:root{
  --bg:#000;
  --panel:#080808;
  --panel-2:#0d0d0d;
  --line:#1b1b1b;
  --line-strong:#292929;
  --text:#f6f6f6;
  --muted:#7d7d7d;
  --muted-2:#a7a7a7;
  --white:#fff;
  --danger:#ff4b55;
  --radius:18px;
  --radius-sm:12px;
  --ease:cubic-bezier(.2,.8,.2,1);
}
*{box-sizing:border-box}
html,body{margin:0;min-height:100%;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
body{min-height:100vh;overflow-x:hidden}
button,input,textarea,select{font:inherit;color:inherit}
button{cursor:pointer}
button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:2px solid #fff;outline-offset:2px}
svg{display:block}
.app-shell{min-height:100vh;background:#000}
.topbar{height:68px;padding:0 24px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;position:sticky;top:0;z-index:40;background:rgba(0,0,0,.94);border-bottom:1px solid #111;backdrop-filter:blur(14px)}
.brand{font-size:12px;letter-spacing:.28em;font-weight:750;color:#d7d7d7}
.top-actions{justify-self:end;display:flex;align-items:center;gap:8px}
.icon-btn{width:38px;height:38px;border:0;background:transparent;color:#a7a7a7;border-radius:11px;display:grid;place-items:center;transition:background .18s var(--ease),color .18s var(--ease),transform .18s var(--ease)}
.icon-btn:hover{background:#111;color:#fff}.icon-btn:active{transform:scale(.94)}
.icon-btn svg{width:19px;height:19px;fill:none;stroke:currentColor;stroke-width:1.75;stroke-linecap:round;stroke-linejoin:round}
#homeBtn svg{fill:currentColor;stroke:none;width:18px;height:18px}
.math-toggle{height:38px;min-width:60px;border-radius:12px;border:1px solid #222;background:#0a0a0a;color:#aaa;padding:0 10px;display:flex;align-items:center;justify-content:space-between;gap:9px;font-weight:700;transition:.22s var(--ease)}
.math-toggle i{width:7px;height:7px;border-radius:50%;background:#343434;box-shadow:0 0 0 3px #111;transition:.22s var(--ease)}
.math-toggle.active{background:#fff;color:#000;border-color:#fff}.math-toggle.active i{background:#000;box-shadow:0 0 0 3px #dedede}
.main-view{width:min(1180px,calc(100% - 44px));margin:0 auto;padding:48px 0 80px}
.view{display:none;opacity:0;transform:translateY(8px)}.view.active{display:block;animation:viewIn .26s var(--ease) forwards}
@keyframes viewIn{to{opacity:1;transform:none}}
.hero-row{display:flex;align-items:flex-end;justify-content:space-between;gap:20px;margin-bottom:30px}
.eyebrow{margin:0 0 8px;font-size:10px;letter-spacing:.18em;color:#666;font-weight:760}
h1{font-size:clamp(34px,5vw,62px);letter-spacing:-.055em;line-height:.98;margin:0;font-weight:720;max-width:650px}
h2,h3,p{margin:0}.primary-btn,.secondary-btn,.danger-btn{border-radius:12px;border:1px solid transparent;height:44px;padding:0 16px;font-weight:680;transition:.18s var(--ease)}
.primary-btn{background:#fff;color:#000}.primary-btn:hover{background:#dedede;transform:translateY(-1px)}
.secondary-btn{background:#0c0c0c;border-color:#252525;color:#d6d6d6}.secondary-btn:hover{border-color:#3c3c3c;background:#111}
.danger-btn{background:#140707;border-color:#371216;color:#ff7e85}.danger-btn:hover{background:#21090c;border-color:#5a1920}
.small{height:36px;padding:0 12px;font-size:13px}
.toolbar-row{display:flex;gap:10px;margin-bottom:18px}.searchbox{height:44px;flex:1;border:1px solid #1e1e1e;background:#080808;border-radius:13px;display:flex;align-items:center;padding:0 13px;gap:10px;transition:border .18s var(--ease),background .18s var(--ease)}
.searchbox:focus-within{border-color:#3b3b3b;background:#0b0b0b}.searchbox svg{width:17px;height:17px;fill:none;stroke:#616161;stroke-width:1.8}.searchbox input{width:100%;border:0;background:transparent;outline:none;font-size:14px}.searchbox input::placeholder{color:#565656}
.dashboard-grid{display:grid;grid-template-columns:1.6fr .8fr .8fr;gap:14px;margin:26px 0 42px}.panel{min-height:190px;background:#070707;border:1px solid #181818;border-radius:18px;padding:18px;overflow:hidden}.panel-wide{min-height:190px}.panel-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:18px}.panel-head h2{font-size:14px;font-weight:680;letter-spacing:-.01em}.panel-head span{font-size:11px;color:#666}.mini-btn{width:27px;height:27px;border-radius:8px;border:1px solid #222;background:#0c0c0c;color:#aaa;font-size:18px;line-height:1}.mini-btn:hover{color:white;border-color:#383838}
.recent-list{display:grid;gap:7px}.recent-item{height:38px;border:0;background:transparent;border-radius:10px;color:#d8d8d8;padding:0 10px;display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;text-align:left;transition:.18s var(--ease)}.recent-item:hover{background:#101010}.recent-item strong{font-size:13px;font-weight:590;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.recent-item span{font-size:11px;color:#5e5e5e;margin-left:10px}.recent-empty{font-size:13px;color:#555;padding:20px 8px}
.class-chips{display:flex;flex-wrap:wrap;gap:8px;align-content:flex-start}.class-chip{border:1px solid #222;background:#0d0d0d;border-radius:999px;color:#aaa;height:30px;padding:0 11px;font-size:12px;transition:.18s var(--ease)}.class-chip:hover,.class-chip.active{background:#fff;color:#000;border-color:#fff}.class-chip .dot{display:inline-block;width:5px;height:5px;border-radius:50%;background:currentColor;margin-right:7px;vertical-align:middle}
.math-widget-main{height:126px;display:flex;flex-direction:column;align-items:flex-start;justify-content:flex-end;position:relative}.math-widget-main p{font-size:12px;line-height:1.45;color:#777;max-width:180px;margin:8px 0 13px}.math-orb{position:absolute;right:4px;top:-1px;width:66px;height:66px;border:1px solid #222;border-radius:18px;display:grid;place-items:center;font-size:24px;font-weight:700;color:#6b6b6b;background:#0b0b0b;transform:rotate(3deg)}
.section-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:13px}.section-head h2{font-size:14px}.filter-pill{font-size:11px;border:1px solid #292929;background:#0c0c0c;border-radius:999px;padding:5px 9px;color:#aaa}.notes-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.note-card{position:relative;min-height:174px;background:#070707;border:1px solid #171717;border-radius:17px;padding:17px;text-align:left;overflow:hidden;transition:transform .2s var(--ease),border .2s var(--ease),background .2s var(--ease);animation:cardIn .28s var(--ease) both}.note-card:hover{transform:translateY(-3px);background:#0a0a0a;border-color:#292929}.note-card .pin-mark{position:absolute;right:14px;top:14px;font-size:11px;color:#555}.note-card h3{font-size:16px;line-height:1.2;margin:0 26px 9px 0;font-weight:650;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.note-card p{font-size:13px;color:#707070;line-height:1.45;display:-webkit-box;-webkit-line-clamp:4;-webkit-box-orient:vertical;overflow:hidden;white-space:pre-wrap}.note-card-foot{position:absolute;left:17px;right:17px;bottom:15px;display:flex;justify-content:space-between;align-items:center}.note-card-foot span{font-size:10px;color:#4e4e4e}.note-card-class{border:1px solid #1f1f1f;border-radius:999px;padding:3px 7px!important;color:#777!important}
@keyframes cardIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.empty-state{text-align:center;border:1px dashed #191919;border-radius:18px;padding:58px 20px;color:#6b6b6b}.empty-icon{margin:0 auto 14px;width:38px;height:38px;border:1px solid #222;border-radius:12px;display:grid;place-items:center;font-size:20px}.empty-state h3{color:#a7a7a7;margin-bottom:5px}.empty-state p{font-size:12px}
.editor-view{max-width:920px;margin:0 auto}.editor-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:38px}.back-btn,.text-btn{border:0;background:transparent;color:#858585;padding:7px 0;font-size:13px}.back-btn:hover,.text-btn:hover{color:#fff}.editor-actions{display:flex;align-items:center;gap:8px}.class-select{height:36px;border:1px solid #222;border-radius:11px;background:#090909;color:#aaa;padding:0 28px 0 10px;font-size:12px}.note-title-input{display:block;width:100%;border:0;background:transparent;outline:0;font-size:clamp(34px,5vw,56px);font-weight:720;letter-spacing:-.045em;padding:0;margin:0 0 8px}.note-title-input::placeholder{color:#242424}.editor-meta{display:flex;gap:12px;color:#4f4f4f;font-size:11px;margin-bottom:26px}.note-body{display:block;width:100%;min-height:55vh;resize:none;border:0;background:transparent;outline:0;color:#d9d9d9;font:400 17px/1.72 ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;padding:0 0 120px}.note-body::placeholder{color:#292929}.math-assist{position:fixed;left:50%;bottom:28px;transform:translateX(-50%);max-width:min(680px,calc(100vw - 40px));min-width:320px;border:1px solid #2d2d2d;background:#0c0c0c;border-radius:14px;padding:12px 14px;box-shadow:0 18px 50px rgba(0,0,0,.65);display:flex;align-items:center;justify-content:space-between;gap:14px;z-index:35;animation:assistIn .18s var(--ease)}.math-assist .expression{font-size:13px;color:#757575;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.math-assist strong{font-size:18px;font-weight:680;white-space:nowrap}.math-assist button{height:30px;border:1px solid #242424;background:#111;border-radius:8px;color:#aaa;font-size:11px;padding:0 10px}.math-assist button:hover{color:#fff;border-color:#3d3d3d}@keyframes assistIn{from{opacity:0;transform:translate(-50%,8px)}to{opacity:1;transform:translate(-50%,0)}}
.context-menu{position:fixed;z-index:90;width:220px;background:#0b0b0b;border:1px solid #272727;border-radius:13px;padding:6px;box-shadow:0 20px 70px rgba(0,0,0,.65);animation:menuIn .12s var(--ease)}@keyframes menuIn{from{opacity:0;transform:scale(.96)}to{opacity:1;transform:none}}.context-menu button{width:100%;height:37px;border:0;background:transparent;border-radius:8px;color:#b9b9b9;padding:0 9px;display:flex;justify-content:space-between;align-items:center;font-size:12px;text-align:left}.context-menu button:hover{background:#151515;color:#fff}.context-menu kbd,.context-menu button span:last-child{font:500 10px/1 ui-monospace,monospace;color:#5b5b5b}.context-menu button:hover span:last-child,.context-menu button:hover kbd{color:#aaa}
.modal-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.72);backdrop-filter:blur(5px);z-index:60;animation:fadeIn .18s var(--ease)}@keyframes fadeIn{from{opacity:0}to{opacity:1}}
.side-panel{position:fixed;z-index:70;right:16px;top:16px;bottom:16px;width:min(520px,calc(100vw - 32px));background:#070707;border:1px solid #202020;border-radius:20px;padding:20px;box-shadow:-25px 0 80px rgba(0,0,0,.7);animation:slidePanel .26s var(--ease)}@keyframes slidePanel{from{opacity:0;transform:translateX(24px)}to{opacity:1;transform:none}}.side-panel-head,.modal-head{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;margin-bottom:18px}.side-panel-head h2,.modal-head h2{font-size:22px;letter-spacing:-.03em}.close-panel{font-size:26px;line-height:1}.graph-controls{display:flex;gap:8px;margin-bottom:10px}.graph-controls input,.class-create input{flex:1;height:40px;border:1px solid #222;border-radius:11px;background:#0b0b0b;padding:0 12px;outline:0}.graph-controls input:focus,.class-create input:focus{border-color:#444}.calculator{height:calc(100% - 135px);min-height:360px;border-radius:14px;overflow:hidden;background:#fff}.graph-footer{height:34px;display:flex;justify-content:space-between;align-items:end;color:#4f4f4f;font-size:10px}
.formula-search{flex:none;width:100%;margin-bottom:10px}.formula-categories{display:flex;gap:6px;overflow:auto;padding:2px 0 12px;scrollbar-width:none}.formula-categories::-webkit-scrollbar{display:none}.formula-category{height:30px;border:1px solid #222;background:#0b0b0b;color:#777;border-radius:999px;padding:0 11px;font-size:11px;white-space:nowrap}.formula-category.active,.formula-category:hover{background:#fff;color:#000;border-color:#fff}.formula-list{overflow:auto;height:calc(100% - 132px);padding-right:4px}.formula-card{border-bottom:1px solid #161616;padding:14px 4px;display:grid;grid-template-columns:1fr auto;gap:15px;align-items:center}.formula-card h3{font-size:13px;font-weight:610;margin-bottom:5px}.formula-card p{font:500 15px/1.4 ui-monospace,monospace;color:#cfcfcf}.formula-card small{font-size:10px;color:#555;display:block;margin-top:5px}.formula-card button{height:28px;border:1px solid #202020;background:#0d0d0d;color:#777;border-radius:8px;padding:0 9px;font-size:10px}.formula-card button:hover{color:white;border-color:#3d3d3d}
.modal{position:fixed;z-index:70;left:50%;top:50%;transform:translate(-50%,-50%);width:min(500px,calc(100vw - 32px));max-height:80vh;overflow:auto;background:#080808;border:1px solid #252525;border-radius:20px;padding:20px;box-shadow:0 30px 100px rgba(0,0,0,.75);animation:modalIn .2s var(--ease)}@keyframes modalIn{from{opacity:0;transform:translate(-50%,calc(-50% + 8px)) scale(.985)}to{opacity:1;transform:translate(-50%,-50%) scale(1)}}.class-create{display:flex;gap:8px;margin-bottom:16px}.class-manager-list{display:grid;gap:7px}.class-manager-item{height:46px;border:1px solid #191919;border-radius:12px;background:#0a0a0a;padding:0 12px;display:flex;align-items:center;justify-content:space-between}.class-manager-item strong{font-size:13px;font-weight:590}.class-manager-item span{font-size:10px;color:#5d5d5d}.class-manager-item button{border:0;background:transparent;color:#5d5d5d;font-size:12px}.class-manager-item button:hover{color:#ff7b82}
.scan-modal{width:min(620px,calc(100vw - 32px))}.drop-zone{min-height:330px;border:1px dashed #292929;border-radius:17px;background:#050505;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;padding:28px;transition:.18s var(--ease)}.drop-zone.drag{border-color:#aaa;background:#0a0a0a}.scan-icon{width:52px;height:52px;border-radius:15px;border:1px solid #222;display:grid;place-items:center;margin-bottom:17px}.scan-icon svg{width:24px;height:24px;fill:none;stroke:#888;stroke-width:1.7}.drop-zone h3{font-size:17px;margin-bottom:6px}.drop-zone p{font-size:12px;color:#666;margin-bottom:18px}.scan-progress{min-height:330px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}.spinner{width:30px;height:30px;border-radius:50%;border:2px solid #1a1a1a;border-top-color:#fff;animation:spin .75s linear infinite;margin-bottom:17px}@keyframes spin{to{transform:rotate(360deg)}}.scan-progress h3{font-size:16px;margin-bottom:6px}.scan-progress p{font-size:12px;color:#5f5f5f}.scan-result textarea{width:100%;height:350px;resize:vertical;border:1px solid #222;border-radius:14px;background:#050505;color:#d8d8d8;padding:14px;outline:0;font:400 14px/1.55 ui-monospace,monospace}.scan-result textarea:focus{border-color:#404040}.scan-result-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:12px}
.toast{position:fixed;z-index:120;left:50%;bottom:24px;transform:translateX(-50%);background:#fff;color:#000;border-radius:999px;padding:9px 14px;font-size:11px;font-weight:700;box-shadow:0 10px 40px rgba(0,0,0,.45);animation:toastIn .2s var(--ease)}@keyframes toastIn{from{opacity:0;transform:translate(-50%,8px)}to{opacity:1;transform:translate(-50%,0)}}
.hidden{display:none!important}
@media (max-width:900px){.dashboard-grid{grid-template-columns:1fr 1fr}.panel-wide{grid-column:1/-1}.notes-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:620px){.topbar{padding:0 14px}.main-view{width:calc(100% - 28px);padding-top:34px}.hero-row{align-items:flex-start;flex-direction:column}.hero-row .primary-btn{width:100%}.toolbar-row{align-items:stretch}.toolbar-row .secondary-btn{padding:0 12px}.dashboard-grid{grid-template-columns:1fr}.panel-wide{grid-column:auto}.notes-grid{grid-template-columns:1fr}.editor-top{align-items:flex-start;gap:14px}.editor-actions{flex-wrap:wrap;justify-content:flex-end}.note-body{font-size:16px}.math-assist{min-width:0;width:calc(100vw - 28px)}.brand{letter-spacing:.2em}.top-actions{gap:2px}.icon-btn{width:36px}.math-toggle{min-width:52px;padding:0 8px}.scan-modal{max-height:90vh}.drop-zone{min-height:290px}}