:root{--bg:#f4f6f8;--card:#fff;--text:#1a2027;--muted:#5a6573;--accent:#0369a1;--border:#d8dee6}*{box-sizing:border-box}body{color:var(--text);background:radial-gradient(circle at 100% 0,#dbeafe 0%,#f4f6f8 40%,#edf2f7 100%);margin:0;font-family:Noto Sans SC,Source Han Sans SC,sans-serif}main{max-width:860px;margin:0 auto;padding:24px 16px 48px}.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:16px;box-shadow:0 8px 24px #0f172a0f}textarea{border:1px solid var(--border);width:100%;min-height:110px;font:inherit;border-radius:10px;padding:10px 12px}button{background:var(--accent);color:#fff;cursor:pointer;border:0;border-radius:10px;margin-top:12px;padding:10px 16px;font-weight:700}pre{white-space:pre-wrap;word-break:break-word;margin:0;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;font-size:12px;line-height:1.5}.muted{color:var(--muted)}