:root {
  --md-primary-fg-color: #7CBDFF;
  --md-accent-fg-color: #7CBDFF;
}
.md-main__inner {
  background: none;
}

body {
  position: relative;
  margin: 0;
}

/* 背景层 */
body::before {
  content: "";
  position: fixed;
  inset: 0;

  background-image: url("../assets/images/bg.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  filter: brightness(0.5); /* 亮度，0~1 变暗，>1 变亮 */
  z-index: -1;
}