:root {
  --bg: #ffd900;
  --surface: #fffdf2;
  --ink: #0b0d0f;
  --muted: #4a4e52;
  --line: #0b0d0f;
  --accent: #1559ff;
  --accent-ink: #ffffff;
  --warning: #9d4600;
  --danger: #bc2c28;
  --success: #095c3e;
  --radius: 0;
  --shadow: 8px 8px 0 #0b0d0f;
}

body {
  background: var(--bg);
}

.site-header {
  min-height: 70px;
  background: var(--ink);
  color: #fffdf2;
  border-bottom: 0;
}

.brand-mark {
  width: 38px;
  color: var(--bg);
  border-color: var(--bg);
  font: 800 0.63rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.header-note {
  color: #dadbd4;
}

.local-icon {
  color: var(--bg);
  font-weight: 900;
}

main {
  width: min(1500px, 100%);
  margin: 0 auto;
  padding: clamp(30px, 5vw, 76px) clamp(16px, 4vw, 64px) 80px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 42px;
  align-items: end;
  padding-bottom: clamp(38px, 5vw, 68px);
}

.marker,
.card-code,
.json-label {
  font: 850 0.7rem/1.3 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.marker {
  margin-bottom: 13px;
}

h1 {
  max-width: 1120px;
  margin-bottom: 21px;
  color: var(--ink);
  font-size: clamp(3.1rem, 8.2vw, 8.8rem);
  line-height: 0.82;
  letter-spacing: -0.072em;
  text-transform: uppercase;
}

h1 span {
  color: var(--accent);
  -webkit-text-stroke: 2px var(--ink);
}

.lede {
  max-width: 820px;
  color: #292b2c;
  font-weight: 620;
}

.hero-stamp {
  display: grid;
  gap: 8px;
  align-self: center;
  padding: 21px;
  border: 3px solid var(--ink);
  background: var(--surface);
  box-shadow: 7px 7px 0 var(--accent);
  transform: rotate(1.5deg);
}

.hero-stamp strong {
  color: var(--danger);
  font-size: 1.05rem;
}

.hero-stamp span {
  padding-top: 8px;
  border-top: 1px solid var(--ink);
  font-size: 0.78rem;
}

.checker-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(350px, 0.88fr);
  border: 3px solid var(--ink);
  background: var(--surface);
  box-shadow: 12px 12px 0 var(--ink);
}

.brief-form,
.result-board {
  padding: clamp(20px, 3vw, 42px);
}

.brief-form {
  border-right: 3px solid var(--ink);
}

.form-title-row,
.result-title-row,
.form-actions,
.format-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.form-title-row,
.result-title-row {
  margin-bottom: 26px;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.75rem, 3vw, 3.2rem);
  line-height: 0.96;
  letter-spacing: -0.045em;
  text-transform: uppercase;
}

.example-button,
.build-button,
.copy-button {
  border: 2px solid var(--ink);
  background: var(--bg);
  color: var(--ink);
  padding: 11px 14px;
  font-weight: 850;
  box-shadow: 3px 3px 0 var(--ink);
}

.example-button:hover,
.build-button:hover,
.copy-button:hover {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}

input,
textarea,
select {
  border: 2px solid var(--ink);
  background: #fff;
}

textarea:focus,
input:focus,
select:focus,
button:focus-visible,
summary:focus-visible {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgb(21 89 255 / 0.2);
}

.constraint-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.constraint-card {
  position: relative;
  padding: 18px 16px 2px;
  border: 2px solid var(--ink);
}

.change-card {
  background: #edf3ff;
  box-shadow: 5px 5px 0 var(--accent);
}

.preserve-card {
  background: #fff5b8;
  box-shadow: 5px 5px 0 var(--ink);
}

.card-code {
  display: inline-block;
  margin-bottom: 16px;
  padding: 5px 7px;
  background: var(--ink);
  color: #fff;
}

.change-card .card-code {
  background: var(--accent);
}

.reference-block {
  margin: 26px 0 8px;
  padding: 20px 18px 2px;
  border: 3px solid var(--accent);
}

.reference-block .marker {
  color: var(--accent);
}

.lower-grid {
  margin-top: 20px;
}

.stripe-field {
  padding: 16px;
  background: repeating-linear-gradient(-45deg, #fff, #fff 8px, #f4f2e6 8px, #f4f2e6 16px);
  border: 2px solid var(--ink);
}

.field-number {
  display: inline-grid;
  place-items: center;
  width: 26px;
  height: 26px;
  margin-right: 8px;
  background: var(--ink);
  color: var(--bg);
  font: 800 0.7rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.format-row {
  align-items: start;
  margin-top: 20px;
}

.format-row .field {
  flex: 1 1 0;
}

.form-actions {
  margin-top: 8px;
  padding-top: 20px;
  border-top: 2px solid var(--ink);
}

.form-actions p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.78rem;
}

.build-button {
  background: var(--accent);
  color: #fff;
  min-width: 210px;
  padding-block: 14px;
}

.result-board {
  background: #f0efea;
}

.readiness-chip {
  padding: 7px 10px;
  border: 2px solid var(--ink);
  background: #fff;
  font: 800 0.74rem/1 ui-monospace, SFMono-Regular, Menlo, monospace;
  text-transform: uppercase;
}

.readiness-chip[data-tone="good"] {
  color: #fff;
  background: var(--success);
}

.readiness-chip[data-tone="warn"] {
  color: var(--ink);
  background: var(--bg);
}

.result-empty {
  min-height: 430px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 24px;
  border: 2px dashed #73736f;
  background: #fff;
  text-align: center;
}

.result-empty p {
  max-width: 330px;
  color: var(--muted);
  line-height: 1.6;
}

.edit-diagram {
  display: flex;
  align-items: center;
  gap: 13px;
}

.edit-diagram span {
  display: grid;
  place-items: center;
  width: 74px;
  height: 74px;
  border: 3px solid var(--ink);
  background: var(--bg);
  font-weight: 900;
}

.edit-diagram span:last-child {
  background: var(--accent);
  color: #fff;
}

.edit-diagram i {
  font-size: 2rem;
  font-style: normal;
}

.coverage-meter {
  padding: 18px;
  border: 2px solid var(--ink);
  background: #fff;
}

.coverage-meter > div:first-child {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

.coverage-meter strong {
  font-size: 1.65rem;
}

.coverage-meter span {
  color: var(--muted);
  font-size: 0.76rem;
}

.meter-track {
  height: 12px;
  margin-top: 12px;
  background: #d9d8d0;
  border: 1px solid var(--ink);
}

.meter-track span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--accent);
  transition: width 180ms ease-out;
}

.finding-group {
  margin-top: 20px;
  padding: 18px;
  border: 2px solid var(--ink);
  background: var(--bg);
}

.finding-group h3 {
  margin-bottom: 10px;
  font-size: 0.9rem;
  text-transform: uppercase;
}

.finding-group ul {
  margin: 0;
  padding-left: 20px;
  line-height: 1.55;
  font-size: 0.84rem;
}

.finding-group li + li {
  margin-top: 7px;
}

.json-card {
  margin-top: 20px;
  border: 2px solid var(--ink);
  background: var(--ink);
  color: #fff;
}

.json-card .result-head {
  padding: 15px;
}

.json-card small {
  display: block;
  margin-top: 5px;
  color: #b9bec5;
}

.json-label {
  color: var(--bg);
}

.copy-button {
  flex: 0 0 auto;
  box-shadow: none;
}

pre {
  max-height: 480px;
  overflow: auto;
  margin: 0;
  padding: 18px;
  border-top: 1px solid #4d5157;
  white-space: pre-wrap;
  word-break: break-word;
  color: #dbe5ff;
  font: 0.78rem/1.65 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.result-disclaimer {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.55;
}

.error-summary {
  margin-bottom: 20px;
  padding: 14px;
  border: 3px solid var(--danger);
  background: #fff0ed;
  color: #7c1c18;
  line-height: 1.5;
}

.error-summary ul {
  margin-bottom: 0;
}

.explanation,
.faq-section {
  margin-top: clamp(72px, 9vw, 130px);
}

.explanation-heading {
  display: grid;
  grid-template-columns: 0.62fr 1.38fr;
  gap: 30px;
  align-items: end;
  padding-bottom: 24px;
  border-bottom: 3px solid var(--ink);
}

.explanation-heading h2,
.faq-section h2 {
  font-size: clamp(2.4rem, 5.5vw, 6rem);
}

.principle-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  background: var(--ink);
  gap: 2px;
  border-bottom: 2px solid var(--ink);
}

.principle-grid article {
  min-height: 260px;
  padding: 22px 18px;
  background: var(--surface);
}

.principle-grid article:nth-child(2) {
  background: #fff3a6;
}

.principle-grid article:nth-child(3) {
  background: #e9efff;
}

.principle-grid span {
  display: inline-block;
  margin-bottom: 44px;
  padding: 4px 7px;
  background: var(--ink);
  color: #fff;
  font: 850 0.67rem/1.2 ui-monospace, SFMono-Regular, Menlo, monospace;
}

.principle-grid h3 {
  font-size: 1.25rem;
  text-transform: uppercase;
}

.principle-grid p,
.faq-list p,
.source-note {
  color: var(--muted);
  line-height: 1.65;
}

.faq-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 3px solid var(--ink);
  background: var(--ink);
  gap: 2px;
}

.faq-list details {
  padding: 21px;
  background: var(--surface);
}

.faq-list summary {
  font-weight: 850;
}

.faq-list p {
  margin: 13px 0 0;
}

.source-note {
  max-width: 800px;
  margin: 22px 0 0;
  font-size: 0.82rem;
}

.source-note a {
  color: var(--accent);
  font-weight: 750;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 24px 4vw;
  background: var(--ink);
  color: #d7d8d1;
  font-size: 0.82rem;
}

.site-footer a {
  color: var(--bg);
}

@media (max-width: 1050px) {
  .checker-shell {
    grid-template-columns: 1fr;
  }

  .brief-form {
    border-right: 0;
    border-bottom: 3px solid var(--ink);
  }

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

@media (max-width: 740px) {
  .header-note {
    display: none;
  }

  .hero,
  .explanation-heading {
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: clamp(3rem, 17vw, 5.4rem);
  }

  h1 span {
    -webkit-text-stroke-width: 1px;
  }

  .hero-stamp {
    max-width: 260px;
  }

  .constraint-grid,
  .faq-list,
  .principle-grid {
    grid-template-columns: 1fr;
  }

  .format-row,
  .form-actions,
  .site-footer {
    align-items: stretch;
    flex-direction: column;
  }

  .build-button {
    width: 100%;
  }
}

@media (max-width: 460px) {
  main {
    padding-inline: 10px;
  }

  .form-title-row,
  .result-title-row {
    align-items: flex-start;
    flex-direction: column;
  }

  .example-button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .meter-track span {
    transition: none;
  }
}