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

:root {
  --primary: #4F46E5;
  --primary-dark: #3730A3;
  --primary-light: #818CF8;
  --bg: #0F172A;
  --bg-card: #1E293B;
  --bg-input: #334155;
  --text: #F1F5F9;
  --text-secondary: #94A3B8;
  --success: #10B981;
  --danger: #EF4444;
  --warning: #F59E0B;
  --border: #334155;
  --radius: 12px;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Navbar */
.navbar {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.logo {
  font-size: 24px;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
}

.logo span {
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 20px;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--text);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 8px;
  border: none;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

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

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

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

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

.btn-lg {
  padding: 14px 32px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

.btn-control {
  padding: 16px 24px;
  font-size: 16px;
  border-radius: var(--radius);
  flex: 1;
}

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

.btn-mic {
  background: var(--warning);
  color: #000;
}

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

.btn-control.active {
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.5);
  position: relative;
}

.btn-control.active::after {
  content: '(Đang stream)';
  display: block;
  font-size: 11px;
  font-weight: 400;
  margin-top: 2px;
}

/* Hero */
.hero {
  padding: 100px 0;
  text-align: center;
}

.hero h1 {
  font-size: 48px;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.2;
}

.highlight {
  color: var(--primary);
}

.hero p {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
}

/* Features */
.features {
  padding: 80px 0;
}

.features h2 {
  text-align: center;
  font-size: 32px;
  margin-bottom: 48px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  transition: transform 0.2s, border-color 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
}

.feature-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.feature-card h3 {
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Auth */
.auth-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: calc(100vh - 73px);
  padding: 40px 20px;
}

.auth-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  width: 100%;
  max-width: 440px;
}

.auth-card h2 {
  margin-bottom: 32px;
  text-align: center;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--text-secondary);
}

.form-group input {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 14px;
  transition: border-color 0.2s;
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary);
}

.error-message {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--danger);
  color: var(--danger);
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 16px;
  font-size: 14px;
  display: none;
}

.success-message {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--success);
  color: var(--success);
  padding: 12px;
  border-radius: 8px;
  font-size: 14px;
}

.auth-link {
  text-align: center;
  margin-top: 24px;
  color: var(--text-secondary);
  font-size: 14px;
}

.auth-link a {
  color: var(--primary);
  text-decoration: none;
}

/* Dashboard */
.dashboard-container {
  padding: 32px 0;
}

.dashboard-container h2 {
  margin-bottom: 24px;
}

.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.panel h3 {
  margin-bottom: 16px;
  font-size: 18px;
}

.empty-state {
  color: var(--text-secondary);
  text-align: center;
  padding: 24px;
  font-size: 14px;
}

/* Kids List */
.kids-list {
  max-height: 300px;
  overflow-y: auto;
}

.kid-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: var(--bg);
  border-radius: 8px;
  margin-bottom: 8px;
  cursor: pointer;
  transition: background 0.2s;
}

.kid-item:hover, .kid-item.selected {
  background: var(--primary);
}

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

.kid-status {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--danger);
}

.kid-status.online {
  background: var(--success);
}

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

.kid-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.kid-state-text {
  font-size: 12px;
  color: var(--text-secondary);
}

.kid-item.selected .kid-state-text {
  color: rgba(255, 255, 255, 0.8);
}

.kid-delete-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  padding: 6px 10px;
  border-radius: 6px;
  opacity: 0.5;
  transition: all 0.2s;
}

.kid-item:hover .kid-delete-btn {
  opacity: 1;
}

.kid-delete-btn:hover {
  background: var(--danger);
  opacity: 1;
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.2s ease;
  padding: 20px;
}

.modal-overlay.open {
  opacity: 1;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  width: 100%;
  max-width: 420px;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  transform: translateY(20px) scale(0.95);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.open .modal-card {
  transform: translateY(0) scale(1);
}

.modal-icon {
  font-size: 40px;
  width: 72px;
  height: 72px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(79, 70, 229, 0.15);
  border-radius: 50%;
}

.modal-icon.danger {
  background: rgba(239, 68, 68, 0.15);
}

.modal-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text);
}

.modal-message {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.5;
  margin-bottom: 24px;
}

.modal-message strong {
  color: var(--text);
}

.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.modal-actions .btn {
  flex: 1;
  max-width: 160px;
}

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

.btn-danger:hover {
  background: #DC2626;
}

.modal-cancel:empty {
  display: none;
}

/* Control Buttons */
.control-buttons {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

/* Stream */
.stream-container {
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.stream-panel {
  grid-column: span 2;
}

#remoteVideo {
  width: 100%;
  max-height: 400px;
  border-radius: 8px;
  background: #000;
}

.location-info {
  text-align: center;
}

.location-info p {
  margin: 8px 0;
  font-size: 18px;
}

/* QR */
#qrVideo {
  width: 100%;
  max-width: 300px;
  border-radius: 8px;
  display: none;
  margin: 16px auto;
}

.qr-panel {
  grid-column: span 2;
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 32px;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .stream-panel, .qr-panel {
    grid-column: span 1;
  }

  .control-buttons {
    flex-direction: column;
  }
}