:root {
  color-scheme: light;
  --background: #f4f7f6;
  --surface: #ffffff;
  --surface-soft: #eaf6f0;
  --text: #17211d;
  --muted: #64706b;
  --border: #dbe4e0;
  --accent: #147a55;
  --accent-dark: #0e5d40;
  --danger: #b42318;
  --shadow: 0 24px 70px rgba(28, 61, 48, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 10% 0%, rgba(20, 122, 85, 0.09), transparent 30rem),
    var(--background);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

button,
input {
  font: inherit;
}

.page-shell {
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 48px 24px;
}

.calculator {
  width: min(100%, 980px);
}

.intro {
  max-width: 680px;
  margin-bottom: 32px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  max-width: 650px;
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.75rem);
  line-height: 1.04;
  letter-spacing: -0.045em;
}

.intro-text {
  max-width: 600px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.calculator-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  overflow: hidden;
  border: 1px solid rgba(219, 228, 224, 0.85);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.inputs-card,
.result-card {
  padding: clamp(28px, 5vw, 48px);
}

.inputs-card {
  display: grid;
  gap: 24px;
}

.field label {
  display: block;
  margin-bottom: 8px;
  font-size: 0.92rem;
  font-weight: 650;
}

.input-wrap {
  position: relative;
}

.input-wrap input {
  width: 100%;
  height: 52px;
  padding: 0 72px 0 15px;
  border: 1px solid var(--border);
  border-radius: 12px;
  outline: none;
  color: var(--text);
  background: #fbfcfc;
  font-size: 1rem;
  font-weight: 600;
  transition: border-color 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.input-wrap input:hover {
  border-color: #b9c8c1;
}

.input-wrap input:focus {
  border-color: var(--accent);
  background: var(--surface);
  box-shadow: 0 0 0 4px rgba(20, 122, 85, 0.11);
}

.input-wrap input:invalid:not(:focus) {
  border-color: #e4b6b2;
}

.input-suffix {
  position: absolute;
  top: 50%;
  right: 16px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 650;
  pointer-events: none;
  transform: translateY(-50%);
}

.field-hint {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.45;
}

.result-card {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 100%;
  background: var(--surface-soft);
}

.result-label {
  margin: 0;
  color: var(--accent-dark);
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.rate {
  margin: 6px 0 0;
  color: var(--accent-dark);
  font-size: clamp(3.7rem, 8vw, 5.5rem);
  font-weight: 780;
  line-height: 1;
  letter-spacing: -0.06em;
}

.rate-unit {
  font-size: 0.32em;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.rounding-note {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.78rem;
}

.breakdown {
  display: grid;
  gap: 0;
  margin: 36px 0 0;
  border-top: 1px solid rgba(14, 93, 64, 0.15);
}

.breakdown-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 0;
  border-bottom: 1px solid rgba(14, 93, 64, 0.15);
}

.breakdown dt {
  color: var(--muted);
  font-size: 0.84rem;
}

.breakdown dd {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 750;
  text-align: right;
  white-space: nowrap;
}

.error-message {
  margin: 20px 0 0;
  color: var(--danger);
  font-size: 0.85rem;
  font-weight: 650;
}

.assumption {
  margin: 18px 4px 0;
  color: var(--muted);
  font-size: 0.76rem;
}

@media (max-width: 760px) {
  .page-shell {
    display: block;
    padding: 32px 16px;
  }

  .intro {
    margin-bottom: 24px;
  }

  .calculator-grid {
    grid-template-columns: 1fr;
    border-radius: 20px;
  }

  .result-card {
    min-height: 380px;
  }
}

@media (max-width: 430px) {
  .page-shell {
    padding: 24px 12px;
  }

  .inputs-card,
  .result-card {
    padding: 28px 22px;
  }

  .inputs-card {
    gap: 20px;
  }

  .breakdown-row {
    align-items: flex-start;
    flex-direction: column;
    gap: 5px;
  }

  .breakdown dd {
    text-align: left;
  }

  .result-card {
    min-height: 340px;
  }
}

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