:root{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}body{margin:0;background:#f6f8fa;color:#24292f}.container{max-width:1100px;margin:0 auto;padding:20px}.card{background:#fff;border:1px solid #d0d7de;border-radius:10px;padding:16px;margin-bottom:16px}.nav button{margin-right:8px;margin-bottom:8px}button{border:1px solid #d0d7de;border-radius:6px;background:#fff;padding:6px 10px;cursor:pointer}.prose{line-height:1.7}.prose pre{background:#f6f8fa;padding:12px;border-radius:8px;overflow:auto}.prose code{background:#f6f8fa;border-radius:4px;padding:1px 4px}.mermaid{background:#fff;border:1px dashed #d0d7de;border-radius:8px;padding:12px}.muted{color:#57606a}.tool textarea{width:100%;min-height:180px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px}.tool-actions{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap}.tip{font-size:13px;color:#57606a;margin-top:8px}