/* study_guide 浮动上一页/下一页导航
 * version: 20251228_v1
 */

.sg-float-nav {
  position: sticky;
  top: var(--sg-float-nav-top, 0px);
  z-index: 1060;
  pointer-events: none;
  display: flex;
  justify-content: space-between;
  gap: 10px;
  padding: 6px 0;
}

.sg-float-nav-btn {
  pointer-events: auto;
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: calc(50% - 10px);
  padding: 7px 9px;
  border-radius: 12px;
  text-decoration: none;
  opacity: 0.22;
  transition: opacity .15s ease;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.sg-float-nav-btn:hover,
.sg-float-nav-btn:focus {
  opacity: 0.95;
  outline: none;
}

.sg-float-prev { margin-left: 8px; }
.sg-float-next { margin-right: 8px; }

.sg-float-nav-arrow {
  font-size: 20px;
  line-height: 1;
  font-weight: 700;
  opacity: 0.9;
}

.sg-float-nav-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.sg-float-nav-label {
  font-size: 9px;
  opacity: 0.85;
}

.sg-float-nav-title {
  font-size: 10px;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 40vw;
}

/* 主题：默认（白天） */
body:not(.dark-mode):not(.scifi-mode):not(.mode-dark):not(.mode-scifi) .sg-float-nav-btn {
  background: rgba(255, 255, 255, 0.55);
  color: #212529;
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.08);
}

/* 主题：深色 */
body.dark-mode .sg-float-nav-btn {
  background: rgba(0, 0, 0, 0.55);
  color: #e9ecef;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
}

/* 主题：科幻 */
body.scifi-mode .sg-float-nav-btn {
  background: rgba(10, 14, 39, 0.62);
  color: #b3d9ff;
  border: 1px solid rgba(0, 255, 136, 0.28);
  box-shadow: 0 0 14px rgba(0, 255, 136, 0.12);
}

body.scifi-mode .sg-float-nav-label {
  color: #00ff88;
  text-shadow: 0 0 6px rgba(0, 255, 136, 0.35);
}

/* 移动端：仍在顶部区域（天气横幅下方），进一步缩紧 */
@media (max-width: 768px) {
  .sg-float-nav-btn {
    max-width: calc(50% - 8px);
    padding: 6px 8px;
    border-radius: 10px;
    opacity: 0.9; /* 移动端更易点按 */
  }

  .sg-float-nav-title { max-width: 38vw; }
}