:root {
  --bg-page: #f8fafc;
  --bg-surface: #ffffff;
  --bg-subtle: #f1f5f9;
  --bg-accent-soft: #eff6ff;
  --text-main: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --border-strong: #94a3b8;
  --border-subtle: #cbd5e1;
  --border-light: #e2e8f0;
  --accent-primary: #1e3a8a;
  --accent-hover: #172554;
  --status-positive: #15803d;
  --status-warning: #b45309;
  --status-danger: #b91c1c;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --shadow-card: 0 1px 3px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
}

[data-theme="dark"] {
  --bg-page: #0b0f19;
  --bg-surface: #111827;
  --bg-subtle: #1e293b;
  --bg-accent-soft: #172554;
  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-strong: #475569;
  --border-subtle: #334155;
  --border-light: #1e293b;
  --accent-primary: #3b82f6;
  --accent-hover: #60a5fa;
  --status-positive: #22c55e;
  --status-warning: #f59e0b;
  --status-danger: #ef4444;
  --shadow-card: 0 2px 6px rgba(0, 0, 0, 0.35);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* Tabular Accounting Numerals */
.num, input[type="number"], table td.num, table th.num, .kpi-value {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.mono {
  font-family: var(--font-mono);
}

/* Print-only elements hidden on screen */
.print-only {
  display: none !important;
}

/* Layout Containers */
.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header & Navigation */
.site-header {
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 40;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 1rem;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--accent-primary);
  color: #ffffff;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9rem;
  border-radius: 4px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s ease;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--accent-primary);
}

.theme-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  padding: 0.35rem 0.65rem;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
}

/* CLS-Safe AdSense Containers */
.ad-slot {
  margin: 1.5rem auto;
  padding: 0.5rem;
  background-color: var(--bg-subtle);
  border: 1px dashed var(--border-subtle);
  border-radius: 4px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.ad-slot-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
  user-select: none;
}

.ad-slot-leaderboard {
  min-height: 106px;
  max-width: 970px;
}

.ad-slot-rectangle {
  min-height: 268px;
  max-width: 728px;
}

/* Page Title & Action Bar */
.page-hero {
  padding: 1.75rem 0 1.25rem;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 1.5rem;
}

.breadcrumb {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}

.page-title-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.page-title {
  margin: 0;
  font-size: 1.75rem;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

.page-subtitle {
  margin: 0.5rem 0 0;
  color: var(--text-secondary);
  font-size: 0.98rem;
  max-width: 780px;
}

.toolbar-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.5rem 0.9rem;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 4px;
  border: 1px solid var(--border-subtle);
  background-color: var(--bg-surface);
  color: var(--text-main);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s ease;
}

.btn:hover {
  background-color: var(--bg-subtle);
  border-color: var(--border-strong);
}

.btn-primary {
  background-color: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #ffffff;
}

.btn-sm {
  padding: 0.3rem 0.6rem;
  font-size: 0.78rem;
}

/* Cards & Panels */
.ledger-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  box-shadow: var(--shadow-card);
  margin-bottom: 1.5rem;
  overflow: hidden;
}

.card-header {
  padding: 0.9rem 1.25rem;
  background-color: var(--bg-subtle);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.card-title {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.card-body {
  padding: 1.25rem;
}

/* Forms & Inputs */
.input-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1rem;
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.field-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.field-hint {
  font-size: 0.74rem;
  color: var(--text-muted);
}

input[type="text"],
input[type="number"],
input[type="date"],
select {
  width: 100%;
  padding: 0.48rem 0.65rem;
  font-size: 0.9rem;
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 4px;
}

input:focus, select:focus {
  outline: 2px solid var(--accent-primary);
  outline-offset: -1px;
  border-color: var(--accent-primary);
}

.input-prefix-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.input-prefix {
  position: absolute;
  left: 0.6rem;
  color: var(--text-muted);
  font-size: 0.88rem;
  pointer-events: none;
}

.input-prefix-wrap input {
  padding-left: 1.45rem;
}

.input-suffix {
  position: absolute;
  right: 0.6rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  pointer-events: none;
}

.input-suffix-wrap input {
  padding-right: 1.8rem;
}

/* KPI Summary Strip */
.kpi-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.85rem;
  margin-bottom: 1.5rem;
}

.kpi-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent-primary);
  border-radius: 5px;
  padding: 0.85rem 1rem;
  box-shadow: var(--shadow-card);
}

.kpi-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.kpi-value {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 0.2rem;
}

.kpi-sub {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.15rem;
}

/* Accounting Tables */
.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.ledger-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.ledger-table th,
.ledger-table td {
  padding: 0.55rem 0.65rem;
  border-bottom: 1px solid var(--border-light);
  text-align: left;
  vertical-align: middle;
}

.ledger-table th {
  background-color: var(--bg-subtle);
  color: var(--text-secondary);
  font-weight: 700;
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-bottom: 2px solid var(--border-subtle);
  white-space: nowrap;
}

.ledger-table th.num,
.ledger-table td.num {
  text-align: right;
}

.ledger-table tbody tr:hover {
  background-color: var(--bg-subtle);
}

.ledger-table tfoot td {
  background-color: var(--bg-subtle);
  font-weight: 700;
  border-top: 2px solid var(--border-strong);
  border-bottom: none;
}

.ledger-table input {
  padding: 0.35rem 0.5rem;
  font-size: 0.85rem;
}

/* Editorial & Reference Guide Section */
.editorial-section {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 2rem;
  margin: 2rem 0;
}

.editorial-section h2 {
  font-size: 1.35rem;
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-light);
}

.editorial-section h2:first-child {
  margin-top: 0;
}

.editorial-section h3 {
  font-size: 1.08rem;
  margin-top: 1.35rem;
  margin-bottom: 0.5rem;
}

.editorial-section p,
.editorial-section li {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.68;
}

.formula-box {
  background-color: var(--bg-subtle);
  border-left: 4px solid var(--accent-primary);
  padding: 1rem 1.25rem;
  margin: 1rem 0;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  overflow-x: auto;
}

.faq-item {
  border-bottom: 1px solid var(--border-light);
  padding: 1rem 0;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-q {
  font-weight: 700;
  color: var(--text-main);
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.faq-a {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.93rem;
}

/* Directory Hub Cards */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 1.25rem;
  margin: 1.5rem 0;
}

.tool-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 6px;
  padding: 1.35rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  color: inherit;
  transition: transform 0.12s ease, border-color 0.12s ease, box-shadow 0.12s ease;
}

.tool-card:hover {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-card);
  transform: translateY(-2px);
}

.tool-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.2rem 0.5rem;
  border-radius: 3px;
  background-color: var(--bg-accent-soft);
  color: var(--accent-primary);
  margin-bottom: 0.65rem;
}

.tool-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.15rem;
}

.tool-card p {
  margin: 0 0 1rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.tool-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
  padding-top: 0.65rem;
  display: flex;
  justify-content: space-between;
}

/* Footer */
.site-footer {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 2.5rem 0;
  margin-top: 3rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-links a:hover {
  text-decoration: underline;
}

/* Status Toast */
.toast-msg {
  position: fixed;
  bottom: 1.25rem;
  right: 1.25rem;
  background-color: var(--text-main);
  color: var(--bg-surface);
  padding: 0.6rem 1rem;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: 600;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
  z-index: 100;
}

.toast-msg.visible {
  opacity: 1;
}

@media (max-width: 768px) {
  .header-inner {
    height: auto;
    padding: 0.75rem 0;
    flex-direction: column;
    align-items: flex-start;
  }
  .editorial-section {
    padding: 1.25rem;
  }
}