* { margin:0; padding:0; box-sizing:border-box; }
html,body { height:100%; overflow:hidden; background:var(--bg); color:var(--text); font-family:'IBM Plex Sans',sans-serif; font-size:13px; }

#topbar { height:36px; background:var(--bg2); border-bottom:1px solid var(--border); display:flex; align-items:center; padding:0 10px; gap:4px; flex-shrink:0; user-select:none; z-index:50; }
.tb-logo { font-family:'IBM Plex Mono',monospace; font-weight:600; font-size:13px; color:var(--white); letter-spacing:1px; margin-right:12px; white-space:nowrap; }
.tb-logo span { color:var(--accent); }
.tb-btn { height:26px; padding:0 8px; background:transparent; border:none; color:var(--text); font-family:'IBM Plex Sans',sans-serif; font-size:12px; cursor:pointer; border-radius:3px; display:flex; align-items:center; gap:5px; white-space:nowrap; transition:background .12s,color .12s; }
.tb-btn:hover { background:var(--bg4); color:var(--white); }
.tb-btn.primary { background:var(--accent); color:#fff; }
.tb-btn.primary:hover { background:var(--accent-h); }
.tb-btn.success { color:var(--accent3); border:1px solid rgba(63,185,80,.4); }
.tb-btn.success:hover { background:rgba(63,185,80,.1); }
.tb-btn.warn { color:var(--accent4); border:1px solid rgba(224,108,117,.4); }
.tb-btn.warn:hover { background:rgba(224,108,117,.1); }
.tb-btn.bond-mode { color:#ffd54f; border:1px solid rgba(255,213,79,.4); }
.tb-btn.bond-mode.active { background:rgba(255,213,79,.15); border-color:#ffd54f; }
.tb-btn.active { background:rgba(0,120,212,.15); border:1px solid rgba(0,120,212,.4); color:var(--accent); }
.tb-sep { width:1px; height:20px; background:var(--border); margin:0 4px; }
.tb-spacer { flex:1; }
#statusChip { font-family:'IBM Plex Mono',monospace; font-size:11px; padding:2px 8px; border-radius:2px; background:rgba(63,185,80,.15); border:1px solid rgba(63,185,80,.3); color:var(--accent3); opacity:0; transition:opacity .3s; max-width:420px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
#statusChip.vis { opacity:1; }


#app { display:flex; height:calc(100vh - 36px); overflow:hidden; }


.resizable-panel { position:relative; flex-shrink:0; }
.resize-handle { position:absolute; top:0; width:5px; height:100%; cursor:col-resize; z-index:100; background:transparent; transition:background .2s; }
.resize-handle:hover, .resize-handle.dragging { background:var(--accent); opacity:.4; }
#leftPanel { width:240px; background:var(--panel); border-right:1px solid var(--border); display:flex; flex-direction:column; overflow:hidden; min-width:150px; max-width:420px; }
#leftPanel .resize-handle { right:-2px; }
#rightPanel { width:210px; background:var(--panel); border-left:1px solid var(--border); display:flex; flex-direction:column; overflow:hidden; min-width:140px; max-width:400px; }
#rightPanel .resize-handle { left:-2px; }


.panel-section { border-bottom:1px solid var(--border); flex-shrink:0; }
.section-header { height:30px; display:flex; align-items:center; justify-content:space-between; padding:0 10px; cursor:pointer; user-select:none; color:var(--text2); font-size:11px; font-weight:600; letter-spacing:.5px; text-transform:uppercase; background:var(--bg2); transition:background .1s; }
.section-header:hover { background:var(--bg4); color:var(--text); }
.section-header .chevron { font-size:9px; transition:transform .2s; }
.section-header.collapsed .chevron { transform:rotate(-90deg); }
.section-body { overflow:hidden; }
.section-body.collapsed { display:none; }


#atomSearch { width:calc(100% - 16px); margin:6px 8px; height:26px; background:var(--bg); border:1px solid var(--border); border-radius:3px; color:var(--text); font-family:'IBM Plex Mono',monospace; font-size:11px; padding:0 8px; outline:none; transition:border-color .15s; }
#atomSearch:focus { border-color:var(--accent); }
#atomSearch::placeholder { color:var(--text3); }
#catTabs { display:flex; flex-wrap:wrap; gap:3px; padding:0 8px 6px; }
.cat-tab { font-size:10px; padding:2px 7px; border-radius:2px; border:1px solid transparent; cursor:pointer; transition:all .12s; color:var(--text2); background:var(--bg3); font-family:'IBM Plex Mono',monospace; }
.cat-tab:hover { border-color:var(--border2); color:var(--text); }
.cat-tab.active { background:var(--accent); color:#fff; border-color:var(--accent); }
#atomGrid { display:grid; grid-template-columns:repeat(4,1fr); gap:3px; padding:4px 8px 8px; max-height:200px; overflow-y:auto; scrollbar-width:thin; scrollbar-color:var(--border) transparent; }
.atom-tile { aspect-ratio:1; display:flex; flex-direction:column; align-items:center; justify-content:center; border:1px solid var(--border); border-radius:3px; cursor:grab; transition:all .12s; padding:3px 2px; background:var(--bg); user-select:none; }
.atom-tile:hover { border-color:var(--accent); background:rgba(0,120,212,.08); transform:scale(1.04); z-index:2; }
.atom-tile:active { cursor:grabbing; transform:scale(.96); }
.atom-tile .sym { font-family:'IBM Plex Mono',monospace; font-weight:600; font-size:13px; line-height:1; }
.atom-tile .num { font-size:8px; color:var(--text3); font-family:'IBM Plex Mono',monospace; line-height:1.2; }
.atom-tile .mass-t { font-size:7px; color:var(--text3); font-family:'IBM Plex Mono',monospace; }


#infoPanel { padding:10px; min-height:100px; font-size:11px; line-height:1.8; }
.info-name { font-size:13px; font-weight:600; color:var(--white); margin-bottom:5px; font-family:'IBM Plex Mono',monospace; }
.info-prop { color:var(--text3); }
.info-val { color:var(--text); font-family:'IBM Plex Mono',monospace; font-size:11px; }
.info-empty { color:var(--text3); font-size:11px; font-style:italic; }


.formula { font-family:'IBM Plex Mono',monospace; font-weight:600; font-size:13px; }
.formula sub { font-size:.6em; vertical-align:sub; }
.formula sup { font-size:.6em; vertical-align:super; }


#recipesPanel { flex:1; overflow-y:auto; padding:6px 8px 8px; scrollbar-width:thin; scrollbar-color:var(--border) transparent; }
.recipe-group-title { font-size:10px; text-transform:uppercase; letter-spacing:.8px; color:var(--accent2); font-weight:600; margin:8px 0 4px; font-family:'IBM Plex Mono',monospace; }
.recipe-row { display:flex; align-items:center; gap:6px; padding:5px 7px; border-radius:3px; font-size:11px; font-family:'IBM Plex Mono',monospace; border:1px solid transparent; margin-bottom:3px; cursor:pointer; transition:all .12s; line-height:1.4; background:var(--bg); }
.recipe-row:hover { background:var(--bg3); border-color:var(--accent); }
.recipe-row .recipe-spawn { margin-left:auto; font-size:10px; color:var(--accent3); opacity:0; transition:opacity .15s; white-space:nowrap; border:1px solid rgba(63,185,80,.3); border-radius:2px; padding:1px 5px; }
.recipe-row:hover .recipe-spawn { opacity:1; }
.recipe-lhs { color:var(--text2); flex:1; }
.recipe-arrow { color:var(--text3); }
.recipe-rhs { color:var(--accent3); font-weight:600; }
#recipeSearch { width:100%; height:26px; background:var(--bg); border:1px solid var(--border); border-radius:3px; color:var(--text); font-family:'IBM Plex Mono',monospace; font-size:11px; padding:0 8px; outline:none; transition:border-color .15s; margin-bottom:4px; }
#recipeSearch:focus { border-color:var(--accent); }
#recipeSearch::placeholder { color:var(--text3); }


#addRecipeForm { background:var(--bg); border:1px solid var(--border); border-radius:3px; padding:8px; margin-bottom:8px; }
#addRecipeForm input,#addRecipeForm select { width:100%; height:26px; background:var(--bg3); border:1px solid var(--border); border-radius:3px; color:var(--text); font-family:'IBM Plex Mono',monospace; font-size:11px; padding:0 6px; outline:none; margin-bottom:4px; transition:border-color .15s; }
#addRecipeForm input:focus { border-color:var(--accent); }
#addRecipeForm label { font-size:10px; color:var(--text2); display:block; margin-bottom:2px; }
.form-row { display:flex; gap:4px; }
.add-recipe-btn { width:100%; height:26px; background:var(--accent); border:none; border-radius:3px; color:#fff; font-size:11px; font-family:'IBM Plex Mono',monospace; cursor:pointer; transition:background .12s; margin-top:2px; }
.add-recipe-btn:hover { background:var(--accent-h); }


.atom-builder-grid { display:flex; flex-wrap:wrap; gap:3px; padding:4px 0; max-height:100px; overflow-y:auto; }
.ab-chip { font-size:11px; font-family:'IBM Plex Mono',monospace; padding:2px 6px; border-radius:2px; cursor:pointer; border:1px solid transparent; transition:all .1s; background:var(--bg3); color:var(--text2); }
.ab-chip:hover { border-color:var(--accent); color:var(--text); }
.ab-selected-atoms { display:flex; flex-wrap:wrap; gap:3px; min-height:26px; background:var(--bg); border:1px solid var(--border); border-radius:3px; padding:4px; margin-bottom:4px; }
.ab-atom-tag { font-size:10px; font-family:'IBM Plex Mono',monospace; padding:2px 6px; border-radius:2px; cursor:pointer; display:flex; align-items:center; gap:3px; }
.ab-atom-tag .x { color:var(--accent4); }
.ab-empty { font-size:10px; color:var(--text3); font-style:italic; }


#canvasWrap { flex:1; position:relative; overflow:hidden; background:var(--bg); }
#simCanvas { display:block; cursor:default; }


#simCanvas.bond-cursor { cursor:crosshair; }


#bondLine { position:absolute; pointer-events:none; top:0;left:0;width:100%;height:100%; z-index:10; }


#viewBar { position:absolute; bottom:14px; left:50%; transform:translateX(-50%); display:flex; background:var(--bg2); border:1px solid var(--border); border-radius:4px; overflow:hidden; }
.vbtn { padding:5px 16px; font-size:11px; font-family:'IBM Plex Mono',monospace; cursor:pointer; border:none; background:transparent; color:var(--text2); transition:all .12s; letter-spacing:.5px; border-right:1px solid var(--border); }
.vbtn:last-child { border-right:none; }
.vbtn:hover { background:var(--bg4); color:var(--text); }
.vbtn.active { background:var(--accent); color:#fff; }
#zoomLabel { position:absolute; bottom:14px; right:14px; font-family:'IBM Plex Mono',monospace; font-size:11px; color:var(--text3); background:var(--bg2); border:1px solid var(--border); padding:4px 8px; border-radius:3px; }


#tooltip { position:absolute; background:var(--bg2); border:1px solid var(--border2); border-radius:4px; padding:7px 10px; font-size:11px; pointer-events:none; z-index:200; line-height:1.7; box-shadow:var(--shadow); max-width:200px; display:none; }
#tooltip b { color:var(--white); font-family:'IBM Plex Mono',monospace; }


.pulse { position:absolute; border-radius:50%; border:2px solid var(--accent3); animation:pout .6s ease-out forwards; pointer-events:none; }
@keyframes pout { 0%{transform:translate(-50%,-50%) scale(.4);opacity:1} 100%{transform:translate(-50%,-50%) scale(2.5);opacity:0} }


#moleculesList { flex:1; overflow-y:auto; padding:6px; scrollbar-width:thin; scrollbar-color:var(--border) transparent; }
.mol-item { display:flex; align-items:center; gap:7px; padding:5px 7px; border:1px solid transparent; border-radius:3px; margin-bottom:2px; font-size:11px; font-family:'IBM Plex Mono',monospace; cursor:pointer; transition:all .12s; background:var(--bg3); }
.mol-item:hover { border-color:var(--accent); background:rgba(0,120,212,.06); }
.mol-item.sel { border-color:var(--accent3); background:rgba(63,185,80,.08); }
.mol-dot { width:9px; height:9px; border-radius:50%; flex-shrink:0; }
.mol-name { color:var(--text); font-weight:500; }
.mol-sub { color:var(--text3); font-size:10px; }
#cellsList { padding:6px; border-top:1px solid var(--border); overflow-y:auto; max-height:180px; scrollbar-width:thin; scrollbar-color:var(--border) transparent; }
.cell-item { display:flex; align-items:center; gap:7px; padding:5px 7px; border-radius:3px; margin-bottom:3px; font-size:11px; font-family:'IBM Plex Mono',monospace; background:var(--bg3); border:1px solid transparent; cursor:pointer; transition:all .12s; }
.cell-item:hover { border-color:var(--accent4); }


#ctxMenu { position:fixed; background:var(--bg2); border:1px solid var(--border2); border-radius:4px; padding:4px 0; z-index:999; box-shadow:var(--shadow); min-width:160px; display:none; }
.ctx-item { padding:6px 14px; font-size:12px; cursor:pointer; transition:background .1s; display:flex; align-items:center; gap:8px; }
.ctx-item:hover { background:var(--bg4); color:var(--white); }
.ctx-sep { height:1px; background:var(--border); margin:3px 0; }
.ctx-item.danger:hover { color:var(--accent4); }


#bondModeBar { display:none; position:absolute; top:10px; left:50%; transform:translateX(-50%); background:rgba(255,213,79,.12); border:1px solid rgba(255,213,79,.5); border-radius:4px; padding:5px 14px; font-size:12px; font-family:'IBM Plex Mono',monospace; color:#ffd54f; pointer-events:none; z-index:20; }
#bondModeBar.vis { display:block; }

::-webkit-scrollbar { width:5px; height:5px; }
::-webkit-scrollbar-track { background:transparent; }
::-webkit-scrollbar-thumb { background:var(--border); border-radius:3px; }
::-webkit-scrollbar-thumb:hover { background:var(--border2); }