:root{--fg:#1f2328;--muted:#59636e;--bg:#fff;--border:#d1d9e0;--accent:#0969da;--code-bg:#f6f8fa;--warn-bg:#fff8c5;color:var(--fg);background:var(--bg);font-family:system-ui,-apple-system,Segoe UI,Hiragino Sans,Noto Sans JP,Meiryo,sans-serif}@media (prefers-color-scheme:dark){:root{--fg:#e6edf3;--muted:#9198a1;--bg:#0d1117;--border:#3d444d;--accent:#4493f8;--code-bg:#151b23;--warn-bg:#3d2e00}}body{flex-direction:column;min-height:100vh;margin:0;display:flex}.toolbar{border-bottom:1px solid var(--border);background:var(--bg);z-index:1;align-items:center;gap:12px;padding:8px 16px;display:flex;position:sticky;top:0}.file-name{font-weight:600}.spacer{flex:1}.save-status{color:var(--muted);font-size:.875rem}button{font:inherit;border:1px solid var(--border);background:var(--code-bg);color:var(--fg);cursor:pointer;border-radius:6px;padding:4px 12px}.notice{background:var(--warn-bg);padding:8px 16px}.editor{box-sizing:border-box;flex:1;width:100%;max-width:860px;margin:0 auto;padding:24px 16px}.editor .ProseMirror{white-space:pre-wrap;word-wrap:break-word;outline:none;min-height:60vh;line-height:1.7}.editor .ProseMirror pre,.editor .ProseMirror code{background:var(--code-bg);border-radius:6px;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.editor .ProseMirror pre{padding:12px 16px;overflow-x:auto}.editor .ProseMirror code{padding:.1em .3em}.editor .ProseMirror pre code{padding:0}.editor .ProseMirror blockquote{border-left:4px solid var(--border);color:var(--muted);margin:0;padding-left:1em}.editor .ProseMirror table{border-collapse:collapse}.editor .ProseMirror th,.editor .ProseMirror td{border:1px solid var(--border);padding:4px 12px}.editor .ProseMirror a{color:var(--accent)}.editor .ProseMirror li[data-item-type=task]{list-style:none}.editor .ProseMirror li[data-item-type=task]:before{content:"☐ "}.editor .ProseMirror li[data-item-type=task][data-checked=true]:before{content:"☑ "}.editor .ProseMirror span[data-type=html]{color:var(--muted);font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.image-placeholder{border:1px dashed var(--border);color:var(--muted);border-radius:6px;padding:2px 8px;font-size:.875rem;display:inline-block}.footer{justify-content:center;gap:16px;padding:12px;font-size:.75rem;display:flex}.footer a{color:var(--muted)}