/* DevBill Premium Modern SaaS Design System */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  --font-main: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Light Palette */
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #ffffff;
  --bg-card: #ffffff;
  --border-color: #e2e8f0;
  --border-subtle: #f1f5f9;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-subtle: #eef2ff;
  --primary-text: #4338ca;

  --success: #10b981;
  --success-subtle: #ecfdf5;
  --success-text: #065f46;

  --warning: #f59e0b;
  --warning-subtle: #fffbeb;
  --warning-text: #92400e;

  --danger: #ef4444;
  --danger-subtle: #fef2f2;
  --danger-text: #991b1b;

  --info: #0ea5e9;
  --info-subtle: #f0f9ff;
  --info-text: #075985;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.06), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  --shadow-glow: 0 0 20px rgba(79, 70, 229, 0.15);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 22px;

  --sidebar-width: 260px;
  --header-height: 68px;
}

/* Dark Palette */
html.dark {
  --bg-body: #090d16;
  --bg-surface: #0f172a;
  --bg-surface-elevated: #1e293b;
  --bg-card: #131c2e;
  --border-color: #1e293b;
  --border-subtle: #192237;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-subtle: rgba(99, 102, 241, 0.15);
  --primary-text: #818cf8;

  --success: #10b981;
  --success-subtle: rgba(16, 185, 129, 0.15);
  --success-text: #34d399;

  --warning: #f59e0b;
  --warning-subtle: rgba(245, 158, 11, 0.15);
  --warning-text: #fbbf24;

  --danger: #f87171;
  --danger-subtle: rgba(239, 68, 68, 0.15);
  --danger-text: #fca5a5;

  --info: #38bdf8;
  --info-subtle: rgba(14, 165, 233, 0.15);
  --info-text: #7dd3fc;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 30px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 25px rgba(99, 102, 241, 0.25);
}

/* Global Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-body);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.2s ease, color 0.2s ease;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover {
  color: var(--primary-hover);
}

/* Layout Hierarchy */
.app-container {
  display: flex;
  min-height: 100vh;
}

/* Sidebar */
.app-sidebar {
  width: var(--sidebar-width);
  background: var(--bg-surface);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 40;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.sidebar-header {
  height: var(--header-height);
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border-color);
}

.logo-badge {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.35);
}

.logo-text h1 {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  line-height: 1.2;
}

.logo-text span {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
  color: var(--text-muted);
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.nav-section-title {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 700;
  color: var(--text-muted);
  padding: 12px 10px 4px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 9px 12px;
  color: var(--text-secondary);
  font-size: 13.5px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all 0.15s ease;
}

.nav-link i, .nav-link svg {
  width: 18px;
  height: 18px;
  color: var(--text-muted);
  transition: color 0.15s ease;
}

.nav-link:hover {
  background: var(--bg-body);
  color: var(--text-primary);
}
.nav-link:hover i {
  color: var(--primary);
}

.nav-link.active {
  background: var(--primary-subtle);
  color: var(--primary-text);
  font-weight: 600;
}
.nav-link.active i {
  color: var(--primary);
}

.sidebar-footer {
  padding: 14px 16px;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.user-mini-card {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow: hidden;
}

.user-avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--primary-subtle);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 13px;
  flex-shrink: 0;
}

.user-info {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.user-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.user-role {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: capitalize;
}

/* Main Content Area */
.app-main {
  flex: 1;
  margin-left: var(--sidebar-width);
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* Top Header */
.app-header {
  height: var(--header-height);
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  backdrop-filter: blur(8px);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.mobile-toggle-btn {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 20px;
  cursor: pointer;
  padding: 4px;
}

.search-trigger-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-body);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 7px 14px;
  color: var(--text-muted);
  font-size: 13px;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
  min-width: 220px;
}
.search-trigger-btn:hover {
  border-color: var(--primary);
  color: var(--text-secondary);
}
.search-shortcut {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-body);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  cursor: pointer;
  position: relative;
  transition: all 0.15s ease;
}
.header-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-color);
  background: var(--border-subtle);
}

.notif-badge-dot {
  position: absolute;
  top: 7px;
  right: 7px;
  width: 8px;
  height: 8px;
  background: var(--danger);
  border-radius: 50%;
  border: 2px solid var(--bg-surface);
}

/* Page Content View */
.page-content {
  padding: 28px;
  flex: 1;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.page-title {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.6px;
  color: var(--text-primary);
}
.page-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Cards & Panels */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  padding: 18px 22px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-body {
  padding: 22px;
}

/* KPI Cards Grid */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-bottom: 28px;
}

.kpi-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.kpi-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.kpi-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.kpi-label {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-secondary);
}

.kpi-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}
.kpi-icon.indigo { background: var(--primary-subtle); color: var(--primary); }
.kpi-icon.emerald { background: var(--success-subtle); color: var(--success); }
.kpi-icon.amber { background: var(--warning-subtle); color: var(--warning); }
.kpi-icon.rose { background: var(--danger-subtle); color: var(--danger); }
.kpi-icon.sky { background: var(--info-subtle); color: var(--info); }

.kpi-value {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.8px;
  color: var(--text-primary);
  line-height: 1.1;
  margin-bottom: 6px;
}

.kpi-subtext {
  font-size: 12px;
  color: var(--text-muted);
}

/* Status Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 9px;
  border-radius: 9999px;
  font-size: 11px;
  font-weight: 600;
  text-transform: capitalize;
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.badge-paid { background: var(--success-subtle); color: var(--success-text); }
.badge-paid .badge-dot { background: var(--success); }

.badge-sent, .badge-generated, .badge-viewed { background: var(--info-subtle); color: var(--info-text); }
.badge-sent .badge-dot, .badge-generated .badge-dot { background: var(--info); }

.badge-partially_paid, .badge-partial { background: var(--warning-subtle); color: var(--warning-text); }
.badge-partially_paid .badge-dot { background: var(--warning); }

.badge-overdue, .badge-failed { background: var(--danger-subtle); color: var(--danger-text); }
.badge-overdue .badge-dot { background: var(--danger); }

.badge-draft, .badge-inactive, .badge-queued { background: var(--border-subtle); color: var(--text-secondary); }
.badge-active { background: var(--success-subtle); color: var(--success-text); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-main);
  font-size: 13.5px;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(79, 70, 229, 0.25);
}
.btn-primary:hover {
  background: var(--primary-hover);
  color: #ffffff;
}

.btn-outline {
  background: var(--bg-surface);
  border-color: var(--border-color);
  color: var(--text-primary);
}
.btn-outline:hover {
  background: var(--bg-body);
  border-color: var(--text-muted);
}

.btn-success {
  background: var(--success);
  color: #ffffff;
}
.btn-success:hover {
  background: #059669;
}

.btn-danger {
  background: var(--danger);
  color: #ffffff;
}
.btn-danger:hover {
  background: #dc2626;
}

.btn-outline-danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.35);
}
.btn-outline-danger:hover {
  background: var(--danger);
  color: #ffffff;
  border-color: var(--danger);
}

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
  border-radius: var(--radius-sm);
}

.btn-icon {
  width: 34px;
  height: 34px;
  padding: 0;
  border-radius: var(--radius-md);
}

/* Forms & Inputs */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.form-control, .form-select {
  width: 100%;
  font-family: var(--font-main);
  font-size: 13.5px;
  padding: 9px 13px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-control:focus, .form-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-subtle);
}

/* Modern Data Table */
.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.table th {
  padding: 12px 16px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-body);
}

.table td {
  padding: 14px 16px;
  font-size: 13.5px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  vertical-align: middle;
}

.table tr:hover td {
  background: var(--bg-body);
}

.table .primary-col {
  font-weight: 600;
  color: var(--text-primary);
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  border-radius: var(--radius-md);
  padding: 12px 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 280px;
  max-width: 420px;
  animation: slideInUp 0.25s ease;
  font-size: 13px;
  font-weight: 500;
}
.toast-success { border-left: 4px solid var(--success); }
.toast-danger { border-left: 4px solid var(--danger); }
.toast-warning { border-left: 4px solid var(--warning); }
.toast-info { border-left: 4px solid var(--info); }

@keyframes slideInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Modal Backdrop & Dialog */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease;
}

.modal-backdrop.open {
  opacity: 1;
  visibility: visible;
}

.modal-dialog {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 580px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.95);
  transition: transform 0.2s ease;
}

.modal-backdrop.open .modal-dialog {
  transform: scale(1);
}

.modal-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
}

.modal-close-btn {
  background: transparent;
  border: none;
  font-size: 20px;
  color: var(--text-muted);
  cursor: pointer;
}
.modal-close-btn:hover { color: var(--text-primary); }

.modal-body {
  padding: 24px;
  overflow-y: auto;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  background: var(--bg-body);
}

/* Tabs */
.tabs-nav {
  display: flex;
  gap: 8px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 20px;
}
.tab-btn {
  padding: 10px 16px;
  background: transparent;
  border: none;
  font-family: var(--font-main);
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: all 0.15s ease;
}
.tab-btn:hover {
  color: var(--text-primary);
}
.tab-btn.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.tab-pane {
  display: none;
}
.tab-pane.active {
  display: block;
}

/* Responsive Breakpoints */
@media (max-width: 1024px) {
  .app-sidebar {
    transform: translateX(-100%);
  }
  .app-sidebar.open {
    transform: translateX(0);
  }
  .app-main {
    margin-left: 0;
  }
  .mobile-toggle-btn {
    display: block;
  }
}