html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background:#000;
}
.sign {
  position: absolute;
  color: #ffffff;
  bottom: 10px;
  left: 10px;
  right: 10px;
  font-size: clamp(8px, 2vw, 10px);
  text-align: center;
  line-height: 1.4;
}
.sign img {
  height: 1em;
  vertical-align: middle;
  margin: 0 3px;
}
a {
  color: #ffffff;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* 响应式调整 */
@media (min-width: 768px) {
  .sign {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex-wrap: wrap;
    left: auto;
    text-align: right;
  }
  
  .sign img {
    margin: 0 5px;
  }
}

#fixed-bg {
  position: fixed;
  left:50%;
  top:50%;
  transform:translate(-50%, -50%);
  width:100vw;
  height:100vh;
}

canvas {
  position: absolute;
  top:50%;
  left:50%;
  transform:translate(-50%, -50%);  
  aspect-ratio: 1;
}

#c {
  width: auto;
  height: 100%;
}

#a {
  width: 100%;
  height: auto;
}

@media (max-aspect-ratio: 1) {
  #c {
    width: 100%;
    height: auto;
  }
  
  #a {
    width: auto;
    height: 100%;
  }
}