:root {
  color-scheme: light;
  --ink: #171714;
  --paper: #f5f0e6;
  --panel: #fffdf7;
  --light-square: #eee8da;
  --dark-square: #71866c;
  --accent: #e3593f;
  --line: #171714;
  --muted: #6c695f;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 300px;
  background:
    linear-gradient(rgba(23, 23, 20, 0.035) 1px, transparent 1px),
    var(--paper);
  background-size: 100% 24px;
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
select,
input {
  font: inherit;
}

button,
select {
  color: inherit;
}

button {
  cursor: pointer;
}

.page {
  width: min(100%, 760px);
  margin: 0 auto;
  padding: 24px 18px 44px;
}

.site-header {
  margin-bottom: 18px;
}

.home-link {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--ink);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-decoration-thickness: 2px;
  text-transform: uppercase;
  text-underline-offset: 4px;
}

.title-row,
.share-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(4rem, 16vw, 7.5rem);
  font-weight: 400;
  letter-spacing: -0.075em;
  line-height: 0.72;
}

.turn-count {
  margin: 0;
  border-bottom: 2px solid var(--line);
  padding: 0 0 4px;
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.1em;
}

.toolbar {
  display: flex;
  align-items: stretch;
  gap: 8px;
  margin: 28px 0 14px;
}

.mode-switch {
  display: flex;
  flex: 1 1 auto;
  border: 2px solid var(--line);
  background: var(--panel);
}

.mode-button,
.new-button,
.copy-row button {
  border: 0;
  background: transparent;
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.055em;
  text-transform: uppercase;
}

.mode-button {
  flex: 1;
  min-height: 44px;
  padding: 8px 12px;
}

.mode-button + .mode-button {
  border-left: 2px solid var(--line);
}

.mode-button.is-active {
  background: var(--ink);
  color: var(--paper);
}

.difficulty {
  display: flex;
  align-items: center;
  gap: 6px;
  border: 2px solid var(--line);
  background: var(--panel);
  padding: 0 8px;
}

.difficulty span {
  color: var(--muted);
  font-size: 0.64rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.difficulty select {
  min-height: 40px;
  border: 0;
  outline: 0;
  background: transparent;
  font-size: 0.76rem;
  font-weight: 850;
}

.new-button {
  border: 2px solid var(--line);
  background: var(--panel);
  padding: 8px 14px;
}

.mode-button:hover,
.new-button:hover,
.copy-row button:hover {
  background: var(--accent);
  color: #fff;
}

.game {
  border: 2px solid var(--line);
  background: var(--panel);
}

.player {
  display: flex;
  min-height: 46px;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  font-size: 0.78rem;
  font-weight: 850;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.player img {
  width: 30px;
  height: 30px;
}

.player strong {
  margin-left: auto;
  color: var(--accent);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
}

.player.is-turn {
  background: var(--ink);
  color: var(--paper);
}

.board-shell {
  border-top: 2px solid var(--line);
  border-bottom: 2px solid var(--line);
  background: var(--line);
}

.board {
  display: grid;
  width: 100%;
  min-width: 0;
  aspect-ratio: 1;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  overflow: hidden;
}

.square {
  position: relative;
  display: grid;
  min-width: 0;
  place-items: center;
  aspect-ratio: 1;
  border: 0;
  padding: 3px;
  background: var(--light-square);
  -webkit-tap-highlight-color: transparent;
}

.square.dark {
  background: var(--dark-square);
}

.square img {
  position: relative;
  z-index: 2;
  width: 86%;
  height: 86%;
  pointer-events: none;
  transition: transform 100ms ease;
}

.square:hover img,
.square:focus-visible img {
  transform: translateY(-3px);
}

.square:focus-visible {
  z-index: 4;
  outline: 4px solid var(--accent);
  outline-offset: -4px;
}

.square.is-selected::after,
.square.was-moved::after {
  position: absolute;
  z-index: 1;
  inset: 7%;
  border: 4px solid var(--accent);
  content: "";
}

.square.was-moved::after {
  border: 0;
  background: color-mix(in srgb, #f6d559 58%, transparent);
}

.square.is-target::before {
  position: absolute;
  z-index: 3;
  width: 20%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: color-mix(in srgb, var(--ink) 68%, transparent);
  content: "";
}

.square.is-target.is-capture::before {
  width: 72%;
  border: 4px solid color-mix(in srgb, var(--accent) 85%, transparent);
  background: transparent;
}

.coordinate {
  position: absolute;
  z-index: 5;
  color: color-mix(in srgb, var(--ink) 72%, transparent);
  font-size: clamp(0.48rem, 1.7vw, 0.68rem);
  font-weight: 900;
  line-height: 1;
  pointer-events: none;
}

.dark .coordinate {
  color: color-mix(in srgb, var(--paper) 82%, transparent);
}

.coordinate.rank {
  top: 5px;
  left: 5px;
}

.coordinate.file {
  right: 5px;
  bottom: 4px;
  text-transform: lowercase;
}

.status-card,
.share-card,
.how-to {
  border: 2px solid var(--line);
  border-top: 0;
  background: var(--panel);
}

.status-card {
  display: grid;
  grid-template-columns: minmax(130px, 0.7fr) 1.3fr;
  gap: 12px;
  align-items: baseline;
  padding: 13px 14px;
}

.status-card p {
  margin: 0;
}

.status-main {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.35rem;
}

.status-detail {
  color: var(--muted);
  font-size: 0.79rem;
  line-height: 1.4;
}

.share-card {
  margin-top: 16px;
  padding: 18px;
  box-shadow: 7px 7px 0 var(--line);
}

.share-card[hidden] {
  display: none;
}

.share-card h2 {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: -0.04em;
}

.link-mark {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 3rem;
  line-height: 0.8;
}

.share-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 18px 0;
  padding: 0;
  counter-reset: steps;
  list-style: none;
}

.share-steps li {
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.4;
  counter-increment: steps;
}

.share-steps li::before {
  display: block;
  margin-bottom: 4px;
  color: var(--accent);
  content: "0" counter(steps);
  font-weight: 900;
  letter-spacing: 0.08em;
}

.copy-row {
  display: flex;
  border: 2px solid var(--line);
}

.copy-row input {
  min-width: 0;
  flex: 1;
  border: 0;
  background: #fff;
  padding: 11px;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 0.72rem;
  outline: 0;
}

.copy-row input:focus {
  box-shadow: inset 0 0 0 3px var(--accent);
}

.copy-row button {
  min-width: 116px;
  border-left: 2px solid var(--line);
  background: var(--ink);
  color: #fff;
  padding: 10px 14px;
}

.privacy-note {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.68rem;
}

.how-to {
  margin-top: 16px;
  border-top: 2px solid var(--line);
}

.how-to summary {
  padding: 12px 14px;
  cursor: pointer;
  font-size: 0.74rem;
  font-weight: 900;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.how-to p {
  margin: 0;
  border-top: 1px solid var(--line);
  padding: 12px 14px;
  color: var(--muted);
  font-size: 0.8rem;
  line-height: 1.55;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding-top: 28px;
  color: var(--muted);
  font-size: 0.62rem;
  font-weight: 750;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

@media (max-width: 600px) {
  .page {
    padding: 18px 10px 32px;
  }

  .home-link {
    margin-bottom: 24px;
  }

  .toolbar {
    flex-wrap: wrap;
  }

  .mode-switch {
    flex-basis: 100%;
  }

  .difficulty {
    flex: 1;
  }

  .status-card {
    grid-template-columns: 1fr;
    gap: 3px;
  }

  .share-steps {
    grid-template-columns: 1fr;
    gap: 7px;
  }

  .share-steps li::before {
    display: inline;
    margin-right: 8px;
  }
}

@media (max-width: 390px) {
  .copy-row {
    display: grid;
  }

  .copy-row button {
    border-top: 2px solid var(--line);
    border-left: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .square img {
    transition: none;
  }
}