/* Electricity study-material tabs and wrapper. The reader itself deliberately reuses
   the same page-by-page viewer system as Human Factors. */
.el-study-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  width: fit-content;
  margin: 18px 0 24px auto;
  padding: 5px;
  border: 1px solid rgba(43,100,117,.16);
  border-radius: 14px;
  background: rgba(240,246,247,.94);
  box-shadow: 0 8px 24px rgba(43,100,117,.06);
}
.el-study-tab {
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: #315d69;
  font: inherit;
  font-weight: 700;
  padding: 10px 18px;
  cursor: pointer;
  transition: .18s ease;
}
.el-study-tab:hover { transform: translateY(-1px); }
.el-study-tab.is-active {
  background: #2b6475;
  color: #fff;
  box-shadow: 0 5px 14px rgba(43,100,117,.22);
}
.el-study-panel {
  display: none;
  margin-top: 6px;
  border: 1px solid rgba(30,92,75,.14);
  border-radius: 22px;
  overflow: hidden;
  background: #fffdf7;
  box-shadow: 0 16px 44px rgba(32,75,64,.08);
}
.el-study-panel.is-open { display: block; }
.el-study-panel .el-reader-hero { background: linear-gradient(135deg,#eef5f6,#fffdf7); }
.el-study-panel .hf-study-copy p {
  margin: 8px 0 0;
  max-width: 760px;
  color: #5f6d69;
  line-height: 1.7;
  text-align: right;
  direction: rtl;
}
.el-study-panel .hf-study-count strong { color: #2b6475; }

@media (max-width: 760px) {
  .el-study-tabs { width: 100%; margin: 12px 0 18px auto; }
  .el-study-tab { flex: 1; padding: 10px 12px; }
  .el-study-panel .hf-study-copy p { font-size: .92rem; line-height: 1.55; }
}