:root {
  --ink: #16202a;
  --muted: #66727e;
  --line: #d8dee5;
  --panel: #ffffff;
  --soft: #f5f7f9;
  --accent: #173f67;
  --accent-strong: #0e2f50;
  --accent-soft: #eaf1f7;
  --stale: #a1a8af;
  --radius: 10px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.5;
}

button, input { font: inherit; }

.page-shell {
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0 64px;
}

.tool-header { margin-bottom: 18px; }

.instruction-line {
  margin: 12px 0 0;
  color: var(--ink);
  font-size: 1rem;
  font-weight: 600;
}

.eyebrow {
  margin: 0 0 7px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.calculator-stack {
  width: 100%;
  max-width: 900px;
}

.input-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius) var(--radius) 0 0;
  background: var(--panel);
  padding: 18px;
}

.input-row {
  display: grid;
  grid-template-columns: minmax(250px, 1.25fr) minmax(165px, 0.9fr) minmax(210px, 1fr) auto;
  gap: 14px;
  align-items: end;
}

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

.scale-fieldset legend,
.field > span {
  display: block;
  margin-bottom: 7px;
  font-size: 0.84rem;
  font-weight: 700;
}

.scale-picker {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--line);
  border-radius: 7px;
  overflow: hidden;
}

.scale-picker label { position: relative; min-width: 0; }
.scale-picker label + label { border-left: 1px solid var(--line); }
.scale-picker input { position: absolute; opacity: 0; pointer-events: none; }

.scale-picker span {
  display: block;
  min-height: 46px;
  padding: 11px 8px;
  text-align: center;
  cursor: pointer;
  font-weight: 700;
  background: #fff;
}

.scale-picker input:checked + span { background: var(--accent); color: #fff; }
.scale-picker input:focus-visible + span { outline: 3px solid #9ec2df; outline-offset: -3px; }

.field { min-width: 0; }

.field input {
  width: 100%;
  min-height: 46px;
  border: 1px solid #aeb8c2;
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  padding: 10px 12px;
  font-variant-numeric: tabular-nums;
}

.field input:focus {
  outline: 3px solid #c9deee;
  border-color: var(--accent);
}

.primary-button {
  min-height: 46px;
  border: 1px solid var(--accent);
  border-radius: 7px;
  background: var(--accent);
  color: #fff;
  padding: 10px 18px;
  font-weight: 700;
  cursor: pointer;
}

.primary-button:hover { background: var(--accent-strong); }


.utility-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}

.secondary-button {
  min-height: 36px;
  border: 1px solid #aeb8c2;
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  padding: 7px 12px;
  font-weight: 700;
  cursor: pointer;
}

.secondary-button:hover {
  border-color: var(--accent);
  background: #f5f8fa;
}

.secondary-button:focus-visible {
  outline: 3px solid #c9deee;
  outline-offset: 1px;
}

.utility-note {
  color: var(--muted);
  font-size: 0.78rem;
}

.form-message {
  min-height: 1.2em;
  margin-top: 8px;
  color: var(--accent);
  font-size: 0.82rem;
}

.result-box {
  min-height: 128px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  background: var(--soft);
  padding: 18px 24px 20px;
  transition: color 120ms ease, background-color 120ms ease;
}

.result-lines {
  text-align: center;
  font-variant-numeric: tabular-nums;
}

.delta-line {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.38em;
  color: var(--ink);
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.2;
  transition: color 120ms ease;
}

.dut1-line {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.34em;
  margin-top: 8px;
  color: var(--ink);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.25;
  transition: color 120ms ease;
}



.result-box.is-empty .delta-line,
.result-box.is-empty .dut1-line {
  color: #b5bbc1;
}

.information-section {
  max-width: 900px;
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.information-section h2 {
  margin: 0;
  font-size: 1.12rem;
}

.information-section p {
  max-width: 820px;
  color: var(--muted);
  font-size: 0.92rem;
}


.text-link { color: var(--accent); font-weight: 700; text-decoration: none; }
.text-link:hover { text-decoration: underline; }

.prototype-note {
  margin-top: 18px;
  padding: 11px 13px;
  border-left: 3px solid #9aa7b3;
  background: #fafbfc;
  color: var(--muted);
  font-size: 0.82rem;
}

@media (max-width: 850px) {
  .input-row {
    grid-template-columns: 1fr 1fr;
  }
  .scale-fieldset { grid-column: 1 / -1; }
  .primary-button { width: 100%; }
  .utility-row { flex-wrap: wrap; }
}

@media (max-width: 560px) {
  .page-shell { width: min(100% - 22px, 980px); padding-top: 28px; }
  .input-panel { padding: 14px; }
  .input-row { grid-template-columns: 1fr; }
  .scale-fieldset { grid-column: auto; }
  .result-box { min-height: 116px; padding-inline: 12px; }
  .delta-line { font-size: 2.4rem; }
  .dut1-line { font-size: 1.15rem; }
}


.eclipse-row {
  display: grid;
  grid-template-columns: minmax(300px, 1fr) minmax(220px, .85fr);
  gap: 14px;
  align-items: end;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.field select {
  width: 100%;
  min-height: 46px;
  border: 1px solid #aeb8c2;
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  padding: 10px 12px;
}

.field select:focus {
  outline: 3px solid #c9deee;
  border-color: var(--accent);
}

.eclipse-note {
  color: var(--muted);
  font-size: .84rem;
  padding-bottom: 10px;
}

.source-line {
  margin-top: 9px;
  font-size: .88rem;
  font-weight: 700;
  color: var(--muted);
}

.source-final { color: #18864b; }
.source-predicted { color: #1f64c8; }
.source-model { color: #b42318; }
.source-historical { color: #747b84; }

@media (max-width: 700px) {
  .eclipse-row { grid-template-columns: 1fr; }
  .eclipse-note { padding-bottom: 0; }
}


/* Result provenance: source type is visible in the numerical result itself. */
.result-box.source-historical .delta-line,
.result-box.source-historical .dut1-line { color:#747b84; }
.result-box.source-calculated .delta-line,
.result-box.source-calculated .dut1-line { color:#18864b; }
.result-box.source-predicted .delta-line,
.result-box.source-predicted .dut1-line { color:#1f64c8; }
.result-box.source-model .delta-line,
.result-box.source-model .dut1-line { color:#b42318; }


.source-calculated { color:#18864b; }



/* V7 calculator form layout */
.utility-row-under-eclipse {
  margin-top: 8px;
  margin-bottom: 14px;
}

.input-layout {
  display: grid;
  grid-template-columns: minmax(250px, 1fr) minmax(150px, 0.55fr);
  gap: 26px;
  align-items: start;
}

.date-time-column {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.date-time-column .field {
  width: 100%;
}

.date-time-column input {
  width: 100%;
  box-sizing: border-box;
}

.calculate-below-date {
  justify-self: start;
  min-width: 150px;
  margin-top: 2px;
}

.scale-fieldset-right {
  margin: 0;
  padding: 0;
  border: 0;
  min-width: 0;
}

.scale-fieldset-right legend {
  margin-bottom: 8px;
  font-weight: 700;
}

.radio-scale-picker {
  display: grid;
  gap: 10px;
}

.radio-option {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-weight: 600;
}

.radio-option input[type="radio"] {
  width: auto;
  margin: 0;
  accent-color: var(--accent);
}

.radio-option span {
  line-height: 1.2;
}

@media (max-width: 680px) {
  .input-layout {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .scale-fieldset-right {
    order: 2;
  }

  .calculate-below-date {
    width: 100%;
  }

  .utility-row-under-eclipse {
    align-items: flex-start;
  }
}


.site-footer {
  max-width: 820px;
  margin: 28px auto 18px;
  padding: 14px 18px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.5;
  text-align: center;
}

.site-footer > div + div {
  margin-top: 3px;
}


/* V10 compact horizontal date/time layout */
.input-layout-horizontal {
  grid-template-columns: auto 1fr;
  gap: 28px;
  align-items: start;
}

.compact-date-time {
  width: auto;
}

.date-time-row {
  display: flex;
  align-items: end;
  gap: 10px;
}

.compact-field {
  width: auto !important;
}

.compact-field input {
  width: auto !important;
}

.date-field.compact-field input {
  width: 145px !important;
}

.time-field.compact-field input {
  width: 145px !important;
}

.scale-fieldset-right {
  justify-self: start;
  padding-top: 1px;
}

.radio-scale-picker {
  display: flex;
  gap: 18px;
  align-items: center;
}

.calculate-below-date {
  margin-top: 10px;
}

@media (max-width: 680px) {
  .input-layout-horizontal {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .date-time-row {
    flex-wrap: wrap;
  }

  .radio-scale-picker {
    flex-wrap: wrap;
  }
}


/* V11 stale-state treatment: preserve provenance color and show explicit status */
.result-box.is-stale .delta-line,
.result-box.is-stale .dut1-line,
.result-box.is-stale .source-line {
  opacity: 0.45;
}

.stale-notice {
  margin-top: 10px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #8a4b00;
  background: #fff4dc;
  border: 1px solid #d9a441;
  border-radius: 6px;
  padding: 7px 10px;
  display: inline-block;
}

.stale-notice[hidden] {
  display: none !important;
}

.uncertainty-line {
  margin-top: 8px;
  color: var(--muted);
  font-size: .86rem;
  font-variant-numeric: tabular-nums;
}