:root {
  --btrc-navy: #00050f;
  --btrc-navy-soft: #071421;
  --btrc-cyan: #23ddd1;
  --btrc-cyan-pale: #c5e8e8;
  --btrc-white: #ffffff;
  --btrc-ink: #211e1c;
  --btrc-muted: #69727a;
  --btrc-line: #d8e1e5;
  --btrc-error: #ff9c91;
}

.btrc,
.btrc * {
  box-sizing: border-box;
}

.btrc {
  width: min(1120px, calc(100% - 32px));
  margin: 72px auto;
  color: var(--btrc-ink);
  font-family: Archivo, Arial, sans-serif;
}

.btrc__intro {
  max-width: 760px;
  margin: 0 auto 34px;
  text-align: center;
}

.btrc__eyebrow,
.btrc__section-label {
  margin: 0 0 12px;
  color: #148f89;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.btrc__intro h2 {
  margin: 0 0 12px;
  color: var(--btrc-ink);
  font-family: "Bodoni Moda", Georgia, serif;
  font-size: clamp(34px, 5vw, 56px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.025em;
}

.btrc__intro > p:last-child {
  max-width: 620px;
  margin: 0 auto;
  color: var(--btrc-muted);
  font-size: 15px;
  line-height: 1.7;
}

.btrc__panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  min-height: 650px;
  overflow: hidden;
  border: 1px solid #101c28;
  background: var(--btrc-navy);
  box-shadow: 0 24px 70px rgba(0, 10, 22, 0.18);
}

.btrc__controls {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  align-content: start;
  padding: clamp(28px, 5vw, 64px);
}

.btrc__field {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.btrc__field label,
.btrc__field legend {
  display: block;
  width: 100%;
  margin: 0 0 10px;
  padding: 0;
  color: #dce6ea;
  font-size: 13px;
  font-weight: 500;
}

.btrc__select-wrap,
.btrc__input-wrap {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 50px;
  border: 1px solid #2b3b48;
  background: var(--btrc-navy-soft);
  transition: border-color 160ms ease, box-shadow 160ms ease;
}

.btrc__select-wrap::after {
  position: absolute;
  right: 16px;
  width: 8px;
  height: 8px;
  border-right: 1px solid var(--btrc-cyan);
  border-bottom: 1px solid var(--btrc-cyan);
  content: "";
  pointer-events: none;
  transform: rotate(45deg) translateY(-3px);
}

.btrc__select-wrap:focus-within,
.btrc__input-wrap:focus-within {
  border-color: var(--btrc-cyan);
  box-shadow: 0 0 0 3px rgba(35, 221, 209, 0.13);
}

.btrc select,
.btrc input {
  width: 100%;
  min-height: 48px;
  margin: 0;
  padding: 0 48px 0 16px;
  border: 0;
  border-radius: 0;
  outline: 0;
  background: transparent;
  color: var(--btrc-white);
  font: 400 15px/1.2 Archivo, Arial, sans-serif;
}

.btrc select {
  appearance: none;
  cursor: pointer;
}

.btrc select option {
  background: var(--btrc-navy-soft);
  color: var(--btrc-white);
}

.btrc__input-wrap span {
  position: absolute;
  right: 16px;
  color: var(--btrc-cyan);
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  text-transform: uppercase;
}

.btrc__quick-values {
  display: flex;
  gap: 7px;
  margin: 0 0 8px;
}

.btrc__quick-values button {
  min-width: 64px;
  min-height: 38px;
  padding: 8px 12px;
  border: 1px solid #2b3b48;
  border-radius: 0;
  background: transparent;
  color: #cbd4d9;
  cursor: pointer;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease;
}

.btrc__quick-values button:hover,
.btrc__quick-values button:focus-visible,
.btrc__quick-values button.is-active {
  border-color: var(--btrc-cyan);
  background: var(--btrc-cyan);
  color: #001014;
  outline: 0;
}

.btrc__results {
  grid-column: 1 / -1;
  margin-top: 8px;
  padding: 30px;
  border-top: 1px solid #2b3b48;
  background: rgba(255, 255, 255, 0.035);
}

.btrc__result-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 32px;
}

.btrc__result-grid span {
  display: block;
  margin-bottom: 5px;
  color: #8f9ba3;
  font-size: 12px;
}

.btrc__result-grid strong {
  display: block;
  color: var(--btrc-cyan);
  font-family: "IBM Plex Mono", monospace;
  font-size: clamp(19px, 2.5vw, 25px);
  font-weight: 500;
  letter-spacing: -0.035em;
}

.btrc__warning {
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 156, 145, 0.28);
  color: var(--btrc-error);
  font-size: 13px;
  line-height: 1.55;
}

.btrc__visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 64px 42px 48px;
  background: var(--btrc-cyan-pale);
}

.btrc__visual .btrc__section-label {
  align-self: flex-start;
  color: #325258;
}

.btrc__syringe {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 154px;
  height: 500px;
  margin-top: 8px;
}

.btrc__plunger {
  position: relative;
  width: 54px;
  height: 60px;
  border-top: 8px solid var(--btrc-navy);
}

.btrc__plunger::before {
  position: absolute;
  top: 0;
  left: 50%;
  width: 12px;
  height: 58px;
  background: #7e8a90;
  content: "";
  transform: translateX(-50%);
}

.btrc__barrel {
  position: relative;
  width: 58px;
  height: 360px;
  border: 3px solid var(--btrc-navy);
  background: rgba(255, 255, 255, 0.74);
}

.btrc__barrel::before,
.btrc__barrel::after {
  position: absolute;
  top: -8px;
  width: 18px;
  height: 12px;
  border-top: 3px solid var(--btrc-navy);
  content: "";
}

.btrc__barrel::before { left: -18px; }
.btrc__barrel::after { right: -18px; }

.btrc__liquid {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  height: 5%;
  border-top: 2px solid #087d78;
  background: linear-gradient(90deg, rgba(35, 221, 209, 0.62), rgba(35, 221, 209, 0.9));
  transition: height 260ms ease;
}

.btrc__ticks {
  position: absolute;
  inset: 0;
  z-index: 2;
}

.btrc__ticks span {
  position: absolute;
  right: 0;
  width: 16px;
  border-top: 1px solid #24313a;
}

.btrc__ticks span::after {
  position: absolute;
  left: 24px;
  top: -7px;
  color: #31454b;
  content: attr(data-label);
  font-family: "IBM Plex Mono", monospace;
  font-size: 9px;
}

.btrc__measure-label {
  position: absolute;
  right: calc(100% + 8px);
  z-index: 3;
  width: max-content;
  padding: 6px 8px;
  background: var(--btrc-navy);
  color: var(--btrc-cyan);
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
  transition: bottom 260ms ease;
}

.btrc__measure-label::after {
  position: absolute;
  top: 50%;
  left: 100%;
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 5px solid var(--btrc-navy);
  content: "";
  transform: translateY(-50%);
}

.btrc__needle {
  width: 2px;
  height: 66px;
  background: linear-gradient(#59696e, #a9b7bb);
}

.btrc__disclaimer {
  margin: 18px auto 0;
  max-width: 850px;
  color: var(--btrc-muted);
  font-size: 11px;
  line-height: 1.65;
  text-align: center;
}

.btrc__disclaimer strong {
  color: #374047;
}

@media (max-width: 860px) {
  .btrc__panel {
    grid-template-columns: 1fr;
  }

  .btrc__visual {
    min-height: 570px;
  }
}

@media (max-width: 580px) {
  .btrc {
    width: min(100% - 20px, 1120px);
    margin: 44px auto;
  }

  .btrc__controls {
    grid-template-columns: 1fr;
    padding: 28px 20px;
  }

  .btrc__results {
    grid-column: auto;
    padding: 24px 18px;
  }

  .btrc__result-grid {
    grid-template-columns: 1fr;
  }

  .btrc__quick-values button {
    flex: 1;
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .btrc *,
  .btrc *::before,
  .btrc *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}