/* ============================================================
   REACTOR · static background: dot grid + accent gradient
   （2026-07 简化：撤掉扫光条/反应堆环/扫描线等全部动画层，
     只保留静态点阵 + 两团强调色渐变。fixed、置底、不吃事件。）
   ============================================================ */
.bg-field{position:fixed;inset:0;z-index:-2;pointer-events:none;
  background:
    radial-gradient(120% 90% at 50% -20%, color-mix(in srgb,var(--accent) 9%,transparent), transparent 55%),
    radial-gradient(90% 70% at 100% 110%, color-mix(in srgb,var(--accent) 6%,transparent), transparent 60%)}

/* ── dotted perforation grid（静态）── */
.bg-dots{position:fixed;inset:0;z-index:-3;pointer-events:none;
  background-image:radial-gradient(var(--dot) 1px, transparent 1.5px);
  background-size:var(--dot-gap) var(--dot-gap);
  mask-image:radial-gradient(120% 100% at 50% 0%, #000 55%, transparent 100%)}

/* corner registration marks on major sections (engineering-drawing flourish) */
.reg{position:relative}
.reg::before,.reg::after{content:"";position:absolute;width:10px;height:10px;
  border:1px solid var(--line-2);pointer-events:none}
.reg::before{top:-1px;left:-1px;border-right:0;border-bottom:0}
.reg::after{bottom:-1px;right:-1px;border-left:0;border-top:0}