:root {
  --bgTop: #0b1622;
  --bgBottom: #1a3248;
  --panel: rgba(10, 20, 32, 0.9);
  --line: rgba(255, 255, 255, 0.14);
  --text: #f0f5ed;
  --muted: #bdc8c3;
  --lightSquare: #f0d9b5;
  --darkSquare: #b58863;
  --accentA: #ffbe0b;
  --accentB: #fb5607;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Verdana, "Trebuchet MS", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 10% 0%, rgba(255, 190, 11, 0.2), transparent 34%),
    linear-gradient(180deg, var(--bgTop), var(--bgBottom));
}

.homeLink {
  display: inline-block;
  margin: 10px 14px 0;
  padding: 8px 12px;
  border-radius: 999px;
  text-decoration: none;
  color: var(--text);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.shell {
  width: min(1180px, calc(100vw - 20px));
  margin: 0 auto;
  padding: 10px 0 18px;
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.panel,
.boardWrap {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.28);
}

.panel {
  padding: 18px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accentA);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.72rem;
}

h1,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 10px;
  font-size: clamp(1.9rem, 5.2vw, 2.8rem);
  line-height: 0.95;
}

.intro {
  color: var(--muted);
  line-height: 1.5;
}

.modeRow {
  display: grid;
  gap: 6px;
  margin-top: 12px;
}

.modeRow label {
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.modeSelect {
  width: 100%;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.1);
  color: var(--text);
  font: inherit;
  padding: 10px 12px;
}

.statusCard {
  margin: 14px 0;
  padding: 12px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
}

.statusCard p {
  margin: 0 0 6px;
}

.statusCard p:last-child {
  margin-bottom: 0;
}

.buttons {
  display: grid;
  gap: 10px;
}

.button {
  width: 100%;
  border: 0;
  border-radius: 999px;
  padding: 12px 14px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.button.primary {
  color: #17202b;
  background: linear-gradient(130deg, var(--accentA), var(--accentB));
}

.button.secondary {
  color: var(--text);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.boardWrap {
  padding: 10px;
}

.board {
  width: min(92vw, 720px);
  aspect-ratio: 1 / 1;
  margin: 0 auto;
  border-radius: 14px;
  overflow: hidden;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
}

.square {
  display: grid;
  place-items: center;
  font-size: clamp(1.3rem, 4.2vw, 2.4rem);
  user-select: none;
  cursor: pointer;
  position: relative;
}

.square.light {
  background: var(--lightSquare);
}

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

.square.selected {
  outline: 3px solid rgba(255, 190, 11, 0.84);
  outline-offset: -3px;
}

.square.canMove::after {
  content: "";
  width: 24%;
  height: 24%;
  border-radius: 999px;
  background: rgba(30, 56, 83, 0.4);
  position: absolute;
}

.piece.white {
  color: #f7f7f7;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.36);
}

.piece.black {
  color: #111;
  text-shadow: 0 1px 1px rgba(255, 255, 255, 0.16);
}

@media (max-width: 940px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .board {
    width: min(95vw, 540px);
  }
}