* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #0f172a;
  color: #e2e8f0;
}

.app {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px;
}

.header {
  margin-bottom: 20px;
}

.header h1 {
  margin: 0 0 8px;
}

.header p {
  margin: 0;
  color: #94a3b8;
}

.chat-wrapper {
  background: #111827;
  border: 1px solid #1f2937;
  border-radius: 16px;
  padding: 16px;
}

.chat {
  height: 60vh;
  overflow-y: auto;
  padding: 8px;
  margin-bottom: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.message {
  max-width: 80%;
  padding: 12px 14px;
  border-radius: 14px;
  white-space: pre-wrap;
  line-height: 1.5;
}

.message.user {
  align-self: flex-end;
  background: #2563eb;
  color: white;
}

.message.bot {
  align-self: flex-start;
  background: #1f2937;
  color: #e5e7eb;
}

.chat-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

textarea {
  width: 100%;
  resize: vertical;
  border-radius: 12px;
  border: 1px solid #334155;
  background: #0b1220;
  color: white;
  padding: 12px;
  font-size: 16px;
}

button {
  align-self: flex-end;
  padding: 10px 18px;
  border: 0;
  border-radius: 10px;
  background: #22c55e;
  color: #052e16;
  font-weight: bold;
  cursor: pointer;
}

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