:root {
  color-scheme: light;
  --base-font-size: 15px;
  --bg: #f6f5f1;
  --surface: #ffffff;
  --surface-2: #ebe8df;
  --ink: #202124;
  --muted: #66706a;
  --line: #d8d3c6;
  --red: #b72d32;
  --teal: #186b70;
  --green: #3d7354;
  --gold: #ae7f2b;
  --shadow: 0 18px 45px rgba(49, 45, 36, 0.12);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #181916;
  --surface: #23251f;
  --surface-2: #303329;
  --ink: #f4f0e7;
  --muted: #b6b2a7;
  --line: #45483c;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.32);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: var(--base-font-size);
}

button,
input,
select {
  font: inherit;
}

button,
select,
input {
  border: 1px solid var(--line);
}

button {
  cursor: pointer;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  background: var(--surface);
  border-right: 1px solid var(--line);
  padding: 18px;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  margin-bottom: 24px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 8px;
  background: var(--red);
  color: #fff;
  font-weight: 800;
}

.brand small,
.eyebrow,
.breadcrumb,
.module-badge,
.metrics-grid span {
  color: var(--muted);
}

.brand strong,
.brand small {
  display: block;
}

.mother-tabs,
.child-tabs {
  display: grid;
  gap: 8px;
}

.tab-button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 42px;
  width: 100%;
  border-radius: 8px;
  background: transparent;
  color: var(--ink);
  padding: 10px 12px;
  text-align: left;
  border-left: 3px solid transparent;
  transition: background 0.15s, color 0.15s, transform 0.15s, border-color 0.15s;
}

.tab-button:hover {
  background: var(--surface-2);
  transform: scale(1.03);
}

.tab-button.active {
  background: var(--ink);
  color: var(--surface);
  border-color: var(--red);
  border-left-width: 3px;
  transform: none;
}

.tab-button small {
  color: inherit;
  opacity: 0.72;
}

.main {
  min-width: 0;
  padding: 18px;
}

.topbar {
  display: grid;
  grid-template-columns: auto minmax(220px, 1fr) auto auto auto;
  gap: 12px;
  align-items: center;
  margin-bottom: 18px;
}

.topbar label {
  display: grid;
  gap: 4px;
  color: var(--muted);
  font-size: 0.82rem;
}

.search span {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

input,
select {
  min-height: 38px;
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  padding: 8px 10px;
}

input[type="range"] {
  padding: 0;
}

.icon-button,
.account-button,
.primary-action,
.secondary-action {
  min-height: 40px;
  border-radius: 8px;
  padding: 8px 14px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  display: inline-grid;
  place-items: center;
}

.primary-action {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
}

.secondary-action {
  border-color: var(--teal);
  color: var(--teal);
}

.home-view,
.module-view {
  display: grid;
  gap: 18px;
}

.hero {
  min-height: min(640px, calc(100vh - 146px));
  display: grid;
  grid-template-columns: minmax(280px, 0.9fr) minmax(320px, 1.1fr);
  align-items: center;
  gap: 28px;
  padding: 34px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(2.4rem, 5vw, 4.8rem);
  line-height: 0.98;
  letter-spacing: 0;
}

.hero-text {
  max-width: 660px;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.7;
}

.quick-actions,
.form-grid,
.result-grid,
.option-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.workflow-visual {
  position: relative;
  min-height: 430px;
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(183, 45, 50, 0.12), transparent 38%),
    linear-gradient(315deg, rgba(24, 107, 112, 0.16), transparent 42%),
    var(--surface-2);
  border: 1px solid var(--line);
  overflow: hidden;
}

.desk-card {
  position: absolute;
  display: grid;
  gap: 12px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.document {
  width: 44%;
  min-height: 56%;
  left: 10%;
  top: 14%;
  transform: rotate(-7deg);
}

.envelope {
  width: 48%;
  min-height: 34%;
  right: 9%;
  top: 26%;
  transform: rotate(5deg);
}

.receipt {
  width: 34%;
  right: 18%;
  bottom: 12%;
  transform: rotate(-2deg);
}

.line,
.address-line,
.barcode {
  display: block;
  height: 10px;
  border-radius: 99px;
  background: var(--line);
}

.line.strong {
  height: 18px;
  background: var(--red);
}

.line.short,
.address-line.short {
  width: 62%;
}

.stamp {
  justify-self: end;
  width: 54px;
  height: 42px;
  border-radius: 6px;
  background: var(--gold);
}

.barcode {
  height: 38px;
  background: repeating-linear-gradient(90deg, var(--ink), var(--ink) 3px, transparent 3px, transparent 8px);
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(140px, 1fr));
  gap: 12px;
}

.metrics-grid article,
.panel,
.module-head {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.metrics-grid article {
  padding: 18px;
}

.metrics-grid strong {
  display: block;
  margin-top: 6px;
  font-size: 1.8rem;
}

.module-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px;
}

.module-head h2 {
  margin: 4px 0 0;
  font-size: 2rem;
}

.module-badge {
  border: 1px solid var(--line);
  border-radius: 99px;
  padding: 8px 12px;
}

.child-tabs {
  grid-template-columns: repeat(7, minmax(120px, 1fr));
}

.panel {
  padding: 20px;
  min-height: 600px;
}

.panel h3 {
  margin-top: 0;
  font-size: 1.45rem;
}

.calculator {
  display: grid;
  grid-template-columns: minmax(260px, 1fr) minmax(260px, 0.8fr);
  gap: 18px;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 14px;
}

.field-grid label {
  display: grid;
  gap: 6px;
  color: var(--muted);
}

.result-card {
  align-self: start;
  display: grid;
  gap: 14px;
  padding: 18px;
  border-radius: 8px;
  background: var(--surface-2);
  border: 1px solid var(--line);
}

.price {
  font-size: 2.4rem;
  font-weight: 800;
}

.result-row,
.timeline-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}

.timeline {
  display: grid;
  gap: 10px;
  max-width: 720px;
}

.timeline-row strong {
  color: var(--green);
}

.empty-state {
  display: grid;
  gap: 14px;
  max-width: 820px;
  color: var(--muted);
  line-height: 1.6;
}

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

  .sidebar {
    position: static;
    height: auto;
  }

  .mother-tabs,
  .child-tabs {
    grid-template-columns: repeat(2, minmax(140px, 1fr));
  }

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

@media (max-width: 720px) {
  .main,
  .sidebar {
    padding: 12px;
  }

  .topbar {
    grid-template-columns: 1fr 1fr;
  }

  .search {
    grid-column: 1 / -1;
  }

  .hero {
    min-height: auto;
    padding: 20px;
  }

  .workflow-visual {
    min-height: 320px;
  }

  .metrics-grid,
  .field-grid,
  .child-tabs,
  .mother-tabs {
    grid-template-columns: 1fr;
  }
}

/* ── Module cards on home ────────────────────────────────────────────────── */
.module-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}

/* ── Screen reader only ──────────────────────────────────────────────────── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}