:root { font-family: system-ui, sans-serif; color: #14283c; background: #f5f7fa; }
    body { margin: 0; height: 100dvh; display: flex; flex-direction: column; }
    header { padding: 16px 24px; background: #fff; border-bottom: 1px solid #dce3eb; }
    h1 { margin: 0; font-size: 22px; } header p { margin: 6px 0 0; font-size: 14px; color: #54677b; }
    #messages { flex: 1; overflow-y: auto; padding: 20px; }
    .message { max-width: 760px; margin: 0 auto 16px; padding: 14px 18px; border-radius: 12px; white-space: pre-wrap; overflow-wrap: anywhere; }
    .user { background: #e1edf7; } .assistant { background: white; border: 1px solid #dce3eb; }
    form { padding: 16px 20px; background: white; display: flex; gap: 10px; border-top: 1px solid #dce3eb; }
    label { position: absolute; width: 1px; height: 1px; overflow: hidden; }
    textarea { flex: 1; min-height: 42px; padding: 10px; font: inherit; border: 1px solid #bac7d4; border-radius: 8px; resize: vertical; }
    button { background: #193e66; color: white; border: 0; border-radius: 8px; padding: 10px 20px; font: inherit; }
    button:disabled { opacity: .6; } #status { padding: 6px 20px; font-size: 13px; min-height: 20px; }