:root {
  color-scheme: light dark;
  --bg: #f4f6f8;
  --surface: #ffffff;
  --text: #1a1d21;
  --muted: #5c6570;
  --border: #d5dbe3;
  --accent: #0b6e4f;
  --accent-soft: #d8f3e7;
  --nsw: #014c8c;
  --vic: #6b2d5c;
  --warn-bg: #fff6e5;
  --warn-border: #e0b84a;
  --danger-bg: #fdeceb;
  --focus: #2563eb;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  --radius: 12px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151a;
    --surface: #1c2128;
    --text: #e8ecf1;
    --muted: #9aa3ad;
    --border: #303840;
    --accent: #3ecf8e;
    --accent-soft: #163528;
    --nsw: #5ba3e0;
    --vic: #d48bbd;
    --warn-bg: #3a3018;
    --warn-border: #c9a227;
    --danger-bg: #3a1e1c;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
}

a {
  color: var(--accent);
}

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--surface);
  padding: 0.5rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.site-header .inner,
.site-footer .inner,
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem 1.25rem;
}

.site-header .inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  text-decoration: none;
  color: var(--text);
}

.brand span {
  color: var(--accent);
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

nav a {
  text-decoration: none;
  color: var(--muted);
  font-weight: 500;
}

nav a[aria-current="page"],
nav a:hover {
  color: var(--accent);
}

main {
  padding-top: 1.5rem;
  padding-bottom: 3rem;
}

h1 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0 0 0.5rem;
  line-height: 1.25;
}

.lede {
  color: var(--muted);
  margin: 0 0 1.25rem;
  max-width: 65ch;
}

.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

.badge.fact {
  background: var(--accent-soft);
}

.badge.assumption {
  background: var(--warn-bg);
  color: #8a6a00;
}

@media (prefers-color-scheme: dark) {
  .badge.assumption {
    color: #f0d878;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  margin-bottom: 1.25rem;
}

.card h2 {
  margin: 0 0 0.75rem;
  font-size: 1.15rem;
}

.form-grid {
  display: grid;
  gap: 1rem;
}

label.field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-weight: 600;
}

label.field .hint {
  font-weight: 400;
  font-size: 0.875rem;
  color: var(--muted);
}

input[type="number"],
input[type="text"] {
  font: inherit;
  font-size: 1.125rem;
  padding: 0.65rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  width: 100%;
  max-width: 24rem;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: flex-start;
}

.toggle {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-weight: 500;
  cursor: pointer;
  max-width: 36rem;
}

.toggle input {
  margin-top: 0.25rem;
  width: 1.15rem;
  height: 1.15rem;
  accent-color: var(--accent);
}

.toggle .toggle-text .hint {
  display: block;
  font-weight: 400;
  font-size: 0.875rem;
  color: var(--muted);
}

.btn {
  font: inherit;
  font-weight: 600;
  padding: 0.65rem 1.1rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
}

@media (prefers-color-scheme: dark) {
  .btn {
    color: #062216;
  }
}

.btn:hover {
  filter: brightness(1.05);
}

.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.results {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .results {
    grid-template-columns: 1fr 1fr;
  }
}

.result-card h3 {
  margin: 0 0 0.25rem;
  font-size: 1rem;
}

.result-card.nsw h3 {
  color: var(--nsw);
}

.result-card.vic h3 {
  color: var(--vic);
}

.duty-amount {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  margin: 0.35rem 0;
  font-family: var(--mono);
}

.formula {
  font-size: 0.9rem;
  color: var(--muted);
  margin: 0.25rem 0 0;
}

.diff-card {
  grid-column: 1 / -1;
  text-align: center;
}

.diff-card .duty-amount {
  font-size: 1.5rem;
}

.note-list {
  margin: 0.75rem 0 0;
  padding-left: 1.1rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.disclaimer,
.oos {
  border-left: 4px solid var(--warn-border);
  background: var(--warn-bg);
}

.disclaimer strong,
.oos strong {
  display: block;
  margin-bottom: 0.35rem;
}

.oos ul {
  margin: 0.5rem 0 0;
  padding-left: 1.2rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th,
td {
  text-align: left;
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  background: var(--bg);
  font-weight: 600;
}

.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.875rem;
}

.site-footer p {
  margin: 0.35rem 0;
}

.links-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  margin-top: 0.75rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.error {
  color: #b42318;
  font-size: 0.9rem;
  margin: 0.5rem 0 0;
}

@media (prefers-color-scheme: dark) {
  .error {
    color: #f97066;
  }
}