body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: radial-gradient(#000011, #000000);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://upload.wikimedia.org/wikipedia/commons/6/6b/Starsinthesky.jpg') repeat;
  background-size: cover;
  animation: starsMove 60s linear infinite;
  z-index: -1;
}

@keyframes starsMove { 
  from { background-position: 0 0; } 
  to { background-position: -1000px 0; } 
}

#panel {
  background: rgba(0,0,0,0.8);
  border-radius: 15px;
  padding: 40px 60px;
  text-align: center;
  box-shadow: 0 0 40px cyan;
  color: white;
  min-width: 300px;
  position: relative;
  transition: box-shadow 0.2s;
}

#panel.flash { box-shadow: 0 0 60px red; }

#balance {
  font-size: 60px;
  color: cyan;
  text-shadow: 0 0 20px cyan;
  margin: 0;
}

#multiplier {
  font-size: 28px;
  color: yellow;
  text-shadow: 0 0 15px yellow;
  margin: 10px 0;
}

.btn {
  padding: 10px 20px;
  font-size: 16px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  margin: 5px;
  color: black;
  font-weight: bold;
  box-shadow: 0 0 10px #fff;
  transition: opacity 0.2s;
}

.btn-start { background: #28a745; box-shadow: 0 0 20px #28a745; }
.btn-cashout { background: #ffc107; box-shadow: 0 0 20px #ffc107; }
.btn-logout { background: #dc3545; box-shadow: 0 0 20px #dc3545; }

.btn:hover { opacity: 0.8; }

.bonus {
  position: absolute;
  top: 50%;
  left: 50%;
  color: #0f0;
  font-weight: bold;
  font-size: 24px;
  animation: popUp 1s ease-out forwards;
  pointer-events: none;
}

@keyframes popUp {
  0% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
  100% { transform: translate(-50%, -150%) scale(1.5); opacity: 0; }
}

#graph {
  margin-top: 20px;
  border: 1px solid cyan;
  background: rgba(0,0,0,0.5);
  border-radius: 8px;
}