/* ===================================================================
   cashflow-tracker — CSS System (I5-T1)
   =================================================================== */

:root {
  /* Colors — derived from design reference */
  --color-primary: #030213;
  --color-primary-fg: #ffffff;
  --color-muted: #ececf0;
  --color-muted-fg: #717182;
  --color-input-bg: #f3f3f5;
  --color-destructive: #d4183d;
  --color-destructive-fg: #ffffff;
  --color-success: #16a34a;
  --color-success-fg: #ffffff;
  --color-border: rgba(0, 0, 0, 0.1);
  --color-border-strong: rgba(0, 0, 0, 0.2);
  --color-hover: #f9fafb;
  --color-body-bg: #ffffff;
  --color-card-bg: #ffffff;

  /* Spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;

  /* Border radius */
  --radius: 10px;
  --radius-sm: 6px;
  --radius-md: 8px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-size-base: 16px;
  --font-size-sm: 14px;
  --font-size-xs: 12px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
}

/* ---------------------------------------------------------------
   Base element styles
   --------------------------------------------------------------- */

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-primary);
  background: var(--color-body-bg);
  margin: 0;
  padding: 0;
}

h1, h2, h3, h4 {
  font-weight: 500;
  margin: 0 0 16px 0;
  line-height: 1.3;
}

h1 { font-size: var(--font-size-2xl); }
h2 { font-size: var(--font-size-xl); }
h3 { font-size: var(--font-size-lg); }
h4 { font-size: var(--font-size-base); }

a {
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

table {
  border-collapse: collapse;
  width: 100%;
  border: 1px solid var(--color-border);
}

th {
  background: var(--color-muted);
  font-weight: 500;
  text-align: left;
  padding: 10px 16px;
  font-size: var(--font-size-sm);
  border-bottom: 1px solid var(--color-border-strong);
}

td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--color-border);
}

tbody tr:hover {
  background: var(--color-hover);
}

input,
select,
textarea {
  display: block;
  width: 100%;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  background: var(--color-input-bg);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-primary);
  transition: border-color 0.15s;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(3, 2, 19, 0.1);
}

textarea {
  resize: vertical;
}

button {
  cursor: pointer;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 500;
}

dl {
  margin: 0;
}

/* ---------------------------------------------------------------
   Layout
   --------------------------------------------------------------- */

.container {
  margin: 0 auto;
}

.container-narrow {
  margin: 0 auto;
}

/* ---------------------------------------------------------------
   SANDBOX banner
   --------------------------------------------------------------- */

.sandbox-banner {
  background: #fef3c7;
  color: #92400e;
  text-align: center;
  padding: 8px;
  font-weight: 500;
  font-size: var(--font-size-sm);
  border-bottom: 1px solid #fed7aa;
}

/* ---------------------------------------------------------------
   Navigation
   --------------------------------------------------------------- */

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px var(--space-3);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-body-bg);
}

.nav-brand {
  font-weight: 500;
  font-size: var(--font-size-lg);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-brand:hover {
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 10px;
}

.nav-links a {
  color: var(--color-muted-fg);
  text-decoration: none;
  font-size: var(--font-size-sm);
  font-weight: 500;
}

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

.nav-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-right span {
  font-size: var(--font-size-sm);
  color: var(--color-muted-fg);
}

.nav-right button {
  font-size: var(--font-size-sm);
  padding: 4px 12px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-body-bg);
  color: var(--color-primary);
  cursor: pointer;
}

.nav-right button:hover {
  background: var(--color-hover);
}

.lang-switch {
  font-size: var(--font-size-sm);
  color: var(--color-muted-fg);
}

.lang-switch a {
  color: var(--color-muted-fg);
  text-decoration: none;
}

.lang-switch a:hover {
  text-decoration: underline;
}

.lang-switch strong {
  color: var(--color-primary);
}

/* ---------------------------------------------------------------
   Cards
   --------------------------------------------------------------- */

.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}

/* ---------------------------------------------------------------
   Buttons
   --------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  font-size: var(--font-size-base);
  border: 1px solid var(--color-border);
  background: var(--color-body-bg);
  color: var(--color-primary);
  cursor: pointer;
  transition: background-color 0.15s;
  text-decoration: none;
  line-height: 1.5;
}

.btn:hover {
  background: var(--color-hover);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-primary-fg);
  border-color: var(--color-primary);
}

.btn-primary:hover {
  opacity: 0.9;
  background: var(--color-primary);
}

.btn-secondary {
  background: var(--color-body-bg);
  color: var(--color-primary);
  border-color: var(--color-border-strong);
}

.btn-destructive {
  background: var(--color-destructive);
  color: var(--color-destructive-fg);
  border-color: var(--color-destructive);
}

.btn-destructive:hover {
  opacity: 0.9;
  background: var(--color-destructive);
}

.btn-lg {
  padding: 12px 24px;
}

.btn-sm {
  padding: 6px 12px;
  font-size: var(--font-size-sm);
}

/* ---------------------------------------------------------------
   Toggle buttons (direction selector)
   --------------------------------------------------------------- */

.toggle-group {
  display: flex;
  gap: 12px;
}

.toggle-btn {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-body-bg);
  color: #374151;
  font-weight: 500;
  text-align: center;
  cursor: pointer;
  transition: all 0.15s;
}

.toggle-btn:hover {
  background: var(--color-hover);
}

.toggle-btn.active {
  background: var(--color-primary);
  color: var(--color-primary-fg);
  border-color: var(--color-primary);
}

/* ---------------------------------------------------------------
   Badges
   --------------------------------------------------------------- */

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 9999px;
  font-size: var(--font-size-xs);
  font-weight: 500;
}

.badge-active {
  background: #dcfce7;
  color: #166534;
}

.badge-voided {
  background: #fee2e2;
  color: #991b1b;
}

.badge-corrected {
  background: #fef3c7;
  color: #92400e;
}

/* ---------------------------------------------------------------
   Flash messages
   --------------------------------------------------------------- */

.flash {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
  border: 1px solid;
}

.flash-success {
  background: #f0fdf4;
  border-color: #bbf7d0;
  color: #166534;
}

.flash-error {
  background: #fef2f2;
  border-color: #fecaca;
  color: #991b1b;
}

/* ---------------------------------------------------------------
   Form sections
   --------------------------------------------------------------- */

.form-section {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}

.form-section-alt {
  background: var(--color-hover);
}

.form-group {
  margin-bottom: 16px;
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-label {
  display: block;
  font-weight: 500;
  margin-bottom: 6px;
  font-size: var(--font-size-base);
}

.form-helper {
  font-size: var(--font-size-sm);
  color: var(--color-muted-fg);
  margin-top: 4px;
}

.checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-weight: 500;
}

.checkbox-label input[type="checkbox"] {
  display: inline-block;
  width: 18px;
  height: 18px;
  margin: 0;
  flex: 0 0 auto;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-error {
  font-size: var(--font-size-sm);
  color: var(--color-destructive);
  margin-top: 4px;
}

/* ---------------------------------------------------------------
   Error summary
   --------------------------------------------------------------- */

.error-summary {
  padding: 16px;
  border: 1px solid var(--color-border);
  background: var(--color-hover);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.error-summary ul {
  margin: 8px 0 0 0;
  padding-left: 20px;
}

.error-summary li {
  color: var(--color-destructive);
  margin-bottom: 4px;
}

/* ---------------------------------------------------------------
   Callouts (info, warning)
   --------------------------------------------------------------- */

.callout {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid;
  font-size: var(--font-size-sm);
}

.callout-info {
  background: #eff6ff;
  border-color: #bfdbfe;
  color: #1e40af;
}

.callout-warning {
  background: #fffbeb;
  border-color: #fed7aa;
  color: #92400e;
}

/* ---------------------------------------------------------------
   Table responsive wrapper
   --------------------------------------------------------------- */

.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* ---------------------------------------------------------------
   Voided row styling
   --------------------------------------------------------------- */

.row-voided {
  opacity: 0.5;
}

.row-voided .amount {
  text-decoration: line-through;
}

/* ---------------------------------------------------------------
   Empty state
   --------------------------------------------------------------- */

.empty-state {
  text-align: center;
  padding: 48px 16px;
  color: var(--color-muted-fg);
}

/* ---------------------------------------------------------------
   Dashboard
   --------------------------------------------------------------- */

.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.card-value {
  font-size: var(--font-size-2xl);
  font-weight: 500;
  line-height: 1.3;
}

.dashboard-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.toolbar-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.filter-form {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.filter-form select {
  width: auto;
  min-width: 180px;
}

/* ---------------------------------------------------------------
   Utility classes
   --------------------------------------------------------------- */

.text-muted { color: var(--color-muted-fg); }
.text-sm { font-size: var(--font-size-sm); }
.text-xs { font-size: var(--font-size-xs); }
.text-right { text-align: right; }
.text-center { text-align: center; }
.mt-2 { margin-top: 8px; }
.mt-4 { margin-top: 16px; }
.mb-4 { margin-bottom: 16px; }
.mb-6 { margin-bottom: 24px; }
.gap-3 { gap: 12px; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.hidden { display: none; }

/* ---------------------------------------------------------------
   Responsive
   --------------------------------------------------------------- */

/* Mobile-first: base styles are for small screens.
   Progressively enhance at tablet (768px) and desktop (1024px). */

.form-row {
  grid-template-columns: 1fr;
}

.container {
  padding: 0 var(--space-3);
}

.container-narrow {
  padding: 0 var(--space-3);
}

@media (min-width: 768px) {
  .form-row {
    grid-template-columns: 1fr 1fr;
  }

  .container {
    padding: 0 var(--space-4);
  }

  .container-narrow {
    padding: 0 var(--space-4);
  }

  .nav {
    gap: var(--space-6);
    padding: var(--space-3) var(--space-4);
  }

  .nav-links {
    gap: var(--space-4);
  }

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

  .dashboard-actions {
    flex-direction: row;
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 1152px;
  }

  .container-narrow {
    max-width: 672px;
  }
}

/* ---------------------------------------------------------------
   T4 page-specific classes
   --------------------------------------------------------------- */

.detail-grid {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--space-2) var(--space-4);
}

.detail-grid dt {
  font-weight: 500;
  color: var(--color-muted-fg);
}

.detail-grid dd {
  margin: 0;
}

.audit-card {
  border-color: #fecaca;
}

.transaction-summary-card {
  background: var(--color-hover);
}

.history-toolbar {
  gap: var(--space-3);
  flex-wrap: wrap;
}

.action-row {
  flex-wrap: wrap;
}

@media (max-width: 767px) {
  .detail-grid {
    grid-template-columns: 1fr;
  }

  .detail-grid dt {
    margin-top: var(--space-2);
  }
}

/* ---------------------------------------------------------------
   Split view (list page — desktop only)
   --------------------------------------------------------------- */

.split-view {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.split-view-col h3 {
  margin-bottom: 12px;
}