.lang-box {
  position: absolute; top: 15px; right: 15px;
  display: flex; background: rgba(0, 0, 0, 0.8);
  padding: 3px; border-radius: 10px;
  border: 1px solid var(--primary); z-index: 9999;
}
.lang-btn {
  padding: 6px 14px; border-radius: 7px; cursor: pointer;
  font-size: 12px; transition: var(--trans); color: var(--dim);
}
.lang-btn.active { background: var(--primary); color: #000; font-weight: bold; }
.header { 
  margin-top: 12vh; /* 增加顶部间距，解决拥挤 */
  text-align: center; z-index: 10; width: 100%; padding: 0 15px; 
}
.header h1 {
  white-space: nowrap;
  font-size: clamp(24px, 8.5vw, 56px);
  letter-spacing: 4px;
  color: #fff;
  text-shadow: 0 0 10px var(--primary);
  margin-bottom: 10px;
  font-weight: 900;
}
.header p { font-size: 12px; color: var(--primary); letter-spacing: 4px; text-transform: uppercase; opacity: 0.7; }