:root{
  --bg0:#05060a;
  --bg1:#070a12;
  --text:#ffffff;
  --muted:rgba(255,255,255,.72);
  --muted2:rgba(255,255,255,.55);
}

*{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  color:var(--text);
  background: radial-gradient(1200px 800px at 50% 40%, #0b1324 0%, var(--bg0) 55%, #04040a 100%);
  overflow:hidden;

  /* 尽量符合你 VI：微软雅黑优先 */
  font-family: "Microsoft YaHei UI","Microsoft YaHei","PingFang SC","Noto Sans SC",system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
}

.xm-bg{
  position:fixed; inset:0;
  pointer-events:none;
}

.xm-nebula{
  background:
    radial-gradient(900px 600px at 50% 42%, rgba(255,255,255,.06) 0%, rgba(255,255,255,0) 60%),
    radial-gradient(700px 500px at 60% 55%, rgba(120,160,255,.06) 0%, rgba(120,160,255,0) 60%),
    radial-gradient(650px 450px at 40% 50%, rgba(160,120,255,.04) 0%, rgba(160,120,255,0) 60%);
  filter: blur(0.2px);
}

.xm-center{
  position:relative;
  height:100%;
  display:flex;
  align-items:center;
  justify-content:center;
  padding: 24px;
  text-align:center; /* 全部左右居中 */
}

.xm-brand{
  width:min(720px, 92vw);
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap: 14px;
}

.xm-logo{
  font-weight: 700; /* YaHei UI Bold */
  letter-spacing: 0.02em;
  line-height: 1;
  font-size: clamp(56px, 7vw, 76px);
  user-select:none;
}

.xm-tagline{
  /* YaHei UI Regular */
  font-weight: 400;
  line-height: 1.2;
  margin-top: -6px;

  /* 初始字号会被 JS 自动缩小以适配 logo 宽度 */
  font-size: 18px;

  /* 关键：保证跟随主 Logo 居中，并允许自动缩放 */
  display:inline-block;
  text-align:center;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;

  color: rgba(255,255,255,.82);
  letter-spacing: 0.06em;
}

.xm-copy{
  margin-top: 10px;
  width: min(560px, 92vw);
}

.xm-copy p{
  margin: 12px 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

.xm-footer{
  margin-top: 18px;
  font-size: 13px;
  color: var(--muted2);
}

/* 右上角语言按钮：尽量低存在感，避免“像功能站” */
.xm-lang{
  position: fixed;
  top: 14px;
  right: 14px;
  z-index: 10;
  padding: 8px 10px;
  font-size: 12px;
  color: rgba(255,255,255,.78);
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.12);
  border-radius: 10px;
  cursor: pointer;
  backdrop-filter: blur(6px);
}
.xm-lang:active{transform: translateY(1px);}