* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --user-bg: #6366f1;
  --assistant-bg: #334155;
  --border: #475569;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.container {
  width: 100%;
  max-width: 900px;
  display: flex;
  flex-direction: column;
  height: 90vh;
  max-height: 800px;
}

header {
  text-align: center;
  margin-bottom: 24px;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 8px;
  background: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.chat-container {
  flex: 1;
  background: var(--bg-secondary);
  border-radius: 16px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--border);
}

.messages {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.messages::-webkit-scrollbar {
  width: 8px;
}

.messages::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

.messages::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 4px;
}

.message {
  display: flex;
  gap: 12px;
  animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message.user {
  flex-direction: row-reverse;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

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

.message.assistant .message-avatar {
  background: var(--assistant-bg);
}

.message-content {
  max-width: 70%;
  padding: 12px 16px;
  border-radius: 12px;
  line-height: 1.6;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.message.user .message-content {
  background: var(--user-bg);
  color: white;
  border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
  background: var(--assistant-bg);
  color: var(--text-primary);
  border-bottom-left-radius: 4px;
}

.input-container {
  padding: 16px;
  background: var(--bg-tertiary);
  border-top: 1px solid var(--border);
  display: flex;
  gap: 12px;
  align-items: flex-end;
}

#messageInput {
  flex: 1;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 16px;
  color: var(--text-primary);
  font-size: 0.95rem;
  resize: none;
  min-height: 44px;
  max-height: 200px;
  font-family: inherit;
  transition: border-color 0.2s;
}

#messageInput:focus {
  outline: none;
  border-color: var(--accent);
}

#messageInput::placeholder {
  color: var(--text-secondary);
}

.send-button {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--accent);
  border: none;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex-shrink: 0;
}

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

.send-button:disabled {
  background: var(--bg-tertiary);
  cursor: not-allowed;
  opacity: 0.5;
}

.loading {
  text-align: center;
  padding: 8px;
  color: var(--text-secondary);
}

.loading-dots {
  display: inline-flex;
  gap: 6px;
}

.loading-dots span {
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) {
  animation-delay: -0.32s;
}

.loading-dots span:nth-child(2) {
  animation-delay: -0.16s;
}

@keyframes bounce {
  0%, 80%, 100% {
    transform: scale(0);
    opacity: 0.5;
  }
  40% {
    transform: scale(1);
    opacity: 1;
  }
}

.error-message {
  background: #ef4444 !important;
  color: white !important;
}

@media (max-width: 768px) {
  header h1 {
    font-size: 2rem;
  }

  .message-content {
    max-width: 85%;
  }

  .container {
    height: 100vh;
    max-height: none;
  }
}