main {
  max-width: 72rem;
  padding-top: 5rem;
}

.site-header {
  margin-bottom: 1.8rem;
}

.search-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 22rem;
  gap: 1rem;
  align-items: start;
}

.search-shell.is-tree-expanded {
  grid-template-columns: minmax(0, 1fr);
}

.search-shell.is-tree-expanded .tree-panel {
  min-height: min(72vh, 46rem);
}

.search-shell.is-tree-expanded .tree-board {
  min-height: min(72vh, 46rem);
}

.search-shell.is-tree-expanded .side-panel {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.maze-panel,
.sudoku-panel,
.knight-panel,
.tree-panel,
.island-panel,
.control-panel,
.status-panel,
.structure-panel {
  background: var(--wa-white);
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
}

.maze-panel,
.sudoku-panel,
.knight-panel,
.tree-panel,
.island-panel {
  padding: 1.1rem;
}

.side-panel {
  display: grid;
  gap: 1rem;
}

.control-panel,
.status-panel,
.structure-panel {
  padding: 1rem;
}

.panel-heading {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
  margin-bottom: 0.9rem;
}

.panel-heading.compact {
  margin-bottom: 0.65rem;
}

.panel-heading h2,
.control-panel h2,
.status-panel h2 {
  margin: 0 0 0.2rem;
  font-size: 1rem;
}

.panel-title-row {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.panel-title-row h2 {
  margin-bottom: 0.2rem;
}

.panel-heading p {
  margin: 0;
  color: var(--wa-ink-light);
  font-size: 0.86rem;
}

.maze-legend {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.35rem 0.75rem;
  color: var(--wa-gray);
  font-size: 0.78rem;
}

.maze-legend span {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.maze-legend i {
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 2px;
  border: 1px solid rgba(26, 26, 26, 0.08);
}

.legend-start {
  background: var(--wa-green);
}

.tree-panel .legend-start {
  border-color: rgba(74, 124, 89, 0.42);
  background: var(--wa-white);
}

.legend-goal {
  background: #b85c7a;
}

.legend-frontier {
  background: var(--wa-orange-pale);
}

.legend-visited {
  background: var(--wa-sea-light);
}

.legend-path {
  background: #ffe08a;
}

.legend-given {
  background: #f2efe7;
}

.legend-current {
  background: var(--wa-orange);
}

.legend-try {
  background: var(--wa-orange-light);
}

.legend-conflict {
  background: #e05050;
}

.legend-backtrack {
  background: var(--wa-sea-light);
}

.legend-water {
  background: #cfe8f2;
}

.legend-land {
  background: #f7d38a;
}

.legend-scan {
  background: #8ec8dd;
}

.maze-grid {
  display: grid;
  grid-template-columns: repeat(17, minmax(0, 1fr));
  gap: 3px;
  aspect-ratio: 17 / 13;
  padding: 0.55rem;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: #efe9dc;
}

.sudoku-board {
  display: grid;
  grid-template-columns: repeat(var(--sudoku-size, 9), minmax(0, 1fr));
  aspect-ratio: 1;
  border: 2px solid var(--wa-ink);
  background: var(--wa-ink);
}

.knight-board {
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  gap: 3px;
  aspect-ratio: 1;
  padding: 0.55rem;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: #efe9dc;
}

.tree-board {
  position: relative;
  min-height: 38rem;
  overflow: hidden;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: linear-gradient(#fffaf0, #f8fbf7);
}

.tree-edges {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.tree-edge {
  stroke: rgba(74, 124, 89, 0.34);
  stroke-width: 1.35;
}

.tree-edge.is-path {
  stroke: #d6a328;
  stroke-width: 1.35;
}

.tree-node {
  position: absolute;
  display: grid;
  place-items: center;
  width: 4.6rem;
  height: 4.6rem;
  transform: translate(-50%, -50%);
  border: 1px solid rgba(74, 124, 89, 0.28);
  border-radius: 50%;
  background: var(--wa-white);
  color: var(--wa-ink);
  font-size: 0.7rem;
  font-weight: 700;
  line-height: 1.25;
  padding: 0.42rem;
  text-align: center;
  box-shadow: 0 4px 10px rgba(26, 26, 26, 0.06);
  word-break: keep-all;
}

.tree-node.is-root {
  border-color: rgba(74, 124, 89, 0.42);
}

.tree-node.is-target {
  border-color: #b85c7a;
  box-shadow: 0 0 0 2px rgba(184, 92, 122, 0.2);
}

.tree-node.is-frontier {
  background: var(--wa-orange-pale);
  box-shadow: 0 0 0 2px rgba(255, 153, 0, 0.16);
}

.tree-node.is-visited {
  background: var(--wa-sea-light);
  color: var(--wa-sea);
}

.tree-node.is-current {
  background: var(--wa-orange);
  color: var(--wa-white);
  transform: translate(-50%, -50%) scale(1.04);
  box-shadow: 0 0 0 3px rgba(255, 153, 0, 0.24);
}

.tree-node.is-path {
  background: #ffe08a;
  color: var(--wa-ink);
}

.island-board {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 3px;
  aspect-ratio: 12 / 8;
  padding: 0.55rem;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: #d9eef5;
}

.sudoku-cell {
  display: grid;
  place-items: center;
  min-width: 0;
  min-height: 0;
  border: 1px solid rgba(26, 26, 26, 0.22);
  background: var(--wa-white);
  color: var(--wa-ink);
  font-size: clamp(1rem, 3.4vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  transition: background-color 0.12s ease, color 0.12s ease, box-shadow 0.12s ease;
}

.sudoku-cell.is-box-right {
  border-right-width: 2px;
}

.sudoku-cell.is-row-end {
  border-right-width: 0;
}

.sudoku-cell.is-box-bottom {
  border-bottom-width: 2px;
}

.sudoku-cell.is-given {
  background: #f2efe7;
  color: var(--wa-ink);
}

.sudoku-cell.is-current {
  background: var(--wa-orange);
  color: var(--wa-white);
  box-shadow: inset 0 0 0 3px rgba(26, 26, 26, 0.12);
}

.sudoku-cell.is-try {
  background: var(--wa-orange-light);
  color: var(--wa-ink);
}

.sudoku-cell.is-conflict {
  background: #e05050;
  color: var(--wa-white);
}

.sudoku-cell.is-backtrack {
  background: var(--wa-sea-light);
  color: var(--wa-sea);
}

.maze-cell,
.knight-cell,
.island-cell {
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  width: 100%;
  min-width: 0;
  min-height: 0;
  border: 0;
  border-radius: 3px;
  background: var(--wa-white);
  color: transparent;
  font: inherit;
  cursor: pointer;
  transition: background-color 0.12s ease, transform 0.12s ease, box-shadow 0.12s ease;
}

.maze-cell:hover,
.knight-cell:hover,
.island-cell:hover {
  box-shadow: inset 0 0 0 2px rgba(255, 153, 0, 0.34);
}

.knight-cell:nth-child(16n + 2),
.knight-cell:nth-child(16n + 4),
.knight-cell:nth-child(16n + 6),
.knight-cell:nth-child(16n + 8),
.knight-cell:nth-child(16n + 9),
.knight-cell:nth-child(16n + 11),
.knight-cell:nth-child(16n + 13),
.knight-cell:nth-child(16n + 15) {
  background: #f7f1e5;
}

.maze-cell.is-wall {
  background: #3f3f3f;
}

.maze-cell.is-frontier,
.knight-cell.is-frontier,
.island-cell.is-frontier {
  background: var(--wa-orange-pale);
  box-shadow: inset 0 0 0 1px rgba(255, 153, 0, 0.28);
}

.maze-cell.is-visited,
.knight-cell.is-visited,
.island-cell.is-visited {
  background: var(--wa-sea-light);
}

.maze-cell.is-current,
.knight-cell.is-current,
.island-cell.is-current {
  background: var(--wa-orange);
  transform: scale(1.04);
  box-shadow: 0 0 0 2px rgba(255, 153, 0, 0.28);
}

.maze-cell.is-path,
.knight-cell.is-path {
  background: #ffe08a;
}

.maze-cell.is-start,
.knight-cell.is-start {
  background: var(--wa-green);
}

.maze-cell.is-goal,
.knight-cell.is-goal {
  background: #b85c7a;
}

.maze-cell.is-start,
.maze-cell.is-goal,
.maze-cell.is-current,
.knight-cell.is-start,
.knight-cell.is-goal,
.knight-cell.is-current,
.island-cell.is-current {
  color: var(--wa-white);
  font-size: 0.8rem;
  font-weight: 700;
}

.island-cell {
  background: #cfe8f2;
}

.island-cell.is-land {
  background: #f7d38a;
}

.island-cell.is-frontier {
  background: var(--wa-orange-light);
}

.island-cell.is-visited {
  background: var(--wa-sea-light);
}

.island-cell.is-current {
  background: var(--wa-orange);
}

.island-cell.is-scanned {
  background: #b8dce8;
}

.island-cell.is-scan-current {
  background: #8ec8dd;
  box-shadow: inset 0 0 0 2px rgba(43, 122, 158, 0.36);
}

.island-cell.is-visited,
.island-cell.is-frontier {
  color: var(--wa-ink);
  font-size: 0.72rem;
  font-weight: 700;
}

.island-cell.is-current {
  color: var(--wa-white);
}

.algorithm-tabs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.25rem;
  margin-bottom: 0.9rem;
  padding: 0.25rem;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: var(--wa-bg);
}

.algorithm-tabs label {
  position: relative;
  cursor: pointer;
}

.algorithm-tabs input {
  position: absolute;
  inset: 0;
  opacity: 0;
}

.algorithm-tabs span {
  display: grid;
  place-items: center;
  min-height: 2.55rem;
  border-radius: 4px;
  color: var(--wa-ink-light);
  font-weight: 700;
}

.algorithm-tabs input:checked + span {
  background: var(--wa-orange);
  color: var(--wa-white);
}

.subject-field {
  margin-bottom: 0.9rem;
}

.order-grid {
  display: grid;
  gap: 0.65rem;
  margin-bottom: 0.9rem;
}

.select-field {
  display: grid;
  gap: 0.35rem;
  color: var(--wa-ink-light);
  font-size: 0.82rem;
}

.check-field {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--wa-ink-light);
  font-size: 0.86rem;
  font-weight: 700;
}

.check-field input {
  width: 1rem;
  height: 1rem;
  accent-color: var(--wa-orange);
}

.field-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.info-button {
  display: inline-grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid rgba(255, 153, 0, 0.45);
  border-radius: 50%;
  background: var(--wa-orange-pale);
  color: var(--wa-orange-dark);
  cursor: pointer;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1;
}

.info-button:hover {
  border-color: var(--wa-orange);
  background: var(--wa-white);
}

.select-field select {
  width: 100%;
  appearance: none;
  border: 1px solid var(--wa-gray-light);
  border-radius: 4px;
  background: var(--wa-white);
  color: var(--wa-ink);
  font: inherit;
  min-height: 2.55rem;
  padding: 0.55rem 0.7rem;
}

.button-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  gap: 0.55rem;
}

.button-grid .btn-primary {
  margin: 0;
}

.button-grid > button {
  flex: 1 1 8.2rem;
  min-width: 0;
}

.action-button {
  appearance: none;
  border: 1px solid var(--wa-gray-light);
  border-radius: 6px;
  background: var(--wa-white);
  color: var(--wa-ink);
  cursor: pointer;
  font: inherit;
  font-weight: 700;
  padding: 0.8rem 0.7rem;
}

.action-button:hover:not(:disabled) {
  border-color: var(--wa-orange);
  color: var(--wa-orange-dark);
}

.action-button:disabled,
.btn-primary:disabled {
  cursor: default;
  opacity: 0.55;
}

.range-field {
  display: grid;
  gap: 0.45rem;
  margin-top: 0.9rem;
  color: var(--wa-ink-light);
  font-size: 0.86rem;
}

.range-field strong {
  color: var(--wa-orange-dark);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.65rem;
  margin: 0;
}

.stat-grid div {
  padding-top: 0.55rem;
  border-top: 1px solid var(--wa-gray-light);
}

.stat-grid dt {
  color: var(--wa-gray);
  font-size: 0.72rem;
}

.stat-grid dd {
  margin: 0.12rem 0 0;
  color: var(--wa-ink);
  font-size: 1.05rem;
  font-weight: 700;
}

.status-text {
  margin-top: 0.75rem;
  color: var(--wa-ink-light);
  font-weight: 700;
}

.structure-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  min-height: 4.8rem;
  max-height: 10rem;
  margin: 0;
  padding: 0;
  overflow: auto;
  list-style: none;
}

.structure-list li {
  border: 1px solid rgba(255, 153, 0, 0.24);
  border-radius: 4px;
  background: var(--wa-orange-pale);
  color: var(--wa-orange-dark);
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1.2;
  padding: 0.35rem 0.45rem;
}

.structure-list li.is-next {
  border-color: var(--wa-orange);
  background: var(--wa-orange);
  color: var(--wa-white);
}

.info-modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: grid;
  place-items: center;
  padding: 1rem;
}

.info-modal.hidden {
  display: none;
}

.info-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(26, 26, 26, 0.42);
}

.info-modal-panel {
  position: relative;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  z-index: 1;
  width: min(100%, 54rem);
  max-height: min(88vh, 46rem);
  overflow: hidden;
  border: 1px solid var(--wa-gray-light);
  border-radius: 8px;
  background: var(--wa-white);
  box-shadow: 0 20px 44px rgba(26, 26, 26, 0.18);
}

.info-modal-header {
  position: sticky;
  top: 0;
  z-index: 2;
  border-bottom: 1px solid var(--wa-gray-light);
  background: var(--wa-white);
  padding: 1.35rem 3.8rem 1rem 1.35rem;
}

.info-modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--wa-gray-light);
  border-radius: 50%;
  background: var(--wa-white);
  color: var(--wa-ink-light);
  cursor: pointer;
  font-size: 1.2rem;
  line-height: 1;
}

.info-modal-kicker {
  margin: 0 0 0.35rem;
  color: var(--wa-orange-dark);
  font-size: 0.78rem;
  font-weight: 700;
}

.info-modal-panel h2 {
  margin: 0;
  font-size: 1.2rem;
}

.info-modal-body {
  display: grid;
  gap: 0.85rem;
  min-height: 0;
  overflow: auto;
  padding: 1.2rem 1.35rem 1.35rem;
  color: var(--wa-ink-light);
  font-size: 0.92rem;
}

.info-modal-body h3 {
  margin: 0 0 0.25rem;
  color: var(--wa-ink);
  font-size: 0.95rem;
}

.info-modal-body p,
.info-modal-body ul {
  margin: 0;
}

.info-modal-body ul {
  padding-left: 1.2rem;
}

@media (max-width: 980px) {
  .search-shell {
    grid-template-columns: 1fr;
  }

  .side-panel {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .search-shell.is-tree-expanded .side-panel {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  main {
    padding-top: 4.5rem;
  }

  .panel-heading {
    display: grid;
  }

  .maze-legend {
    justify-content: flex-start;
  }

  .side-panel {
    grid-template-columns: 1fr;
  }

  .maze-grid {
    gap: 2px;
    padding: 0.35rem;
  }

  .knight-board {
    gap: 2px;
    padding: 0.35rem;
  }

  .tree-board {
    min-height: 28rem;
  }

  .tree-node {
    width: 3.8rem;
    height: 3.8rem;
    font-size: 0.58rem;
  }

  .island-board {
    gap: 2px;
    padding: 0.35rem;
  }

  .maze-cell.is-start,
  .maze-cell.is-goal,
  .maze-cell.is-current,
  .knight-cell.is-start,
  .knight-cell.is-goal,
  .knight-cell.is-current,
  .island-cell.is-current {
    font-size: 0.64rem;
  }
}