/* 各页面共用：重置 + 屏幕角落的小按钮（语言选择器 / Cookies 偏好） */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 语言选择器：右上角固定，样式与 .action-btn 一致（等宽字体、直角、反色高亮） */
.lang-switch {
  position: fixed;
  top: 16px;
  right: 16px;
  z-index: 20;             /* 高于 .bg 与 footer */
  display: flex;
  gap: 6px;
}

/* 左上角按钮组：位置与 .lang-switch 对称 */
.corner-switch {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 20;
  display: flex;
  gap: 6px;
}

.lang-btn,
.corner-btn {
  padding: 0 0.6em;
  line-height: 1.6;
  color: #ffffff;
  border: 2px solid rgba(255, 255, 255, 0.4);
  border-radius: 0;
  background: rgba(255, 255, 255, 0.06);
  font-family: "SFMono-Regular", "Menlo", "Consolas", "Courier New", "PingFang SC", monospace;
  font-size: clamp(11px, 1vw, 16px);
  font-weight: 600;
  letter-spacing: 0.04em;
  white-space: nowrap;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.lang-btn:hover,
.corner-btn:hover {
  background: rgba(255, 255, 255, 0.16);
}

.lang-btn:focus-visible,
.corner-btn:focus-visible {
  outline: 2px solid #ffffff;
  outline-offset: 2px;
}

.lang-btn.active {
  background: #ffffff;
  color: #000000;
  border-color: #ffffff;
}