/* =========================================================
   Battleship, on squared paper.

   Exercise-book paper with a red margin rule. The grids are
   drawn in blue biro, the ships outlined by hand, the hits
   crossed out in red. Everything the player "writes" is in a
   handwriting face; everything the worksheet was printed with
   is not.
   ========================================================= */

:root {
  --paper: #fcfcf8;
  --paper-shade: #f2f1ea;
  --rule: #cddceb;
  --rule-strong: #a9c3dc;
  --margin-rule: #e8a9a2;

  --biro: #22407e;
  --biro-soft: #6a83b4;
  --red-biro: #bf3b2f;
  --pencil: #5f646b;

  --hand: "Caveat", "Segoe Script", cursive;
  --print: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --cell: 34px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

.defs {
  position: absolute;
  width: 0;
  height: 0;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--paper);
  /* the faint ruled lines of an exercise book */
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0 27px,
    rgba(169, 195, 220, 0.28) 27px 28px
  );
  color: var(--biro);
  font-family: var(--print);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

button {
  cursor: pointer;
  font-family: inherit;
  color: inherit;
}

:focus-visible {
  outline: 2px solid var(--red-biro);
  outline-offset: 3px;
}

.sheet {
  position: relative;
  max-width: 1000px;
  margin-inline: auto;
  padding: 2rem clamp(1rem, 4vw, 2rem) 3rem clamp(2.75rem, 7vw, 4.5rem);
}

/* the red margin rule down the left of the page */
.sheet::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: clamp(1.75rem, 5vw, 3.25rem);
  width: 1.5px;
  background: var(--margin-rule);
  opacity: 0.85;
}

/* --- masthead --- */

.masthead h1 {
  margin: 0;
  font-family: var(--hand);
  font-weight: 700;
  font-size: clamp(3rem, 9vw, 4.75rem);
  line-height: 0.95;
  letter-spacing: 0.01em;
  color: var(--biro);
  transform: rotate(-1.1deg);
  transform-origin: left center;
}

.subtitle {
  margin: 0.5rem 0 0;
  max-width: 54ch;
  color: var(--pencil);
  min-height: 3em;
}

.subtitle b {
  color: var(--biro);
}

/* --- the ship tray --- */

.setup {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 1rem 1.5rem;
  margin-top: 1.25rem;
  min-height: 4.5rem;
}

.setup[hidden] {
  display: none !important;
}

.tray {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.75rem 1rem;
}

.tray-ship {
  display: flex;
  flex-direction: column;
  gap: 2px;
  cursor: grab;
  touch-action: none;
}

.tray-ship.is-placed {
  opacity: 0.25;
  pointer-events: none;
}

.tray-label {
  font-family: var(--hand);
  font-size: 1.05rem;
  line-height: 1;
  color: var(--pencil);
}

.hull {
  width: calc(var(--len, 1) * var(--cell));
  height: var(--cell);
  border: 2px solid var(--biro);
  border-radius: calc(var(--cell) / 2);
  background: rgba(34, 64, 126, 0.06);
  filter: url(#wobble);
}

.setup-buttons {
  display: flex;
  gap: 0.6rem;
  margin-left: auto;
}

.pen {
  font-family: var(--hand);
  font-size: 1.35rem;
  line-height: 1;
  padding: 0.3rem 0.9rem 0.4rem;
  background: transparent;
  color: var(--biro);
  border: 2px solid var(--biro);
  border-radius: 14px 12px 15px 11px / 12px 15px 11px 14px;
  filter: url(#wobble-hard);
}

.pen:hover:not(:disabled) {
  background: rgba(34, 64, 126, 0.08);
}

.pen.strong {
  color: var(--red-biro);
  border-color: var(--red-biro);
}

.pen.strong:hover:not(:disabled) {
  background: rgba(191, 59, 47, 0.08);
}

.pen:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.pen[hidden] {
  display: none !important;
}

/* --- the boards --- */

.boards {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(1.25rem, 5vw, 3rem);
  margin-top: 1.75rem;
}

.board-figure {
  margin: 0;
}

.board-figure figcaption {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  margin-bottom: 0.35rem;
  flex-wrap: wrap;
}

.board-name {
  font-family: var(--hand);
  font-size: 1.7rem;
  line-height: 1;
  color: var(--biro);
}

.board-note {
  font-family: var(--hand);
  font-size: 1.15rem;
  line-height: 1;
  color: var(--pencil);
}

.board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(10, var(--cell));
  grid-template-rows: repeat(10, var(--cell));
  width: calc(10 * var(--cell));
  /* the page ruled lines would otherwise run straight through the grid and
     fight with it; the paper still shows all around */
  background: var(--paper);
  border-left: 1.5px solid var(--rule-strong);
  border-top: 1.5px solid var(--rule-strong);
  touch-action: none;
}

.cell {
  position: relative;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 0;
  background: transparent;
  border-top: 0;
  border-left: 0;
  display: block;
}

/* every fifth line a little stronger, like real squared paper */
.cell[data-x="4"],
.cell[data-x="9"] {
  border-right-color: var(--rule-strong);
}

.cell[data-y="4"],
.cell[data-y="9"] {
  border-bottom-color: var(--rule-strong);
}

.board[data-side="theirs"] .cell:not(:disabled) {
  cursor: crosshair;
}

.board[data-side="theirs"] .cell:not(:disabled):hover {
  background: rgba(191, 59, 47, 0.09);
}

.cell:disabled {
  cursor: default;
}

/* --- what gets drawn on the squares --- */

.mark {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

/* a biro dot for open water */
.mark.miss::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 7px;
  height: 7px;
  margin: -3.5px 0 0 -3.5px;
  border-radius: 50%;
  background: var(--biro-soft);
}

/* two hard strokes for a hit */
.mark.hit::before,
.mark.hit::after {
  content: "";
  position: absolute;
  left: 14%;
  right: 14%;
  top: 50%;
  height: 2.5px;
  background: var(--red-biro);
  border-radius: 2px;
  filter: url(#wobble-hard);
}

.mark.hit::before {
  transform: rotate(42deg);
}

.mark.hit::after {
  transform: rotate(-42deg);
}

.mark.sunk {
  background: rgba(191, 59, 47, 0.14);
}

/*
 * The hull outline drawn over the squares a ship occupies.
 *
 * A grid item spanning the ship's tracks, so it is sized by the grid itself
 * and stays right at any board size. It shares those tracks with the cells
 * underneath, which is allowed — grid items may overlap.
 */
.hull-overlay {
  position: relative;
  z-index: 2;
  margin: 2px;
  border: 2.5px solid var(--biro);
  border-radius: calc(var(--cell) / 2);
  pointer-events: none;
  filter: url(#wobble);
}

.hull-overlay.enemy {
  border-color: var(--red-biro);
  border-style: dashed;
}

/* live feedback while a ship is being dragged over the grid */
.cell.drop-ok {
  background: rgba(34, 64, 126, 0.16);
}

.cell.drop-bad {
  background: rgba(191, 59, 47, 0.16);
}

/* the ship following the pointer */
.ghost {
  position: fixed;
  z-index: 20;
  pointer-events: none;
  height: var(--cell);
  border: 2px solid var(--biro);
  border-radius: calc(var(--cell) / 2);
  background: rgba(252, 252, 248, 0.85);
  filter: url(#wobble);
}

.ghost.vertical {
  height: auto;
}

/* the last square the computer fired at */
.cell.last-shot::after {
  content: "";
  position: absolute;
  inset: -3px;
  border: 2px dashed var(--red-biro);
  border-radius: 6px;
  pointer-events: none;
}

/* --- margin notes --- */

.margin-notes {
  margin-top: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: flex-start;
}

.scoreline {
  display: flex;
  gap: clamp(1.25rem, 5vw, 3rem);
}

.score {
  margin: 0;
  font-family: var(--hand);
  font-size: 1.3rem;
  line-height: 1;
  color: var(--pencil);
}

.score-num {
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--biro);
}

#score-theirs .score-num {
  color: var(--red-biro);
}

.log {
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--hand);
  font-size: 1.25rem;
  line-height: 1.35;
  color: var(--pencil);
  max-height: 9rem;
  overflow-y: auto;
  width: 100%;
  max-width: 46ch;
}

.log li {
  padding: 0.05rem 0;
}

.log li.theirs {
  color: var(--red-biro);
}

.log li.mine {
  color: var(--biro);
}

.colophon {
  margin-top: 2.5rem;
  font-size: 0.8rem;
  color: var(--pencil);
}

.colophon p {
  margin: 0;
}

.colophon a {
  color: var(--biro);
  text-underline-offset: 3px;
}

/* --- smaller screens --- */

@media (max-width: 900px) {
  :root {
    --cell: 30px;
  }
}

@media (max-width: 680px) {
  :root {
    --cell: 28px;
  }

  .boards {
    gap: 1.5rem;
  }

  .setup-buttons {
    margin-left: 0;
  }
}

@media (max-width: 380px) {
  :root {
    --cell: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}