/* Civil Transportation Engineering Suite — page-scoped UI */

:root { scroll-behavior: smooth; }

.shell { overflow: visible; }

.rail {
  position: sticky;
  top: 16px;
  align-self: start;
  height: calc(100vh - 32px);
  overflow: hidden;
  border-radius: calc(var(--radius) - 2px) 0 0 calc(var(--radius) - 2px);
}
.rail__nav {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding-right: 4px;
  scrollbar-gutter: stable;
}
.rail__jump {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1.5px solid var(--line);
}
.rail__jump-label {
  margin: 0 0 6px;
  padding: 0 8px;
  color: var(--faint);
  font-size: 9px;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.rail__nav .rail__jump-list { gap: 1px; }
.rail__nav .rail__jump-list a {
  padding: 5px 8px;
  font-size: 11px;
  line-height: 1.25;
}
.rail__jump a:focus-visible,
.mobile-jump-nav a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.transport-hero .hero__lede { max-width: 64ch; }
.transport-unit-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 2px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 5px 9px;
  background: var(--surface);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.transport-unit-badge::before {
  content: '';
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
}

.transport-disclaimer {
  margin-top: 18px;
  padding: 13px 15px;
  border: 1.5px solid var(--line);
  border-left: 4px solid var(--accent);
  background: var(--surface-alt);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.tool-stack {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.tool-panel {
  min-width: 0;
  border: 2px solid var(--line-strong);
  border-radius: 10px;
  padding: 20px 22px;
  background: var(--surface);
  scroll-margin-top: 20px;
}
.tool-panel__head { margin-bottom: 18px; }
.tool-panel__title {
  margin: 0 0 7px;
  font-size: clamp(1.25rem, 3vw, 1.6rem);
  letter-spacing: -.022em;
}
.tool-panel__lede { margin: 0; max-width: 68ch; color: var(--muted); font-size: 14px; }
.reference-state {
  display: inline-block;
  margin-top: 10px;
  padding: 4px 8px;
  border: 1.5px solid var(--dash);
  border-radius: var(--radius-sm);
  color: var(--muted);
  background: var(--surface-alt);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
}

.transport-workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, .95fr);
  gap: 18px;
  align-items: start;
}
.transport-form,
.transport-results {
  border: 2px solid var(--line-strong);
  border-radius: 10px;
  padding: 18px;
  background: var(--surface);
  min-width: 0;
}
.transport-form__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 13px 12px;
}
.transport-field { min-width: 0; }
.transport-field--wide { grid-column: 1 / -1; }
.transport-field[hidden] { display: none; }
.transport-label {
  display: block;
  margin: 0 0 5px;
  font-size: 11px;
  font-weight: 700;
  color: var(--ink);
}
.transport-help {
  display: block;
  margin-top: 4px;
  color: var(--faint);
  font-size: 10px;
  line-height: 1.35;
}
.transport-input,
.transport-select {
  width: 100%;
  min-width: 0;
  border: 2px solid var(--dash);
  border-radius: var(--radius-sm);
  padding: 8px 9px;
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-size: 14px;
  font-feature-settings: 'tnum' 1, 'zero' 1;
}
.transport-input:hover,
.transport-select:hover { border-color: var(--muted); }
.transport-input:focus,
.transport-select:focus { border-color: var(--ink); }
.transport-input[aria-invalid="true"],
.transport-select[aria-invalid="true"] { border-color: var(--accent); }
.transport-error {
  margin: 4px 0 0;
  color: var(--accent);
  font-size: 11px;
  font-weight: 650;
}
.transport-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin-top: 17px;
}
.transport-actions .btn { cursor: pointer; }

.transport-results {
  background: var(--surface-alt);
  min-height: 220px;
}
.transport-results__idle {
  margin: 0;
  color: var(--faint);
  font-size: 13px;
  line-height: 1.5;
}
.result-status {
  display: inline-block;
  margin-bottom: 9px;
  font-size: 10px;
  font-weight: 750;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.result-status--ok { color: var(--ink); }
.result-status--warning { color: var(--accent); }
.result-primary {
  margin: 0 0 7px;
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  font-weight: 800;
  letter-spacing: -.04em;
  line-height: 1.05;
  overflow-wrap: anywhere;
}
.result-interpretation { margin: 0 0 15px; color: var(--muted); font-size: 13px; line-height: 1.5; }
.result-warning {
  margin: 0 0 14px;
  padding: 9px 10px;
  border-left: 3px solid var(--accent);
  background: var(--surface);
  color: var(--ink);
  font-size: 12px;
  line-height: 1.45;
}
.result-group {
  margin-top: 13px;
  padding-top: 12px;
  border-top: 1.5px solid var(--line);
}
.result-group h4 {
  margin: 0 0 7px;
  color: var(--faint);
  font-size: 10px;
  letter-spacing: .06em;
  text-transform: uppercase;
}
.result-list { margin: 0; padding-left: 18px; color: var(--muted); font-size: 12px; line-height: 1.5; }
.result-list li { margin-bottom: 4px; }

.transport-details {
  margin-top: 14px;
  border-top: 1.5px solid var(--line);
  padding-top: 11px;
}
.transport-details summary {
  cursor: pointer;
  color: var(--faint);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.transport-details summary:hover { color: var(--ink); }
.transport-details__body { margin-top: 9px; color: var(--muted); font-size: 12px; line-height: 1.55; }
.transport-details__body p,
.transport-details__body ul { margin: 0 0 8px; }
.transport-details__body ul { padding-left: 18px; }
.transport-equation {
  display: block;
  overflow-x: auto;
  margin: 8px 0;
  padding: 9px 11px;
  border: 1.5px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-tint);
  color: var(--ink);
  font-size: 12px;
  white-space: nowrap;
}
.approach-grid {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1.2fr repeat(3, 1fr);
  gap: 8px;
  align-items: end;
  padding-top: 4px;
}
.approach-grid__head { color: var(--faint); font-size: 9px; font-weight: 700; text-transform: uppercase; }

.nbdf-disclaimer { background: var(--surface-alt); }
.nbdf-disclaimer__text {
  max-width: 72ch;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.mobile-jump-nav {
  display: none;
  margin-top: 18px;
  border: 2px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--surface-alt);
}
.mobile-jump-nav summary {
  padding: 11px 13px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
}
.mobile-jump-nav ol {
  margin: 0;
  padding: 0 13px 12px 34px;
}
.mobile-jump-nav li { margin-top: 5px; }
.mobile-jump-nav a {
  color: var(--muted);
  font-size: 12px;
}
.mobile-jump-nav a:hover { color: var(--ink); }

@media (max-width: 860px) {
  .transport-workspace { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .rail {
    position: static;
    height: auto;
    overflow: visible;
    border-radius: calc(var(--radius) - 2px) calc(var(--radius) - 2px) 0 0;
  }
  .rail__nav {
    overflow: visible;
    padding-right: 0;
  }
  .mobile-jump-nav { display: block; }
}
@media (max-width: 540px) {
  .tool-panel { padding: 16px; }
  .transport-form__grid { grid-template-columns: 1fr; }
  .transport-field--wide { grid-column: auto; }
  .transport-form,
  .transport-results { padding: 14px; }
  .transport-actions { display: grid; }
  .transport-actions .btn { width: 100%; }
  .approach-grid { grid-template-columns: 1fr; }
  .approach-grid__head { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  :root { scroll-behavior: auto; }
}