* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #f5f7fa;
  --card-bg: #fff;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --success: #059669;
  --warning: #d97706;
  --danger: #dc2626;
  --border: #e5e7eb;
  --radius: 8px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

/* Navbar */
.navbar {
  background: var(--text);
  color: #fff;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-brand { font-weight: 700; font-size: 18px; }
.nav-links { display: flex; gap: 16px; }
.nav-links a { color: #a5b4c8; text-decoration: none; font-size: 14px; padding: 4px 8px; border-radius: 4px; }
.nav-links a:hover, .nav-links a.active { color: #fff; background: rgba(255,255,255,0.1); }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 24px; }

/* Stats Grid */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; margin-bottom: 24px; }
.stat-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat-number { font-size: 28px; font-weight: 700; }
.stat-label { font-size: 13px; color: var(--text-muted); margin-top: 4px; }
.stat-success .stat-number { color: var(--success); }
.stat-danger .stat-number { color: var(--danger); }

/* Cards */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 16px;
}
.card h3 { margin-bottom: 16px; font-size: 16px; }
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 16px; margin-bottom: 16px; }

/* Table */
.table { width: 100%; border-collapse: collapse; font-size: 14px; }
.table th, .table td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); }
.table th { font-weight: 600; font-size: 12px; text-transform: uppercase; color: var(--text-muted); background: #f9fafb; }
.table tr:hover { background: #f9fafb; }

/* Badges */
.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
}
.badge-success { background: #d1fae5; color: var(--success); }
.badge-warning { background: #fef3c7; color: var(--warning); }
.badge-danger { background: #fee2e2; color: var(--danger); }
.badge-info { background: #dbeafe; color: var(--primary); }
.badge-default { background: #f3f4f6; color: var(--text-muted); }

/* Buttons */
.btn {
  display: inline-block;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  background: var(--card-bg);
  color: var(--text);
  text-decoration: none;
  transition: background 0.15s;
}
.btn:hover { background: #f3f4f6; }
.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); }
.btn-sm { padding: 4px 10px; font-size: 12px; }
.btn:disabled { opacity: 0.6; cursor: not-allowed; }

/* Forms */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 4px; }
.input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  max-width: 300px;
}

/* Alerts */
.alert { padding: 12px 16px; border-radius: 6px; margin: 12px 0; font-size: 14px; }
.alert-warning { background: #fef3c7; color: #92400e; }
.alert-success { background: #d1fae5; color: #065f46; }
.alert-danger { background: #fee2e2; color: #991b1b; }
.alert-info { background: #dbeafe; color: #1e40af; }

/* Section */
.section { margin-bottom: 32px; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.section-header h2 { font-size: 20px; }

/* DL (definition list) */
dl { display: grid; grid-template-columns: auto 1fr; gap: 8px 16px; }
dt { font-weight: 600; font-size: 13px; color: var(--text-muted); }
dd { font-size: 14px; }

/* Code */
code { background: #f3f4f6; padding: 2px 6px; border-radius: 4px; font-size: 13px; word-break: break-all; }
.code-block {
  background: #1e1e2e;
  color: #cdd6f4;
  padding: 16px;
  border-radius: var(--radius);
  font-size: 12px;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 400px;
  overflow-y: auto;
}
.hash { display: block; margin-top: 4px; }

/* QR */
.qr-code { max-width: 200px; }

/* Breadcrumb */
.breadcrumb { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; }
.breadcrumb a { color: var(--primary); text-decoration: none; }

/* Invoice header */
.invoice-header { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 24px; flex-wrap: wrap; gap: 12px; }
.invoice-header h1 { display: inline; margin-right: 12px; }
.invoice-actions { display: flex; gap: 8px; }

/* Onboarding */
.onboarding-steps { display: flex; flex-direction: column; gap: 24px; }
.step { padding: 16px; border: 1px solid var(--border); border-radius: var(--radius); }
.step h4 { margin-bottom: 8px; }

/* Utility */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); font-size: 13px; }
.text-success { color: var(--success); }

/* Responsive */
@media (max-width: 768px) {
  .container { padding: 16px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .card-grid { grid-template-columns: 1fr; }
  .table { font-size: 12px; }
  .table th, .table td { padding: 8px 6px; }
  .invoice-header { flex-direction: column; }
}