:root {
  --bg: #fafafa;
  --fg: #1c1c1e;
  --muted: #8a8a8e;
  --cell-empty: #eef0f2;
  --cell-empty-border: #d8dbe0;
  --cell-eligible-border: #6aa9ff;
  --cell-correct-bg: #cfe8ff;
  --cell-correct-border: #7fb8f5;
  --cell-incorrect-bg: #ffe1b3;
  --cell-incorrect-border: #f0a94e;
  --cell-center-bg: #d8f5d8;
  --cell-center-border: #7fd67f;
  --gold: #f4c430;
  --bonus-blue: #3d7dfc;
  --accent: #3d7dfc;
  --card-bg: #ffffff;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121214;
    --fg: #f0f0f2;
    --muted: #98989c;
    --cell-empty: #232326;
    --cell-empty-border: #3a3a3e;
    --cell-eligible-border: #5b93e6;
    --cell-correct-bg: #163a5c;
    --cell-correct-border: #2f6fae;
    --cell-incorrect-bg: #5c3d16;
    --cell-incorrect-border: #ae7f2f;
    --cell-center-bg: #1c4a25;
    --cell-center-border: #3f8f52;
    --bonus-blue: #5b93e6;
    --card-bg: #1c1c1f;
    --shadow: 0 2px 14px rgba(0, 0, 0, 0.5);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.app-header {
  display: flex;
  align-items: baseline;
  gap: 0.6em;
  padding: 0.8rem 1rem 0.2rem;
}

.app-header h1 {
  font-size: 1.3rem;
  margin: 0;
  letter-spacing: 0.02em;
}

.puzzle-nav {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.puzzle-number {
  color: var(--muted);
  font-size: 0.85rem;
  min-width: 2.6em;
  text-align: center;
}

.nav-btn,
.help-btn {
  background: none;
  border: 1.5px solid var(--cell-empty-border);
  color: var(--fg);
  border-radius: 50%;
  width: 26px;
  height: 26px;
  line-height: 1;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-btn:hover,
.help-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.nav-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.nav-btn:disabled:hover {
  border-color: var(--cell-empty-border);
  color: var(--fg);
}

.help-btn {
  margin-left: auto;
  font-weight: 700;
}

.rule-hint {
  margin: 0;
  color: var(--muted);
  font-size: 0.8rem;
  text-align: center;
  max-width: 90%;
}

main {
  width: 100%;
  max-width: 640px;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0.5rem 0.5rem 2rem;
  gap: 0.75rem;
}

.board-wrap {
  position: relative;
  width: 100%;
  overflow: auto;
  border-radius: 10px;
  -webkit-overflow-scrolling: touch;
}

.board {
  display: grid;
  grid-template-columns: repeat(7, minmax(76px, 1fr));
  grid-template-rows: repeat(7, minmax(54px, 1fr));
  gap: 4px;
  width: max-content;
  min-width: 100%;
  margin: 0 auto;
}

.cell {
  position: relative;
  width: 76px;
  height: 54px;
  background: var(--cell-empty);
  border: 1.5px solid var(--cell-empty-border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  transition: transform 120ms ease, background-color 150ms ease;
}

.cell.eligible {
  border: 1.5px dashed var(--cell-eligible-border);
  cursor: pointer;
}

.cell.has-star::before {
  content: "\2605";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gold);
  font-size: 1.6rem;
  opacity: 0.9;
  z-index: 0;
  pointer-events: none;
}

/* Once a star cell is claimed and/or a word earns bonus stars, real DOM
   elements take over from the ::before pseudo-element above (a variable-
   length row of icons isn't something a single pseudo-element can produce):
   a gold outline star first if the square's star was claimed, then one
   filled blue star per bonus star earned, wrapping onto a second line if
   they don't all fit across the top of the cell. */
.corner-stars {
  position: absolute;
  top: 1px;
  left: 3px;
  right: 3px;
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  z-index: 0;
  pointer-events: none;
}

.corner-star {
  font-size: 0.65rem;
  line-height: 1;
}

.corner-star.gold {
  color: var(--gold);
  opacity: 0.7;
}

.corner-star.blue {
  color: var(--bonus-blue);
  opacity: 0.7;
}

.cell.correct {
  background: var(--cell-correct-bg);
  border-color: var(--cell-correct-border);
}

.cell.incorrect {
  background: var(--cell-incorrect-bg);
  border-color: var(--cell-incorrect-border);
  cursor: pointer;
  overflow: visible;
}

.cell.center {
  background: var(--cell-center-bg);
  border-color: var(--cell-center-border);
}

.cell.selected {
  transform: scale(1.12);
  z-index: 5;
  box-shadow: var(--shadow);
  overflow: visible;
}

.cell-word {
  position: relative;
  z-index: 1;
  font-size: clamp(0.55rem, 2.8vw, 0.9rem);
  font-weight: 600;
  line-height: 1.1;
  text-align: center;
  padding: 2px 4px;
  word-break: break-word;
  hyphens: auto;
}

.cell-input {
  position: relative;
  z-index: 1;
  width: 92%;
  height: 60%;
  border: none;
  background: transparent;
  text-align: center;
  font-size: clamp(0.55rem, 2.6vw, 0.85rem);
  font-weight: 600;
  color: var(--fg);
  outline: none;
}

.define-badge {
  position: absolute;
  top: -12px;
  right: -12px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 1.5px solid var(--cell-correct-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  box-shadow: var(--shadow);
  z-index: 6;
  cursor: pointer;
}

.toast {
  min-height: 1.2rem;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

.tray-row {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.stars-tray {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.star-vessels,
.bonus-stars {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.star-slot,
.bonus-star {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  background: var(--cell-empty);
  border: 1.5px solid var(--cell-empty-border);
}

.star-slot.filled {
  color: var(--gold);
  border-color: var(--gold);
  background: transparent;
}

.star-slot.blocked {
  color: var(--cell-incorrect-border);
  border-color: var(--cell-incorrect-border);
  background: transparent;
  font-size: 0.85rem;
}

.bonus-star.filled {
  color: var(--bonus-blue);
  border-color: var(--bonus-blue);
  background: transparent;
}

.actions-row {
  display: flex;
  gap: 1rem;
}

.text-btn {
  background: none;
  border: 1.5px solid var(--muted);
  color: var(--fg);
  border-radius: 8px;
  padding: 0.4rem 0.9rem;
  font-size: 0.85rem;
  cursor: pointer;
}

.text-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  z-index: 20;
}

.modal.hidden {
  display: none;
}

.modal-card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 1.2rem;
  max-width: 420px;
  width: 100%;
  box-shadow: var(--shadow);
  text-align: center;
}

.modal-card h2 {
  margin-top: 0;
  font-size: 1.1rem;
}

.share-text {
  text-align: left;
  font-size: 0.75rem;
  line-height: 1.15;
  background: var(--cell-empty);
  border-radius: 8px;
  padding: 0.6rem;
  overflow-x: auto;
  white-space: pre;
}

.share-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  justify-content: center;
  margin: 0.8rem 0;
}

.share-buttons button {
  border: none;
  border-radius: 8px;
  padding: 0.5rem 0.8rem;
  font-size: 0.8rem;
  color: white;
  cursor: pointer;
}

.define-content {
  text-align: left;
  max-height: 50vh;
  overflow-y: auto;
  margin: 0.6rem 0;
}

.define-pos {
  font-style: italic;
  color: var(--muted);
  font-size: 0.8rem;
  margin-top: 0.6rem;
  text-transform: capitalize;
}

.define-pos:first-child {
  margin-top: 0;
}

.define-content ol {
  margin: 0.2rem 0 0;
  padding-left: 1.2rem;
  font-size: 0.9rem;
}

.define-content li {
  margin-bottom: 0.3rem;
}

.rules-card {
  max-width: 480px;
  text-align: left;
}

.rules-card h2 {
  text-align: center;
}

.rules-card > p {
  margin: 0.6rem 0;
}

.rules-example {
  display: block;
  width: 100%;
  height: auto;
  margin: 0.8rem 0;
}

.rules-cell-empty {
  fill: var(--cell-empty);
  stroke: var(--cell-empty-border);
  stroke-width: 1.5;
}

.rules-cell {
  fill: var(--cell-correct-bg);
  stroke: var(--cell-correct-border);
  stroke-width: 1.5;
}

.rules-cell-star {
  fill: var(--cell-center-bg);
  stroke: var(--cell-center-border);
}

.rules-word {
  fill: var(--fg);
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  text-anchor: middle;
}

.rules-corner-star {
  fill: var(--gold);
  font-size: 12px;
  opacity: 0.8;
}

.rules-list {
  margin: 0.4rem 0 1rem;
  padding-left: 1.4rem;
  font-size: 0.9rem;
}

.rules-list li {
  margin-bottom: 0.3rem;
}

.rules-card .text-btn {
  display: block;
  margin: 0 auto;
}