/* ===== 鼠标悬停卡片白色炫彩边框（仅当 enableClickRainbow 开启时加载） ===== */
:root {
  --rainbow-duration:0.5s;
  --border-width: 2px;
}

/* 彩虹边框层 —— 利用 mask-composite 仅留 1~2px 边框区域 */
.glass-card::before,
.glass-shell::before {
  content: "";
  position: absolute;
  inset: 0;
  padding: var(--border-width);
  border-radius: inherit;
  background: conic-gradient(
    from 0deg,
    #ff0000, #ff9900, #ffff00, #00ff00, #0099ff, #9900ff, #ff0000
  );
  -webkit-mask: linear-gradient(#fff 0 0) content-box,
                linear-gradient(#fff 0 0);
  mask: linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
  mask-composite: exclude;
  -webkit-mask-composite: xor;
  z-index: -1;
  opacity: 0;
  transition: opacity var(--rainbow-duration) ease;
  pointer-events: none;
}

.glass-card:hover::before,
.glass-shell:hover::before {
  opacity: 1;
}