*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
:root{
  --bg:#0a0a0c;--fg:#e8e6e3;--fg2:#9a9692;--fg3:#5a5854;
  --accent:#c8ff5a;--accent2:#9adf2a;
  --card-bg:#141418;--card-border:#222228;
  --panel-bg:#111115;--panel-w:380px;
  --radius:10px;
  --font:'Space Grotesk',system-ui,sans-serif;
  --mono:'JetBrains Mono',monospace;
}
html,body{height:100%;overflow:hidden}
body{font-family:var(--font);color:var(--fg);background:var(--bg);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}

/* ---- Header ---- */
header{
  position:fixed;top:0;left:0;right:0;z-index:100;height:52px;
  display:flex;align-items:center;gap:1.5rem;
  padding:0 1.25rem;
  background:rgba(10,10,12,0.85);backdrop-filter:blur(16px);
  border-bottom:1px solid rgba(255,255,255,0.05);
}
.logo{font-size:1.1rem;font-weight:600;letter-spacing:-0.02em;flex-shrink:0}
.logo .dot{color:var(--accent)}

.mode-tabs{display:flex;gap:2px;background:rgba(255,255,255,0.04);border-radius:8px;padding:3px}
.tab{
  padding:6px 14px;border:none;background:none;color:var(--fg2);
  font-family:var(--font);font-size:0.78rem;font-weight:500;
  border-radius:6px;cursor:pointer;transition:all 0.2s;white-space:nowrap;
}
.tab:hover{color:var(--fg)}
.tab.active{background:rgba(200,255,90,0.12);color:var(--accent)}

.header-stats{
  margin-left:auto;display:flex;gap:1rem;
  font-family:var(--mono);font-size:0.72rem;color:var(--fg3);
}

/* ---- Layout ---- */
.app-layout{
  position:fixed;top:52px;left:0;right:0;bottom:0;
  display:flex;
}

/* ---- Viewport ---- */
.viewport-wrap{
  flex:1;position:relative;background:#000;
  display:flex;align-items:center;justify-content:center;
}
#renderCanvas{
  width:100%;height:100%;display:block;
  image-rendering:pixelated;
}
.viewport-overlay{
  position:absolute;inset:0;display:flex;align-items:center;justify-content:center;
  background:rgba(0,0,0,0.4);cursor:pointer;transition:opacity 0.3s;
}
.viewport-overlay.hidden{opacity:0;pointer-events:none}
.overlay-hint{
  font-size:0.95rem;color:var(--fg2);padding:12px 24px;
  border:1px solid var(--card-border);border-radius:var(--radius);
  background:rgba(20,20,24,0.9);
}
.viewport-controls{
  position:absolute;bottom:1rem;left:1rem;display:flex;gap:6px;
}
.viewport-controls button{
  width:36px;height:36px;border:1px solid var(--card-border);
  background:rgba(20,20,24,0.85);color:var(--fg2);
  border-radius:8px;cursor:pointer;font-size:1rem;
  display:flex;align-items:center;justify-content:center;
  backdrop-filter:blur(8px);transition:border-color 0.2s;
}
.viewport-controls button:hover{border-color:var(--accent);color:var(--fg)}

.scene-picker{
  position:absolute;bottom:1rem;right:1rem;display:flex;align-items:center;gap:6px;
}
.quality-picker{
  position:absolute;bottom:3.2rem;right:1rem;display:flex;align-items:center;gap:6px;
}
.picker-label{font-size:0.72rem;color:var(--fg3);font-weight:500}
.scene-btn,.quality-btn{
  padding:5px 12px;border:1px solid var(--card-border);background:rgba(20,20,24,0.85);
  color:var(--fg2);font-family:var(--font);font-size:0.72rem;font-weight:500;
  border-radius:6px;cursor:pointer;transition:all 0.2s;backdrop-filter:blur(8px);
}
.scene-btn:hover,.quality-btn:hover{border-color:var(--fg3)}
.scene-btn.active,.quality-btn.active{background:rgba(200,255,90,0.1);border-color:var(--accent);color:var(--accent)}

/* ---- Info Panel ---- */
.info-panel{
  width:var(--panel-w);flex-shrink:0;
  background:var(--panel-bg);border-left:1px solid var(--card-border);
  display:flex;flex-direction:column;
  transition:margin-right 0.3s ease;
  overflow:hidden;
}
.info-panel.collapsed{margin-right:calc(-1 * var(--panel-w))}
.panel-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:1rem 1.25rem;border-bottom:1px solid var(--card-border);
  flex-shrink:0;
}
.panel-header h2{font-size:1rem;font-weight:600;letter-spacing:-0.01em}
.panel-toggle{
  background:none;border:none;color:var(--fg3);cursor:pointer;
  font-size:1rem;padding:4px;line-height:1;
}
.panel-toggle:hover{color:var(--fg)}
.panel-content{
  flex:1;overflow-y:auto;padding:1.25rem;
  font-size:0.85rem;line-height:1.7;color:var(--fg2);
  scrollbar-width:thin;scrollbar-color:var(--card-border) transparent;
}
.panel-content::-webkit-scrollbar{width:4px}
.panel-content::-webkit-scrollbar-thumb{background:var(--card-border);border-radius:2px}

.panel-content h3{
  color:var(--fg);font-size:0.88rem;font-weight:600;
  margin:1.2rem 0 0.4rem;letter-spacing:-0.01em;
}
.panel-content h3:first-child{margin-top:0}
.panel-content p{margin-bottom:0.7rem}
.panel-content code{
  font-family:var(--mono);font-size:0.76rem;
  background:rgba(255,255,255,0.05);padding:2px 6px;border-radius:4px;
  color:var(--accent);
}
.panel-content .formula{
  display:block;background:rgba(255,255,255,0.03);
  border:1px solid var(--card-border);border-radius:8px;
  padding:0.75rem 1rem;margin:0.6rem 0;
  font-family:var(--mono);font-size:0.76rem;color:var(--fg);
  line-height:1.8;overflow-x:auto;
}
.panel-content .key-point{
  border-left:2px solid var(--accent);
  padding:0.5rem 0.75rem;margin:0.6rem 0;
  background:rgba(200,255,90,0.03);border-radius:0 6px 6px 0;
}
.panel-content .comparison{
  display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:0.6rem 0;
}
.panel-content .comparison div{
  background:rgba(255,255,255,0.03);padding:0.6rem;border-radius:6px;
  font-size:0.78rem;
}
.panel-content .comparison .label{
  font-weight:600;color:var(--fg);margin-bottom:0.3rem;font-size:0.72rem;
  text-transform:uppercase;letter-spacing:0.05em;
}
.panel-content ul{margin:0.4rem 0 0.7rem 1rem}
.panel-content li{margin-bottom:0.3rem}

/* ---- Comparison Bar ---- */
.comparison-bar{display:none} /* Reserved for future */

/* ---- Responsive ---- */
@media(max-width:800px){
  .info-panel{
    position:fixed;top:52px;right:0;bottom:0;z-index:50;
    width:100%;max-width:380px;
    transform:translateX(100%);transition:transform 0.3s ease;
  }
  .info-panel.open{transform:translateX(0)}
  .info-panel.collapsed{margin-right:0;transform:translateX(100%)}
  .header-stats{display:none}
  .mode-tabs{overflow-x:auto;flex-shrink:1}
}