:root {
  --ink: #12232e;
  --sea: #1b6ca8;
  --sea-deep: #0b3954;
  --ship: #37474f;
  --miss: #cfd8dc;
  --hit: #e4572e;
  --sunk: #7a1f12;
  --ok: #3f9b5e;
  --bad: #b23a48;
  --cell: 2rem;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 1.5rem;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--ink);
  background: #f4f7fa;
}

h1 {
  margin: 0 0 0.25rem;
}

h2 {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 0.5rem;
}

.phase {
  margin: 0 0 1.5rem;
  font-size: 1.05rem;
}

main {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  align-items: flex-start;
}

.grid {
  display: grid;
  grid-template-columns: 1.25rem repeat(10, var(--cell));
  gap: 2px;
}

.label {
  display: grid;
  place-items: center;
  font-size: 0.7rem;
  color: #62757f;
}

.cell {
  width: var(--cell);
  height: var(--cell);
  display: grid;
  place-items: center;
  padding: 0;
  font: inherit;
  font-size: 1rem;
  line-height: 1;
  color: #fff;
  background: var(--sea);
  border: 1px solid #15517d;
  border-radius: 2px;
  cursor: default;
}

.grid.interactive .cell[aria-disabled="false"] {
  cursor: pointer;
}

.grid.interactive .cell[aria-disabled="false"]:hover {
  background: var(--sea-deep);
}

.cell:focus-visible {
  outline: 3px solid #111;
  outline-offset: 2px;
  z-index: 1;
}

.cell.ship {
  background: var(--ship);
  border-color: #1f2b30;
}

.cell.miss {
  background: var(--miss);
  color: #37474f;
}

.cell.hit {
  background: var(--hit);
}

.cell.sunk {
  background: var(--sunk);
}

.cell.revealed {
  background: repeating-linear-gradient(
    45deg,
    var(--ship),
    var(--ship) 4px,
    #55686f 4px,
    #55686f 8px
  );
}

.cell.preview {
  background: var(--ok);
}

.cell.invalid {
  background: var(--bad);
}

.cell.shake {
  animation: shake 0.25s;
}

@keyframes shake {
  25% { transform: translateX(-2px); }
  75% { transform: translateX(2px); }
}

.fleet {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
  width: calc(1.25rem + 10 * (var(--cell) + 2px));
  font-size: 0.9rem;
}

.fleet li {
  display: flex;
  justify-content: space-between;
  padding: 0.1rem 0;
}

.fleet li.sunk {
  color: var(--sunk);
  text-decoration: line-through;
}

.sidebar {
  min-width: 16rem;
  max-width: 22rem;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
}

button {
  padding: 0.5rem 0.75rem;
  font: inherit;
  color: inherit;
  background: #fff;
  border: 1px solid var(--sea-deep);
  border-radius: 4px;
  cursor: pointer;
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

button:not(:disabled):hover {
  background: var(--sea-deep);
  color: #fff;
}

kbd {
  font: inherit;
  font-size: 0.75rem;
  border: 1px solid currentColor;
  border-radius: 3px;
  padding: 0 0.25rem;
}

.scoreboard {
  display: grid;
  grid-template-columns: auto auto;
  gap: 0.15rem 1rem;
  margin: 0 0 1.5rem;
  font-size: 0.9rem;
}

.scoreboard dt {
  color: #62757f;
}

.scoreboard dd {
  margin: 0;
  text-align: right;
}

.announcer {
  min-height: 1.4em;
  margin: 0 0 0.5rem;
  font-weight: 600;
}

.log {
  margin: 0 0 1.5rem;
  padding-left: 2.6rem; /* room for three-digit markers beside the scroll box */
  max-height: 14rem;
  overflow-y: auto;
  font-size: 0.85rem;
}

.hint {
  font-size: 0.85rem;
  color: #62757f;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}