:root {
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-dark: #1a1a1a;
  --color-text: var(--color-dark);
  --color-text-on-accent: #ffffff;
  --color-text-muted: #6b7280;
  --color-text-subtle: #374151;
  --color-letter-value: #4b5563;
  --color-accent: #2051be;
  --color-success: #0e9a41;
  --color-warning: #f8cc3a;
  --color-danger: #fecaca;
  --color-disabled: #9ca3af;
  --color-button-bg: #e5e7eb;
  --color-backdrop: rgb(0 0 0 / 50%);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  font-family: system-ui, sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
}

header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

header h1 {
  margin: 0;
  font-size: 1.75rem;
}

#score-display,
#timer-display {
  font-size: 1.25rem;
  font-variant-numeric: tabular-nums;
}

footer {
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  color: var(--color-text-muted);
}

#how-to-play {
  max-width: 20rem;
  font-size: 0.875rem;
  color: var(--color-text-subtle);
}

#how-to-play h2 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
}

#how-to-play ul {
  margin: 0;
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

button {
  font-size: 1rem;
  padding: 0.5rem 1.25rem;
  border: none;
  border-radius: 0.25rem;
  cursor: pointer;
}

button:disabled {
  cursor: not-allowed;
}

.mode-buttons {
  display: flex;
  gap: 0.5rem;
}

.mode-buttons button {
  background-color: var(--color-button-bg);
  color: var(--color-text);
}

.mode-buttons button.active {
  background-color: var(--color-dark);
  color: var(--color-text-on-accent);
}

.action-buttons {
  display: flex;
  gap: 0.5rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(var(--size), 3rem);
  grid-template-rows: repeat(var(--size), 3rem);
  gap: 2px;
  background-color: var(--color-dark);
  padding: 2px;
}

.cell-wrapper {
  position: relative;
}

.cell {
  width: 100%;
  height: 100%;
  border: none;
  text-align: center;
  font-size: 1.5rem;
  font-weight: bold;
  text-transform: uppercase;
  background-color: var(--color-surface);
  color: var(--color-text);
}

.letter-value {
  position: absolute;
  bottom: 2px;
  right: 4px;
  font-size: 0.65rem;
  line-height: 1;
  color: var(--color-letter-value);
  pointer-events: none;
}

.cell:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.cell--starter {
  background-color: var(--color-accent);
  color: var(--color-text-on-accent);
  /* Double-tap triggers the definition lookup - stop iOS's native
     text-selection callout/magnifier from appearing over it instead. */
  -webkit-touch-callout: none;
  user-select: none;
}

.cell--valid {
  background-color: var(--color-success);
  color: var(--color-text-on-accent);
}

/* Explicit color, not just background: a starter cell can simultaneously
   be part of an invalid crossing word, and this must win over the starter
   rule's white text for readability against the lighter invalid background. */
.cell--invalid {
  background-color: var(--color-danger);
  color: var(--color-text);
}

.cell--duplicate {
  background-color: var(--color-warning);
  color: var(--color-text);
}

.cell--blocked {
  background-color: var(--color-dark);
}

.cell--starter + .letter-value,
.cell--valid + .letter-value {
  color: var(--color-text-on-accent);
}

#submit-button {
  background-color: var(--color-accent);
  color: var(--color-text-on-accent);
}

#submit-button:disabled {
  background-color: var(--color-disabled);
}

#clear-button {
  background-color: var(--color-button-bg);
  color: var(--color-text);
}

#clear-button:disabled {
  background-color: var(--color-disabled);
  color: var(--color-text-on-accent);
}

#share-button {
  background-color: var(--color-accent);
  color: var(--color-text-on-accent);
}

#share-button:disabled {
  background-color: var(--color-disabled);
}

dialog#definition-dialog,
dialog#share-dialog {
  width: min(24rem, 90vw);
  border: none;
  border-radius: 0.5rem;
  padding: 1.5rem;
}

dialog#definition-dialog::backdrop,
dialog#share-dialog::backdrop {
  background-color: var(--color-backdrop);
}

#definition-content h2 {
  margin: 0 0 0.25rem;
  text-transform: capitalize;
}

#definition-content .definition-phonetic {
  margin: 0 0 1rem;
  color: var(--color-text-muted);
  font-style: italic;
}

#definition-content .definition-part-of-speech {
  margin: 1rem 0 0.25rem;
  font-weight: bold;
  text-transform: capitalize;
}

#definition-content ol {
  margin: 0;
  padding-left: 1.25rem;
}

.definition-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

#definition-search-link {
  font-size: 0.9rem;
  color: var(--color-accent);
  text-decoration: none;
}

#definition-search-link:hover {
  text-decoration: underline;
}

dialog#definition-dialog button,
dialog#share-dialog button {
  background-color: var(--color-button-bg);
  color: var(--color-text);
}

#share-dialog h2 {
  margin: 0 0 1rem;
}

#share-preview {
  margin: 0;
  padding: 0.75rem;
  border-radius: 0.25rem;
  background-color: var(--color-bg);
  font-family: inherit;
  font-size: 0.9rem;
  white-space: pre-wrap;
  overflow-wrap: break-word;
}

.share-words-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1rem;
  font-size: 0.9rem;
}

.share-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

#share-copy-button {
  background-color: var(--color-accent);
  color: var(--color-text-on-accent);
}