:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --secondary-color: #f8fafc;
  --text-color: #334155;
  --text-light: #64748b;
  --bg-color: #f1f5f9;
  --white: #ffffff;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --danger-color: #ef4444;
  --danger-hover: #dc2626;
  --success-color: #10b981;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

html {
  -webkit-text-size-adjust: 100%;
}

img, iframe, table {
  max-width: 100%;
}

/* Header Navbar */
.navbar {
  background-color: var(--white);
  box-shadow: var(--shadow-sm);
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
  line-height: 1.2;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-color);
  font-weight: 500;
  transition: color 0.2s ease;
}

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

.btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  font-size: 1rem;
  line-height: 1.25;
  text-align: center;
}

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

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

.btn-danger {
  background-color: var(--danger-color);
  color: var(--white);
}

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

/* Main Content Area */
.container {
  max-width: 1200px;
  width: 100%;
  margin: 2rem auto;
  padding: 0 2rem;
  flex: 1;
}

/* Cards */
.card {
  background-color: var(--white);
  border-radius: 0.5rem;
  box-shadow: var(--shadow-md);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-color);
}

/* Forms */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-color);
}

.form-control {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

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

/* Tables */
.table-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
}
.table th, .table td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}
.table th {
  background-color: var(--secondary-color);
  font-weight: 600;
}

/* Filters */
.filter-bar {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  background: var(--white);
  padding: 1rem;
  border-radius: 0.5rem;
  box-shadow: var(--shadow-sm);
  align-items: center;
  flex-wrap: wrap;
}

.filter-bar .form-group {
  margin-bottom: 0;
  flex: 1;
  min-width: 200px;
}

/* Status Badges */
.badge {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-pending { background-color: #fef3c7; color: #b45309; }
.badge-active { background-color: #d1fae5; color: #047857; }
.badge-expired { background-color: #fee2e2; color: #b91c1c; }

/* Grid Layouts */
.grid-cols-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.5rem; }
.grid-cols-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.5rem; }

/* Footer */
footer {
  background-color: var(--white);
  text-align: center;
  padding: 2rem;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  color: var(--text-light);
}

/* Utility */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.flex { display: flex; }
.justify-between { justify-content: space-between; }
.items-center { align-items: center; }
.text-danger { color: var(--danger-color); }

@media (max-width: 768px) {
  body {
    font-size: 0.95rem;
  }

  .navbar {
    padding: 0.75rem 0.85rem;
    position: static;
  }

  .nav-container {
    width: 100%;
    align-items: stretch;
    flex-direction: column;
    gap: 0.65rem;
  }

  .nav-logo {
    display: block;
    font-size: 1.02rem;
    max-width: 100%;
    text-align: center;
  }

  .nav-links {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.45rem;
    overflow: visible;
    padding-bottom: 0;
  }

  .nav-links a {
    display: flex;
    min-height: 42px;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
    border-radius: 0.45rem;
    background: var(--secondary-color);
    font-size: 0.82rem;
    line-height: 1.15;
    padding: 0.45rem 0.35rem;
    text-align: center;
    white-space: normal;
  }

  .nav-links .btn {
    border-color: var(--primary-color);
    padding: 0.45rem 0.35rem;
    width: auto;
  }

  .container {
    margin: 1rem auto;
    padding: 0 1rem;
  }

  .card {
    border-radius: 0.45rem;
    padding: 1rem;
    margin-bottom: 1rem;
  }

  .card:hover {
    transform: none;
    box-shadow: var(--shadow-md);
  }

  .card-title {
    font-size: 1.05rem;
    line-height: 1.35;
    overflow-wrap: anywhere;
  }

  .grid-cols-2,
  .grid-cols-3 {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .filter-bar {
    padding: 1rem;
    margin-bottom: 1rem;
  }

  .filter-bar form,
  .filter-bar .flex {
    flex-direction: column;
    align-items: stretch !important;
    gap: 0.75rem !important;
  }

  .filter-bar .form-group {
    width: 100%;
    min-width: 0;
  }

  .filter-bar .btn {
    width: 100%;
  }

  .flex.justify-between,
  .flex.items-center {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .table-container {
    margin-left: -1rem;
    margin-right: -1rem;
    border-radius: 0;
  }

  .table {
    min-width: 720px;
    font-size: 0.875rem;
  }

  .table th,
  .table td {
    padding: 0.65rem 0.75rem;
  }

  button,
  input,
  select,
  textarea {
    font-size: 1rem;
  }

  footer {
    padding: 1.25rem 1rem;
    font-size: 0.875rem;
  }
}

@media (max-width: 480px) {
  .nav-logo {
    font-size: 0.98rem;
  }

  .nav-links {
    gap: 0.35rem;
  }

  .nav-links a {
    min-height: 40px;
    font-size: 0.76rem;
    padding: 0.4rem 0.25rem;
  }

  .container {
    padding: 0 0.75rem;
  }

  .card {
    padding: 0.9rem;
  }

  .form-control {
    padding: 0.65rem 0.7rem;
  }

  .btn {
    width: 100%;
    padding: 0.65rem 0.8rem;
  }

  .nav-links .btn {
    width: auto;
  }

  .badge {
    font-size: 0.68rem;
  }
}