:root {
  --bg-primary: #0f172a;
  --bg-surface: #1e293b;
  --bg-surface-elevated: #334155;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: #334155;
  --border-light: #475569;
  
  --color-success: #10b981;
  --color-success-bg: rgba(16, 185, 129, 0.15);
  --color-warning: #f59e0b;
  --color-warning-bg: rgba(245, 158, 11, 0.15);
  --color-danger: #ef4444;
  --color-danger-bg: rgba(239, 68, 68, 0.15);
  --color-accent: #0284c7;
  --color-accent-hover: #0369a1;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

.app-container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* Header & Status Bar */
header {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-card);
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-badge {
  font-size: 0.75rem;
  background-color: var(--bg-surface-elevated);
  color: var(--text-secondary);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.status-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.connectivity-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.35rem 0.75rem;
  border-radius: 9999px;
  background-color: var(--color-success-bg);
  color: var(--color-success);
}

.connectivity-badge.offline {
  background-color: var(--color-warning-bg);
  color: var(--color-warning);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: currentColor;
}

/* Navigation Tabs */
.nav-tabs {
  display: flex;
  gap: 0.5rem;
  background-color: var(--bg-surface);
  padding: 0.35rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.tab-btn {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab-btn:hover {
  color: var(--text-primary);
  background-color: var(--bg-surface-elevated);
}

.tab-btn.active {
  color: var(--text-primary);
  background-color: var(--color-accent);
}

/* Main Content Panels */
.tab-content {
  display: none;
  flex-direction: column;
  gap: 1.25rem;
}

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

.panel-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
}

.panel-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.panel-description {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 1.25rem;
}

/* Forms & Inputs */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

input, textarea, select {
  width: 100%;
  padding: 0.65rem 0.85rem;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.875rem;
}

input:focus, textarea:focus, select:focus {
  outline: 2px solid var(--color-accent);
  border-color: transparent;
}

textarea {
  resize: vertical;
  min-height: 100px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.8125rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.15s ease;
}

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

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

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

.btn-secondary:hover {
  background-color: var(--border-light);
}

/* Verification Result Box */
.verify-result {
  margin-top: 1.25rem;
  padding: 1.25rem;
  border-radius: var(--radius-md);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
}

.verify-result.valid {
  border-left: 4px solid var(--color-success);
}

.verify-result.invalid {
  border-left: 4px solid var(--color-danger);
}

.verify-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.verify-header.valid {
  color: var(--color-success);
}

.verify-header.invalid {
  color: var(--color-danger);
}

/* Roster Table */
.roster-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.875rem;
}

.roster-table th {
  padding: 0.75rem 1rem;
  background-color: var(--bg-surface-elevated);
  color: var(--text-secondary);
  font-weight: 600;
  border-bottom: 1px solid var(--border-color);
}

.roster-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
}

.roster-table tr:hover td {
  background-color: rgba(255, 255, 255, 0.02);
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-success {
  background-color: var(--color-success-bg);
  color: var(--color-success);
}

.badge-warning {
  background-color: var(--color-warning-bg);
  color: var(--color-warning);
}

.badge-danger {
  background-color: var(--color-danger-bg);
  color: var(--color-danger);
}

/* Queue List */
.queue-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.queue-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

.queue-meta {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.queue-title {
  font-size: 0.875rem;
  font-weight: 600;
}

.queue-seq {
  font-size: 0.75rem;
  color: var(--text-muted);
}