:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --panel: #ffffff;
  --text: #17202a;
  --muted: #667085;
  --line: #d9dee7;
  --accent: #c7352d;
  --accent-dark: #9f261f;
  --user: #17324d;
  --assistant: #f8efe7;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.chat-shell {
  width: min(960px, 100%);
  height: min(760px, calc(100vh - 48px));
  display: grid;
  grid-template-rows: auto 1fr auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 48px rgba(23, 32, 42, 0.12);
  overflow: hidden;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
  background: #fffaf6;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
}

.status {
  flex: 0 0 auto;
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  font-size: 13px;
  background: #ffffff;
}

.messages {
  overflow-y: auto;
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.message.user {
  justify-content: flex-end;
}

.avatar {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  background: var(--accent);
  font-weight: 700;
  flex: 0 0 auto;
}

.message.user .avatar {
  order: 2;
  background: var(--user);
}

.bubble {
  max-width: min(680px, 82%);
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--assistant);
  line-height: 1.65;
  white-space: pre-wrap;
  word-break: break-word;
}

.message.user .bubble {
  color: #ffffff;
  background: var(--user);
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  padding: 14px;
  border-top: 1px solid var(--line);
  background: #ffffff;
}

textarea {
  width: 100%;
  max-height: 140px;
  resize: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 13px;
  font: inherit;
  line-height: 1.5;
  outline: none;
}

textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(199, 53, 45, 0.12);
}

button {
  min-width: 76px;
  border: 0;
  border-radius: 8px;
  color: #ffffff;
  background: var(--accent);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

button:hover {
  background: var(--accent-dark);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

@media (max-width: 640px) {
  .app {
    padding: 0;
  }

  .chat-shell {
    height: 100vh;
    border: 0;
    border-radius: 0;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .bubble {
    max-width: 86%;
  }
}