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

:root {
  --bg: #0f1117;
  --bg-card: #1a1d27;
  --bg-input: #242836;
  --bg-hover: #2a2e3d;
  --border: #2e3348;
  --text: #e4e6ef;
  --text-muted: #6b7194;
  --primary: #25D366;
  --primary-hover: #1eba57;
  --primary-bg: rgba(37, 211, 102, 0.1);
  --blue: #4a9eff;
  --blue-bg: rgba(74, 158, 255, 0.1);
  --orange: #ff8c42;
  --orange-bg: rgba(255, 140, 66, 0.1);
  --purple: #a78bfa;
  --purple-bg: rgba(167, 139, 250, 0.1);
  --red: #ef4444;
  --red-bg: rgba(239, 68, 68, 0.1);
  --green: #25D366;
  --green-bg: rgba(37, 211, 102, 0.1);
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --sidebar-w: 240px;
  --transition: 0.2s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

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

/* Sidebar */
.sidebar {
  width: var(--sidebar-w);
  background: var(--bg-card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  z-index: 100;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--border);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--primary);
  font-weight: 700;
  font-size: 16px;
}

.sidebar-nav {
  flex: 1;
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  width: 100%;
}

.nav-item:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.nav-item.active {
  background: var(--primary-bg);
  color: var(--primary);
}

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--border);
}

.api-key-section label {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.api-key-section input {
  width: 100%;
  padding: 8px 10px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 12px;
}

/* Main */
.main {
  flex: 1;
  margin-left: var(--sidebar-w);
  padding: 28px 32px;
  max-width: 900px;
}

/* Pages */
.page { display: none; }
.page.active { display: block; }

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.page-header h1 {
  font-size: 22px;
  font-weight: 600;
}

/* Stats */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.stat-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.stat-icon.green { background: var(--green-bg); color: var(--green); }
.stat-icon.blue { background: var(--blue-bg); color: var(--blue); }
.stat-icon.orange { background: var(--orange-bg); color: var(--orange); }
.stat-icon.purple { background: var(--purple-bg); color: var(--purple); }

.stat-info {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
}

.stat-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}

.card h2 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 14px;
}

/* Sessions */
.sessions-grid {
  display: grid;
  gap: 12px;
}

.session-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.session-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.session-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  text-transform: uppercase;
}

.session-details h3 {
  font-size: 14px;
  font-weight: 600;
}

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

.session-actions {
  display: flex;
  gap: 8px;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.status-badge.open { background: var(--green-bg); color: var(--green); }
.status-badge.connecting { background: var(--orange-bg); color: var(--orange); }
.status-badge.closed { background: var(--red-bg); color: var(--red); }

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

/* Mini sessions list (dashboard) */
.sessions-mini-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.session-mini {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
}

.session-mini-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.session-mini-left strong {
  font-size: 13px;
}

.session-mini-right {
  font-size: 12px;
  color: var(--text-muted);
}

/* Forms */
.form-card {
  max-width: 560px;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 14px;
  font-family: inherit;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-bg);
}

.form-group small {
  display: block;
  margin-top: 4px;
  font-size: 11px;
}

.batch-info {
  padding: 10px 14px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 18px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

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

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

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

.btn-ghost:hover {
  background: var(--bg-hover);
  color: var(--text);
}

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

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

.btn-sm {
  padding: 5px 10px;
  font-size: 12px;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 14px;
}

.btn-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 24px;
  cursor: pointer;
  line-height: 1;
}

/* Result Box */
.result-box {
  margin-top: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-family: 'SF Mono', monospace;
  white-space: pre-wrap;
  word-break: break-all;
}

.result-box.success {
  background: var(--green-bg);
  color: var(--green);
  border: 1px solid rgba(37, 211, 102, 0.2);
}

.result-box.error {
  background: var(--red-bg);
  color: var(--red);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  backdrop-filter: blur(4px);
}

.modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 420px;
  max-width: 90vw;
  box-shadow: var(--shadow);
}

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

.modal-header h2 {
  font-size: 16px;
}

.modal-body {
  padding: 20px;
}

.modal-footer {
  padding: 14px 20px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.qr-body {
  text-align: center;
}

.qr-body p {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.qr-display {
  background: #fff;
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 14px;
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.qr-display canvas {
  max-width: 100%;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  z-index: 300;
  animation: slideIn 0.3s ease;
  box-shadow: var(--shadow);
}

.toast.success {
  background: var(--primary);
  color: #fff;
}

.toast.error {
  background: var(--red);
  color: #fff;
}

@keyframes slideIn {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.text-muted { color: var(--text-muted); }

/* Spinner */
.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid #e0e0e0;
  border-top-color: #25D366;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto;
}

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

/* Responsive */
@media (max-width: 768px) {
  .sidebar {
    width: 60px;
    overflow: hidden;
  }
  .sidebar-header { padding: 16px 10px; }
  .logo span { display: none; }
  .nav-item span { display: none; }
  .nav-item { justify-content: center; padding: 12px; }
  .sidebar-footer { display: none; }
  .main { margin-left: 60px; padding: 20px 16px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}