/* Lectures 3–4 Practice: Current, Electron Energy and Overpotential (CHM2001)
   Layout only - every colour comes from the model-shell palette at runtime, through the --ekp-*
   custom properties that the script sets on the model container. Same pattern as the CHE7403
   practice pages (enthalpy-practice.css). */

.ekp-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
}

.ekp-layout > * {
  min-width: 0;
}

.ekp-layout [hidden] {
  display: none !important;
}

/* ---------------- equation sheet, key terms and problem tiles ---------------- */
.ekp-sheet {
  border: 2px solid var(--ekp-grid, #ccc);
  border-radius: 10px;
  padding: 0.4rem 0.8rem;
  margin-bottom: 0.6rem;
}

.ekp-sheet summary {
  font-weight: 800;
  cursor: pointer;
}

.ekp-sheet ul {
  margin: 0.4rem 0 0.2rem;
  padding-left: 1.2rem;
  columns: 2;
  column-gap: 2rem;
}

.ekp-sheet li {
  margin: 0.2rem 0;
  break-inside: avoid;
}

.ekp-terms {
  margin: 0.4rem 0 0.2rem;
  columns: 2;
  column-gap: 2rem;
}

.ekp-terms dt {
  font-weight: 800;
  break-after: avoid;
}

.ekp-terms dd {
  margin: 0.1rem 0 0.5rem;
  line-height: 1.45;
  break-inside: avoid;
}

.ekp-top {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  align-items: center;
  gap: 0.4rem 0.8rem;
  margin: 0 0 0.4rem;
}

.ekp-score {
  margin: 0;
  font-weight: 800;
}

.ekp-clear {
  font-size: 0.85rem;
}

.ekp-tiles {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.6rem;
}

.ekp-tile {
  position: relative;
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 0.6rem;
  align-items: center;
  padding: 0.55rem 0.7rem;
  font: inherit;
  text-align: left;
  color: var(--ekp-fg, #111);
  background: var(--ekp-bg, #fff);
  border: 2px solid var(--ekp-grid, #ccc);
  border-radius: 12px;
  cursor: pointer;
}

.ekp-tile:hover {
  border-color: var(--ekp-fg, #111);
}

.ekp-tile[aria-current="true"] {
  border-color: var(--ekp-accent, red);
  box-shadow: inset 0 0 0 2px var(--ekp-accent, red);
}

.ekp-tile.is-done {
  border-color: var(--ekp-green, green);
  background: var(--ekp-green-t, #f1f8f1);
}

.ekp-ic {
  display: grid;
  place-items: center;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 10px;
  background: var(--ekp-panel, #f4f4f4);
}

.ekp-tile-title {
  display: block;
  font-weight: 800;
  line-height: 1.25;
}

.ekp-tile-tags {
  display: block;
  margin-top: 0.2rem;
}

.ekp-tick {
  position: absolute;
  top: 0.3rem;
  right: 0.5rem;
  font-weight: 900;
  color: var(--ekp-green, green);
}

.ekp-chip {
  display: inline-block;
  margin: 0 0.25rem 0.15rem 0;
  padding: 0 0.5rem;
  font-size: 0.75rem;
  font-weight: 800;
  border: 1.5px solid;
  border-radius: 999px;
}

.ekp-chip--fmt { color: var(--ekp-accent, red); border-color: var(--ekp-accent, red); }
.ekp-chip--ctx { color: var(--ekp-blue, blue); border-color: var(--ekp-blue, blue); }
.ekp-chip--lec { color: var(--ekp-fg, #111); border-color: var(--ekp-fg, #111); }

/* ---------------- one problem ---------------- */
.ekp-q h3 {
  margin: 0.3rem 0 0.3rem;
  font-size: 1.3rem;
}

.ekp-intro {
  margin: 0 0 0.6rem;
  line-height: 1.5;
}

/* the optional reminder for students who are new to the topic */
.ekp-tip {
  margin: 0 0 0.7rem;
  padding: 0.35rem 0.8rem;
  border-left: 4px solid var(--ekp-blue, blue);
  border-radius: 0 10px 10px 0;
  background: var(--ekp-blue-t, #f2f5fc);
}

.ekp-tip summary {
  font-weight: 800;
  cursor: pointer;
}

.ekp-tip p {
  margin: 0.35rem 0 0.2rem;
  line-height: 1.5;
}

.ekp-reaction {
  margin: 0 0 0.4rem;
  font-size: 1.1rem;
  font-weight: 700;
}

.ekp-fig {
  margin: 0.4rem 0 0.8rem;
  padding: 0.5rem;
  border-radius: 10px;
  background: var(--ekp-panel, #f4f4f4);
}

.ekp-fig svg {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
}

.ekp-data {
  width: 100%;
  max-width: 420px;
  border-collapse: collapse;
  font-size: 0.95rem;
  background: var(--ekp-bg, #fff);
}

.ekp-data caption {
  text-align: left;
  font-weight: 700;
  font-size: 0.88rem;
  padding-bottom: 0.25rem;
}

.ekp-data th,
.ekp-data td {
  padding: 0.2rem 0.5rem;
  border-bottom: 1px solid var(--ekp-grid, #ccc);
  text-align: right;
}

.ekp-data th:first-child,
.ekp-data td:first-child {
  text-align: left;
}

.ekp-fig table + table { margin-top: 0.5rem; }

.ekp-lookup {
  display: block;
  margin-top: 0.4rem;
  font-size: 0.88rem;
}

.ekp-part {
  margin: 0.5rem 0;
  padding: 0.5rem 0.7rem;
  border: 2px solid var(--ekp-grid, #ccc);
  border-radius: 10px;
}

.ekp-part.is-active { border-color: var(--ekp-accent, red); }
.ekp-part.is-done { border-color: var(--ekp-green, green); background: var(--ekp-green-t, #f1f8f1); }
.ekp-part.is-locked { opacity: 0.5; }

.ekp-label {
  margin: 0 0 0.4rem;
  font-weight: 700;
}

.ekp-student {
  margin: 0.2rem 0 0.5rem;
  padding: 0.4rem 0.7rem;
  border: 2px dashed var(--ekp-orange, orange);
  border-radius: 10px;
  background: var(--ekp-orange-t, #fff8f0);
  font-size: 1.02rem;
}

.ekp-num {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.ekp-num input {
  width: 9rem;
  padding: 0.25rem 0.5rem;
  font: inherit;
  box-sizing: border-box;
}

.ekp-opts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.4rem;
}

.ekp-opt {
  padding: 0.45rem 0.6rem;
  font: inherit;
  text-align: left;
  color: var(--ekp-fg, #111);
  background: var(--ekp-bg, #fff);
  border: 2px solid var(--ekp-fg, #111);
  border-radius: 8px;
  cursor: pointer;
}

.ekp-opt:disabled {
  cursor: default;
  color: var(--ekp-fg, #111);
}

.ekp-opt.is-right {
  font-weight: 800;
  border-width: 3px;
  border-color: var(--ekp-green, green);
  background: var(--ekp-green-t, #e8f5e9);
}

.ekp-opt.is-wrong {
  border-color: var(--ekp-red, red);
  background: var(--ekp-red-t, #fdecea);
  text-decoration: line-through;
  opacity: 0.75;
}

.ekp-feedback {
  margin: 0.4rem 0 0;
  line-height: 1.45;
}

.ekp-feedback:empty {
  display: none;
}

.ekp-working {
  margin: 0.7rem 0 0;
  padding: 0.5rem 0.8rem 0.5rem 1.9rem;
  border-radius: 10px;
  background: var(--ekp-panel, #f4f4f4);
  line-height: 1.5;
}

.ekp-working:empty {
  display: none;
}

.ekp-working li {
  margin: 0.2rem 0;
}

/* sort and true-or-false cards */
.ekp-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.6rem;
}

.ekp-card {
  padding: 0.5rem 0.7rem;
  border: 2px solid var(--ekp-grid, #ccc);
  border-radius: 10px;
}

.ekp-card.is-done {
  border-color: var(--ekp-green, green);
  background: var(--ekp-green-t, #f1f8f1);
}

.ekp-card p {
  margin: 0 0 0.4rem;
}

.ekp-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
}

.ekp-why {
  margin: 0.4rem 0 0;
  font-size: 0.93rem;
  line-height: 1.4;
}

/* matching tasks to equations */
.ekp-pool {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  min-height: 2.4rem;
}

.ekp-boxes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
  margin-top: 0.6rem;
}

.ekp-cell {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-height: 6rem;
  padding: 0.4rem;
  border: 2px dashed var(--ekp-grid, #ccc);
  border-radius: 10px;
  cursor: pointer;
}

.ekp-cell.is-target {
  border-color: var(--ekp-accent, red);
}

.ekp-cap {
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1.35;
}

.ekp-cap small {
  font-weight: 600;
  font-size: 0.8rem;
}

.ekp-token {
  padding: 0.35rem 0.5rem;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  text-align: left;
  color: var(--ekp-fg, #111);
  background: var(--ekp-bg, #fff);
  border: 2px solid var(--ekp-fg, #111);
  border-radius: 8px;
  cursor: pointer;
}

.ekp-token[aria-pressed="true"] {
  border-color: var(--ekp-accent, red);
  box-shadow: 0 0 0 2px var(--ekp-accent, red);
}

.ekp-token.is-right {
  border-color: var(--ekp-green, green);
  background: var(--ekp-green-t, #e8f5e9);
}

.ekp-token.is-wrong {
  border-color: var(--ekp-red, red);
  background: var(--ekp-red-t, #fdecea);
}

.ekp-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 0.8rem;
}

.ekp-strong {
  font-weight: 800;
}

@media (max-width: 900px) {
  .ekp-tiles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .ekp-sheet ul,
  .ekp-terms {
    columns: 1;
  }
}

@media (max-width: 560px) {
  .ekp-tiles,
  .ekp-cards,
  .ekp-opts,
  .ekp-boxes {
    grid-template-columns: minmax(0, 1fr);
  }
  .ekp-tile {
    padding: 0.4rem 0.6rem;
  }
}