body{margin:0;font-family:Arial,sans-serif;background:#f4f7fb;color:#1a1a1a}.app-shell{max-width:960px;margin:0 auto;padding:24px}.card{background:white;border-radius:12px;box-shadow:0 8px 24px #00000014;padding:20px}h1{margin-top:0}.form-row{margin-bottom:16px}label{display:block;font-weight:600;margin-bottom:8px}select,input,textarea{width:100%;box-sizing:border-box;padding:10px 12px;border:1px solid #cbd5e1;border-radius:8px;font-size:14px}button{background:#1d4ed8;border:0;color:#fff;padding:12px 18px;border-radius:8px;font-size:15px;cursor:pointer}button[disabled]{opacity:.65;cursor:not-allowed}.chat-window{background:#eef2ff;border-radius:12px;min-height:320px;padding:16px;overflow-y:auto}.message{margin-bottom:14px;padding:14px 16px;border-radius:16px}.message.user{background:#e0f2fe;text-align:right}.message.assistant{background:#f3f4f6}.message.system{background:#fef3c7}.error{color:#b91c1c;margin-bottom:14px}