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

body {
  background-color: #343541;
  color: #fefefe;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chat-container {
  width: 100%;
  max-width: 800px;
  background-color: #40414f;
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  height: 90vh;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.6);
}

header {
  background-color: #202123;
  padding: 1rem;
  border-bottom: 1px solid #555;
  text-align: center;
}

header h1 {
  font-size: 1.25rem;
  color: #ffffff;
}

main#chat-window {
  flex-grow: 1;
  padding: 1rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.message {
  margin: 0.5rem 0;
  max-width: 80%;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  line-height: 1.4;
  word-wrap: break-word;
}

.message.user {
  background-color: #0b7285;
  align-self: flex-end;
  border-bottom-right-radius: 0;
}

.message.ai {
  background-color: #3e3f4b;
  align-self: flex-start;
  border-bottom-left-radius: 0;
}

footer {
  background-color: #202123;
  padding: 0.75rem;
  border-top: 1px solid #555;
}

.input-container {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#user-input {
  flex-grow: 1;
  border: none;
  border-radius: 4px;
  padding: 0.75rem;
  background-color: #40414f;
  color: #fefefe;
}

#user-input:focus {
  outline: 2px solid #3e7ddf;
}

#send-btn {
  background-color: #3e7ddf;
  border: none;
  border-radius: 4px;
  padding: 0.75rem 1rem;
  color: #fefefe;
  cursor: pointer;
}

#send-btn:hover {
  background-color: #336dbf;
}