*{box-sizing:border-box}
html,body{height:100%;margin:0;font-family:system-ui,-apple-system,'Segoe UI',Roboto,'Helvetica Neue',Arial}
.presentation{height:100vh;display:flex;flex-direction:column;background:#0f1724;color:#e6eef8}
.controls{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;background:linear-gradient(90deg,rgba(255,255,255,0.03),transparent);}
.controls button{background:transparent;border:1px solid rgba(255,255,255,0.12);color:#e6eef8;padding:8px 14px;border-radius:6px;cursor:pointer;font-size:20px}
#progress{font-size:14px;color:#cfe4ff}
#slides{flex:1;display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden}
.stage #slides{flex:1}

/* Stage wraps sidebar + slides */
.stage{display:flex;flex:1;overflow:hidden}

/* Sidebar / thumbnails */
.sidebar{width:220px;background:rgba(255,255,255,0.02);border-right:1px solid rgba(255,255,255,0.03);padding:10px 8px;overflow:auto}
.sidebar .item{padding:8px 10px;border-radius:6px;color:#cfe4ff;cursor:pointer;display:flex;align-items:center;gap:8px}
.sidebar .item:hover{background:rgba(255,255,255,0.02)}
.sidebar .item.active{background:linear-gradient(90deg,rgba(13,110,253,0.14),transparent);border-left:3px solid #0d6efd}
.sidebar .thumb{width:42px;height:28px;background:rgba(255,255,255,0.03);border-radius:4px;flex-shrink:0}
.sidebar .label{font-size:13px;color:#cfe4ff}
.slide{min-width:100%;min-height:100%;padding:60px 80px;display:none;flex-direction:column;align-items:center;justify-content:center;text-align:left}
.slide.active{display:flex}
.slide h1{font-size:36px;margin:0 0 10px}
.slide h2{font-size:28px;margin:0 0 10px}
.lead{font-size:18px;color:#cfe4ff}
.small{color:#9fb6da;font-size:13px}
ul,ol,dl{color:#cfe4ff}
.diagram img{max-width:90%;height:auto;border:1px solid rgba(255,255,255,0.04);background:#fff;padding:8px;border-radius:6px}
.notes{padding:10px 20px;font-size:13px;color:#9fb6da;background:linear-gradient(90deg,transparent,rgba(255,255,255,0.02))}
footer{background:transparent}
@media (max-width:800px){.slide{padding:30px 20px}.controls{padding:8px}.slide h1{font-size:28px}.slide h2{font-size:20px}}
@media (max-width:900px){
	.sidebar{display:none}
	.stage{flex-direction:column}
	#slides{padding-left:0}
}