:root{--bg: #fafafa;--surface: #ffffff;--border: #e5e7eb;--text: #111827;--text-secondary: #6b7280;--accent: #4f6ef7;--accent-light: #eef2ff;--danger: #ef4444;--success: #10b981;--warning: #f59e0b;--radius: 8px;--shadow: 0 1px 3px rgba(0, 0, 0, .08);--shadow-lg: 0 4px 12px rgba(0, 0, 0, .1)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans SC,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}button{font-family:inherit;cursor:pointer;border:none;border-radius:var(--radius);padding:8px 16px;font-size:14px;transition:all .15s ease}button:disabled{opacity:.5;cursor:not-allowed}input,textarea,select{font-family:inherit;font-size:14px;border:1px solid var(--border);border-radius:var(--radius);padding:8px 12px;outline:none;transition:border-color .15s ease;width:100%}input:focus,textarea:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-light)}textarea{resize:vertical;line-height:1.6}.btn-primary{background:var(--accent);color:#fff}.btn-primary:hover:not(:disabled){filter:brightness(1.1)}.btn-secondary{background:var(--surface);color:var(--text);border:1px solid var(--border)}.btn-secondary:hover:not(:disabled){border-color:var(--accent);color:var(--accent)}.btn-danger{background:var(--danger);color:#fff}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-4px)}75%{transform:translate(4px)}}.markdown-preview h1{font-size:1.5em;margin:.6em 0 .3em}.markdown-preview h2{font-size:1.3em;margin:.6em 0 .3em}.markdown-preview h3{font-size:1.15em;margin:.5em 0 .2em}.markdown-preview h4{font-size:1em;margin:.5em 0 .2em}.markdown-preview p{margin:.4em 0}.markdown-preview ul,.markdown-preview ol{margin:.4em 0;padding-left:1.5em}.markdown-preview li{margin:.2em 0}.markdown-preview blockquote{border-left:3px solid var(--border);padding-left:12px;margin:.5em 0;color:var(--text-secondary)}.markdown-preview code{background:var(--bg);padding:2px 6px;border-radius:4px;font-family:SF Mono,Consolas,Liberation Mono,Menlo,monospace;font-size:.9em}.markdown-preview pre{background:var(--bg);padding:12px 16px;border-radius:var(--radius);overflow-x:auto;margin:.5em 0}.markdown-preview pre code{background:none;padding:0}.markdown-preview a{color:var(--accent);text-decoration:none}.markdown-preview a:hover{text-decoration:underline}.markdown-preview img{max-width:100%;border-radius:var(--radius);margin:.5em 0}.markdown-preview hr{border:none;border-top:1px solid var(--border);margin:1em 0}