:root {
  --navy: #102833;
  --navy-deep: #0b1c24;
  --teal: #0e6e68;
  --teal-ink: #0a4f4b;
  --paper: #eef3f4;
  --card: #ffffff;
  --line: #d3e0e2;
  --muted: #3e555c;
  --text: #17262c;
  --bad: #8d2c2c;
  --sand: #f6f1e7;
  --bronze: #8a5a12;
  --max: 1100px;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html { scroll-padding: 12px; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.5;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
}

.wrap {
  width: 100%;
  max-width: var(--max);
  margin-inline: auto;
  padding: 18px;
  padding-left: max(18px, env(safe-area-inset-left));
  padding-right: max(18px, env(safe-area-inset-right));
}

.skip {
  position: absolute;
  left: 8px;
  top: 8px;
  transform: translateY(-160%);
  background: #fff;
  color: var(--navy);
  padding: 12px 16px;
  min-height: 48px;
  z-index: 5;
  text-decoration: none;
  border: 2px solid var(--navy);
}

.skip:focus { transform: none; }

.site-header {
  background: var(--navy-deep);
  color: #f4f7f7;
  position: static;
}

.brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand {
  color: #f4f7f7;
  text-decoration: none;
  font-weight: 700;
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  letter-spacing: 0.01em;
}

@media (max-width: 800px) {
  .brand-row { justify-content: center; }
}

a { color: var(--teal-ink); }
a:visited { color: var(--teal-ink); }
.site-header a, .site-header a:visited { color: #f4f7f7; }

:focus-visible {
  outline: 3px solid var(--teal);
  outline-offset: 2px;
}

.hero { margin: 0 0 12px; max-width: 40rem; }
.hero .kicker {
  margin: 0 0 6px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal-ink);
}
.hero h1 {
  margin: 0 0 6px;
  font-family: Georgia, "Iowan Old Style", Palatino, "Palatino Linotype", serif;
  font-size: 1.45rem;
  font-weight: 600;
  line-height: 1.15;
  color: var(--navy);
}
.hero h1::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background: var(--teal);
  margin-top: 8px;
}
.hero p { margin: 0; }

@media (max-width: 800px) {
  .hero { margin-left: auto; margin-right: auto; text-align: center; }
  .hero h1::after { margin-left: auto; margin-right: auto; }
}

@media (min-width: 801px) {
  .hero { text-align: left; }
  .hero h1 { font-size: 2rem; }
}

h2, h3 {
  font-family: Georgia, "Iowan Old Style", Palatino, "Palatino Linotype", serif;
  color: var(--navy);
  line-height: 1.25;
  margin: 0 0 8px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
  margin-top: 16px;
}

.tool-card { margin-top: 0; border-top: 4px solid var(--teal); }
.tool-card h2 { font-size: 1.25rem; }

.fields {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 801px) {
  .fields-primary { grid-template-columns: 1fr 1fr; }
  .field-wide { grid-column: 1 / -1; }
}

.field { display: flex; flex-direction: column; align-items: stretch; gap: 8px; text-align: left; }
.field label { text-align: left; font-weight: 700; }
.hint, .model-note, .live-status { margin: 0; color: var(--muted); text-align: left; }
.hint { font-size: 0.92rem; }

input,
select,
textarea {
  min-width: 0;
}

input[type="text"] {
  min-height: 48px;
  width: 100%;
  padding: 12px;
  font: inherit;
  font-size: 16px;
  color: var(--text);
  background: #fff;
  border: 1px solid #8ea3a8;
  border-radius: 10px;
}

input[aria-invalid="true"] { border: 2px solid var(--bad); }

.field-error { margin: 0; color: var(--bad); font-weight: 650; text-align: left; }

.methods { margin-top: 16px; }
.methods summary {
  min-height: 48px;
  display: flex;
  align-items: center;
  cursor: pointer;
  font-weight: 700;
  color: var(--navy);
  text-align: left;
}
.method-body { display: grid; gap: 12px; padding: 4px 0 8px; }
.method-body ul { margin: 0; padding-left: 1.2rem; }
.method-body li { margin: 8px 0; }

.assumptions { margin-top: 16px; border-top: 1px solid var(--line); }
.assumptions summary {
  min-height: 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  gap: 4px;
  padding: 12px 0;
  cursor: pointer;
  text-align: left;
}
.summary-label { font-weight: 700; color: var(--navy); }
.summary-values { font-weight: 650; }
.assumption-body { display: grid; gap: 12px; padding-bottom: 8px; }
.assumption-note { margin: 0; color: var(--muted); }

.model-note { margin-top: 16px; }

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

button, .button {
  min-height: 48px;
  min-width: 48px;
  padding: 12px 16px;
  font: inherit;
  border-radius: 10px;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn-primary { background: var(--navy); color: #f7fbfb; border: 2px solid var(--navy); }
.btn-secondary { background: transparent; color: var(--navy); border: 2px solid var(--navy); }
.btn-primary:visited, .btn-secondary:visited { color: inherit; }

.error-summary {
  margin-top: 12px;
  padding: 12px 16px;
  border: 2px solid var(--bad);
  border-radius: 10px;
  background: #fff7f4;
}
.error-summary ul { margin: 8px 0 0; padding-left: 1.2rem; }

.live-status { min-height: 1.5em; margin-top: 12px; }

.result-grid { display: grid; grid-template-columns: 1fr; gap: 12px; margin: 16px 0; }
@media (min-width: 801px) {
  .result-grid { grid-template-columns: 1fr 1fr; }
}
.result-stat { background: var(--sand); border-radius: 12px; padding: 12px 16px; }
.result-stat span { display: block; color: var(--muted); font-size: 0.88rem; }
.result-stat strong {
  display: block;
  margin-top: 4px;
  font-size: 1.15rem;
  overflow-wrap: anywhere;
  font-variant-numeric: tabular-nums;
}

.status-lead { font-size: 1.05rem; margin: 0 0 8px; }
.chart-frame { margin-top: 8px; }
.chart-frame svg { width: 100%; height: auto; aspect-ratio: 640 / 280; display: block; }
.chart-legend { display: flex; flex-wrap: wrap; gap: 12px; margin: 8px 0; }
.swatch { display: inline-flex; align-items: center; gap: 8px; min-height: 32px; }
.swatch i { width: 28px; height: 4px; display: inline-block; }
.swatch-port i { background: var(--teal); }
.swatch-coast i { background: var(--navy); }
.swatch-stop i { background: var(--bronze); }

.table-note { margin: 8px 0; }
.table-wrap { width: 100%; max-width: 100%; overflow-x: auto; margin-top: 8px; }
table { border-collapse: collapse; width: 100%; min-width: 640px; }
caption { text-align: left; caption-side: top; padding-bottom: 8px; font-weight: 650; }
th, td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
  white-space: nowrap;
}
th { color: var(--navy); }

.caveat, .prose p { margin: 0 0 12px; }
.caveat {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.read-grid { display: grid; grid-template-columns: 1fr; gap: 12px; }
@media (min-width: 801px) {
  .read-grid { grid-template-columns: 1fr 1fr 1fr; }
}
.read-grid .card { margin-top: 0; }
.read-grid h3 { font-size: 1.05rem; }

.formula {
  font-family: ui-monospace, "Cascadia Code", "Segoe UI Mono", Menlo, Consolas, monospace;
  background: var(--sand);
  padding: 12px 16px;
  border-radius: 12px;
  white-space: pre-wrap;
  margin: 0 0 12px;
}

.bounds { min-width: 520px; }

.site-footer {
  margin-top: 24px;
  background: #e7eeee;
  border-top: 1px solid var(--line);
}
.site-footer .wrap { padding-bottom: calc(24px + env(safe-area-inset-bottom)); }
.footer-links { display: flex; flex-wrap: wrap; gap: 8px 12px; margin: 8px 0 12px; }
.footer-links a {
  min-height: 48px;
  min-width: 44px;
  box-sizing: border-box;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.email-link { font-size: 1.15rem; font-weight: 700; min-height: 48px; display: inline-flex; align-items: center; }

.page-section { margin-top: 16px; }
.page-section h2 { margin-top: 20px; }

::selection { background: #d5ecea; color: var(--navy); }

/* Release polish: keep long values readable on narrow screens. */
.metric-value, dd { overflow-wrap: anywhere; }
.related-tools { margin-block: 2rem; }
details.card > summary { cursor: pointer; font-weight: 650; padding: .75rem 0; min-height: 44px; box-sizing: border-box; }