:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --card-hover: #f1f5f9;
  --muted: #64748b;
  --text: #1e293b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius: 12px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Inter', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header Styles */
header {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
  border: 1px solid var(--border);
}

.brand-text h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.125rem;
}

.brand-text .sub {
  color: var(--muted);
  font-size: 0.875rem;
}

.header-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.date-display {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(241, 245, 249, 0.7);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  border: 1px solid var(--border);
  font-size: 0.875rem;
}

.status-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--success);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { opacity: 1; }
  50% { opacity: 0.5; }
  100% { opacity: 1; }
}

.nav-menu {
  display: flex;
  gap: 0.5rem;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-item:hover {
  background: var(--card-hover);
}

.nav-item.active {
  background: var(--accent);
  color: white;
}

.logout-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.logout-btn:hover {
  background: rgba(239, 68, 68, 0.1);
  border-color: var(--danger);
  color: var(--danger);
}

/* Main Content */
main {
  flex: 1;
  padding: 2rem 1.5rem;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.tip {
  background: rgba(241, 245, 249, 0.5);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 1rem;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.tip i {
  color: var(--accent);
  margin-top: 0.125rem;
}

/* Dashboard Card */
.dashboard-card {
  background: var(--card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  margin-bottom: 2rem;
}

.card-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.card-header h3 {
  font-size: 1.25rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.card-header h3 i {
  color: var(--accent);
}

/* Controls */
.controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  padding: 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(248, 250, 252, 0.5);
}

.control-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.control-group label {
  font-size: 0.875rem;
  color: var(--muted);
  white-space: nowrap;
}

.form-select, .form-input {
  background: rgba(248, 250, 252, 0.5);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.625rem 1rem;
  color: var(--text);
  font-size: 0.875rem;
  transition: var(--transition);
  min-width: 140px;
}

.form-select:focus, .form-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.radio-group {
  display: flex;
  gap: 1rem;
}

.radio-option {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.radio-option input[type="radio"] {
  margin: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  border-radius: 8px;
  font-weight: 500;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-size: 0.875rem;
  white-space: nowrap;
}

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

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

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

.btn-outline:hover {
  background: rgba(0, 0, 0, 0.05);
  border-color: var(--accent);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.75rem;
}

.actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: auto;
}

/* Table Styles */
.table-container {
  overflow: auto;
  max-height: 70vh;
}

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

.data-table th {
  text-align: left;
  padding: 1rem 1.25rem;
  background: rgba(241, 245, 249, 0.7);
  color: var(--muted);
  font-weight: 600;
  font-size: 0.875rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.data-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.875rem;
  vertical-align: middle;
}

.data-table tr:hover td {
  background: var(--card-hover);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 500;
  white-space: nowrap;
}

.badge-in {
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-out {
  background: rgba(239, 68, 68, 0.1);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.badge-late {
  background: rgba(245, 158, 11, 0.1);
  color: var(--warning);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.badge-uid {
  background: rgba(148, 163, 184, 0.1);
  color: var(--muted);
  border: 1px solid rgba(148, 163, 184, 0.2);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

.badge-reader {
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.student-info {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.student-name {
  font-weight: 500;
}

.student-grade {
  font-size: 0.75rem;
  color: var(--muted);
}

.time-info {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.time-full {
  font-size: 0.875rem;
}

.time-relative {
  font-size: 0.75rem;
  color: var(--muted);
}

.direction-info {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pickup-info {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.25rem;
}

.empty-state {
  padding: 3rem 2rem;
  text-align: center;
  color: var(--muted);
}

.empty-state i {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.hidden {
  display: none !important;
}

/* Responsive Styles */
@media (max-width: 1024px) {
  .controls {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .actions {
    margin-left: 0;
    width: 100%;
    justify-content: flex-start;
  }
}

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .header-info {
    width: 100%;
    justify-content: space-between;
  }
  
  .nav-menu {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 0.5rem;
  }
  
  .card-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .control-group {
    width: 100%;
    justify-content: space-between;
  }
  
  .form-select, .form-input {
    flex: 1;
  }
  
  .data-table {
    min-width: 800px;
  }
}

@media (max-width: 480px) {
  .radio-group {
    flex-direction: column;
    gap: 0.5rem;
  }
}