body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #0f172a;
  color: #e5e7eb;
}

.app {
  max-width: 900px;
  margin: 40px auto;
  padding: 24px;
  background: #020617;
  border-radius: 12px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
}

h1 {
  margin-top: 0;
  text-align: center;
  color: #f97316;
}

section {
  margin-top: 24px;
}

.chat-log {
  border: 1px solid #1f2937;
  border-radius: 8px;
  padding: 12px;
  height: 260px;
  overflow-y: auto;
  background: #020617;
}

.message {
  margin-bottom: 10px;
  padding: 8px 10px;
  border-radius: 6px;
  max-width: 80%;
  line-height: 1.4;
}

.message.user {
  background: #1d4ed8;
  margin-left: auto;
}

.message.bot {
  background: #111827;
  margin-right: auto;
}

.chat-input-row {
  display: flex;
  margin-top: 10px;
  gap: 8px;
}

input[type="text"] {
  flex: 1;
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid #374151;
  background: #020617;
  color: #e5e7eb;
}

button {
  padding: 8px 14px;
  border-radius: 6px;
  border: none;
  background: #f97316;
  color: #111827;
  font-weight: 600;
  cursor: pointer;
}