/* Ion Intelligence Board — infographic-style layout
   Inspired by the SO3²⁻ reference image: hub-and-spoke,
   colour-coded reaction categories, dense visual + textual.
*/

.ion-board {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 16px;
}

.ion-board-title {
  text-align: center;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 800;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  margin-bottom: 4px;
}
.ion-board-subtitle {
  text-align: center;
  color: var(--ink-dim);
  margin-bottom: 28px;
  font-size: 1rem;
}

/* Hub-and-spoke layout: 4 panels in a 2×2 grid + center hub */
.ion-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  position: relative;
}
@media (max-width: 880px) {
  .ion-grid { grid-template-columns: 1fr; }
}

.ion-panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
  position: relative;
  overflow: hidden;
}
.ion-panel::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 4px;
}
.ion-panel.panel-structure::before { background: var(--accent); }
.ion-panel.panel-reactions::before { background: var(--accent-2); }
.ion-panel.panel-industry::before  { background: var(--warn); }
.ion-panel.panel-env::before       { background: var(--good); }

.ion-panel-title {
  font-size: 1.05rem;
  font-weight: 800;
  margin: 0 0 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.ion-panel.panel-structure .ion-panel-title { color: var(--accent); }
.ion-panel.panel-reactions .ion-panel-title { color: var(--accent-2); }
.ion-panel.panel-industry  .ion-panel-title { color: var(--warn); }
.ion-panel.panel-env       .ion-panel-title { color: var(--good); }

.ion-panel-title .num {
  background: var(--bg-soft);
  color: var(--ink);
  width: 28px; height: 28px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center; justify-content: center;
  font-size: .9rem;
  border: 1px solid var(--line);
}

/* Sub-section within a panel */
.ion-sub {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
}
.ion-sub:first-of-type { border-top: 0; margin-top: 0; padding-top: 0; }
.ion-sub-title {
  font-weight: 700;
  font-size: .9rem;
  color: var(--ink);
  text-transform: uppercase;
  letter-spacing: .04em;
  margin-bottom: 6px;
}
.ion-sub-title .badge {
  display: inline-block;
  font-size: .7rem;
  padding: 2px 8px;
  border-radius: 99px;
  margin-left: 6px;
  background: var(--bg-soft);
  color: var(--ink-dim);
  text-transform: none;
  letter-spacing: 0;
  font-weight: 500;
}

.ion-eqn {
  font-family: "Cambria Math", "Latin Modern Math", serif;
  font-size: 1.05rem;
  background: var(--bg-soft);
  padding: 8px 12px;
  border-radius: 8px;
  margin: 6px 0;
  text-align: center;
  overflow-x: auto;
  white-space: nowrap;
}
.ion-eqn .arrow { color: var(--accent); margin: 0 4px; }
.ion-eqn .ppt   { color: var(--warn); font-weight: 600; }
.ion-eqn .gas   { color: var(--accent); font-weight: 600; }
.ion-eqn .red   { color: var(--bad); }
.ion-eqn .grn   { color: var(--good); }

/* Property list */
.ion-props {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 14px;
  font-size: .92rem;
}
.ion-props dt { color: var(--ink-dim); font-weight: 500; }
.ion-props dd { margin: 0; color: var(--ink); }

/* Tags */
.ion-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 99px;
  font-size: .78rem;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  margin: 2px 4px 2px 0;
  color: var(--ink);
}
.ion-tag.warn { border-color: var(--warn); color: var(--warn); }
.ion-tag.good { border-color: var(--good); color: var(--good); }
.ion-tag.bad  { border-color: var(--bad);  color: var(--bad); }
.ion-tag.acc  { border-color: var(--accent); color: var(--accent); }

/* Hub (centre) — appears between rows on wide screens */
.ion-hub {
  text-align: center;
  background: linear-gradient(180deg, var(--accent), var(--accent-2));
  color: #0b1020;
  font-weight: 800;
  font-size: 1.6rem;
  padding: 20px;
  border-radius: 14px;
  margin: -2px 0;
  letter-spacing: .02em;
}

/* Examiner / examiner-trap inline tile */
.ion-exam {
  background: linear-gradient(180deg, rgba(125,211,252,.07), rgba(192,132,252,.04));
  border: 1px solid var(--accent);
  border-radius: 12px;
  padding: 14px 18px;
  margin-top: 18px;
}
.ion-exam .head { font-weight: 700; color: var(--accent); margin-bottom: 6px; }

/* Lab tests panel */
.ion-tests {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
  margin-top: 8px;
}
.ion-test {
  background: var(--bg-soft);
  border-radius: 10px;
  padding: 10px 12px;
  border-left: 3px solid var(--accent-2);
}
.ion-test .nm { font-weight: 700; font-size: .9rem; }
.ion-test .obs { color: var(--ink-dim); font-size: .85rem; margin-top: 2px; }

/* Connected concepts (cross-unit links) */
.connected {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent-2);
  border-radius: 10px;
  padding: 14px 16px;
  margin: 18px 0;
}
.connected .head {
  font-weight: 700;
  color: var(--accent-2);
  margin-bottom: 8px;
}
.connected-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 8px;
}
.connected-list a {
  display: block;
  padding: 8px 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: .9rem;
}
.connected-list a:hover {
  border-color: var(--accent-2);
  text-decoration: none;
}
.connected-list .unit {
  font-size: .75rem;
  color: var(--ink-dim);
  display: block;
  margin-bottom: 2px;
}

/* "Chemistry in One Page" — ultra-dense summary */
.one-page {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
  margin-top: 18px;
}
.one-page .block {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px;
}
.one-page .block h4 {
  margin: 0 0 8px;
  font-size: .95rem;
  color: var(--accent);
  border-bottom: 1px dashed var(--line);
  padding-bottom: 4px;
}
.one-page .block ul {
  margin: 0;
  padding-left: 18px;
  font-size: .88rem;
  line-height: 1.55;
}
.one-page .block li { margin-bottom: 3px; }
.one-page .block .equation { font-size: .85rem; padding: 4px 6px; }