:root{color-scheme:light dark;font-family:system-ui,sans-serif}body{margin:0;height:100vh}.chat{display:flex;flex-direction:column;height:100vh;max-width:720px;margin:0 auto;padding:1rem;box-sizing:border-box}.messages{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:.75rem;padding:.5rem 0}.message{padding:.6rem .9rem;border-radius:.75rem;white-space:pre-wrap;max-width:80%}.message.user{align-self:flex-end;background:#2563eb;color:#fff}.message.assistant{align-self:flex-start;background:#80808033}.composer{display:flex;gap:.5rem;padding-top:.5rem}.composer input{flex:1;padding:.6rem .8rem;border-radius:.5rem;border:1px solid rgba(128,128,128,.4)}.composer button{padding:.6rem 1.2rem;border-radius:.5rem;border:none;background:#2563eb;color:#fff;cursor:pointer}.composer button:disabled{opacity:.6;cursor:default}