0, 0, 0, 0.26);
  font: 0.76em/1.7 var(--reader-mono);
}

.reader-content strong {
  color: #fff;
  font-weight: 600;
}

.reader-content em {
  color: #d8d4cb;
}

.reader-loading,
.reader-error {
  width: min(100%, var(--reader-measure));
  margin: 80px auto;
  padding: 28px;
  border: 1px solid var(--reader-line);
  color: var(--reader-soft);
  line-height: 1.8;
}

.reader-error strong {
  display: block;
  margin-bottom: 8px;
  color: var(--reader-danger);
}

/* Observation and phenomenon layers */
.phenomenon {
  position: relative;
  isolation: isolate;
}

.residual {
  transition: margin 220ms ease, padding 220ms ease, background 220ms ease, color 220ms ease, border-color 220ms ease;
}

.observer-mode .residual.observed {
  margin-left: -14px;
  margin-right: -14px;
  padding: 8px 14px;
  border-left: 1px solid rgba(122, 217, 230, 0.26);
  background: linear-gradient(90deg, rgba(122, 217, 230, 0.035), transparent 68%);
}

.residual-marker {
  display: none;
  position: absolute;
  left: -18px;
  top: 1.15em;
  width: 5px;
  height: 5px;
  border: 1px solid rgba(122, 217, 230, 0.72);
  border-radius: 50%;
  box-shadow: 0 0 9px rgba(122, 217, 230, 0.34);
}

.observer-mode .residual.observed .residual-marker {
  display: block;
  animation: residual-marker-arrive 900ms ease both;
}

.phenomenon-active[data-effect='echo'] {
  animation: phenomenon-echo 900ms cubic-bezier(.2,.8,.2,1);
}

.phenomenon-active[data-effect='phase'],
.phenomenon-active[data-effect='signal'] {
  animation: phenomenon-phase 850ms cubic-bezier(.2,.8,.2,1);
}

.phenomenon-active[data-effect='absence'] {
  animation: phenomenon-absence 820ms ease;
}

.phenomenon-active[data-effect='entangle'] {
  animation: phenomenon-entangle 980ms ease;
}

.phenomenon-active[data-effect='branch'] {
  animation: phenomenon-branch 900ms ease;
}

.phenomenon-active[data-effect='silence'] {
  animation: phenomenon-silence-text 1300ms ease;
}

.branch-ripple {
  position: fixed;
  width: 10px;
  height: 10px;
  border: 1px solid rgba(207, 182, 109, 0.7);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 18px rgba(122, 217, 230, 0.2);
  animation: branch-ripple 950ms ease-out forwards;
}

.entanglement-flash {
  position: fixed;
  left: 5vw;
  right: 5vw;
  height: 1px;
  animation: entanglement-fade 1050ms ease-out forwards;
}

.entangle-line {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 1px;
  transform: scaleX(0);
  transform-origin: center;
  background: linear-gradient(90deg, transparent, rgba(122,217,230,.32), rgba(207,182,109,.42), rgba(122,217,230,.32), transparent);
  box-shadow: 0 0 12px rgba(122, 217, 230, 0.12);
  animation: entangle-line 820ms cubic-bezier(.2,.8,.2,1) forwards;
}

.entangle-node {
  position: absolute;
  top: -3px;
  width: 7px;
  height: 7px;
  border: 1px solid rgba(122, 217, 230, 0.72);
  border-radius: 50%;
  box-shadow: 0 0 14px rgba(122, 217, 230, 0.35);
  animation: entangle-node 820ms ease-out 90ms both;
}

.entangle-node.left { left: 0; }
.entangle-node.right {
  right: 0;
  border-color: rgba(207, 182, 109, 0.74);
  box-shadow: 0 0 14px rgba(207, 182, 109, 0.28);
}

.observation-summary {
  padding: 16px;
  border: 1px solid var(--reader-line);
  background: rgba(255, 255, 255, 0.018);
}

.observation-summary strong {
  display: block;
  margin-bottom: 8px;
  color: var(--reader-ink);
  font-size: 13px;
  font-weight: 500;
}

.observation-summary p {
  margin: 0;
  color: var(--reader-soft);
  font-size: 12px;
  line-height: 1.72;
}

.observation-list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}

.observation-entry {
  padding: 12px;
  border: 1px solid var(--reader-line);
  background: rgba(122, 217, 230, 0.025);
  color: var(--reader-soft);
  animation: observation-arrive 520ms ease both;
}

.observation-entry .entry-id {
  display: block;
  margin-bottom: 7px;
  color: var(--reader-gold);
  font: 500 9px/1 var(--reader-mono);
  letter-spacing: 0.1em;
}

.observation-entry p {
  margin: 0;
  font-size: 12px;
  line-height: 1.7;
}

.observation-empty {
  margin-top: 14px;
  color: var(--reader-dim);
  font: 400 10px/1.7 var(--reader-mono);
}

@keyframes residual-marker-arrive {
  0% { opacity: 0; transform: scale(.45); }
  45% { opacity: 1; transform: scale(1.35); }
  100% { opacity: .85; transform: scale(1); }
}

@keyframes phenomenon-echo {
  0%, 100% { transform: translateX(0); text-shadow: none; }
  24% { transform: translateX(-.6px); text-shadow: 1.2px 0 rgba(122,217,230,.28), -1.2px 0 rgba(207,182,109,.2); }
  38% { transform: translateX(.7px); text-shadow: -1.4px 0 rgba(122,217,230,.22), 1.4px 0 rgba(207,182,109,.26); }
  58% { transform: translateX(-.35px); text-shadow: .7px 0 rgba(122,217,230,.18); }
}

@keyframes phenomenon-phase {
  0%, 100% { filter: none; transform: translateZ(0); }
  36% { filter: drop-shadow(-1px 0 rgba(122,217,230,.28)) drop-shadow(1px 0 rgba(207,182,109,.18)); }
  48% { filter: drop-shadow(1.2px 0 rgba(122,217,230,.2)) drop-shadow(-1px 0 rgba(207,182,109,.24)); }
}

@keyframes phenomenon-absence {
  0%, 100% { opacity: 1; letter-spacing: .012em; }
  36% { opacity: .62; letter-spacing: .018em; }
  54% { opacity: .86; }
}

@keyframes phenomenon-entangle {
  0%, 100% { text-shadow: none; }
  28% { text-shadow: -1.1px 0 rgba(122,217,230,.25), 1.1px 0 rgba(207,182,109,.25); }
  50% { text-shadow: 1.1px 0 rgba(122,217,230,.2), -1.1px 0 rgba(207,182,109,.2); }
}

@keyframes phenomenon-branch {
  0%, 100% { background: transparent; }
  35% { background: radial-gradient(circle at 50% 50%, rgba(207,182,109,.065), transparent 70%); }
}

@keyframes phenomenon-silence-text {
  0%, 100% { opacity: 1; filter: none; }
  40% { opacity: .82; filter: contrast(.94) saturate(.72); }
  70% { opacity: .94; }
}

@keyframes branch-ripple {
  0% { width: 10px; height: 10px; opacity: .8; }
  100% { width: min(65vw, 620px); height: min(65vw, 620px); opacity: 0; border-color: rgba(122,217,230,.12); }
}

@keyframes entangle-line {
  0% { opacity: 0; transform: scaleX(0); }
  35% { opacity: .8; transform: scaleX(1); }
  100% { opacity: 0; transform: scaleX(1); }
}

@keyframes entangle-node {
  0% { opacity: 0; transform: scale(.4); }
  45% { opacity: 1; transform: scale(1.45); }
  100% { opacity: 0; transform: scale(.8); }
}

@keyframes entanglement-fade {
  0%, 70% { opacity: 1; }
  100% { opacity: 0; }
}

@keyframes observation-arrive {
  from { opacity: 0; transform: translateY(5px); border-color: rgba(122,217,230,.28); }
  to { opacity: 1; transform: none; border-color: var(--reader-line); }
}

.chapter-footer {
  width: min(100%, var(--reader-measure));
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 84px auto 0;
  padding-top: 28px;
  border-top: 1px solid var(--reader-line);
}

.chapter-nav-button {
  min-height: 86px;
  padding: 16px;
  border: 1px solid var(--reader-line);
  background: transparent;
  color: var(--reader-soft);
  text-decoration: none;
  cursor: pointer;
  transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.chapter-nav-button.next { text-align: right; }

.chapter-nav-button:hover {
  border-color: rgba(122, 217, 230, 0.5);
  background: rgba(122, 217, 230, 0.045);
  color: var(--reader-ink);
}

.chapter-nav-button span {
  display: block;
  margin-bottom: 8px;
  color: var(--reader-dim);
  font: 500 9px/1 var(--reader-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.chapter-nav-button.disabled {
  pointer-events: none;
  opacity: 0.28;
}

.mobile-ledger-button {
  display: none;
}

.mobile-ledger-indicator {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: transparent;
  box-shadow: none;
}

.mobile-ledger-indicator.active {
  background: var(--reader-gold);
  box-shadow: 0 0 12px rgba(207, 182, 109, 0.72);
  animation: ledger-indicator 1500ms ease-in-out infinite;
}

@keyframes ledger-indicator {
  0%, 100% { opacity: .5; transform: scale(.8); }
  50% { opacity: 1; transform: scale(1.25); }
}

.reader-footer {
  padding: 26px;
  border-top: 1px solid var(--reader-line);
  color: var(--reader-dim);
  text-align: center;
  font: 400 10px/1.6 var(--reader-mono);
}

@media (max-width: 1100px) {
  .reader-layout {
    grid-template-columns: 150px minmax(0, 1fr);
  }

  .observation-panel {
    position: fixed;
    right: 16px;
    bottom: 72px;
    top: auto;
    z-index: 80;
    width: min(330px, calc(100% - 32px));
    max-height: min(70vh, 620px);
    padding: 18px;
    border: 1px solid var(--reader-line);
    background: var(--reader-panel);
    box-shadow: 0 24px 70px rgba(0, 0, 0, 0.5);
    transform: translateY(18px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 180ms ease, transform 180ms ease;
  }

  .observation-panel.open {
    transform: none;
    opacity: 1;
    pointer-events: auto;
  }

  .observer-mode .mobile-ledger-button {
    display: inline-flex;
    position: fixed;
    right: 16px;
    bottom: 16px;
    z-index: 90;
    align-items: center;
    gap: 8px;
    min-height: 42px;
    padding: 0 14px;
    border: 1px solid rgba(122, 217, 230, 0.45);
    background: var(--reader-panel);
    color: var(--reader-cyan);
    font: 500 10px/1 var(--reader-mono);
    letter-spacing: 0.08em;
  }
}

@media (max-width: 780px) {
  .reader-topbar {
    grid-template-columns: 1fr auto;
    padding: 0 14px;
  }

  .chapter-select { display: none; }
  .reader-brand span { display: none; }
  .reader-control.labelled span { display: none; }

  .reader-layout {
    display: block;
    width: min(100% - 28px, 760px);
    padding-top: 46px;
  }

  .chapter-rail { display: none; }

  .chapter-header {
    margin-bottom: 40px;
    padding-bottom: 32px;
  }

  .chapter-title {
    font-size: clamp(36px, 12vw, 56px);
  }

  .reader-content {
    --reader-size: 18px;
    line-height: 2;
  }

  .observer-mode .residual.observed {
    margin-left: -8px;
    margin-right: -8px;
    padding-left: 12px;
    padding-right: 8px;
  }

  .residual-marker { left: -4px; }

  .chapter-footer {
    grid-template-columns: 1fr;
    margin-top: 60px;
  }

  .chapter-nav-button.next { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .phenomena-layer { display: none; }
  body.phenomenon-absence::after,
  body.phenomenon-silence::after { background: radial-gradient(circle at center, transparent 44%, rgba(0,0,0,.34) 100%); }
  body.phenomenon-silence .reader-atmosphere { opacity: .38; filter: none; }
}

@media print {
  .reader-topbar,
  .reading-progress,
  .chapter-rail,
  .observation-panel,
  .mobile-ledger-button,
  .chapter-footer,
  .reader-footer { display: none !important; }

  body,
  body.theme-warm {
    background: white;
    color: #111;
  }

  .reader-layout { display: block; width: auto; padding: 0; }
  .reader-content, .chapter-header { width: auto; max-width: 720px; }
  .reader-content { font-size: 12pt; line-height: 1.85; }
}