:root {
  --primary: #FF6B35;
  --primary-hover: #E85820;
  --primary-light: #FFF0EB;
  --primary-gradient: linear-gradient(135deg, #FF6B35 0%, #FF8E53 100%);
  --bg: #F8FAFC;
  --card-bg: #FFFFFF;
  --text-main: #0F172A;
  --text-muted: #64748B;
  --border: #E2E8F0;
  --radius: 12px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px -2px rgba(0, 0, 0, 0.08);
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
  font-family: var(--font);
  background-color: var(--bg);
  color: var(--text-main);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* App Layout */
.app-layout {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Navigation Bar */
.top-nav {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-icon {
  width: 42px;
  height: 42px;
  background: var(--primary-gradient);
  color: #FFFFFF;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(255, 107, 53, 0.3);
}

.brand-text h1 {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.2;
}

.brand-text span {
  font-size: 12px;
  color: var(--text-muted);
}

.session-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #F1F5F9;
  padding: 8px 14px;
  border-radius: 20px;
  font-size: 12.5px;
  font-weight: 500;
  color: #334155;
  border: 1px solid var(--border);
}

.session-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--warning);
}

.session-dot.online {
  background-color: var(--success);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
}

.icon-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  padding: 2px;
}

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

/* Main Container */
.main-container {
  max-width: 1280px;
  width: 100%;
  margin: 28px auto;
  padding: 0 24px;
  flex: 1;
}

.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
}

@media (max-width: 900px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}

/* Cards */
.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  margin-bottom: 20px;
}

.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.step-num {
  width: 22px;
  height: 22px;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
  font-size: 12px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-header h2 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-main);
}

.card-content {
  padding: 20px;
}

/* Students Selector */
.students-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 12px;
}

.student-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 14px;
  border: 2px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  background: #FAFAFA;
}

.student-card:hover {
  border-color: #CBD5E1;
}

.student-card.selected {
  border-color: var(--primary);
  background: var(--primary-light);
}

.student-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-gradient);
  color: #FFFFFF;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  overflow: hidden;
  flex-shrink: 0;
}

.student-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.student-info h4 {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-main);
}

.student-info p {
  font-size: 12px;
  color: var(--text-muted);
}

.loading-placeholder {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-muted);
  font-size: 13px;
  padding: 12px 0;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid #E2E8F0;
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.manual-id-details summary {
  font-size: 12.5px;
  color: var(--primary);
  cursor: pointer;
  margin-top: 4px;
  user-select: none;
}

.manual-input-row {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.manual-input-row input {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 12.5px;
  outline: none;
}

.manual-input-row input:focus {
  border-color: var(--primary);
}

/* Date Filters */
.quick-dates-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.pill-btn {
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: #FFFFFF;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.pill-btn:hover {
  border-color: #94A3B8;
}

.pill-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #FFFFFF;
}

.date-inputs-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.date-field {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.date-field label {
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-muted);
}

.date-field input {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 13px;
  outline: none;
}

.date-field input:focus {
  border-color: var(--primary);
}

/* Checkboxes */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.custom-checkbox {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  cursor: pointer;
  position: relative;
  user-select: none;
}

.custom-checkbox input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}

.checkmark {
  width: 18px;
  height: 18px;
  border: 2px solid #CBD5E1;
  border-radius: 5px;
  margin-top: 2px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.custom-checkbox input:checked ~ .checkmark {
  background-color: var(--primary);
  border-color: var(--primary);
}

.custom-checkbox input:checked ~ .checkmark::after {
  content: "";
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  margin-bottom: 2px;
}

.checkbox-label {
  display: flex;
  flex-direction: column;
}

.checkbox-label strong {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-main);
}

.checkbox-label small {
  font-size: 12px;
  color: var(--text-muted);
}

/* Action Box */
.hero-action-card {
  padding: 24px;
}

.action-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.action-header h3 {
  font-size: 16px;
  font-weight: 800;
}

.speed-setting {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-muted);
}

.speed-setting select {
  padding: 4px 8px;
  border-radius: 6px;
  border: 1px solid var(--border);
  font-size: 12px;
  outline: none;
}

.primary-controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 22px;
}

.primary-action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 14px 20px;
  background: var(--primary-gradient);
  color: #FFFFFF;
  border: none;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(255, 107, 53, 0.35);
  transition: all 0.2s ease;
}

.primary-action-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 107, 53, 0.45);
}

.primary-action-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.secondary-controls-row {
  display: flex;
  gap: 10px;
}

.secondary-btn, .danger-btn {
  flex: 1;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid var(--border);
  background: #FFFFFF;
  transition: all 0.2s ease;
}

.secondary-btn:hover {
  background: #F1F5F9;
}

.danger-btn {
  color: var(--danger);
  border-color: #FECACA;
}

.danger-btn:hover {
  background: #FEF2F2;
}

/* Progress Bar */
.progress-section {
  margin-bottom: 20px;
}

.progress-labels {
  display: flex;
  justify-content: space-between;
  font-size: 12.5px;
  font-weight: 600;
  margin-bottom: 6px;
}

.progress-bar-track {
  width: 100%;
  height: 10px;
  background: #E2E8F0;
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--primary-gradient);
  border-radius: 10px;
  transition: width 0.3s ease;
}

/* Metrics Grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.metric-card {
  background: #F8FAFC;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
}

.metric-value {
  font-size: 17px;
  font-weight: 800;
  color: var(--text-main);
}

.metric-label {
  font-size: 11.5px;
  color: var(--text-muted);
}

/* Terminal Log */
.log-card {
  display: flex;
  flex-direction: column;
  height: 320px;
}

.log-header h3 {
  font-size: 14px;
  font-weight: 700;
}

.link-btn {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 12px;
  cursor: pointer;
}

.terminal-log-body {
  flex: 1;
  background: #0F172A;
  color: #E2E8F0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 12px;
  padding: 14px;
  overflow-y: auto;
  line-height: 1.6;
}

.log-line.info { color: #94A3B8; }
.log-line.success { color: #34D399; }
.log-line.warn { color: #FBBF24; }
.log-line.error { color: #F87171; }