.chat {
  --base: 1px;
  display: flex;
  flex-direction: column;
  height: 100%;
  width: 100%;
  overflow: hidden;
  font-family: var(--font-sans);
  font-size: calc(var(--base) * 17);
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--dur-base) var(--ease-standard);
}

.chat-light {
  --chat-bg: var(--chat-light-bg);
  --chat-bubble-in: var(--chat-light-bubble-in);
  --chat-bubble-in-text: var(--chat-light-bubble-in-text);
  --chat-bubble-out: var(--chat-light-bubble-out);
  --chat-bubble-out-text: var(--chat-light-bubble-out-text);
  --chat-header-bg: var(--chat-light-header-bg);
  --chat-header-border: var(--chat-light-header-border);
  --chat-timestamp: var(--chat-light-timestamp);
  --chat-typing-dot: var(--chat-light-typing-dot);
  --chat-shadow-typing: var(--chat-light-shadow-typing);
  background: var(--chat-bg);
  color: var(--chat-bubble-in-text);
}

.chat-dark {
  --chat-bg: var(--chat-dark-bg);
  --chat-bubble-in: var(--chat-dark-bubble-in);
  --chat-bubble-in-text: var(--chat-dark-bubble-in-text);
  --chat-bubble-out: var(--chat-dark-bubble-out);
  --chat-bubble-out-text: var(--chat-dark-bubble-out-text);
  --chat-header-bg: var(--chat-dark-header-bg);
  --chat-header-border: var(--chat-dark-header-border);
  --chat-timestamp: var(--chat-dark-timestamp);
  --chat-typing-dot: var(--chat-dark-typing-dot);
  --chat-shadow-typing: var(--chat-dark-shadow-typing);
  background: var(--chat-bg);
  color: var(--chat-bubble-in-text);
}

.chat-header {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: calc(var(--base) * 4);
  height: calc(var(--base) * 60);
  padding: 0 calc(var(--base) * 12);
  background: var(--chat-header-bg);
  border-bottom: var(--border-hairline) solid var(--chat-header-border);
  flex-shrink: 0;
}

.chat-header-avatar {
  width: calc(var(--base) * 28);
  height: calc(var(--base) * 28);
  border-radius: 50%;
  background: var(--chat-bubble-in);
  color: var(--chat-bubble-in-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: calc(var(--base) * 13);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.02em;
}

.chat-header-name {
  font-size: calc(var(--base) * 13);
  font-weight: var(--weight-medium);
  color: var(--chat-bubble-in-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}

.chat-body {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  padding: calc(var(--base) * 12) calc(var(--base) * 12) calc(var(--base) * 16);
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 4);
}

.chat-date-separator {
  align-self: center;
  color: var(--chat-timestamp);
  font-size: calc(var(--base) * 11);
  font-weight: var(--weight-medium);
  margin: calc(var(--base) * 12) 0;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.chat-message-row {
  display: flex;
  flex-direction: column;
  max-width: 100%;
}

.chat-message-row.in {
  align-items: flex-start;
}

.chat-message-row.out {
  align-items: flex-end;
}

.chat-message-row.group-gap {
  margin-top: calc(var(--base) * 8);
}

.chat-bubble {
  position: relative;
  max-width: 75%;
  padding: calc(var(--base) * 8) calc(var(--base) * 12);
  border-radius: calc(var(--base) * 18);
  font-size: calc(var(--base) * 17);
  line-height: 1.4;
  word-wrap: break-word;
  overflow-wrap: break-word;
  white-space: pre-wrap;
  transition: opacity var(--dur-bubble) var(--ease-out), transform var(--dur-bubble) var(--ease-out);
}

.chat-message-row.in .chat-bubble {
  background: var(--chat-bubble-in);
  color: var(--chat-bubble-in-text);
}

.chat-message-row.out .chat-bubble {
  background: var(--chat-bubble-out);
  color: var(--chat-bubble-out-text);
}

.chat-message-row.in.only-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18);
}

.chat-message-row.in.first-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18) calc(var(--base) * 18) calc(var(--base) * 18) calc(var(--base) * 6);
}

.chat-message-row.in.mid-in-group .chat-bubble {
  border-radius: calc(var(--base) * 6) calc(var(--base) * 18) calc(var(--base) * 18) calc(var(--base) * 6);
}

.chat-message-row.in.last-in-group .chat-bubble {
  border-radius: calc(var(--base) * 6) calc(var(--base) * 18) calc(var(--base) * 18) calc(var(--base) * 18);
}

.chat-message-row.out.only-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18);
}

.chat-message-row.out.first-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18) calc(var(--base) * 18) calc(var(--base) * 6) calc(var(--base) * 18);
}

.chat-message-row.out.mid-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18) calc(var(--base) * 6) calc(var(--base) * 6) calc(var(--base) * 18);
}

.chat-message-row.out.last-in-group .chat-bubble {
  border-radius: calc(var(--base) * 18) calc(var(--base) * 6) calc(var(--base) * 18) calc(var(--base) * 18);
}

.chat-timestamp {
  color: var(--chat-timestamp);
  font-size: calc(var(--base) * 11);
  margin-top: calc(var(--base) * 4);
  align-self: flex-end;
}

.chat-delivery {
  color: var(--chat-timestamp);
  font-size: calc(var(--base) * 11);
  margin-top: calc(var(--base) * 4);
  align-self: flex-end;
}

.chat-reaction {
  position: absolute;
  bottom: calc(var(--base) * -8);
  right: calc(var(--base) * -4);
  background: var(--chat-header-bg);
  border: var(--border-hairline) solid var(--chat-header-border);
  border-radius: var(--radius-pill);
  padding: 0 calc(var(--base) * 6);
  font-size: calc(var(--base) * 14);
  line-height: calc(var(--base) * 22);
  min-width: calc(var(--base) * 22);
  text-align: center;
}

.chat-message-row.in .chat-reaction {
  right: auto;
  left: calc(var(--base) * -4);
}

.chat-typing-indicator {
  display: inline-flex;
  align-items: center;
  gap: calc(var(--base) * 4);
  background: var(--chat-bubble-in);
  padding: calc(var(--base) * 10) calc(var(--base) * 14);
  border-radius: calc(var(--base) * 18);
  box-shadow: var(--chat-shadow-typing);
}

.chat-typing-dot {
  width: calc(var(--base) * 8);
  height: calc(var(--base) * 8);
  border-radius: 50%;
  background: var(--chat-typing-dot);
  animation: chat-typing-bob 1.2s infinite ease-in-out;
}

.chat-typing-dot:nth-child(2) {
  animation-delay: 0.15s;
}

.chat-typing-dot:nth-child(3) {
  animation-delay: 0.3s;
}

@keyframes chat-typing-bob {
  0%, 60%, 100% {
    transform: translateY(0);
    opacity: 0.6;
  }
  30% {
    transform: translateY(calc(var(--base) * -4));
    opacity: 1;
  }
}

.chat-avatar {
  width: calc(var(--base) * 28);
  height: calc(var(--base) * 28);
  border-radius: 50%;
  background: var(--chat-bubble-in);
  color: var(--chat-bubble-in-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: calc(var(--base) * 12);
  font-weight: var(--weight-semibold);
}

.chat-scene-transition {
  position: absolute;
  inset: 0;
  background: var(--chat-bg);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-slow) var(--ease-standard);
}

.chat-scene-transition.visible {
  opacity: 1;
}

@media (prefers-reduced-motion: reduce) {
  .chat-typing-dot {
    animation: none;
    opacity: 0.6;
  }

  .chat-bubble {
    transition: none;
  }

  .chat-scene-transition {
    transition: none;
  }
}