* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  background: #fafafa;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  padding: 0;
}

.canvas-root {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 30px 20px;
}

.diagram {
  position: relative;
  width: 780px;
  height: 320px;
}

/* Entity base styles */
.entity {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

/* Client - starts grey, becomes blue */
.client { left: 0; top: 100px; }
.client .entity-box {
  width: 130px;
  height: 80px;
  border-radius: 16px;
  background: #f5f5f5;
  border: 3px solid #9e9e9e;
  color: #9e9e9e;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
  transition: all 0.5s ease;
  text-align: center;
  line-height: 1.3;
  gap: 2px;
}

.client .entity-box.alive {
  background: #e3f2fd;
  border-color: #1976d2;
  color: #1976d2;
}

.client .entity-box.active {
  background: #bbdefb;
  border-color: #1976d2;
  color: #1976d2;
  box-shadow: 0 4px 20px rgba(25, 118, 210, 0.3);
}

/* Load Balancer */
.lb { left: 200px; top: 105px; }
.lb .entity-box {
  width: 80px;
  height: 70px;
  background: linear-gradient(180deg, #fafafa 0%, #e0e0e0 100%);
  border: 2px solid #9e9e9e;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #616161;
  font-weight: 600;
  font-size: 13px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

/* Server cluster bounding box */
.server-cluster {
  position: absolute;
  left: 400px;
  top: 0;
  width: 300px;
  height: 320px;
  border: 3px solid #ef6c00;
  border-radius: 20px;
  background: rgba(255, 243, 224, 0.3);
}

.cluster-label {
  position: absolute;
  top: -14px;
  left: 24px;
  background: #fafafa;
  padding: 4px 16px;
  font-size: 16px;
  font-weight: 600;
  color: #ef6c00;
  white-space: nowrap;
}

/* Server nodes - horizontal layout with badge to right */
.server {
  flex-direction: row;
  align-items: center;
  gap: 12px;
  left: 420px;
}
.server-1 { top: 25px; }
.server-2 { top: 130px; }
.server-3 { top: 235px; }

.server .entity-box {
  width: 100px;
  height: 55px;
  border-radius: 12px;
  background: #f5f5f5;
  border: 3px solid #bdbdbd;
  color: #9e9e9e;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 13px;
  transition: all 0.5s ease;
  text-align: center;
  gap: 2px;
}

.server .entity-box.alive {
  background: #fff3e0;
  border-color: #ef6c00;
  color: #ef6c00;
}

.server .entity-box.active {
  background: #ffe0b2;
  border-color: #ef6c00;
  color: #ef6c00;
  box-shadow: 0 4px 20px rgba(239, 108, 0, 0.3);
}

.server .entity-box.error {
  background: #ffebee;
  border-color: #c62828;
  color: #c62828;
  animation: shake 0.4s ease;
}

.server .entity-box.waiting {
  animation: waitingPulse 1s ease-in-out infinite;
}

@keyframes waitingPulse {
  0%, 100% {
    background: #fff3e0;
    border-color: #ef6c00;
    box-shadow: 0 4px 20px rgba(239, 108, 0, 0.2);
  }
  50% {
    background: #ffe0b2;
    border-color: #e65100;
    box-shadow: 0 4px 30px rgba(239, 108, 0, 0.5);
  }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}

.entity-status {
  font-size: 9px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  opacity: 0;
  transition: opacity 0.3s ease;
  padding: 2px 6px;
  border-radius: 3px;
}

.entity-status.visible {
  opacity: 1;
}

.entity-status.waiting {
  background: #e65100;
  color: white;
  animation: statusBlink 0.8s ease-in-out infinite;
}

@keyframes statusBlink {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.05); }
}

/* State badge - shows session + capabilities */
.state-badge {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  padding: 8px 10px;
  border-radius: 8px;
  font-size: 10px;
  font-weight: 600;
  transition: all 0.4s ease;
  /* Default: gray/inactive state */
  background: #f5f5f5;
  border: 1px solid #e0e0e0;
  color: #9e9e9e;
  min-width: 140px;
  min-height: 64px;
}

.state-badge.active {
  background: #e8f5e9;
  border: 1px solid #a5d6a7;
  color: #2e7d32;
}

.state-badge.error {
  background: #ffebee;
  border-color: #ef9a9a;
  color: #c62828;
}

.state-badge .badge-title {
  font-size: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: #888;
  font-weight: 500;
}

.state-badge .session-id {
  font-family: 'SF Mono', Monaco, monospace;
  font-size: 10px;
  display: none;
}

.state-badge.active .session-id,
.state-badge.error .session-id {
  display: block;
}

.state-badge.session .session-id {
  display: block;
}

.state-badge.session .empty-state {
  display: none;
}

.state-badge .caps-row {
  display: none;
  gap: 4px;
  flex-wrap: wrap;
}

.state-badge.active .caps-row,
.state-badge.error .caps-row {
  display: flex;
}

.state-badge .cap {
  font-family: 'SF Mono', Monaco, monospace;
  font-size: 8px;
  background: white;
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid #e0e0e0;
}

.state-badge.active .cap {
  border-color: #c8e6c9;
}

.state-badge.error .cap {
  border-color: #ef9a9a;
}

.state-badge .empty-state {
  font-size: 9px;
  color: #bdbdbd;
  font-style: italic;
}

.state-badge.active .empty-state,
.state-badge.error .empty-state {
  display: none;
}

/* Client state badge stays below */
.client .state-badge {
  align-items: center;
}

.client .state-badge .caps-row {
  justify-content: center;
}

/* Connection lines */
.connection {
  position: absolute;
  height: 2px;
  background: #bdbdbd;
}

.conn-client-lb {
  left: 140px;
  width: 60px;
  top: 140px;
}

.conn-lb-servers {
  left: 290px;
  width: 110px;
  top: 140px;
}

/* The moving message */
.message {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
  z-index: 100;
  transform: translateX(-50%);
}

.message.visible {
  opacity: 1;
}

.message-header {
  display: flex;
  align-items: center;
  gap: 5px;
}

.message-arrow {
  font-size: 24px;
  font-weight: bold;
}

.message-type {
  padding: 5px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
}

.message-detail {
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 9px;
  font-family: 'SF Mono', Monaco, monospace;
  background: rgba(255,255,255,0.95);
  color: #666;
  border: 1px solid #e0e0e0;
}

.message-session {
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 9px;
  font-family: 'SF Mono', Monaco, monospace;
  background: #e8f5e9;
  color: #2e7d32;
  border: 1px solid #a5d6a7;
}

.message-session.caps {
  display: flex;
  flex-direction: column;
  gap: 3px;
  align-items: flex-start;
}

.message-session .session-label {
  font-size: 8px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  color: #2e7d32;
}

.message-session .cap-row {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.message-session .cap-chip {
  font-family: 'SF Mono', Monaco, monospace;
  font-size: 8px;
  background: white;
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid #c8e6c9;
  color: #2e7d32;
}

.message-session.error {
  background: #ffebee;
  color: #c62828;
  border-color: #ef9a9a;
}

.message.request .message-arrow { color: #1976d2; }
.message.request .message-type {
  background: #1976d2;
  color: white;
}

.message.response .message-arrow { color: #ef6c00; }
.message.response .message-type {
  background: #ef6c00;
  color: white;
}

.message.notification .message-arrow { color: #7b1fa2; }
.message.notification .message-type {
  background: #7b1fa2;
  color: white;
}

.message.server-request .message-arrow { color: #ef6c00; }
.message.server-request .message-type {
  background: #ef6c00;
  color: white;
}

.message.client-response .message-arrow { color: #1976d2; }
.message.client-response .message-type {
  background: #1976d2;
  color: white;
}

.message.error-response .message-arrow { color: #c62828; }
.message.error-response .message-type {
  background: #c62828;
  color: white;
}

/* Narration */
.narration {
  margin-top: 25px;
  padding: 14px 20px;
  background: white;
  border: 2px solid #e0e0e0;
  border-radius: 12px;
  font-size: 14px;
  color: #333;
  max-width: 700px;
  text-align: center;
  min-height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.narration .step-num {
  display: inline-block;
  width: 26px;
  height: 26px;
  background: #9e9e9e;
  color: white;
  border-radius: 50%;
  font-size: 13px;
  font-weight: 600;
  line-height: 26px;
  text-align: center;
  margin-right: 12px;
  flex-shrink: 0;
  transition: background 0.3s ease;
}

.narration.request-state .step-num { background: #1976d2; }
.narration.response-state .step-num { background: #ef6c00; }
.narration.notification-state .step-num { background: #7b1fa2; }
.narration.waiting-state .step-num { background: #e65100; }
.narration.error-state .step-num { background: #c62828; }
.narration.error-state { border-color: #ef9a9a; background: #fff8f8; }
.narration.success-state .step-num { background: #4caf50; }