:root {
  font-family: Arial, Helvetica, sans-serif;
  color: #172129;
  background: #f7f7f3;
  line-height: 1.55;
  color-scheme: light;
  font-size: 16px;
  --olive: #52613d;
  --line: #cbd0c5;
  --error: #922b20;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
}
button,
a {
  touch-action: manipulation;
}
button {
  cursor: pointer;
}
button:disabled {
  cursor: default;
  color: #62675d;
  background: #eceee6;
}
a {
  color: inherit;
  text-underline-offset: 0.25em;
}
button {
  border: 1px solid #919b88;
  border-radius: 3px;
  padding: 0.7rem 0.95rem;
  background: #fff;
  font-weight: 600;
}
button:hover:not(:disabled) {
  background: #edf0e5;
}
button.primary {
  background: #1c2b34;
  color: #fff;
  border-color: #1c2b34;
}
button.primary:hover:not(:disabled) {
  background: #324550;
}
button[aria-disabled="true"] {
  background: #e8ece3;
  color: #384b27;
  border-color: #a3ab9a;
  cursor: wait;
}
button.text-button {
  border-color: transparent;
  background: transparent;
  padding-left: 0;
  text-decoration: underline;
  text-underline-offset: 0.22em;
  font-weight: 500;
}
button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid #657834;
  outline-offset: 4px;
}
header {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  max-width: 1400px;
  margin: auto;
  padding: 1.1rem 3rem;
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 800;
  font-size: 2.2rem;
  letter-spacing: -0.08em;
  text-decoration: none;
  line-height: 1;
}
.brand span {
  color: var(--olive);
}
.brand-note {
  font-size: 0.625rem;
  letter-spacing: 0.18em;
  line-height: 1.4;
  font-weight: 700;
  border-left: 1px solid var(--line);
  padding-left: 1.4rem;
}
nav {
  display: flex;
  gap: 1.3rem;
  margin-left: auto;
  align-items: center;
  font-size: 0.875rem;
}
nav button {
  padding: 0.35rem;
  border: 0;
  background: none;
}
main,
footer {
  max-width: 1280px;
  padding: 0 2rem;
  margin: auto;
}
h1,
h2,
h3,
p {
  margin-top: 0;
}
h1 {
  font-size: clamp(1.8rem, 3.4vw, 2.65rem);
  line-height: 1.1;
  letter-spacing: -0.045em;
  max-width: 36ch;
  margin-bottom: 0.75rem;
}
h2 {
  font-size: 1.4rem;
  line-height: 1.22;
  letter-spacing: -0.025em;
}
h3 {
  font-size: 1rem;
  line-height: 1.35;
}
.intro {
  padding: 1.4rem 0 0.45rem;
}
.eyebrow {
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  font-weight: 700;
  color: var(--olive);
  margin-bottom: 0.75rem;
}
.subtitle {
  font-size: 1.07rem;
  max-width: 85ch;
}
.scenario-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
  border-top: 1px solid var(--line);
  padding-top: 0.85rem;
}
.scenario-bar button {
  display: flex;
  gap: 0.6rem;
  align-items: center;
  font-size: 0.87rem;
  text-align: left;
  background: transparent;
  line-height: 1.3;
  min-height: 3.2rem;
}
.scenario-bar [aria-pressed="true"] {
  background: #edf0e2;
  border-color: var(--olive);
  box-shadow: inset 0 -3px var(--olive);
}
.letter {
  color: var(--olive);
  font-size: 0.75rem;
}
.instruction {
  margin: 0.8rem 0 1rem;
  max-width: 80ch;
}
.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.42fr) minmax(0, 1fr);
  align-items: start;
  border: 1px solid var(--line);
}
.form-card {
  padding: 1.65rem 1.8rem;
  background: white;
}
.notice {
  font-size: 0.86rem;
  line-height: 1.5;
  padding: 0.7rem 0.85rem;
  background: #eff1e7;
  border-left: 3px solid #677849;
}
.required {
  font-size: 0.84rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
}
#initialization {
  font-size: 0.8rem;
}
#initialization:empty {
  display: none;
}
.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.field.wide {
  grid-column: 1/-1;
}
fieldset {
  border: 0;
  padding: 0;
  margin: 0;
  min-inline-size: 0;
}
label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.25rem;
}
input,
textarea,
select {
  width: 100%;
  border: 1px solid #727e73;
  background: white;
  border-radius: 2px;
  padding: 0.62rem 0.75rem;
}
textarea {
  resize: vertical;
  min-height: 6rem;
}
input[readonly],
textarea[readonly] {
  background: #f6f7f3;
  color: #3d4540;
}
.hint {
  font-size: 0.78rem;
  line-height: 1.5;
  color: #515950;
  margin-bottom: 0.45rem;
}
.field .hint {
  min-height: 2.35em;
}
input[aria-invalid="true"],
textarea[aria-invalid="true"] {
  border: 2px solid var(--error);
}
.field-error {
  color: var(--error);
  font-size: 0.86rem;
  font-weight: 600;
  margin: 0.35rem 0 0;
}
.error-summary {
  border: 2px solid var(--error);
  border-left-width: 5px;
  padding: 1rem;
  margin-bottom: 1.3rem;
  background: #fffaf8;
}
.error-summary:focus {
  outline: 3px solid #657834;
  outline-offset: 4px;
}
.error-summary h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}
.error-summary ul {
  padding-left: 1.1rem;
  margin-bottom: 0;
}
.error-summary li {
  margin: 0.3rem 0;
}
.error-summary a {
  color: var(--error);
}
#fill {
  margin-top: 0.6rem;
  font-size: 0.85rem;
}
.current-message {
  padding: 1rem 0 0.2rem;
  margin-top: 0.5rem;
  border-top: 1px solid var(--line);
  font-size: 0.95rem;
}
.current-message p {
  margin-bottom: 0.65rem;
}
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: center;
}
.wording {
  border-top: 1px solid var(--line);
  padding-top: 1.1rem;
  margin-top: 1.5rem;
}
.wording label {
  font-size: 0.84rem;
}
.wording select {
  font-size: 0.85rem;
}
.wording .hint {
  margin-top: 0.6rem;
}
.observatory {
  padding: 1.7rem 1.8rem;
  background: #f0f2e9;
  border-left: 1px solid var(--line);
  min-height: 100%;
}
#known-state {
  font-size: 0.9rem;
}
.registry {
  border-top: 1px solid var(--line);
  padding-top: 1.1rem;
  margin-top: 1.25rem;
}
.badge {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: #4a5939;
}
.counts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1rem 0;
}
.counts dt {
  font-size: 0.8rem;
}
.counts dd {
  margin: 0;
  font-size: 1.85rem;
  font-weight: 650;
}
.reference {
  display: flex;
  flex-direction: column;
  font-size: 0.78rem;
  gap: 0.2rem;
}
.reference strong {
  font-size: 1.1rem;
}
.timeline {
  list-style: none;
  padding: 0;
  counter-reset: event;
  margin: 1rem 0 1.5rem;
  font-size: 0.8rem;
}
.timeline li {
  border-left: 2px solid #a6b297;
  padding: 0.35rem 0.7rem;
  margin: 0 0 0.2rem 0;
  overflow-wrap: anywhere;
}
.finding {
  border-top: 1px solid var(--line);
  padding-top: 1.25rem;
}
.finding p {
  font-size: 0.88rem;
}
details {
  border-top: 1px solid var(--line);
  padding: 1rem 0;
}
summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.87rem;
}
details p {
  font-size: 0.85rem;
  margin-top: 0.8rem;
}
details button {
  font-size: 0.8rem;
}
.status-control {
  margin: 1rem 0;
  font-size: 0.8rem;
}
pre {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font-size: 0.72rem;
  padding: 1rem;
  background: #fafbf7;
  border: 1px solid var(--line);
}
.evidence {
  padding: 2rem 0;
  border-bottom: 1px solid var(--line);
}
.evidence h2 {
  font-size: 1.15rem;
}
.evidence p {
  font-size: 0.86rem;
}
.evidence button {
  font-size: 0.83rem;
}
#export-panel {
  margin-top: 1rem;
}
#proof-output {
  font-family: monospace;
  font-size: 0.78rem;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
.method {
  padding: 3rem 0;
}
.method > h2 {
  font-size: 1.9rem;
}
.method-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem 3rem;
  margin: 2rem 0;
}
.method-grid article {
  border-top: 1px solid var(--line);
  padding-top: 1rem;
}
.method-grid p,
.method li,
.method > p {
  font-size: 0.9rem;
}
.method-grid ol {
  padding-left: 1.25rem;
}
.source-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem 1.8rem;
  list-style: none;
  padding: 0;
}
.source-links a {
  font-size: 0.86rem;
}
.primary-sources {
  line-height: 2;
}
.method .primary-sources {
  font-size: 0.79rem;
}
footer {
  border-top: 1px solid var(--line);
  padding-top: 1.5rem;
  padding-bottom: 2rem;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.77rem;
}
dialog {
  max-width: 35rem;
  padding: 2rem;
  border: 1px solid var(--line);
  color: inherit;
  background: #fff;
}
dialog::backdrop {
  background: #17212999;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.skip {
  position: absolute;
  top: -10rem;
  left: 1rem;
  background: white;
  padding: 1rem;
  z-index: 10;
}
.skip:focus {
  top: 0.5rem;
}
[hidden] {
  display: none !important;
}
@media (max-width: 760px) {
  header {
    padding: 1.1rem;
    gap: 0.8rem;
  }
  .brand {
    font-size: 1.9rem;
  }
  .brand-note {
    display: none;
  }
  main,
  footer {
    padding-left: 1rem;
    padding-right: 1rem;
  }
  .intro {
    padding-top: 1.6rem;
  }
  h1 {
    font-size: 2rem;
  }
  .subtitle {
    font-size: 1rem;
  }
  .scenario-bar {
    grid-template-columns: 1fr 1fr;
  }
  .scenario-bar button {
    font-size: 0.8rem;
  }
  .workspace {
    grid-template-columns: 1fr;
  }
  .form-card,
  .observatory {
    padding: 1.2rem;
  }
  .observatory {
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .field-grid {
    grid-template-columns: 1fr;
  }
  .field .hint {
    min-height: 0;
  }
  .actions > button {
    max-width: 100%;
  }
  .method-grid {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }
  .method > h2 {
    font-size: 1.6rem;
  }
  footer {
    flex-direction: column;
  }
  dialog {
    width: calc(100% - 2rem);
    padding: 1.25rem;
  }
}
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto;
  }
}
@media (forced-colors: active) {
  button[aria-pressed="true"] {
    border: 3px solid Highlight;
  }
  .error-summary {
    border-color: CanvasText;
  }
}