:root {
  /* Primary colors */
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --background: #f9fafb;
  --text: #111827;
  --surface: #ffffff;
  --border: #e5e7eb;
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  --radius: 8px;
  --font: 'Inter', Arial, sans-serif;
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: var(--background);
  font-family: var(--font);
  color: var(--text);
  font-size: 15px;
  min-height: 100vh;
}

/* Main container */
#app {
  min-height: 100vh;
}

/* Auth section */
.auth-section {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #2563eb33, #3b82f622);
}

.auth-container {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: 0 3px 18px rgba(48,48,69,.12);
  padding: 38px 32px;
  width: 100%;
  max-width: 420px;
}

.auth-header {
  text-align: center;
  margin-bottom: 28px;
}

.brand-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 6px;
}

.brand-subtitle {
  color: var(--text);
  font-size: 15px;
}

.auth-form {
  margin-bottom: 10px;
}

.auth-form h2 {
  text-align: center;
  font-size: 22px;
  margin-bottom: 16px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text);
  font-size: 14px;
}

.form-group input {
  width: 100%;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--background);
  font-size: 15px;
  color: var(--text);
}

.form-group input:focus {
  border-color: var(--primary);
  outline: none;
}

.btn {
  display: inline-block;
  border-radius: var(--radius);
  background: var(--primary);
  color: #fff;
  padding: 12px 20px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: background .2s;
}

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

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-sm {
  font-size: 13px;
  padding: 8px 14px;
}

/* Main app layout */
.main-app {
  display: grid;
  grid-template-areas:
    "navbar navbar"
    "sidebar content";
  grid-template-columns: 220px 1fr;
  min-height: 100vh;
}

/* Navbar */
.navbar {
  grid-area: navbar;
  background: var(--surface);
  padding: 0 24px;
  border-bottom: 1px solid var(--border);
  height: 60px;
  display: flex;
  align-items: center;
}

.navbar-content {
  display: flex;
  justify-content: space-between;
  width: 100%;
  align-items: center;
}

.navbar h1 {
  font-size: 19px;
  font-weight: 700;
  color: var(--primary);
}

/* Sidebar */
.sidebar {
  grid-area: sidebar;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 20px 0;
  height: 100%;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
}

.nav-item {
  display: flex;
  align-items: center;
  padding: 12px 20px;
  font-weight: 500;
  font-size: 15px;
  color: #4b5563;
  cursor: pointer;
  border-left: 4px solid transparent;
  transition: background .18s, border-color .18s;
  text-decoration: none;
}

.nav-item.active,
.nav-item:hover {
  background: var(--background);
  color: var(--primary);
  border-left: 4px solid var(--primary);
}

.nav-icon {
  font-size: 18px;
  margin-right: 10px;
}

/* Content */
.main-content {
  grid-area: content;
  padding: 28px;
  background: var(--background);
  overflow-y: auto;
  min-height: 90vh;
}

.content-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 26px;
}

.content-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}

.content-actions {
  display: flex;
  gap: 10px;
}

/* Table styles */
.table-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: auto;
  margin-top: 10px;
}

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

.table th,
.table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.table th {
  background: var(--background);
  font-size: 13px;
  color: var(--primary);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.table td {
  font-size: 15px;
  color: var(--text);
}

.table tbody tr:hover {
  background: var(--surface);
}

/* Status badges */
.status-badge {
  border-radius: 5px;
  padding: 4px 8px;
  font-size: 13px;
  font-weight: 500;
}

.status-active { background: #dcfce7; color: #256029;}
.status-pending { background: #fef9c3; color: #92400e;}
.status-bounced { background: #fee2e2; color: #991b1b;}
.status-sent { background: #dbeafe; color: #1e40af;}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: 0 1px 5px rgba(60,60,110,.06);
  margin-bottom: 20px;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--primary);
}

/* Utility */
.hidden {
  display: none !important;
}
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}

/* Responsive */
@media (max-width: 900px) {
  .main-app {
    grid-template-columns: 1fr;
    grid-template-areas:
      "navbar"
      "content";
  }
  .sidebar {
    display: none;
  }
  .auth-container { padding: 18px; }
  .main-content { padding: 12px; }
  .table th, .table td { padding: 9px 8px; }
}