:root{
  --void:#05070c;
  --panel:#0c1424;
  --panel-glass:rgba(12,20,36,0.55);
  --panel-glass-strong:rgba(10,16,28,0.78);
  --line:rgba(120,200,255,0.18);
  --cyan:#34eaff;
  --cyan-dim:rgba(52,234,255,0.35);
  --magenta:#ff3d9a;
  --green:#35ffa0;
  --amber:#ffbe3d;
  --text:#eaf6ff;
  --text-dim:#89a0c0;
  --font-display:'Orbitron',sans-serif;
  --font-body:'Chakra Petch',sans-serif;
}

*{box-sizing:border-box; margin:0; padding:0; -webkit-tap-highlight-color:transparent;}
html,body{
  width:100%; height:100%; overflow:hidden;
  background:var(--void);
  font-family:var(--font-body);
  color:var(--text);
  user-select:none;
}

/* reduced motion */
@media (prefers-reduced-motion: reduce){
  *{animation-duration:0.001ms !important; animation-iteration-count:1 !important; transition-duration:0.001ms !important;}
}

#stage{
  position:relative;
  width:100vw; height:100vh;
  overflow:hidden;
}

/* ================= CAMERA / AR BACKGROUND ================= */
#video{
  position:absolute; inset:0;
  width:100%; height:100%;
  object-fit:cover;
  transform:scaleX(-1); /* mirror for natural selfie interaction */
  filter:brightness(0.55) saturate(1.15) contrast(1.05);
  z-index:1;
}
#bgFallback{
  position:absolute; inset:0; z-index:1;
  background:
    radial-gradient(circle at 20% 20%, rgba(52,234,255,0.10), transparent 45%),
    radial-gradient(circle at 80% 80%, rgba(255,61,154,0.10), transparent 45%),
    var(--void);
  display:none;
}
#bgFallback.show{display:block;}

/* subtle scanline / vignette overlay to sell the AR feel */
#scan{
  position:absolute; inset:0; z-index:2; pointer-events:none;
  background:
    linear-gradient(rgba(52,234,255,0.035) 1px, transparent 1px);
  background-size:100% 3px;
  mix-blend-mode:screen;
  opacity:0.5;
}
#vignette{
  position:absolute; inset:0; z-index:2; pointer-events:none;
  box-shadow: inset 0 0 18vw 4vw rgba(0,0,0,0.75);
}

/* hand landmark canvas */
#handCanvas{
  position:absolute; inset:0; z-index:5; pointer-events:none;
  width:100%; height:100%;
}

/* ================= TOP BAR ================= */
#topbar{
  position:absolute; top:0; left:0; right:0; z-index:20;
  display:flex; align-items:center; justify-content:space-between;
  padding:14px 22px;
  gap:16px;
}
.brand{
  display:flex; flex-direction:column; line-height:1.1;
}
.brand .kicker{
  font-family:var(--font-body); font-size:11px; letter-spacing:0.22em;
  color:var(--cyan); text-transform:uppercase; opacity:0.85;
}
.brand .title{
  font-family:var(--font-display); font-weight:900; font-size:20px;
  letter-spacing:0.03em;
  background:linear-gradient(90deg,#fff, var(--cyan) 70%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
}
.hud{
  display:flex; gap:12px;
}
.hud-chip{
  background:var(--panel-glass);
  backdrop-filter:blur(14px) saturate(1.4);
  -webkit-backdrop-filter:blur(14px) saturate(1.4);
  border:1px solid var(--line);
  border-radius:14px;
  padding:8px 16px;
  min-width:96px;
  text-align:center;
  box-shadow:0 6px 22px rgba(0,0,0,0.35);
}
.hud-chip .label{
  font-size:10px; letter-spacing:0.18em; color:var(--text-dim); text-transform:uppercase;
}
.hud-chip .value{
  font-family:var(--font-display); font-weight:700; font-size:22px; color:var(--text);
  font-variant-numeric:tabular-nums;
}
.hud-chip.time .value{color:var(--cyan);}
.hud-chip.time.low .value{color:var(--magenta); animation:pulseWarn 0.6s infinite;}
.hud-chip.score .value{color:var(--green);}
@keyframes pulseWarn{0%,100%{opacity:1;}50%{opacity:0.35;}}

#modeToggleBtn{
  font-family:var(--font-body); font-weight:600; font-size:13px;
  color:var(--cyan);
  background:rgba(52,234,255,0.12);
  border:1px solid rgba(52,234,255,0.4);
  border-radius:14px;
  padding:10px 16px;
  cursor:pointer;
  display:flex; align-items:center; gap:6px;
  transition:all 0.15s ease;
  white-space:nowrap;
}
#modeToggleBtn:hover{
  background:var(--cyan);
  color:var(--void);
  box-shadow:0 0 16px rgba(52,234,255,0.5);
}
#modeToggleBtn.mouse-mode{
  color:var(--amber);
  background:rgba(255,170,0,0.12);
  border-color:rgba(255,170,0,0.4);
}
#modeToggleBtn.mouse-mode:hover{
  background:var(--amber);
  color:var(--void);
  box-shadow:0 0 16px rgba(255,170,0,0.5);
}

#hintBtn{
  font-family:var(--font-body); font-weight:600; font-size:13px;
  color:var(--void);
  background:linear-gradient(120deg,var(--cyan),#8ff5ff);
  border:none; border-radius:14px;
  padding:10px 18px;
  cursor:pointer;
  box-shadow:0 6px 20px rgba(52,234,255,0.35);
  display:flex; align-items:center; gap:8px;
  transition:transform 0.15s ease, box-shadow 0.15s ease, opacity 0.2s;
  white-space:nowrap;
}
#hintBtn:active{transform:scale(0.95);}
#hintBtn:disabled{
  opacity:0.35; cursor:not-allowed; filter:grayscale(0.6);
  box-shadow:none;
}
#hintBtn .count{
  background:rgba(5,7,12,0.25); border-radius:8px; padding:1px 7px; font-family:var(--font-display);
}

/* ================= MODE / STATUS TAG ================= */
#modeTag{
  position:absolute; top:14px; left:50%; transform:translateX(-50%);
  z-index:20;
  font-size:11px; letter-spacing:0.14em; text-transform:uppercase;
  color:var(--text-dim);
  background:var(--panel-glass); border:1px solid var(--line); border-radius:20px;
  padding:6px 14px;
  display:flex; align-items:center; gap:8px;
  opacity:0.9;
}
#modeTag .dot{width:7px;height:7px;border-radius:50%;background:var(--green); box-shadow:0 0 8px var(--green);}
#modeTag.cam-off .dot{background:var(--amber); box-shadow:0 0 8px var(--amber);}

/* ================= MOTHERBOARD ================= */
#boardWrap{
  position:absolute; z-index:10;
  left:50%; top:50%;
  transform:translate(-50%,-48%);
  width:min(640px, 54vw);
}
#board{
  position:relative;
  aspect-ratio:4/3;
  background:
    linear-gradient(155deg, rgba(16,26,44,0.72), rgba(8,12,22,0.72));
  border:1px solid rgba(120,200,255,0.28);
  border-radius:18px;
  backdrop-filter:blur(6px);
  -webkit-backdrop-filter:blur(6px);
  box-shadow:
    0 0 0 1px rgba(52,234,255,0.06),
    0 20px 60px rgba(0,0,0,0.55),
    inset 0 0 60px rgba(52,234,255,0.05);
  overflow:visible;
}
/* circuit trace svg drawn behind slots */
#traceSvg{position:absolute; inset:0; width:100%; height:100%; z-index:1;}
.trace-line{
  fill:none; stroke:var(--cyan); stroke-width:1.4; opacity:0.28;
  stroke-dasharray:6 5;
  animation:traceFlow 3.2s linear infinite;
}
.trace-line.live{opacity:0.85; stroke:var(--green); filter:drop-shadow(0 0 4px var(--green));}
@keyframes traceFlow{to{stroke-dashoffset:-110;}}

.slot{
  position:absolute; z-index:2;
  border:1.5px dashed rgba(120,200,255,0.45);
  border-radius:8px;
  display:flex; align-items:center; justify-content:center;
  flex-direction:column;
  transition:border-color 0.2s, box-shadow 0.2s, background 0.2s;
  background:rgba(52,234,255,0.03);
}
.slot .slot-label{
  font-family:var(--font-display); font-size:10.5px; letter-spacing:0.08em;
  color:var(--text-dim); text-transform:uppercase; pointer-events:none;
}
.slot.next-required{
  border-color:var(--amber);
  box-shadow:0 0 0 2px rgba(255,190,61,0.15), 0 0 22px rgba(255,190,61,0.25);
  animation:nextPulse 1.4s ease-in-out infinite;
}
@keyframes nextPulse{0%,100%{box-shadow:0 0 0 2px rgba(255,190,61,0.12),0 0 14px rgba(255,190,61,0.18);}50%{box-shadow:0 0 0 3px rgba(255,190,61,0.28),0 0 30px rgba(255,190,61,0.4);}}
.slot.hover-target{border-color:var(--cyan); background:rgba(52,234,255,0.14); box-shadow:0 0 24px rgba(52,234,255,0.35);}
.slot.filled{
  border-style:solid; border-color:var(--green);
  background:rgba(53,255,160,0.10);
  box-shadow:0 0 20px rgba(53,255,160,0.25);
}
.slot.locked{opacity:0.4;}

/* slot geometry (percentages of board) */
#slotCPU   { left:38%; top:32%; width:24%; height:24%; }
#slotCOOLER{ left:35%; top:27%; width:30%; height:34%; z-index:3; pointer-events:none; }
#slotRAM   { left:66%; top:14%; width:9%;  height:70%; }
#slotGPU   { left:8%;  top:66%; width:52%; height:16%; }
#slotSSD   { left:8%;  top:14%; width:18%; height:14%; }
#slotPSU   { left:8%;  top:34%; width:20%; height:24%; }

/* small icon glyphs drawn with CSS inside filled slots */
.slot .placed-part{
  width:78%; height:78%; border-radius:6px;
  display:flex; align-items:center; justify-content:center;
  font-size:20px;
}

/* ================= 2-SIDE TRAYS (Left & Right) ================= */
.tray-bar{
  position:absolute; top:88px; bottom:24px; z-index:15;
  width:124px;
  padding:14px 10px;
  display:flex; flex-direction:column; align-items:center;
  background:rgba(3,5,9,0.65);
  border:1px solid var(--line);
  border-radius:18px;
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  overflow-y:auto; overflow-x:hidden;
  box-shadow:0 12px 32px rgba(0,0,0,0.6);
}
.tray-bar.left{
  left:32px;
  border-color:rgba(52,234,255,0.25);
}
.tray-bar.right{
  right:32px;
  border-color:rgba(255,61,154,0.25);
}
.tray-label{
  font-family:var(--font-display); font-size:10px; letter-spacing:0.14em;
  color:var(--text-dim); text-transform:uppercase; text-align:center;
  margin-bottom:12px; opacity:0.85; flex-shrink:0; line-height:1.4;
}
.tray-bar.left .tray-label{ color:var(--cyan); }
.tray-bar.right .tray-label{ color:var(--magenta); }

.tray-container{
  display:flex; flex-direction:column; align-items:center;
  gap:12px; margin:0; width:100%;
}
.part{
  position:relative;
  width:92px; height:92px;
  background:var(--panel-glass-strong);
  border:1px solid var(--line);
  border-radius:16px;
  display:flex; flex-direction:column; align-items:center; justify-content:center;
  gap:4px;
  flex-shrink:0;
  cursor:grab;
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  box-shadow:0 8px 24px rgba(0,0,0,0.4);
  transition:transform 0.15s ease, box-shadow 0.15s ease, opacity 0.25s ease,
             height 0.3s ease, margin 0.3s ease, padding 0.3s ease, border-width 0.3s ease;
  touch-action:none;
  overflow:hidden;
}
.part:hover{transform:scale(1.05); box-shadow:0 12px 28px rgba(52,234,255,0.25);}
.part .icon{font-size:28px; filter:drop-shadow(0 0 6px rgba(52,234,255,0.5));}
.part .name{font-family:var(--font-body); font-size:11px; font-weight:600; letter-spacing:0.03em; color:var(--text);}
.part.dragging{
  position:fixed; z-index:100; pointer-events:none;
  box-shadow:0 0 30px rgba(52,234,255,0.55);
  border-color:var(--cyan);
  transform:scale(1.08);
}
.part.placed{
  opacity:0; transform:scale(0.5); pointer-events:none;
  height:0; min-height:0; margin-top:0; margin-bottom:0;
  padding:0; border-width:0;
}
.part.grabbed-glow{border-color:var(--cyan); box-shadow:0 0 22px rgba(52,234,255,0.5);}

/* ================= CURSOR (hand pointer) ================= */
#cursor{
  position:absolute; z-index:90; width:34px; height:34px;
  left:0; top:0; transform:translate(-50%,-50%);
  pointer-events:none;
  border-radius:50%;
  border:2px solid var(--cyan);
  box-shadow:0 0 16px rgba(52,234,255,0.7);
  transition:width 0.12s ease, height 0.12s ease, border-color 0.12s ease, background 0.12s ease;
  display:none;
}
#cursor.grabbing{
  width:22px; height:22px;
  background:rgba(255,61,154,0.35);
  border-color:var(--magenta);
  box-shadow:0 0 20px rgba(255,61,154,0.8);
}
#cursor::after{
  content:''; position:absolute; inset:-8px; border-radius:50%;
  border:1px solid rgba(52,234,255,0.3);
}

/* ================= POPUPS / TOASTS ================= */
#toastLayer{
  position:absolute; z-index:60; left:50%; top:18%;
  transform:translateX(-50%);
  display:flex; flex-direction:column; align-items:center; gap:8px;
  pointer-events:none;
}
.toast{
  font-family:var(--font-display); font-weight:700;
  padding:10px 20px; border-radius:12px;
  backdrop-filter:blur(8px);
  animation:toastPop 1.4s ease forwards;
  white-space:nowrap;
  box-shadow:0 8px 24px rgba(0,0,0,0.4);
}
.toast.good{background:rgba(53,255,160,0.16); color:var(--green); border:1px solid rgba(53,255,160,0.5);}
.toast.bad{background:rgba(255,61,154,0.16); color:var(--magenta); border:1px solid rgba(255,61,154,0.5);}
.toast.info{background:rgba(52,234,255,0.16); color:var(--cyan); border:1px solid rgba(52,234,255,0.5);}
@keyframes toastPop{
  0%{opacity:0; transform:translateY(10px) scale(0.9);}
  12%{opacity:1; transform:translateY(0) scale(1);}
  78%{opacity:1;}
  100%{opacity:0; transform:translateY(-16px) scale(0.96);}
}

#factCard{
  position:absolute; z-index:55; left:calc(50% - 84px); bottom:32px; transform:translateX(-50%) translateY(20px);
  background:var(--panel-glass-strong);
  border:1px solid var(--cyan-dim);
  border-radius:16px;
  padding:14px 20px;
  max-width:420px; text-align:center;
  opacity:0; pointer-events:none;
  transition:opacity 0.3s ease, transform 0.3s ease;
}
#factCard.show{opacity:1; transform:translateX(-50%) translateY(0);}
#factCard .fh{font-family:var(--font-display); color:var(--green); font-size:13px; margin-bottom:4px; letter-spacing:0.05em;}
#factCard .fb{font-size:13.5px; color:var(--text); line-height:1.5;}

/* particle burst */
.particle{
  position:absolute; z-index:70; width:6px; height:6px; border-radius:50%;
  pointer-events:none;
  animation:particleFly 0.75s ease-out forwards;
}
@keyframes particleFly{
  0%{transform:translate(0,0) scale(1); opacity:1;}
  100%{transform:translate(var(--dx), var(--dy)) scale(0); opacity:0;}
}

/* ================= OVERLAY SCREENS ================= */
.overlay-screen{
  position:absolute; inset:0; z-index:200;
  display:flex; align-items:center; justify-content:center;
  background:radial-gradient(circle at 50% 40%, rgba(15,25,45,0.92), rgba(3,5,9,0.97));
  backdrop-filter:blur(4px);
  opacity:1; transition:opacity 0.4s ease;
}
.overlay-screen.hidden{opacity:0; pointer-events:none;}
.panel-card{
  width:min(480px,88vw);
  background:var(--panel-glass-strong);
  border:1px solid var(--line);
  border-radius:24px;
  padding:36px 32px;
  text-align:center;
  box-shadow:0 24px 80px rgba(0,0,0,0.6), inset 0 0 60px rgba(52,234,255,0.04);
}
.panel-card .eyebrow{
  font-size:11px; letter-spacing:0.28em; color:var(--cyan); text-transform:uppercase; margin-bottom:10px;
}
.panel-card h1{
  font-family:var(--font-display); font-weight:900; font-size:clamp(24px,4vw,34px);
  background:linear-gradient(90deg,#fff,var(--cyan));
  -webkit-background-clip:text; background-clip:text; color:transparent;
  margin-bottom:14px; line-height:1.2;
}
.panel-card p{color:var(--text-dim); font-size:14px; line-height:1.65; margin-bottom:22px;}
.panel-card .stat-row{
  display:flex; justify-content:center; gap:22px; margin-bottom:24px;
}
.panel-card .stat{
  background:rgba(255,255,255,0.03); border:1px solid var(--line); border-radius:12px;
  padding:10px 18px; min-width:90px;
}
.panel-card .stat .n{font-family:var(--font-display); font-size:24px; color:var(--green);}
.panel-card .stat .l{font-size:10px; letter-spacing:0.14em; color:var(--text-dim); text-transform:uppercase;}
.btn{
  font-family:var(--font-body); font-weight:700; font-size:15px;
  color:var(--void);
  background:linear-gradient(120deg,var(--cyan),#9df2ff);
  border:none; border-radius:14px;
  padding:14px 30px;
  cursor:pointer;
  box-shadow:0 10px 28px rgba(52,234,255,0.35);
  transition:transform 0.15s ease;
  margin:6px;
}
.btn:active{transform:scale(0.96);}
.btn.ghost{
  background:transparent; color:var(--text); border:1px solid var(--line);
  box-shadow:none;
}
.btn.ghost:hover{border-color:var(--cyan); color:var(--cyan);}
.cam-note{
  margin-top:16px; font-size:12px; color:var(--text-dim); line-height:1.6;
  border-top:1px solid var(--line); padding-top:14px;
}

/* wrong-sequence flash */
.slot.seq-error{animation:seqError 0.5s ease;}
@keyframes seqError{
  0%,100%{border-color:var(--magenta);}
  50%{border-color:var(--magenta); box-shadow:0 0 26px rgba(255,61,154,0.6);}
}

/* responsive */
@media (max-width:720px){
  /* narrow screens: side rail is too cramped, fall back to a bottom tray */
  #trayBar{
    top:auto; right:0; left:0; bottom:0; width:auto; height:auto;
    flex-direction:row; align-items:center;
    padding:12px 14px 16px;
    background:linear-gradient(0deg, rgba(3,5,9,0.88) 35%, rgba(3,5,9,0));
    border:none; border-radius:0;
    overflow-x:auto; overflow-y:hidden;
  }
  #trayLabel{
    writing-mode:horizontal-tb; margin:0 10px 0 0; flex-shrink:0;
    font-size:9px; line-height:1.2;
  }
  #tray{flex-direction:row; flex-wrap:nowrap; gap:10px; width:auto;}
  .part{width:72px; height:72px; flex-shrink:0;}
  .part.placed{height:72px; width:0; min-width:0; margin-left:0; margin-right:0;}
  #boardWrap{width:92vw; left:50%; top:40%;}
  #factCard{left:50%; bottom:112px;}
  .hud-chip{min-width:74px; padding:6px 10px;}
  .hud-chip .value{font-size:17px;}
  .brand .title{font-size:15px;}
  #hintBtn{padding:8px 12px; font-size:12px;}
  .slot .slot-label{font-size:8.5px;}
}