:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #11263d;
  background: #f4f8fa;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.calculator-shell {
  min-height: 100vh;
  padding: 16px;
  display: grid;
  place-items: start center;
}

.calculator-card {
  width: min(100%, 680px);
  padding: 24px 20px;
  background: #ffffff;
  border: 1px solid #d9e5e9;
  border-radius: 16px;
  box-shadow: 0 12px 34px rgb(17 38 61 / 8%);
}

.eyebrow {
  margin: 0 0 8px;
  color: #287ac0;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(1.65rem, 7vw, 2.4rem);
  letter-spacing: -0.035em;
  line-height: 1.08;
}

.intro {
  margin: 14px 0 24px;
  color: #4f6476;
  line-height: 1.55;
}

form {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  gap: 7px;
}

label {
  font-size: 0.92rem;
  font-weight: 750;
}

input,
select,
button {
  min-height: 48px;
  border-radius: 9px;
  font: inherit;
}

input,
select {
  width: 100%;
  padding: 0 13px;
  color: #11263d;
  background: #fff;
  border: 1px solid #9db1bd;
}

input:focus,
select:focus,
button:focus-visible {
  outline: 3px solid rgb(40 122 192 / 25%);
  outline-offset: 2px;
}

.volume-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 112px;
  gap: 9px;
}

.field-help {
  margin: 0;
  color: #657887;
  font-size: 0.8rem;
}

button {
  padding: 0 18px;
  border: 0;
  color: #fff;
  background: #155b91;
  font-weight: 800;
  cursor: pointer;
}

button:hover {
  background: #0d456f;
}

.status {
  min-height: 24px;
  margin-top: 14px;
  color: #9c342d;
  font-weight: 650;
}

.result {
  padding: 22px;
  background: linear-gradient(145deg, #eff9f6, #f2f8fc);
  border: 1px solid #b8ded2;
  border-radius: 12px;
}

.result-label,
.system-label,
.activation,
.qualification {
  margin: 0;
}

.result-label {
  color: #426457;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.result-value {
  margin: 7px 0;
  color: #123f34;
  font-size: clamp(2.5rem, 12vw, 4rem);
  font-weight: 850;
  letter-spacing: -0.06em;
  line-height: 1;
}

.result-value span:last-child {
  font-size: 0.38em;
  letter-spacing: 0;
}

.system-label {
  font-weight: 750;
}

.activation {
  margin-top: 14px;
  line-height: 1.5;
}

.qualification,
.boundary-note {
  color: #5c6e79;
  font-size: 0.8rem;
  line-height: 1.5;
}

.qualification {
  margin-top: 9px;
}

.boundary-note {
  margin: 18px 0 0;
}

@media (min-width: 640px) {
  .calculator-shell {
    padding: 32px;
  }

  .calculator-card {
    padding: 36px;
  }
}