:root {
  color-scheme: dark;
  --bg: #06101d;
  --surface: #0a1929;
  --surface-2: #10263a;
  --surface-3: #153047;
  --line: rgba(163, 196, 222, .17);
  --line-strong: rgba(163, 196, 222, .31);
  --text: #f5f8fb;
  --muted: #a7bacb;
  --muted-2: #7890a5;
  --p: #39bdf8;
  --s: #ff4d4f;
  --alert: #a78bfa;
  --sound: #2dd4bf;
  --danger: #fb7185;
  --success: #4ade80;
  --yellow: #fcd34d;
  --shadow: 0 26px 80px rgba(0, 0, 0, .33);
  --radius: 20px;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #edf4f8;
  --surface: #ffffff;
  --surface-2: #f3f8fb;
  --surface-3: #e7f0f5;
  --line: rgba(38, 75, 101, .15);
  --line-strong: rgba(38, 75, 101, .28);
  --text: #10283a;
  --muted: #486779;
  --muted-2: #6a8495;
  --p: #0879b7;
  --s: #c62828;
  --alert: #7254d8;
  --sound: #0b897e;
  --danger: #d43e5a;
  --success: #178b4d;
  --yellow: #976900;
  --shadow: 0 24px 68px rgba(36, 71, 94, .14);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 6% -4%, rgba(56, 189, 248, .16), transparent 34rem),
    radial-gradient(circle at 94% 6%, rgba(45, 212, 191, .10), transparent 34rem),
    linear-gradient(180deg, #071422 0%, var(--bg) 42%, #050c16 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
  transition: color .22s ease, background .22s ease;
}

button, input, select { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }

.shell {
  width: min(1560px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0 54px;
}

.topbar {
  position: sticky;
  top: 10px;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 64px;
  padding: 11px 14px 11px 18px;
  border: 1px solid rgba(168, 196, 220, .2);
  border-radius: 17px;
  background: rgba(6, 16, 29, .88);
  box-shadow: 0 14px 42px rgba(0, 0, 0, .3);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  min-width: max-content;
  gap: 13px;
  color: inherit;
  text-decoration: none;
}

.brand-logo-panel {
  display: flex;
  align-items: center;
  width: 176px;
  height: 44px;
  padding: 3px 7px;
  border: 0;
  border-radius: 5px;
  background: linear-gradient(90deg, rgba(255, 255, 255, .98), rgba(255, 255, 255, .88));
  box-shadow: none;
  transition: opacity .18s ease;
}

.brand:hover .brand-logo-panel {
  opacity: .86;
}

.brand-logo-panel img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.brand-module {
  padding-left: 13px;
  border-left: 1px solid var(--line-strong);
}

.brand-module strong {
  display: block;
  font-size: .78rem;
  line-height: 1.1;
  letter-spacing: .11em;
  text-transform: uppercase;
}

.brand-module span {
  display: block;
  margin-top: 4px;
  color: var(--muted-2);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.topbar-spacer { flex: 1; }

.sim-clock {
  display: flex;
  align-items: baseline;
  gap: 11px;
  min-width: 210px;
  padding-right: 8px;
}

.sim-clock-label {
  color: var(--muted-2);
  font-size: .74rem;
  font-weight: 760;
  letter-spacing: .09em;
  text-transform: uppercase;
}

.sim-clock-time {
  font-size: 1.5rem;
  font-variant-numeric: tabular-nums;
  font-weight: 730;
  letter-spacing: -.045em;
}

.button-row { display: flex; gap: 8px; }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 0 15px;
  border: 1px solid var(--line-strong);
  border-radius: 11px;
  color: var(--text);
  background: rgba(255, 255, 255, .04);
  cursor: pointer;
  transition: border-color .18s ease, background .18s ease, transform .18s ease;
}

.button:hover {
  border-color: rgba(185, 213, 235, .48);
  background: rgba(255, 255, 255, .08);
}

.button:active { transform: translateY(1px); }

.button.primary {
  border-color: rgba(45, 212, 191, .4);
  color: #031714;
  background: var(--sound);
  font-weight: 770;
}

.button.primary:hover { background: #5eead4; }
.button svg { width: 16px; height: 16px; }

.button.theme-button {
  border-color: rgba(252, 211, 77, .34);
  color: #ffe28a;
  background: rgba(252, 211, 77, .07);
}

.button.theme-button:hover {
  border-color: rgba(252, 211, 77, .56);
  background: rgba(252, 211, 77, .12);
}

.button.sound-button {
  border-color: rgba(45, 212, 191, .33);
  color: #99f6e4;
  background: rgba(45, 212, 191, .08);
}

.button.sound-button:hover {
  border-color: rgba(45, 212, 191, .56);
  background: rgba(45, 212, 191, .13);
}

.button.sound-button.is-muted {
  border-color: var(--line-strong);
  color: var(--muted);
  background: rgba(255, 255, 255, .035);
}

.button.sound-button.needs-activation {
  border-color: rgba(252, 211, 77, .5);
  color: var(--yellow);
  background: rgba(252, 211, 77, .09);
}

.lead {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(300px, .55fr);
  gap: 26px;
  align-items: end;
  padding: 38px 8px 22px;
}

.eyebrow,
.section-label {
  display: block;
  color: #89e8da;
  font-size: .75rem;
  font-weight: 800;
  letter-spacing: .13em;
  text-transform: uppercase;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 11px;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--sound);
}

h1 {
  max-width: 960px;
  margin: 0;
  font-size: clamp(2rem, 4vw, 4rem);
  font-weight: 670;
  letter-spacing: -.055em;
  line-height: 1.02;
}

.lead p {
  max-width: 980px;
  margin: 13px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.45vw, 1.16rem);
  line-height: 1.6;
}

.key-idea {
  padding: 18px 20px;
  border: 1px solid rgba(45, 212, 191, .28);
  border-radius: 16px;
  background: linear-gradient(145deg, rgba(45, 212, 191, .1), rgba(10, 25, 41, .76));
}

.key-idea span {
  display: block;
  color: #99f6e4;
  font-size: .75rem;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.key-idea strong {
  display: block;
  margin-top: 7px;
  font-size: 1.05rem;
  line-height: 1.45;
}

.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(155deg, rgba(16, 36, 56, .96), rgba(7, 20, 34, .97));
  box-shadow: var(--shadow);
}

.stage-panel { overflow: hidden; }

.stage-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
}

.stage-head h2,
.section-heading h2,
.controls-head h2,
.sequence-head h2 {
  margin: 5px 0 0;
  font-size: clamp(1.35rem, 2vw, 1.8rem);
  font-weight: 690;
  letter-spacing: -.03em;
}

.phase {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  max-width: 420px;
  padding: 9px 13px;
  border: 1px solid rgba(56, 189, 248, .27);
  border-radius: 999px;
  color: #c2e8fb;
  background: rgba(56, 189, 248, .08);
  font-size: .78rem;
  font-weight: 780;
  letter-spacing: .06em;
  line-height: 1.25;
  text-align: center;
  text-transform: uppercase;
}

.phase::before {
  content: "";
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 11px currentColor;
}

.stage-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 330px;
  min-height: 535px;
}

.diagram-column {
  min-width: 0;
  padding: 13px 12px 12px;
  border-right: 1px solid var(--line);
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  padding: 0 8px 12px;
  color: var(--muted);
  font-size: .8rem;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.legend-item.p { color: var(--p); }
.legend-item.s { color: var(--s); }
.legend-item.alert { color: var(--alert); }
.legend-item.sound { color: var(--sound); }
.legend-item.blind { color: var(--danger); }

.legend-swatch {
  width: 19px;
  height: 4px;
  border-radius: 999px;
  background: currentColor;
  box-shadow: 0 0 10px currentColor;
}

.canvas-scroll {
  width: 100%;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-width: thin;
  scrollbar-color: rgba(124, 157, 181, .5) rgba(7, 18, 31, .5);
}

.canvas-frame {
  position: relative;
  width: 100%;
  min-width: 0;
  padding-top: 44px;
  border-radius: 14px;
  background:
    radial-gradient(ellipse 245px 78px at 62px -8px, rgba(255, 255, 255, .98), rgba(255, 255, 255, .92) 52%, rgba(255, 255, 255, 0) 100%),
    #071422;
  overflow: hidden;
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0 0 14px 14px;
  transform: translate3d(0, 0, 0);
  transform-origin: center;
  transition: filter .22s ease;
}

.simulation-watermark {
  position: absolute;
  top: 7px;
  left: 14px;
  z-index: 2;
  display: flex;
  align-items: center;
  width: 132px;
  height: 30px;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  opacity: .8;
  transition: opacity .18s ease;
}

.simulation-watermark:hover {
  opacity: 1;
}

.simulation-watermark img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

canvas.seismic-shake { animation: seismic-chart-shake .16s linear infinite; }

@keyframes seismic-chart-shake {
  0%, 100% { transform: translate3d(0, 0, 0) rotate(0); }
  12% { transform: translate3d(-4px, 1px, 0) rotate(-.08deg); }
  25% { transform: translate3d(3px, -2px, 0) rotate(.06deg); }
  38% { transform: translate3d(-2px, 3px, 0) rotate(-.05deg); }
  50% { transform: translate3d(4px, 1px, 0) rotate(.08deg); }
  63% { transform: translate3d(-3px, -2px, 0) rotate(-.06deg); }
  76% { transform: translate3d(2px, 3px, 0) rotate(.05deg); }
  88% { transform: translate3d(-1px, -2px, 0) rotate(-.03deg); }
}

.scroll-hint {
  display: none;
  margin: 8px 8px 0;
  color: var(--muted-2);
  font-size: .76rem;
}

.live-guide {
  display: flex;
  flex-direction: column;
  padding: 25px 23px;
  background:
    radial-gradient(circle at 100% 0%, rgba(56, 189, 248, .10), transparent 18rem),
    rgba(8, 22, 36, .72);
}

.live-step {
  display: flex;
  align-items: center;
  gap: 11px;
}

.step-number {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 1px solid rgba(56, 189, 248, .45);
  border-radius: 50%;
  color: #d8f2ff;
  background: rgba(56, 189, 248, .13);
  font-size: 1rem;
  font-weight: 800;
  box-shadow: 0 0 22px rgba(56, 189, 248, .12);
}

.step-kicker {
  color: var(--muted-2);
  font-size: .75rem;
  font-weight: 800;
  letter-spacing: .1em;
}

.live-guide h3 {
  margin: 21px 0 0;
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -.035em;
  line-height: 1.12;
}

.live-guide > p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: .98rem;
  line-height: 1.62;
}

.current-reading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  margin-top: 23px;
  padding: 13px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.current-reading span {
  max-width: 160px;
  color: var(--muted-2);
  font-size: .76rem;
  line-height: 1.35;
}

.current-reading strong {
  color: #d8e6f1;
  font-size: 1.25rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: -.03em;
  text-align: right;
}

.reaction-result {
  margin-top: 22px;
  padding: 17px;
  border: 1px solid rgba(252, 211, 77, .22);
  border-radius: 15px;
  background: linear-gradient(145deg, rgba(252, 211, 77, .09), rgba(252, 211, 77, .025));
}

.reaction-result > span {
  color: #d7bc5d;
  font-size: .7rem;
  font-weight: 800;
  letter-spacing: .09em;
  line-height: 1.35;
}

.reaction-result strong {
  display: block;
  margin-top: 6px;
  color: var(--yellow);
  font-size: clamp(2.75rem, 4.2vw, 4.4rem);
  font-variant-numeric: tabular-nums;
  font-weight: 680;
  letter-spacing: -.075em;
  line-height: 1;
}

.reaction-result strong.negative { color: var(--danger); }

.reaction-result p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: .78rem;
  line-height: 1.48;
}

.progress-block { margin-top: auto; padding-top: 26px; }

.progress-copy {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted-2);
  font-size: .72rem;
}

.progress-track {
  height: 7px;
  margin-top: 9px;
  overflow: hidden;
  border-radius: 999px;
  background: rgba(255, 255, 255, .08);
}

.progress-track span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--p), var(--alert), var(--sound), var(--s));
  transition: width .12s linear;
}

.explanation-section { padding: 55px 4px 20px; }
.section-heading { margin-bottom: 20px; }

.explanation-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr)) minmax(250px, .9fr);
  gap: 12px;
}

.explain-card,
.sound-rule {
  min-height: 235px;
  padding: 23px;
  border: 1px solid var(--line);
  border-radius: 17px;
  background: rgba(10, 26, 42, .8);
}

.explain-number {
  color: var(--p);
  font-size: .78rem;
  font-weight: 820;
  letter-spacing: .1em;
}

.explain-card:nth-child(2) .explain-number { color: var(--alert); }
.explain-card:nth-child(3) .explain-number { color: var(--sound); }

.explain-card h3 {
  margin: 27px 0 0;
  font-size: 1.17rem;
  font-weight: 700;
  letter-spacing: -.02em;
  line-height: 1.3;
}

.explain-card p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.62;
}

.sound-rule {
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-color: rgba(45, 212, 191, .27);
  background: linear-gradient(145deg, rgba(45, 212, 191, .11), rgba(10, 26, 42, .86));
}

.sound-rule span {
  color: #99f6e4;
  font-size: .73rem;
  font-weight: 800;
  letter-spacing: .1em;
}

.sound-rule strong {
  display: block;
  margin-top: 10px;
  font-size: clamp(2rem, 3.1vw, 3.1rem);
  letter-spacing: -.06em;
  line-height: 1;
}

.sound-rule p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: .86rem;
  line-height: 1.58;
}

.controls-panel { margin-top: 32px; overflow: hidden; }

.controls-head,
.sequence-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 21px 23px;
  border-bottom: 1px solid var(--line);
}

.speed-control {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: .82rem;
}

.speed-control select {
  border: 1px solid var(--line-strong);
  border-radius: 9px;
  padding: 7px 10px;
  color: var(--text);
  background: #0a1b2c;
}

.control-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
}

.control-group {
  padding: 22px;
  background: rgba(8, 23, 38, .98);
}

.group-title {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  min-height: 65px;
}

.group-title > span {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 31px;
  height: 31px;
  border: 1px solid rgba(45, 212, 191, .35);
  border-radius: 9px;
  color: #9ff5e8;
  background: rgba(45, 212, 191, .08);
  font-size: .78rem;
  font-weight: 800;
}

.group-title strong {
  display: block;
  font-size: .96rem;
}

.group-title small {
  display: block;
  margin-top: 5px;
  color: var(--muted-2);
  font-size: .76rem;
  line-height: 1.45;
}

.control {
  display: block;
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.control-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 15px;
}

.control-label {
  max-width: 72%;
  color: var(--muted);
  font-size: .82rem;
  font-weight: 690;
  line-height: 1.4;
}

.control-value {
  min-width: max-content;
  color: var(--text);
  font-size: .92rem;
  font-variant-numeric: tabular-nums;
  font-weight: 760;
}

input[type="range"] {
  width: 100%;
  height: 5px;
  margin: 5px 0 9px;
  border-radius: 999px;
  outline: none;
  accent-color: var(--sound);
  background: rgba(255, 255, 255, .14);
  cursor: pointer;
}

.control-scale {
  display: flex;
  justify-content: space-between;
  color: var(--muted-2);
  font-size: .72rem;
  font-variant-numeric: tabular-nums;
}

.sequence-panel { margin-top: 18px; overflow: hidden; }

.sequence-head > p {
  max-width: 710px;
  margin: 0;
  color: var(--muted);
  font-size: .82rem;
  line-height: 1.5;
  text-align: right;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
}

.event {
  position: relative;
  min-height: 118px;
  padding: 18px;
  background: rgba(8, 23, 38, .98);
  transition: background .2s ease;
}

.event::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 3px;
  background: var(--event-color, var(--line-strong));
  opacity: .16;
  transform: scaleX(0);
  transform-origin: left;
  transition: opacity .2s ease, transform .25s ease;
}

.event.reached { background: rgba(17, 39, 58, .98); }
.event.reached::after { opacity: .95; transform: scaleX(1); }

.event-time {
  color: var(--event-color, var(--muted));
  font-size: 1.3rem;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: -.035em;
}

.event-name {
  margin-top: 7px;
  color: #dbe6ef;
  font-size: .84rem;
  font-weight: 680;
  line-height: 1.35;
}

.event-place {
  margin-top: 5px;
  color: var(--muted-2);
  font-size: .75rem;
  line-height: 1.35;
}

.assumptions {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--muted);
  background: rgba(7, 18, 31, .62);
}

.assumptions summary {
  padding: 15px 18px;
  color: #a9bdcf;
  font-size: .82rem;
  font-weight: 700;
  cursor: pointer;
}

.assumptions p {
  margin: 0;
  padding: 0 18px 17px;
  color: var(--muted-2);
  font-size: .78rem;
  line-height: 1.6;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 23px 4px 0;
  color: #5f788d;
  font-size: .74rem;
}

.equipment-modal {
  width: min(1040px, calc(100vw - 34px));
  max-width: none;
  max-height: calc(100vh - 28px);
  padding: 0;
  border: 1px solid rgba(164, 196, 220, .24);
  border-radius: 22px;
  color: var(--text);
  background: #0a1827;
  box-shadow: 0 34px 110px rgba(0, 0, 0, .58);
  overflow-x: hidden;
  overflow-y: auto;
}

.equipment-modal::backdrop {
  background: rgba(2, 8, 16, .76);
  backdrop-filter: blur(8px);
}

.equipment-modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  z-index: 3;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid rgba(140, 170, 194, .24);
  border-radius: 50%;
  color: var(--text);
  background: rgba(7, 20, 34, .78);
  cursor: pointer;
  transition: border-color .18s ease, background .18s ease, transform .18s ease;
}

.equipment-modal-close:hover {
  border-color: rgba(255, 255, 255, .42);
  background: rgba(15, 37, 57, .94);
  transform: rotate(4deg);
}

.equipment-modal-close svg { width: 19px; height: 19px; }

.equipment-modal-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(330px, .92fr);
  min-height: 590px;
}

.equipment-visual {
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
  min-width: 0;
  background: #f4f5f5;
}

.equipment-image-card {
  display: grid;
  place-items: center;
  min-height: 390px;
  padding: 45px 42px 24px;
  overflow: hidden;
}

.equipment-image-card img {
  display: block;
  width: min(100%, 510px);
  height: auto;
  object-fit: contain;
}

.equipment-key-panel {
  min-height: 158px;
  padding: 26px 33px 25px;
  color: #ffffff;
  background: linear-gradient(120deg, #162e3d, #0f2635);
}

.equipment-key-panel > span,
.equipment-kicker {
  display: block;
  font-size: .72rem;
  font-weight: 830;
  letter-spacing: .15em;
  text-transform: uppercase;
}

.equipment-key-panel > span { color: #b9c8d2; }

.equipment-key-panel ul {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 26px;
  margin: 19px 0 0;
  padding: 0;
  list-style: none;
}

.equipment-key-panel li {
  position: relative;
  padding-left: 18px;
  color: #ffffff;
  font-size: .91rem;
  font-weight: 650;
  line-height: 1.35;
}

.equipment-key-panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .46em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #ed7c2c;
  box-shadow: 0 0 10px rgba(237, 124, 44, .52);
}

.equipment-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 76px 58px 60px;
  background:
    radial-gradient(circle at 100% 0%, rgba(56, 189, 248, .09), transparent 24rem),
    #0a1827;
}

.equipment-kicker { color: #ed8a3d; }

.equipment-copy h2 {
  margin: 15px 0 0;
  font-size: clamp(2.2rem, 5vw, 4.25rem);
  font-weight: 660;
  letter-spacing: -.055em;
  line-height: .98;
}

.equipment-copy p {
  margin: 25px 0 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.72;
}

.equipment-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  align-self: flex-start;
  gap: 10px;
  min-width: 164px;
  min-height: 50px;
  margin-top: 30px;
  padding: 0 22px;
  border-radius: 7px;
  color: #ffffff;
  background: #ed7c2c;
  box-shadow: 0 13px 26px rgba(237, 124, 44, .2);
  font-size: .92rem;
  font-weight: 800;
  text-decoration: none;
  transition: background .18s ease, transform .18s ease, box-shadow .18s ease;
}

.equipment-cta:hover {
  background: #fa8a38;
  box-shadow: 0 15px 30px rgba(237, 124, 44, .28);
  transform: translateY(-1px);
}

.equipment-cta svg { width: 18px; height: 18px; }

:root[data-theme="light"] body {
  background:
    radial-gradient(circle at 6% -4%, rgba(14, 133, 190, .13), transparent 34rem),
    radial-gradient(circle at 94% 6%, rgba(11, 137, 126, .10), transparent 34rem),
    linear-gradient(180deg, #f7fbfd 0%, var(--bg) 45%, #e8f0f5 100%);
}

:root[data-theme="light"] .topbar {
  border-color: rgba(47, 87, 113, .18);
  background: rgba(255, 255, 255, .9);
  box-shadow: 0 14px 40px rgba(41, 74, 96, .13);
}

:root[data-theme="light"] .brand-logo-panel {
  padding: 0;
  background: transparent;
}

:root[data-theme="light"] .button {
  background: rgba(25, 72, 101, .035);
}

:root[data-theme="light"] .button:hover {
  border-color: rgba(37, 81, 108, .42);
  background: rgba(25, 72, 101, .075);
}

:root[data-theme="light"] .button.primary {
  border-color: rgba(11, 137, 126, .42);
  color: #ffffff;
  background: #0b897e;
}

:root[data-theme="light"] .button.primary:hover { background: #08756c; }

:root[data-theme="light"] .button.theme-button {
  border-color: rgba(45, 78, 135, .28);
  color: #294c80;
  background: rgba(45, 78, 135, .07);
}

:root[data-theme="light"] .button.theme-button:hover {
  border-color: rgba(45, 78, 135, .46);
  background: rgba(45, 78, 135, .11);
}

:root[data-theme="light"] .button.sound-button {
  border-color: rgba(11, 137, 126, .3);
  color: #08756c;
  background: rgba(11, 137, 126, .07);
}

:root[data-theme="light"] .button.sound-button:hover {
  border-color: rgba(11, 137, 126, .48);
  background: rgba(11, 137, 126, .12);
}

:root[data-theme="light"] .button.sound-button.is-muted {
  color: var(--muted);
  background: rgba(25, 72, 101, .035);
}

:root[data-theme="light"] .eyebrow,
:root[data-theme="light"] .section-label { color: #087b72; }

:root[data-theme="light"] .key-idea {
  border-color: rgba(11, 137, 126, .24);
  background: linear-gradient(145deg, rgba(11, 137, 126, .09), rgba(255, 255, 255, .88));
}

:root[data-theme="light"] .key-idea span,
:root[data-theme="light"] .sound-rule span { color: #08756c; }

:root[data-theme="light"] .panel {
  background: linear-gradient(155deg, rgba(255, 255, 255, .98), rgba(242, 248, 251, .98));
}

:root[data-theme="light"] .phase {
  border-color: rgba(8, 121, 183, .24);
  color: #176d9b;
  background: rgba(8, 121, 183, .07);
}

:root[data-theme="light"] .canvas-scroll {
  scrollbar-color: rgba(79, 111, 132, .46) rgba(220, 231, 238, .7);
}

:root[data-theme="light"] .canvas-frame {
  border: 1px solid rgba(42, 79, 103, .12);
  background:
    linear-gradient(90deg, rgba(255, 255, 255, .98), rgba(238, 245, 249, .92) 280px),
    #eef5f9;
}

:root[data-theme="light"] canvas {
  border: 0;
  filter: invert(1) hue-rotate(180deg) saturate(.86) contrast(.92);
}

:root[data-theme="light"] .live-guide {
  background:
    radial-gradient(circle at 100% 0%, rgba(8, 121, 183, .09), transparent 18rem),
    rgba(238, 246, 250, .82);
}

:root[data-theme="light"] .step-number {
  border-color: rgba(8, 121, 183, .35);
  color: #176d9b;
  background: rgba(8, 121, 183, .09);
  box-shadow: 0 0 22px rgba(8, 121, 183, .08);
}

:root[data-theme="light"] .current-reading strong { color: #18394e; }

:root[data-theme="light"] .reaction-result {
  border-color: rgba(151, 105, 0, .21);
  background: linear-gradient(145deg, rgba(246, 187, 45, .13), rgba(255, 255, 255, .36));
}

:root[data-theme="light"] .reaction-result > span { color: #7c5a0b; }
:root[data-theme="light"] .progress-track { background: rgba(31, 72, 98, .1); }

:root[data-theme="light"] .explain-card,
:root[data-theme="light"] .sound-rule {
  background: rgba(255, 255, 255, .7);
}

:root[data-theme="light"] .sound-rule {
  border-color: rgba(11, 137, 126, .23);
  background: linear-gradient(145deg, rgba(11, 137, 126, .09), rgba(255, 255, 255, .76));
}

:root[data-theme="light"] .speed-control select {
  color: var(--text);
  background: #ffffff;
}

:root[data-theme="light"] .control-group,
:root[data-theme="light"] .event {
  background: rgba(255, 255, 255, .93);
}

:root[data-theme="light"] .group-title > span {
  border-color: rgba(11, 137, 126, .28);
  color: #08756c;
  background: rgba(11, 137, 126, .07);
}

:root[data-theme="light"] input[type="range"] { background: rgba(31, 72, 98, .16); }
:root[data-theme="light"] .event.reached { background: rgba(226, 239, 246, .96); }
:root[data-theme="light"] .event-name { color: #1b3a4d; }

:root[data-theme="light"] .assumptions {
  background: rgba(255, 255, 255, .58);
}

:root[data-theme="light"] .assumptions summary { color: #3f6174; }
:root[data-theme="light"] .footer { color: #6c8494; }

:root[data-theme="light"] .equipment-modal {
  border-color: rgba(47, 87, 113, .2);
  color: #10283a;
  background: #ffffff;
  box-shadow: 0 34px 100px rgba(21, 55, 77, .28);
}

:root[data-theme="light"] .equipment-modal-close {
  border-color: rgba(47, 87, 113, .18);
  color: #23495f;
  background: rgba(255, 255, 255, .9);
}

:root[data-theme="light"] .equipment-modal-close:hover { background: #ffffff; }

:root[data-theme="light"] .equipment-copy {
  background:
    radial-gradient(circle at 100% 0%, rgba(8, 121, 183, .08), transparent 24rem),
    #ffffff;
}

:root[data-theme="light"] .equipment-copy p { color: #526f80; }

@media (max-width: 1120px) {
  .button { min-width: 42px; padding-inline: 11px; }
  .button .button-label { display: none; }
}

@media (max-width: 1250px) {
  .stage-layout { grid-template-columns: 1fr; }
  .diagram-column { border-right: 0; border-bottom: 1px solid var(--line); }
  .live-guide {
    display: grid;
    grid-template-columns: .72fr 1fr 1fr;
    gap: 22px;
    align-items: center;
  }
  .live-guide h3 { margin-top: 12px; }
  .live-guide > p { margin-top: 7px; }
  .current-reading { margin-top: 13px; }
  .reaction-result { margin: 0; }
  .progress-block { margin-top: 0; padding-top: 0; grid-column: 1 / -1; }
  .explanation-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 980px) {
  .lead { grid-template-columns: 1fr; padding-top: 34px; }
  .control-groups { grid-template-columns: 1fr; }
  .group-title { min-height: 0; }
  .timeline { grid-template-columns: 1fr 1fr; }
  .sequence-head { align-items: flex-start; flex-direction: column; }
  .sequence-head > p { text-align: left; }
  .equipment-modal { width: min(760px, calc(100vw - 26px)); }
  .equipment-modal-grid { grid-template-columns: 1fr; }
  .equipment-image-card { min-height: 330px; padding: 37px 34px 18px; }
  .equipment-copy { padding: 44px 38px 46px; }
}

@media (max-width: 760px) {
  .shell { width: min(100% - 18px, 1560px); padding-top: 9px; }
  .topbar { top: 6px; flex-wrap: wrap; gap: 10px; padding: 10px; }
  .brand-logo-panel { width: 148px; height: 38px; padding: 2px 5px; }
  .brand-module { display: none; }
  .topbar-spacer { display: none; }
  .sim-clock {
    order: 3;
    flex: 1 0 100%;
    justify-content: space-between;
    min-width: 0;
    padding: 7px 4px 0;
    border-top: 1px solid var(--line);
  }
  .button { min-width: 42px; padding: 0 11px; }
  .button .button-label { display: none; }
  .lead { padding: 33px 3px 18px; }
  .stage-head,
  .controls-head { align-items: flex-start; flex-direction: column; }
  .phase { width: 100%; max-width: none; justify-content: center; }
  .diagram-column { padding-inline: 8px; }
  .legend { gap: 10px 15px; padding-inline: 4px; }
  .canvas-frame { width: 1000px; max-width: none; }
  .canvas-scroll canvas { width: 100%; max-width: none; }
  .simulation-watermark { top: 7px; left: 13px; width: 126px; height: 29px; }
  .scroll-hint { display: block; }
  .live-guide { display: block; padding: 21px; }
  .live-guide h3 { margin-top: 18px; }
  .current-reading { margin-top: 20px; }
  .reaction-result { margin-top: 18px; }
  .progress-block { padding-top: 20px; }
  .explanation-section { padding-top: 42px; }
  .explanation-grid { grid-template-columns: 1fr; }
  .explain-card, .sound-rule { min-height: 0; }
  .speed-control { width: 100%; justify-content: space-between; }
  .footer { flex-direction: column; }
  .equipment-key-panel ul { grid-template-columns: 1fr; gap: 10px; }
}

@media (max-width: 520px) {
  h1 { font-size: 2rem; }
  .timeline { grid-template-columns: 1fr; }
  .stage-head,
  .controls-head,
  .sequence-head { padding: 17px; }
  .control-group { padding: 18px; }
  .equipment-modal { width: calc(100vw - 18px); border-radius: 17px; }
  .equipment-image-card { min-height: 270px; padding: 36px 22px 16px; }
  .equipment-key-panel { padding: 23px 24px; }
  .equipment-copy { padding: 37px 25px 40px; }
  .equipment-copy h2 { font-size: 2.45rem; }
  .equipment-copy p { margin-top: 19px; font-size: .94rem; }
  .equipment-cta { width: 100%; margin-top: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  canvas.seismic-shake { animation: none !important; }
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}