:root {
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #eef8f3;
  background: #06130f;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  --page: #06130f;
  --surface: rgba(16, 45, 35, 0.82);
  --surface-strong: #12372a;
  --line: rgba(181, 225, 203, 0.18);
  --muted: #a7bdb4;
  --accent: #7be5b3;
  --accent-strong: #9af5c9;
  --danger: #ffb4ae;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--page);
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  background:
    radial-gradient(circle at 50% -10%, rgba(67, 179, 126, 0.22), transparent 38rem),
    linear-gradient(180deg, #0b2119 0%, var(--page) 56%);
}

input,
select {
  font: inherit;
}

select {
  cursor: pointer;
}

.page-shell {
  width: min(100%, 48rem);
  margin: 0 auto;
  padding: max(1.25rem, env(safe-area-inset-top)) max(1rem, env(safe-area-inset-right)) max(2rem, env(safe-area-inset-bottom)) max(1rem, env(safe-area-inset-left));
}

.calculator {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 1.5rem;
  background: rgba(7, 25, 19, 0.78);
  box-shadow: 0 1.5rem 5rem rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(18px);
}

.intro,
form,
.results,
footer {
  padding: 1.4rem;
}

.intro {
  padding-bottom: 1rem;
}

.eyebrow {
  margin: 0 0 0.45rem;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 13ch;
  margin-bottom: 0.75rem;
  font-size: clamp(2rem, 10vw, 3.65rem);
  line-height: 0.98;
  letter-spacing: -0.055em;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.45rem, 6vw, 2.2rem);
  letter-spacing: -0.035em;
}

.lede {
  max-width: 60ch;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.55;
}

form {
  border-top: 1px solid var(--line);
}

.settings-grid {
  display: grid;
  gap: 0.75rem;
  margin-bottom: 1.1rem;
}

.unit-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.unit-row label {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

select {
  min-height: 2.75rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  padding: 0 2.4rem 0 0.8rem;
  color: #eef8f3;
  background-color: var(--surface-strong);
}

.measurement-list {
  display: grid;
  gap: 0.9rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.measurement {
  border: 1px solid var(--line);
  border-radius: 1rem;
  padding: 1rem;
  background: var(--surface);
}

.measurement label {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  margin-bottom: 0.7rem;
  font-weight: 750;
}

.step-label {
  flex: 0 0 auto;
  color: var(--accent);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.input-wrap {
  position: relative;
}

input {
  width: 100%;
  min-height: 3.65rem;
  border: 1px solid rgba(181, 225, 203, 0.26);
  border-radius: 0.8rem;
  padding: 0.7rem 5.2rem 0.7rem 0.9rem;
  color: #ffffff;
  background: rgba(3, 15, 11, 0.72);
  font-size: 1.35rem;
  font-weight: 750;
  font-variant-numeric: tabular-nums;
  outline: none;
}

input:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(123, 229, 179, 0.2);
  outline: none;
}

input::placeholder {
  color: #708a7f;
  font-weight: 500;
}

.input-unit {
  position: absolute;
  top: 50%;
  right: 0.9rem;
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 750;
  pointer-events: none;
  transform: translateY(-50%);
}

.measurement-note {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.45;
}

.error-message {
  margin: 1rem 0 0;
  border: 1px solid rgba(255, 180, 174, 0.35);
  border-radius: 0.75rem;
  padding: 0.8rem;
  color: var(--danger);
  background: rgba(83, 25, 25, 0.45);
  font-size: 0.9rem;
}

.results {
  scroll-margin-top: 1rem;
  border-top: 1px solid var(--line);
  background: rgba(16, 48, 36, 0.46);
}

.result-heading {
  margin-bottom: 1rem;
}

.target-grid {
  display: grid;
  gap: 0.8rem;
}

.target-card {
  display: grid;
  gap: 0.45rem;
  border: 1px solid var(--line);
  border-radius: 1rem;
  padding: 1rem;
  background: rgba(4, 20, 14, 0.72);
}

.target-card.featured {
  border-color: rgba(123, 229, 179, 0.48);
  background: linear-gradient(135deg, rgba(36, 109, 78, 0.74), rgba(9, 38, 27, 0.88));
}

.target-card span,
.transfer-callout span {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.target-card strong {
  color: #ffffff;
  font-size: clamp(1.8rem, 9vw, 2.8rem);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.045em;
}

.transfer-callout {
  display: grid;
  gap: 0.35rem;
  margin-top: 0.8rem;
  border-radius: 1rem;
  padding: 1rem;
  color: #092219;
  background: var(--accent-strong);
}

.transfer-callout span,
.transfer-callout small {
  color: #164b37;
}

.transfer-callout strong {
  font-size: clamp(1.65rem, 8vw, 2.35rem);
  font-variant-numeric: tabular-nums;
}

.transfer-callout small {
  line-height: 1.4;
}

.details {
  display: grid;
  gap: 0.6rem;
  margin: 0.8rem 0 0;
}

.details div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--line);
  padding: 0.75rem 0;
}

.details dt {
  color: var(--muted);
  font-size: 0.82rem;
}

.details dd {
  margin: 0;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

footer {
  border-top: 1px solid var(--line);
  color: #829a90;
  font-size: 0.75rem;
  line-height: 1.45;
}

[hidden] {
  display: none !important;
}

@media (min-width: 42rem) {
  .page-shell {
    padding-top: 3rem;
    padding-bottom: 3rem;
  }

  .intro,
  form,
  .results,
  footer {
    padding-right: 2rem;
    padding-left: 2rem;
  }

  .measurement-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .settings-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .target-grid,
  .details {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

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