.app-layout{display:flex;height:calc(100vh - 56px);overflow:hidden}.sidebar{width:280px;min-width:280px;background:var(--color-surface);border-right:1px solid var(--color-border);display:flex;flex-direction:column;transition:transform .3s,background .3s}.sidebar__header{padding:16px;border-bottom:1px solid var(--color-border);display:flex;flex-direction:column;gap:10px}.sidebar__search{width:100%;padding:9px 12px;border:1px solid var(--color-border);border-radius:var(--radius-sm);font-size:13.5px;background:var(--color-bg);color:var(--color-text);outline:none;font-family:inherit;transition:border-color .2s,box-shadow .2s}.sidebar__search:focus{border-color:var(--color-primary);box-shadow:var(--shadow-glow)}.sidebar__search::placeholder{color:var(--color-text-muted)}.sidebar__list{flex:1;overflow-y:auto;padding:8px}.sidebar__empty{text-align:center;padding:32px 16px;color:var(--color-text-muted);font-size:14px}@media(max-width: 768px){.sidebar{position:fixed;top:56px;left:0;bottom:0;z-index:50;transform:translateX(-100%);box-shadow:var(--shadow-lg)}.sidebar.open{transform:translateX(0)}}.note-item{padding:12px;border-radius:var(--radius-sm);cursor:pointer;margin-bottom:2px;transition:background .15s,box-shadow .15s;border:1px solid rgba(0,0,0,0)}.note-item:hover{background:var(--color-surface-alt)}.note-item.active{background:var(--color-primary-light);border-color:rgba(26,143,173,.15)}.note-item__title{font-size:13.5px;font-weight:600;margin:0 0 3px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.note-item__preview{font-size:12px;color:var(--color-text-muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;margin:0 0 3px}.note-item__date{font-size:11px;color:var(--color-text-muted)}.editor-main{flex:1;display:flex;flex-direction:column;overflow:hidden;min-width:0}.editor-header{display:flex;align-items:center;gap:12px;padding:10px 16px;border-bottom:1px solid var(--color-border);background:var(--color-surface)}.editor-header__title{flex:1;padding:5px 10px;border:1px solid rgba(0,0,0,0);border-radius:var(--radius-sm);font-size:16px;font-weight:600;background:rgba(0,0,0,0);color:var(--color-text);outline:none;font-family:inherit;letter-spacing:-0.01em;transition:border-color .2s,background .2s,box-shadow .2s}.editor-header__title:focus,.editor-header__title:focus-visible{border-color:var(--color-primary);background:var(--color-bg);box-shadow:var(--shadow-glow)}.richtext-toolbar{display:flex;align-items:center;gap:2px;padding:6px 12px;background:var(--color-surface);border-bottom:1px solid var(--color-border);flex-wrap:wrap;overflow-x:auto}.richtext-toolbar .separator{width:1px;height:20px;background:var(--color-border);margin:0 6px}.richtext-toolbar button,.richtext-toolbar select{display:inline-flex;align-items:center;justify-content:center;padding:6px 8px;border:none;border-radius:var(--radius-sm);background:rgba(0,0,0,0);color:var(--color-text-secondary);font-size:13px;cursor:pointer;transition:all .15s;font-family:inherit}.richtext-toolbar button svg,.richtext-toolbar select svg{width:16px;height:16px}.richtext-toolbar button:hover,.richtext-toolbar select:hover{background:var(--color-surface-alt);color:var(--color-text)}.richtext-toolbar button.active,.richtext-toolbar select.active{background:var(--color-primary-light);color:var(--color-primary);font-weight:600}.richtext-toolbar select{padding:5px 8px;background:var(--color-bg);border:1px solid var(--color-border);border-radius:var(--radius-sm);color:var(--color-text);transition:border-color .2s}.richtext-toolbar select:focus,.richtext-toolbar select:focus-visible{border-color:var(--color-primary);outline:none;box-shadow:var(--shadow-glow)}.richtext-editor{flex:1;padding:24px;overflow-y:auto;background:var(--color-bg);color:var(--color-text);font-size:15px;line-height:1.75;outline:none;min-height:200px;transition:background .3s,color .3s}.richtext-editor:focus-visible{box-shadow:inset 0 0 0 2px var(--color-primary)}.richtext-editor:empty::before{content:attr(data-placeholder);color:var(--color-text-muted)}.richtext-editor p{margin:0 0 12px}.richtext-editor ul,.richtext-editor ol{margin:0 0 12px;padding-left:24px}.richtext-editor h1,.richtext-editor h2,.richtext-editor h3{margin:0 0 14px;letter-spacing:-0.02em}.richtext-editor a{color:var(--color-primary)}