:root{--bg: #ffffff;--sidebar-bg: #f9fafb;--border: #e5e7eb;--hover: #f3f4f6;--active: #e5e7eb;--text: #1f2937;--muted: #6b7280;--button-hover: #e5e7eb;--primary: #3b82f6}[data-theme=dark]{--bg: #0f172a;--sidebar-bg: #111827;--border: #334155;--hover: #1f2937;--active: #334155;--text: #f8fafc;--muted: #94a3b8;--button-hover: #1f2937;--primary: #60a5fa}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:var(--bg);color:var(--text);transition:background-color .25s ease,color .25s ease}.app{display:flex;height:100vh;overflow:hidden}.sidebar{width:280px;background:var(--sidebar-bg);border-right:1px solid var(--border);padding:12px;display:flex;flex-direction:column}.sidebar-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;font-size:14px;font-weight:600}.note-item{display:flex;align-items:center;gap:8px;padding:8px 10px;border-radius:6px;cursor:pointer}.note-item:hover{background:var(--hover)}.note-item.active{background:var(--active)}.note-title-input{flex:1;border:none;background:transparent;color:var(--text);font-size:14px;outline:none}.button{border:none;background:transparent;cursor:pointer;padding:6px;border-radius:4px;color:var(--muted)}.button:hover{background:var(--button-hover);color:var(--text)}.main{flex:1;padding:16px 24px;background:var(--bg);display:flex;flex-direction:column;overflow:hidden}.toolbar{display:flex;gap:6px;margin-bottom:12px;flex-wrap:wrap;position:relative;z-index:20;overflow:visible}.tool-button{border:1px solid var(--border);background:transparent;padding:6px 10px;border-radius:6px;cursor:pointer;font-weight:600;color:var(--text)}.tool-button:hover{background:var(--hover)}.tool-select{border:1px solid var(--border);background-color:var(--bg);padding:6px 36px 6px 12px;border-radius:6px;color:var(--text);cursor:pointer;font-size:14px;font-weight:500;outline:none;position:relative;z-index:30}.tool-select:hover{border-color:var(--primary)}.tool-select:focus{border-color:var(--primary)}.editor{flex:1;border:1px dashed var(--border);border-radius:8px;padding:16px;outline:none;line-height:1.6;overflow-y:auto;position:relative;z-index:1}.editor:empty:before{content:attr(data-placeholder);color:var(--muted)}.editor img{max-width:100%;border-radius:6px;margin:8px 0}@media(max-width:768px){.app{flex-direction:column}.sidebar{width:100%;border-right:none;border-bottom:1px solid var(--border)}.main{padding:12px}}