:root {
  --bg: #f8f1e9;
  --bg-deep: #ecd9ca;
  --ink: #13212b;
  --ink-soft: rgba(19, 33, 43, 0.66);
  --ink-faint: rgba(19, 33, 43, 0.36);
  --line: rgba(19, 33, 43, 0.11);
  --line-strong: rgba(19, 33, 43, 0.2);
  --accent: #d62d3a;
  --accent-soft: rgba(214, 45, 58, 0.1);
  --monitor-tint: rgba(255, 255, 255, 0.28);
  --shell: min(1360px, calc(100vw - 44px));
  --paper-left: 0px;
  --paper-top: 0px;
  --paper-width: 100%;
  --paper-height: 100%;
  --paper-minor: 12px;
  --paper-major: 60px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  font-family: "Manrope", sans-serif;
  background:
    radial-gradient(circle at 8% 10%, rgba(255, 255, 255, 0.86), transparent 18%),
    radial-gradient(circle at 90% 14%, rgba(214, 45, 58, 0.14), transparent 24%),
    radial-gradient(circle at 82% 78%, rgba(214, 45, 58, 0.12), transparent 24%),
    linear-gradient(180deg, #fcf7f2 0%, #f2e6db 48%, #e7d4c6 100%);
}

body.is-loading {
  overflow: hidden;
}

body.simulator-active {
  background:
    radial-gradient(circle at 10% 12%, rgba(255, 255, 255, 0.7), transparent 18%),
    radial-gradient(circle at 88% 12%, rgba(214, 45, 58, 0.12), transparent 20%),
    linear-gradient(180deg, #fbf6f1 0%, #f0e0d3 54%, #ebd7c8 100%);
}

a,
button {
  color: inherit;
  font: inherit;
}

button {
  cursor: pointer;
}

img,
canvas {
  display: block;
  max-width: 100%;
}

.ambient,
.grid-overlay,
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
}

.ambient {
  z-index: -4;
  filter: blur(60px);
}

.ambient--one {
  inset: -10% auto auto -10%;
  width: 42vw;
  height: 42vw;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.56);
}

.ambient--two {
  inset: auto -12% 8% auto;
  width: 36vw;
  height: 36vw;
  border-radius: 50%;
  background: rgba(214, 45, 58, 0.15);
}

.grid-overlay {
  z-index: -3;
  background-image:
    linear-gradient(rgba(214, 45, 58, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(214, 45, 58, 0.045) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(circle at center, black 32%, transparent 86%);
}

.grain {
  z-index: -2;
  opacity: 0.07;
  background-image:
    radial-gradient(circle at 16% 20%, rgba(19, 33, 43, 0.2) 0 1px, transparent 1px),
    radial-gradient(circle at 82% 36%, rgba(19, 33, 43, 0.14) 0 1px, transparent 1px);
  background-size: 180px 180px, 220px 220px;
}

.page {
  width: var(--shell);
  margin: 0 auto;
  padding: 22px 0 48px;
}

.masthead {
  display: flex;
  align-items: center;
  min-height: 76px;
  position: relative;
  z-index: 3;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
}

.brand__logo {
  width: 48px;
  height: 48px;
  object-fit: contain;
}

.brand__copy {
  display: grid;
  gap: 2px;
}

.brand__top,
.brand__bottom,
.eyebrow,
.monitor__eyebrow,
.monitor__readout span,
.monitor__calibration span,
.monitor__foot span,
.simulator-shell__stats span,
.response p,
.link-action,
.choice__index,
.quiz__hint {
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.brand__top {
  font-size: 0.58rem;
  font-weight: 800;
  color: var(--ink-soft);
}

.brand__bottom {
  font-size: 0.82rem;
  font-weight: 800;
}

.eyebrow,
.monitor__eyebrow {
  margin: 0 0 12px;
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--accent);
}

.title,
.quiz__head h2 {
  margin: 0;
  font-family: "Anton", sans-serif;
  font-weight: 400;
  text-transform: uppercase;
  line-height: 0.88;
}

.title {
  display: grid;
  font-size: clamp(3.8rem, 10vw, 8.6rem);
}

.title--cover {
  gap: 10px;
  justify-items: center;
  font-size: clamp(4.2rem, 9vw, 9rem);
}

.lead {
  max-width: 42rem;
  margin: 18px 0 0;
  font-size: clamp(1rem, 1.5vw, 1.16rem);
  line-height: 1.65;
  color: var(--ink-soft);
}

.cover {
  min-height: calc(100svh - 98px);
  display: grid;
  place-items: center;
  padding: 34px 0 58px;
}

.cover__inner {
  display: grid;
  justify-items: center;
  text-align: center;
  gap: 0;
}

.mode-stage,
.simulator-shell {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(42px);
}

.mode-stage.is-visible,
.simulator-shell.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
}

.mode-stage {
  min-height: calc(100svh - 110px);
  display: grid;
  place-items: center;
}

.mode-stage__inner {
  width: min(780px, 100%);
  display: grid;
}

.mode-stage__title {
  margin: 0;
  font-family: "Anton", sans-serif;
  font-size: clamp(3rem, 7vw, 5.4rem);
  font-weight: 400;
  line-height: 0.9;
  text-transform: uppercase;
}

.mode-stage__lead {
  max-width: 34rem;
  margin: 18px 0 0;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.lead--cover {
  max-width: 31rem;
}

.start-action {
  margin-top: 34px;
  padding: 0;
  border: 0;
  background: transparent;
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.24em;
}

.simulator-shell {
  display: grid;
  gap: 26px;
  min-height: calc(100svh - 110px);
}

.simulator-shell__head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.simulator-shell__intro {
  display: grid;
  gap: 4px;
}

.simulator-shell__intro-wrap {
  display: grid;
  gap: 18px;
}

.simulator-shell__meta {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.4;
  color: var(--ink-soft);
}

.simulator-shell__stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 14px 18px;
  color: var(--ink-soft);
}

.simulator-shell__stats span {
  font-size: 0.62rem;
  font-weight: 800;
}

.change-mode {
  justify-self: start;
  padding: 0;
  border: 0;
  background: transparent;
  font-size: 0.66rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.22em;
}

.simulator {
  display: grid;
  grid-template-columns: minmax(0, 1.42fr) minmax(320px, 0.74fr);
  gap: clamp(30px, 4vw, 72px);
  align-items: start;
}

.monitor {
  display: grid;
  gap: 18px;
}

.monitor__head,
.monitor__foot {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
}

.monitor__eyebrow {
  margin: 0;
}

.monitor__meta {
  display: grid;
  justify-items: end;
  gap: 8px;
}

.monitor__readout,
.monitor__foot {
  color: var(--ink-soft);
}

.monitor__readout span,
.monitor__calibration span,
.monitor__foot span {
  font-size: 0.62rem;
  font-weight: 800;
}

.monitor__readout,
.monitor__calibration {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px 14px;
}

.monitor__calibration {
  color: rgba(214, 45, 58, 0.9);
}

.monitor__stage {
  position: relative;
  min-height: 480px;
  padding: 30px 0;
  overflow: hidden;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.32), rgba(255, 255, 255, 0.08));
}

.monitor__stage::before,
.monitor__stage::after {
  content: "";
  position: absolute;
  inset: 30px auto 30px 0;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--line), transparent);
}

.monitor__stage::after {
  inset: 30px 0 30px auto;
}

#ecgCanvas {
  width: 100%;
  height: 100%;
  min-height: 420px;
  position: relative;
  z-index: 2;
}

.monitor__grid {
  position: absolute;
  pointer-events: none;
}

.monitor__grid {
  left: var(--paper-left);
  top: var(--paper-top);
  width: var(--paper-width);
  height: var(--paper-height);
}

.monitor__grid {
  background-image:
    linear-gradient(rgba(214, 45, 58, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(214, 45, 58, 0.12) 1px, transparent 1px),
    linear-gradient(rgba(214, 45, 58, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(214, 45, 58, 0.045) 1px, transparent 1px);
  background-size:
    var(--paper-major) var(--paper-major),
    var(--paper-major) var(--paper-major),
    var(--paper-minor) var(--paper-minor),
    var(--paper-minor) var(--paper-minor);
  outline: 1px solid rgba(214, 45, 58, 0.08);
  opacity: 0.95;
}

.quiz {
  display: grid;
  align-content: start;
  gap: 22px;
  padding-top: 2px;
}

.quiz__head {
  display: grid;
  gap: 0;
}

.quiz__head h2 {
  max-width: 12ch;
  font-size: clamp(2.5rem, 4vw, 3.95rem);
}

.quiz__note {
  max-width: 28rem;
  margin: 14px 0 0;
  font-size: 0.96rem;
  line-height: 1.55;
  color: var(--ink-soft);
}

.mode-switch {
  display: grid;
  border-top: 1px solid var(--line-strong);
}

.mode-switch--stage {
  margin-top: 26px;
}

.mode-switch--stage .mode-switch__button {
  grid-template-columns: 44px minmax(0, 1fr) auto;
  padding: 16px 0;
}

.mode-switch--stage .mode-switch__label {
  font-size: 1rem;
}

.mode-switch__button {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: baseline;
  padding: 12px 0;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  text-align: left;
  color: var(--ink);
  transition: transform 180ms ease, color 180ms ease;
}

.mode-switch__button:hover,
.mode-switch__button:focus-visible {
  transform: translateX(4px);
}

.mode-switch__index,
.mode-switch__count {
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.mode-switch__label {
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.mode-switch__button.is-active .mode-switch__label,
.mode-switch__button:hover .mode-switch__label,
.mode-switch__button:focus-visible .mode-switch__label,
.mode-switch__button.is-active .mode-switch__index,
.mode-switch__button:hover .mode-switch__index,
.mode-switch__button:focus-visible .mode-switch__index {
  color: var(--accent);
}

.choices {
  display: grid;
  border-top: 1px solid var(--line-strong);
}

.choice {
  position: relative;
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  width: 100%;
  padding: 18px 0;
  border: 0;
  border-bottom: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  text-align: left;
  transition: color 180ms ease, transform 180ms ease;
}

.choice::before {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width 220ms ease;
}

.choice:hover,
.choice:focus-visible {
  transform: translateX(6px);
}

.choice:hover::before,
.choice:focus-visible::before,
.choice.is-correct::before {
  width: 100%;
}

.choice__index {
  font-size: 0.62rem;
  font-weight: 800;
  color: var(--ink-faint);
  transition: color 180ms ease;
}

.choice__label {
  font-size: 1.08rem;
  font-weight: 700;
  line-height: 1.28;
  transition: color 180ms ease;
}

.choice.is-correct .choice__label,
.choice:hover .choice__label,
.choice:focus-visible .choice__label,
.choice:hover .choice__index,
.choice:focus-visible .choice__index,
.choice.is-correct .choice__index {
  color: var(--accent);
}

.choice.is-wrong .choice__label,
.choice.is-wrong .choice__index {
  color: rgba(19, 33, 43, 0.42);
}

.choice:focus-visible,
.link-action:focus-visible,
.start-action:focus-visible,
.change-mode:focus-visible,
.mode-switch__button:focus-visible {
  outline: none;
}

.response {
  min-height: 44px;
  padding-top: 2px;
}

.response p {
  margin: 0;
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--ink-soft);
}

.response p.is-correct {
  color: var(--accent);
}

.response p.is-wrong {
  color: var(--ink);
}

.quiz__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 24px;
  padding-top: 8px;
}

.link-action {
  padding: 0;
  border: 0;
  background: transparent;
  font-size: 0.7rem;
  font-weight: 800;
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 0.22em;
}

.quiz__hint {
  margin: 0;
  padding-top: 8px;
  font-size: 0.62rem;
  font-weight: 800;
  color: var(--ink-faint);
}

@media (max-width: 1180px) {
  .simulator {
    grid-template-columns: 1fr;
  }

  .quiz__head h2 {
    max-width: none;
  }
}

@media (max-width: 900px) {
  .mode-stage__title {
    font-size: clamp(2.8rem, 12vw, 4.6rem);
  }

  .simulator-shell__head {
    align-items: start;
    flex-direction: column;
  }

  .simulator-shell__stats {
    justify-content: flex-start;
  }

  .monitor__head,
  .monitor__foot {
    align-items: start;
    flex-direction: column;
  }

  .monitor__meta,
  .monitor__readout,
  .monitor__calibration {
    justify-items: start;
    justify-content: flex-start;
  }
}

@media (max-width: 720px) {
  .page {
    width: min(100vw - 24px, 1360px);
    padding: 14px 0 28px;
  }

  .title,
  .title--cover {
    font-size: clamp(3rem, 16vw, 5rem);
  }

  .cover {
    min-height: calc(100svh - 82px);
    padding-bottom: 34px;
  }

  .simulator-shell {
    gap: 20px;
  }

  .mode-stage {
    min-height: calc(100svh - 88px);
  }

  .monitor__stage {
    min-height: 340px;
    padding: 22px 0;
  }

  .monitor__stage::before,
  .monitor__stage::after {
    inset-block: 22px;
  }

  #ecgCanvas {
    min-height: 296px;
  }

  .quiz__head h2 {
    font-size: clamp(2rem, 11vw, 3rem);
  }

  .choice {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 12px;
    padding: 16px 0;
  }

  .mode-switch__button {
    grid-template-columns: 32px minmax(0, 1fr) auto;
    gap: 10px;
  }

  .choice__label {
    font-size: 1rem;
  }
}