:root{
  --bg:#071427; --panel:#0c1724; --muted:#9aa6b2; --accent:#6c8cff; --glass: rgba(255,255,255,0.03);
  --cell:48px; --g-radius:12px; --smooth:0.28s; --text:#e6eef8;
  --light-bg:#f7f9fc; --light-panel:#ffffff; --light-text:#0b1220;
}

/* base */
*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial;background:linear-gradient(180deg,var(--bg),#06101a);color:var(--text);-webkit-font-smoothing:antialiased}
body.light-on{background:linear-gradient(180deg,var(--light-bg),#e9eef6);color:var(--light-text)}
#app{display:flex;flex-direction:column;min-height:100vh}

/* header */
.topbar{display:flex;align-items:center;justify-content:space-between;padding:12px 18px;gap:12px}
.brand h1{margin:0;font-size:18px}
.brand .subtitle{font-size:12px;color:var(--muted)}

/* controls */
.controls{display:flex;gap:12px;align-items:center}
.mode-row select{padding:8px;border-radius:8px;border:1px solid rgba(255,255,255,0.03);background:transparent;color:inherit}
.top-actions button{margin-left:6px}

/* switch (dark/light) */
.switch{position:relative;display:inline-block;width:56px;height:30px}
.switch input{opacity:0;width:0;height:0}
.slider{position:absolute;cursor:pointer;top:0;left:0;right:0;bottom:0;background:#253042;border-radius:30px;transition:all .28s}
.switch input:checked + .slider{background:linear-gradient(90deg,var(--accent),#5db1ff)}
.slider::before{content:'';position:absolute;height:22px;width:22px;left:4px;top:4px;background:white;border-radius:50%;transition:all .28s}
.switch input:checked + .slider::before{transform:translateX(26px)}

/* layout */
.main-grid{display:grid;grid-template-columns:280px 1fr 320px;gap:14px;padding:14px;flex:1;align-items:start}
.panel{background:linear-gradient(180deg,rgba(255,255,255,0.02),transparent);border-radius:var(--g-radius);padding:12px;box-shadow:0 8px 24px rgba(2,6,23,0.45)}
.left .section{margin-bottom:14px}

/* palette */
.palette-grid{display:grid;grid-template-columns:repeat(5,minmax(36px,1fr));gap:8px}
.palette-item{height:44px;border-radius:8px;background:var(--glass);display:flex;align-items:center;justify-content:center;font-size:22px;cursor:pointer;border:1px solid rgba(255,255,255,0.03);transition:transform .18s,box-shadow .18s}
.palette-item.active{outline:3px solid rgba(108,140,255,0.12);transform:translateY(-3px)}

/* center */
.center.panel{display:flex;flex-direction:column;gap:10px;min-height:60vh}
.canvas-toolbar{display:flex;justify-content:space-between;align-items:center;padding:6px 8px}
.viewport{background:linear-gradient(180deg, rgba(255,255,255,0.01), rgba(0,0,0,0.06));border-radius:12px;overflow:auto;position:relative;border:1px solid rgba(255,255,255,0.03);height:60vh}
.grid-wrap{position:absolute;left:0;top:0;transform-origin:0 0;display:grid;gap:6px;padding:12px}
.matrix-canvas{position:absolute;inset:0;pointer-events:none;opacity:0;transition:opacity .6s}
.matrix-canvas.active{opacity:0.98;mix-blend-mode:screen}

/* custom element styling */
emoji-cell{display:block;width:var(--cell);height:var(--cell);border-radius:9px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.04));display:flex;align-items:center;justify-content:center;font-size:24px;cursor:pointer;user-select:none;box-shadow:inset 0 -2px 0 rgba(0,0,0,0.06);transition:transform .18s, box-shadow .18s}
emoji-cell.empty{opacity:0.25;color:transparent}
emoji-cell.highlight{box-shadow:0 8px 20px rgba(35,80,255,0.18);transform:translateY(-6px)}

/* right pane */
.levels-list{display:flex;flex-direction:column;gap:8px}
.level-item{padding:8px;border-radius:8px;background:rgba(255,255,255,0.02);display:flex;justify-content:space-between;align-items:center}

/* footer */
.foot{text-align:center;padding:8px;color:var(--muted);font-size:13px}

/* buttons */
button{padding:8px 10px;border-radius:8px;border:none;background:transparent;color:inherit;cursor:pointer}
button.primary{background:linear-gradient(90deg,var(--accent),#5db1ff);color:#031124;box-shadow:0 8px 24px rgba(93,177,255,0.12)}
input[type=range]{width:140px}

/* light theme overrides */
body.light-on .panel{background:var(--light-panel);box-shadow:0 6px 20px rgba(16,24,40,0.04)}
body.light-on .palette-item{background:#f7f8fb;border:1px solid rgba(20,24,30,0.04)}
body.light-on emoji-cell{background:linear-gradient(180deg,#ffffff,#f4f7fb);color:var(--light-text)}

/* mobile responsiveness */
@media (max-width:1100px){
  .main-grid{grid-template-columns:1fr;grid-auto-rows:auto;padding:10px}
  .left,.right{order:2}
  .center{order:1}
  .viewport{height:55vh}
}

/* super small mobiles */
@media (max-width:480px){
  .palette-grid{grid-template-columns:repeat(6, minmax(28px,1fr))}
  --cell:36px;
  emoji-cell{font-size:18px}
}

/* misc */
.toast{position:fixed;right:18px;bottom:18px;background:#0b1220;color:#fff;padding:8px 12px;border-radius:8px;z-index:99999;box-shadow:0 10px 30px rgba(0,0,0,0.35)}