html, body { 
  margin:0; 
  height:100%; 
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  overflow:hidden; 
  font-family: 'Hiragino Sans', 'Yu Gothic', 'Meiryo', sans-serif;
}

/* Header styles */
.main-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  z-index: 1000;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.header-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 20px;
  font-weight: 600;
  color: white;
  text-decoration: none;
  font-size: 1.1rem;
  transition: color 0.3s ease;
}

.header-link:hover {
  color: #60a5fa;
}

.header-logo {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

canvas { display:block; }
.hud {
  position:fixed; 
  left:20px; 
  top:80px; 
  color:#eaeaf2;
  font-size: 16px;
  line-height: 1.6;
  user-select:none;
  background: rgba(0,0,0,0.3);
  padding: 15px 20px;
  border-radius: 15px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.1);
}
.score {
  font-size: 24px;
  font-weight: bold;
  color: #ff6b9d;
  margin-bottom: 8px;
}
.global {
  opacity: 0.7;
  font-size: 14px;
}
.controls {
  margin-top: 15px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.control-range {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,.25);
  background: rgba(255,255,255,.08);
  color: #eaeaf2;
  font-size: 14px;
  user-select: none;
}
.control-range input[type="range"] {
  width: 160px;
}
button {
  padding: 8px 16px; 
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,.25); 
  background: rgba(255,255,255,.08);
  color: #eaeaf2; 
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s;
  font-family: inherit;
}
button:hover {
  background: rgba(255,255,255,.15);
  transform: translateY(-2px);
}
button:active {
  transform: translateY(0);
}
.active {
  background: rgba(255,107,157,.3);
  border-color: rgba(255,107,157,.5);
}
.instructions {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255,255,255,0.5);
  font-size: 14px;
  text-align: center;
  padding: 10px 20px;
  background: rgba(0,0,0,0.3);
  border-radius: 10px;
  backdrop-filter: blur(10px);
}