.chat-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: 1400px;
  margin: 0 auto;
  background: var(--background);
}

.chat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem 2rem;
  background: var(--background);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.header-logo {
  width: 40px;
  height: auto;
}

.chat-header h1 {
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.025em;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 2rem;
  background: var(--background);
}

/* Modern Section Cards - No Bubbles */
.message {
  margin-bottom: 1.25rem;
  animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message-user {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 1rem;
}

.message-user .message-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--primary-color);
  padding: 0.875rem 1.25rem;
  border-radius: 8px;
  max-width: 85%;
  box-shadow: var(--shadow-sm);
}

.message-user .message-content::before {
  content: "You";
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary-color);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.message-assistant {
  display: flex;
  justify-content: flex-start;
  margin-bottom: 1rem;
}

.message-assistant .message-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-color);
  border-radius: 8px;
  padding: 0.875rem 1.25rem;
  box-shadow: var(--shadow-sm);
  max-width: 85%;
}

.message-assistant .message-content::before {
  content: "Assistant";
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-color);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.message-content {
  word-wrap: break-word;
  line-height: 1.7;
  font-size: 0.9375rem;
  color: var(--text-primary);
}

.message-content ul {
  margin: 0.75rem 0;
  padding-left: 1.75rem;
}

.message-content li {
  margin: 0.5rem 0;
  line-height: 1.6;
}

.message-content.error {
  background: var(--danger-light);
  border: 1px solid rgba(239, 68, 68, 0.3);
  border-left: 3px solid var(--danger-color);
  color: var(--danger-color);
}

.message-content.error::before {
  color: var(--danger-color) !important;
  content: "Error" !important;
}

.message-content strong {
  font-weight: 600;
  color: var(--text-primary);
}

.message-content h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-top: 1.25rem;
  margin-bottom: 0.625rem;
  color: var(--text-primary);
}

.message-content h3:first-of-type {
  margin-top: 0;
}

.message-content p {
  margin-bottom: 0.75rem;
}

.message-content code {
  background: var(--surface-elevated);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.875rem;
  font-family: 'Monaco', 'Menlo', 'Courier New', monospace;
  color: var(--info-color);
  border: 1px solid var(--border);
}

.chat-input-container {
  padding: 1.5rem 2rem;
  background: var(--background);
  border-top: 1px solid var(--border);
  backdrop-filter: blur(10px);
}

#chatForm {
  display: flex;
  gap: 0.625rem;
  align-items: flex-end;
}

.btn-upload {
  padding: 0.75rem;
  border-radius: 8px;
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  height: 44px;
}

.btn-upload:hover:not(:disabled) {
  background: var(--surface-hover);
  border-color: var(--primary-color);
  color: var(--primary-color);
  transform: translateY(-1px);
}

.btn-upload:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

#chatInput {
  flex: 1;
  padding: 0.875rem 1.5rem;
  border: 1px solid var(--border);
  border-radius: 24px;
  font-size: 0.9375rem;
  font-family: inherit;
  line-height: 1.6;
  background: var(--surface-elevated);
  color: var(--text-primary);
  transition: all 0.2s ease;
  resize: vertical;
  min-height: 44px;
  max-height: 200px;
  overflow-y: auto;
}

#chatInput::placeholder {
  color: var(--text-muted);
}

#chatInput:focus {
  outline: none;
  border-color: var(--primary-color);
  background: var(--surface);
  box-shadow: 0 0 0 3px var(--primary-light);
}

#chatInput:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#chatForm button[type="submit"] {
  padding: 0.875rem 1.75rem;
  border-radius: 8px;
  background: var(--primary-color);
  color: white;
  border: none;
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
  min-height: 44px;
}

#chatForm button[type="submit"]:hover:not(:disabled) {
  background: var(--primary-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

#chatForm button[type="submit"]:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.typing-indicator {
  display: flex;
  gap: 0.5rem;
  padding: 0.625rem 0;
  margin-top: 0.5rem;
  align-items: center;
}

.typing-indicator::before {
  content: 'Assistant is typing';
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-right: 0.625rem;
  font-weight: 500;
}

.typing-indicator span {
  width: 6px;
  height: 6px;
  background: var(--primary-color);
  border-radius: 50%;
  animation: typing 1.4s infinite;
}

.typing-indicator span:nth-child(1) {
  animation-delay: 0s;
}

.typing-indicator span:nth-child(2) {
  animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
  animation-delay: 0.4s;
}

@keyframes typing {
  0%, 60%, 100% {
    opacity: 0.3;
    transform: translateY(0);
  }
  30% {
    opacity: 1;
    transform: translateY(-8px);
  }
}

/* Scrollbar Styling */
.chat-messages::-webkit-scrollbar {
  width: 8px;
}

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

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

.chat-messages::-webkit-scrollbar-thumb:hover {
  background: var(--border-light);
}

/* Responsive */
@media (max-width: 768px) {
  .chat-header {
    padding: 1rem 1.5rem;
  }

  .chat-header h1 {
    font-size: 1.25rem;
  }

  .chat-messages {
    padding: 1.5rem 1rem;
  }

  .message-user .message-content {
    max-width: 90%;
  }

  .message-assistant .message-content {
    padding: 1rem 1.25rem;
  }

  .chat-input-container {
    padding: 1rem 1.5rem;
  }

  #chatForm button[type="submit"] {
    padding: 0.875rem 1.5rem;
  }
}

@media (max-width: 480px) {
  .user-info span {
    display: none;
  }

  .chat-messages {
    padding: 1rem;
  }

  .message-content {
    font-size: 0.9rem;
  }

  .message-assistant .message-content::before,
  .message-user .message-content::before {
    font-size: 0.7rem;
  }

  #chatInput {
    font-size: 16px; /* Prevents zoom on iOS */
  }

  .chat-input-container {
    padding: 1rem;
  }

  #chatForm {
    gap: 0.5rem;
  }
}