*{ margin:0; padding:0; box-sizing:border-box; font-family:Segoe UI; }
body{
  background:#020617;
  overflow:hidden;
  color:white;
}

.bg{
  position:fixed; inset:0;
  background:
    radial-gradient(circle at center, rgba(34,197,94,0.12), transparent 40%),
    radial-gradient(circle at top left, rgba(59,130,246,0.08), transparent 30%);
  z-index:-1;
}

.core-container{
  width:100%;
  height:100vh;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:center;
}

.back-btn{
  position:absolute;
  top:30px;
  left:30px;
  text-decoration:none;
  color:white;
  padding:14px 20px;
  border-radius:18px;
  background:rgba(255,255,255,0.05);
  border:1px solid rgba(255,255,255,0.05);
  transition:0.2s;
}
.back-btn:hover{
  background:rgba(34,197,94,0.12);
  border-color:rgba(34,197,94,0.2);
}

.orb-wrapper{
  display:flex;
  flex-direction:column;
  align-items:center;
}

.orb{
  width:260px;
  height:260px;
  border-radius:50%;
  display:flex;
  justify-content:center;
  align-items:center;
  position:relative;
  background:radial-gradient(circle at top, #4ade80, #14532d);
  box-shadow:0 0 120px rgba(34,197,94,0.45), 0 0 260px rgba(34,197,94,0.12);
  transition:0.4s;
}

.orb-core{
  width:55%;
  height:55%;
  border-radius:50%;
  background:rgba(255,255,255,0.15);
  backdrop-filter:blur(20px);
}

.orb.idle{ animation:idleFloat 4s ease-in-out infinite; }
.orb.thinking{ animation:thinkingPulse 1s infinite; }
.orb.listening{ animation:listeningExpand 0.8s infinite; }
.orb.generating{ animation:generatingEnergy 0.6s infinite; }

@keyframes idleFloat{
  0%{ transform:translateY(0px); }
  50%{ transform:translateY(-14px); }
  100%{ transform:translateY(0px); }
}
@keyframes thinkingPulse{
  0%{ transform:scale(1); }
  50%{ transform:scale(1.08); }
  100%{ transform:scale(1); }
}
@keyframes listeningExpand{
  0%{ transform:scale(1); }
  50%{ transform:scale(1.15); }
  100%{ transform:scale(1); }
}
@keyframes generatingEnergy{
  0%{ transform:scale(1); filter:hue-rotate(0deg); }
  50%{ transform:scale(1.12); filter:hue-rotate(40deg); }
  100%{ transform:scale(1); filter:hue-rotate(0deg); }
}

.orb-status{
  margin-top:25px;
  letter-spacing:4px;
  color:rgba(255,255,255,0.65);
}

.controls{
  display:flex;
  gap:18px;
  margin-top:50px;
  flex-wrap:wrap;
  justify-content:center;
}
.controls button{
  padding:14px 22px;
  border:none;
  border-radius:18px;
  cursor:pointer;
  background:rgba(255,255,255,0.06);
  color:white;
  transition:0.25s;
  font-size:14px;
}
.controls button:hover{
  background:rgba(34,197,94,0.18);
  transform:translateY(-2px);
}

@media(max-width:600px){
  .orb{ width:180px; height:180px; }
  .controls{ gap:12px; }
  .controls button{ padding:12px 18px; font-size:13px; }
  .back-btn{ top:16px; left:16px; padding:10px 16px; }
}

body.dark{ background:#020617; }
body.emerald{ background:#021b12; }
body.emerald .orb{ background:radial-gradient(circle at top, #4ade80, #14532d); }
body.blue{ background:#07111f; }
body.blue .orb{ background:radial-gradient(circle at top, #60a5fa, #1e3a5f); box-shadow:0 0 120px rgba(59,130,246,0.3); }
body.purple{ background:#13071f; }
body.purple .orb{ background:radial-gradient(circle at top, #a855f7, #3b0764); box-shadow:0 0 120px rgba(168,85,247,0.3); }
body.red{ background:#1f0707; }
body.red .orb{ background:radial-gradient(circle at top, #ef4444, #450a0a); box-shadow:0 0 120px rgba(239,68,68,0.3); }