:root {
  --paper: #f8f1e4;
  --paper-deep: #eee0ca;
  --ink: #1e1a17;
  --muted: #6f6359;
  --navy: #152638;
  --navy-soft: #20364d;
  --red: #b24332;
  --red-dark: #863022;
  --amber: #d49b39;
  --green: #357b5f;
  --line: #d8c7ad;
  --white: #fffaf0;
  --shadow: 0 24px 70px rgba(35, 28, 20, 0.16);
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background:
    linear-gradient(90deg, rgba(21, 38, 56, 0.05) 1px, transparent 1px) 0 0 / 48px 48px,
    linear-gradient(180deg, rgba(178, 67, 50, 0.06), transparent 32rem),
    var(--paper);
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

code,
input,
select,
.result-list dd,
.steps-box {
  font-family: "Courier New", Courier, monospace;
}

.page-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 42px 0 56px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 28px;
  align-items: end;
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--red);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(3rem, 8vw, 6.4rem);
  line-height: 0.88;
  letter-spacing: -0.07em;
}

h2 {
  margin: 0 0 14px;
  font-size: clamp(1.45rem, 3vw, 2.1rem);
  letter-spacing: -0.035em;
}

h3 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.hero-lede {
  max-width: 680px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  line-height: 1.55;
}

.review-note {
  border-left: 5px solid var(--amber);
  background: rgba(255, 250, 240, 0.72);
  padding: 18px 20px;
  color: var(--muted);
  line-height: 1.45;
}

.review-note strong {
  display: block;
  color: var(--ink);
  margin-bottom: 4px;
}

.calculator-board {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(380px, 1.08fr);
  gap: 22px;
  align-items: stretch;
  margin-bottom: 28px;
}

.console-panel,
.result-panel,
.guide-card,
.faq-section {
  border: 1px solid var(--line);
  background: rgba(255, 250, 240, 0.88);
  box-shadow: var(--shadow);
}

.console-panel,
.result-panel {
  min-height: 100%;
  padding: 26px;
}

.calc-form label,
.field label,
.mode-field legend {
  display: block;
  margin-bottom: 9px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.input-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  border: 2px solid var(--ink);
  background: var(--white);
}

.math-prefix,
.math-suffix {
  padding: 0 14px;
  color: var(--red);
  font-size: 1.45rem;
  font-weight: 700;
}

.input-row input {
  width: 100%;
  min-height: 58px;
  border: 0;
  background: transparent;
  color: var(--ink);
  font-size: 1.15rem;
  outline: none;
}

.field-help {
  margin: 10px 0 22px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.45;
}

.control-grid {
  display: grid;
  grid-template-columns: 0.65fr 1fr 0.7fr 0.7fr;
  gap: 14px;
  align-items: end;
}

.field input,
.field select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 0;
  background: var(--white);
  color: var(--ink);
  padding: 9px 10px;
}

.mode-field {
  min-height: 44px;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--white);
  padding: 8px 10px;
}

.mode-field label {
  display: inline-flex;
  gap: 6px;
  align-items: center;
  margin: 0 12px 0 0;
  color: var(--ink);
  font-weight: 400;
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.primary-action,
.secondary-action {
  border: 1px solid var(--ink);
  padding: 11px 16px;
  min-height: 44px;
  transition: transform 160ms ease, background 160ms ease, color 160ms ease;
}

.primary-action {
  background: var(--red);
  color: var(--white);
  border-color: var(--red-dark);
  font-weight: 700;
}

.secondary-action {
  background: transparent;
  color: var(--ink);
}

.primary-action:hover,
.secondary-action:hover {
  transform: translateY(-1px);
}

.primary-action:focus-visible,
.secondary-action:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(178, 67, 50, 0.35);
  outline-offset: 2px;
}

.result-panel {
  background: var(--navy);
  color: var(--white);
}

.result-head {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: start;
  border-bottom: 1px solid rgba(255, 250, 240, 0.2);
  padding-bottom: 16px;
}

.result-head h2 {
  color: var(--white);
}

.status-pill {
  border: 1px solid rgba(255, 250, 240, 0.25);
  background: var(--navy-soft);
  color: var(--white);
  padding: 7px 10px;
  font-size: 0.8rem;
}

.status-pill.review {
  background: rgba(212, 155, 57, 0.2);
  color: #ffe2a4;
}

.result-list {
  display: grid;
  gap: 13px;
  margin: 20px 0;
}

.result-list div {
  display: grid;
  grid-template-columns: 135px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}

.result-list dt {
  color: #d9c9ad;
  font-size: 0.86rem;
  font-weight: 700;
}

.result-list dd {
  margin: 0;
  overflow-wrap: anywhere;
}

.steps-box {
  border: 1px solid rgba(255, 250, 240, 0.18);
  background: rgba(255, 250, 240, 0.06);
  padding: 16px;
}

.steps-box ol {
  margin: 0;
  padding-left: 22px;
  line-height: 1.55;
}

.interpretation {
  color: #d9c9ad;
  line-height: 1.5;
}

.result-actions .secondary-action {
  border-color: rgba(255, 250, 240, 0.28);
  color: var(--white);
}

.feedback {
  min-height: 1.2em;
  margin: 12px 0 0;
  color: #f0d486;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.guide-card,
.faq-section {
  padding: 24px;
}

.guide-card p,
.guide-card li,
.faq-section p {
  color: var(--muted);
  line-height: 1.62;
}

.guide-card.wide {
  grid-column: 1 / -1;
}

.example-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.example-button {
  min-height: 72px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  padding: 12px;
  text-align: left;
}

.faq-section {
  margin-top: 18px;
}

.faq-list {
  display: grid;
  gap: 10px;
}

details {
  border-top: 1px solid var(--line);
  padding: 14px 0;
}

summary {
  cursor: pointer;
  font-weight: 700;
}

@media (max-width: 920px) {
  .hero,
  .calculator-board,
  .content-grid {
    grid-template-columns: 1fr;
  }

  .calculator-board {
    gap: 16px;
  }

  .control-grid,
  .example-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 560px) {
  .page-shell {
    width: min(100% - 22px, 1180px);
    padding-top: 24px;
  }

  h1 {
    font-size: clamp(2.65rem, 16vw, 4.2rem);
  }

  .console-panel,
  .result-panel,
  .guide-card,
  .faq-section {
    padding: 18px;
  }

  .control-grid,
  .example-grid,
  .result-list div {
    grid-template-columns: 1fr;
  }

  .mode-field label {
    display: flex;
    margin: 6px 0;
  }

  .action-row {
    flex-direction: column;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }
}