:root {
  --bg: #f8f9fb;
  --surface: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --paid-bg: #dcfce7;
  --paid-text: #166534;
  --unpaid-bg: #fee2e2;
  --unpaid-text: #991b1b;
  --radius: 0.5rem;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
}

* {
  box-sizing: border-box;
}

html {
  scrollbar-gutter: stable;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 0.9375rem;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  text-decoration: underline;
}

h1, h2, p {
  margin-top: 0;
}

h1 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.125rem;
  font-weight: 600;
}

/* Layout */

.app-shell {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 3rem;
}

.page-content {
  display: grid;
  gap: 1.25rem;
  margin-top: 1.25rem;
}

/* Nav */

.main-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.main-nav form {
  margin: 0;
  padding: 0;
  background: none;
  border: none;
  border-radius: 0;
  box-shadow: none;
}

.nav-links {
  display: flex;
  gap: 0.25rem;
}

.nav-links a {
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.875rem;
  color: var(--muted);
  transition: background 0.15s, color 0.15s;
}

.nav-links a:hover {
  background: var(--bg);
  color: var(--text);
  text-decoration: none;
}

/* Flash */

.flash {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  margin-top: 1.25rem;
}

.flash-notice {
  background: var(--paid-bg);
  color: var(--paid-text);
}

.flash-alert {
  background: var(--unpaid-bg);
  color: var(--unpaid-text);
}

/* Page header */

.page-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.page-header h1 {
  margin-bottom: 0.125rem;
}

.page-header form {
  margin: 0;
  padding: 0;
  background: none;
  border: none;
  border-radius: 0;
  box-shadow: none;
}

.page-subtitle {
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 0;
}

/* Buttons */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.5rem 1rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.875rem;
  font-family: inherit;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, border-color 0.15s;
  text-decoration: none;
}

.button:hover {
  text-decoration: none;
}

.button-small {
  padding: 0.3rem 0.625rem;
  font-size: 0.8125rem;
}

.button-primary {
  background: var(--primary);
  color: #fff;
}

.button-primary:hover {
  background: var(--primary-hover);
}

.button-secondary {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text);
}

.button-secondary:hover {
  background: var(--bg);
}

.button-danger {
  background: var(--danger);
  color: #fff;
}

.button-danger:hover {
  background: var(--danger-hover);
}

/* Status badges */

.status-badge {
  display: inline-flex;
  align-items: center;
  border-radius: 9999px;
  padding: 0.25rem 0.625rem;
  font-weight: 500;
  font-size: 0.8125rem;
}

.status-paid {
  background: var(--paid-bg);
  color: var(--paid-text);
}

.status-unpaid {
  background: var(--unpaid-bg);
  color: var(--unpaid-text);
}

/* Tables */

.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  margin: 0;
}

.data-table {
  width: 100%;
  min-width: 700px;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

.data-table th {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted);
  background: var(--bg);
}

.data-table tr:last-child td {
  border-bottom: 0;
}

.data-table tbody tr:hover {
  background: #f9fafb;
}

/* Rule rows */

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

.inline-actions {
  display: flex;
  gap: 0.375rem;
  align-items: flex-start;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.inline-actions form {
  margin: 0;
  padding: 0;
  background: none;
  border: none;
  border-radius: 0;
  box-shadow: none;
}

.rule-link {
  color: var(--text);
  text-decoration: none;
}

.rule-link:hover {
  color: var(--primary);
}

.rule-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.35rem;
}

.rule-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.5rem;
  border-radius: 9999px;
  background: #eff6ff;
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 500;
}

.rule-tag:hover {
  background: #dbeafe;
  text-decoration: none;
}

/* Empty state */

.empty-state {
  padding: 2.5rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-align: center;
}

.empty-state p {
  color: var(--muted);
}

/* Detail cards */

.detail-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

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

.detail-list {
  margin: 0;
}

.detail-list div + div {
  margin-top: 0.75rem;
}

.detail-list dt {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.detail-list dd {
  margin: 0.125rem 0 0;
}

/* Forms */

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

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.form-field label {
  font-weight: 500;
  font-size: 0.875rem;
}

.form-field input {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  font: inherit;
  transition: border-color 0.15s;
}

.form-field input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.form-errors {
  margin-bottom: 1rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  border: 1px solid rgba(220, 38, 38, 0.2);
  background: var(--unpaid-bg);
  font-size: 0.875rem;
}

.stack-form {
  display: grid;
  gap: 0.875rem;
}

/* Auth */

.auth-card {
  width: min(100%, 24rem);
  margin: 6rem auto 0;
  padding: 2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.auth-card form {
  padding: 0;
  border: none;
  box-shadow: none;
}

.auth-card__intro {
  margin-bottom: 1.5rem;
}

.auth-card__intro h1 {
  margin-bottom: 0.25rem;
}

.helper-copy {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.8125rem;
}

/* Hero card (unused currently but kept for parity) */

.hero-card {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1.5rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-card__content {
  max-width: 42rem;
}

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

.eyebrow {
  margin-bottom: 0.375rem;
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Responsive */

@media (max-width: 720px) {
  .app-shell {
    padding: 1rem 0.75rem 2rem;
  }

  .main-nav,
  .page-header,
  .hero-card {
    flex-direction: column;
    align-items: stretch;
  }

  .rule-title-row,
  .form-actions,
  .hero-actions,
  .inline-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .auth-card {
    margin-top: 2rem;
    width: 100%;
  }
}