:root {
  /* Brand Colors */
  --primary-color: #2563EB;
  --primary-hover: #1D4ED8;
  --secondary-color: #0D9488;
  --secondary-hover: #0F766E;

  /* State Colors */
  --success-color: #10B981;
  --success-bg: #D1FAE5;
  --warning-color: #F59E0B;
  --warning-bg: #FEF3C7;
  --danger-color: #EF4444;
  --danger-bg: #FEE2E2;
  --info-color: #3B82F6;
  --info-bg: #DBEAFE;

  /* Neutral Colors */
  --background-color: #F3F4F6;
  --surface-color: #FFFFFF;
  --text-primary: #111827;
  --text-secondary: #4B5563;
  --text-muted: #9CA3AF;
  --border-color: #E5E7EB;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;

  /* Typography */
  --font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Effects */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--background-color);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.25;
}

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

a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  width: 100%;
}

main {
  flex: 1;
  padding: var(--spacing-xl) 0;
}

/* Navbar */
.navbar {
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}

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

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.brand span {
  font-weight: 400;
  color: var(--text-primary);
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius);
}

.nav-link:hover {
  background-color: var(--background-color);
  color: var(--text-primary);
  text-decoration: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius);
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
  font-size: 0.875rem;
  gap: var(--spacing-sm);
}

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

.btn-primary:hover {
  background-color: var(--primary-hover);
  text-decoration: none;
}

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

.btn-secondary:hover {
  background-color: var(--background-color);
  text-decoration: none;
}

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

.btn-danger:hover {
  background-color: #DC2626;
  text-decoration: none;
}

.btn-outline {
  background-color: transparent;
  border-color: var(--border-color);
  color: var(--text-secondary);
}

.btn-outline:hover, .btn-outline.active {
  background-color: var(--background-color);
  border-color: var(--text-secondary);
  color: var(--text-primary);
  text-decoration: none;
}

/* Cards */
.card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
  overflow: hidden;
}

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

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.card-subtitle {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

@media (max-width: 768px) {
  .grid-cols-2, .grid-cols-3, .grid-cols-4 {
    grid-template-columns: 1fr;
  }
}

/* Details List */
.details-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-md);
}

.detail-item {
  display: flex;
  flex-direction: column;
}

.detail-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.detail-value {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-primary);
}

/* Tables */
.table-container {
  width: 100%;
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  background-color: var(--surface-color);
}

th {
  text-align: left;
  padding: var(--spacing-md);
  background-color: var(--background-color);
  color: var(--text-secondary);
  font-weight: 600;
  border-bottom: 1px solid var(--border-color);
  white-space: nowrap;
}

td {
  padding: var(--spacing-md);
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  vertical-align: top;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background-color: #F9FAFB;
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.5rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: capitalize;
}

.badge-success { background-color: var(--success-bg); color: var(--success-color); }
.badge-warning { background-color: var(--warning-bg); color: var(--warning-color); }
.badge-danger { background-color: var(--danger-bg); color: var(--danger-color); }
.badge-info { background-color: var(--info-bg); color: var(--info-color); }
.badge-neutral { background-color: var(--background-color); color: var(--text-secondary); border: 1px solid var(--border-color); }

/* Tabs */
.tabs {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: var(--spacing-lg);
  overflow-x: auto;
}

.tab-btn {
  padding: var(--spacing-md) var(--spacing-lg);
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 500;
  border-bottom: 2px solid transparent;
  transition: var(--transition);
  white-space: nowrap;
}

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

.tab-btn.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
}

.tab-content {
  display: none;
  animation: fadeIn 0.2s ease-in-out;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Avatar */
.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
  font-size: 1.25rem;
}

.avatar-practitioner { background-color: var(--secondary-color); }
.avatar-patient { background-color: var(--primary-color); }

/* Utility */
.text-right { text-align: right; }
.text-center { text-align: center; }
.mt-4 { margin-top: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-md); }
.w-full { width: 100%; }
.flex { display: flex; }
.gap-2 { gap: var(--spacing-sm); }
.gap-4 { gap: var(--spacing-md); }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.code-block {
  font-family: var(--font-mono);
  background-color: var(--background-color);
  padding: var(--spacing-sm);
  border-radius: var(--radius);
  font-size: 0.75rem;
  word-break: break-all;
  color: var(--text-primary);
}

/* Flash Message */
.flash-message {
  padding: var(--spacing-md);
  border-radius: var(--radius);
  margin-bottom: var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.flash-success {
  background-color: var(--success-bg);
  border: 1px solid var(--success-color);
  color: #065F46;
}

/* Accordion/Details */
details > summary {
  list-style: none;
  cursor: pointer;
  padding: var(--spacing-sm) 0;
  font-weight: 600;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

details > summary::-webkit-details-marker {
  display: none;
}

details > summary::before {
  content: '▶';
  font-size: 0.75rem;
  transition: transform 0.2s;
}

details[open] > summary::before {
  transform: rotate(90deg);
}