* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #eef3f8;
  color: #172033;
}

.app {
  max-width: 960px;
  margin: 32px auto;
  padding: 24px;
  background: #fff;
  border: 1px solid #d8e0eb;
  border-radius: 8px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

h1 {
  margin: 0;
  color: #1f4d78;
}

button {
  border: 0;
  border-radius: 6px;
  background: #1f6fb2;
  color: #fff;
  padding: 10px 16px;
  font-weight: 700;
  cursor: pointer;
}

textarea {
  width: 100%;
  resize: vertical;
  border: 1px solid #b8c4d4;
  border-radius: 6px;
  padding: 12px;
  font: inherit;
}

.field {
  display: grid;
  gap: 6px;
  margin-bottom: 12px;
  font-weight: 700;
}

select {
  max-width: 260px;
  border: 1px solid #b8c4d4;
  border-radius: 6px;
  padding: 9px 10px;
  font: inherit;
  background: #fff;
}

.models {
  white-space: pre-wrap;
  background: #f4f7fb;
  border: 1px solid #d8e0eb;
  border-radius: 6px;
  padding: 12px;
  margin-bottom: 16px;
}

.chat {
  min-height: 280px;
  border: 1px solid #d8e0eb;
  border-radius: 6px;
  padding: 12px;
  margin-bottom: 16px;
  background: #fbfcfe;
}

.message {
  max-width: 80%;
  margin: 8px 0;
  padding: 10px 12px;
  border-radius: 6px;
  white-space: pre-wrap;
}

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

.message.assistant {
  margin-right: auto;
  background: #eef0f3;
}