/* ===== 年级选择器：小动物图标 + 年级名 + 数字徽章 ===== */
.grade-tabs {
  display: flex;
  gap: 10px;
  padding: 12px 16px 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.grade-tabs::-webkit-scrollbar { display: none; }
.grade-tab {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  width: 64px;
  padding: 10px 6px 8px;
  border-radius: 18px;
  background: rgba(255,255,255,0.85);
  color: var(--gc-foreground);
  font-size: 11px;
  font-weight: 700;
  border: 2px solid rgba(0,0,0,0.06);
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  white-space: nowrap;
  position: relative;
}
.grade-tab:hover {
  transform: translateY(-2px);
  border-color: rgba(79,140,255,0.3);
}
.grade-tab:active {
  transform: translateY(0) scale(0.96);
}
.grade-tab.active {
  background: linear-gradient(160deg, #4F8CFF 0%, #6366F1 100%);
  color: white;
  border-color: transparent;
  box-shadow: 0 8px 20px rgba(79,140,255,0.35);
  transform: translateY(-3px);
}
.grade-tab.active:hover {
  transform: translateY(-5px);
}
/* 年级图标（小动物） */
.grade-tab .grade-icon {
  font-size: 26px;
  line-height: 1;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.12));
}
.grade-tab.active .grade-icon {
  filter: drop-shadow(0 2px 6px rgba(0,0,0,0.2));
}
/* 年级数字徽章 */
.grade-tab .grade-badge {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: rgba(255,255,255,0.9);
  color: #4F8CFF;
  font-size: 10px;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
}
.grade-tab.active .grade-badge {
  background: #FFD166;
  color: #8B4513;
  box-shadow: 0 2px 6px rgba(255,209,102,0.5);
}
.grade-tab .grade-name {
  font-size: 11px;
  font-weight: 700;
  line-height: 1.2;
  opacity: 0.85;
}
.grade-tab.active .grade-name {
  opacity: 1;
}

/* 切换中提示 */
.switching-toast {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0,0,0,0.78);
  color: white;
  padding: 16px 24px;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 600;
  z-index: 9999;
  pointer-events: none;
  animation: float-feedback 1.2s ease-out forwards;
}