:root {
  --bg: #f2efe9;
  --board-light: #f0d9b5;
  --board-dark: #b58863;
  --accent: #2a4d69;
  --accent-2: #4b86b4;
  --text: #222;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Noto Serif", "Georgia", serif;
  color: var(--text);
  background: radial-gradient(circle at top, #fff 0%, var(--bg) 65%);
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px;
}

header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}

h1 {
  margin: 0;
  font-size: 32px;
  letter-spacing: 0.5px;
  color: var(--accent);
}

.status {
  padding: 8px 12px;
  border-radius: 8px;
  background: #fff;
  border: 1px solid #ddd;
  font-weight: 600;
}

main {
  display: grid;
  grid-template-columns: minmax(320px, 640px) 1fr;
  gap: 24px;
  margin-top: 20px;
}

.board {
  width: 100%;
  aspect-ratio: 1 / 1;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.2);
  border: 2px solid #333;
}

.square {
  display: grid;
  place-items: center;
  font-size: clamp(20px, 5vw, 46px);
  cursor: pointer;
  user-select: none;
  transition: transform 0.08s ease, background-color 0.2s ease;
}

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

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

.square.highlight {
  box-shadow: inset 0 0 0 4px rgba(255, 255, 255, 0.7);
}

.square.move {
  background: color-mix(in srgb, var(--accent-2) 35%, transparent);
}

.square.capture {
  background: color-mix(in srgb, #c0392b 40%, transparent);
}

.square.selected {
  transform: scale(1.04);
  outline: 3px solid #222;
  outline-offset: -3px;
}

.panel {
  background: #fff;
  border-radius: 12px;
  padding: 16px;
  border: 1px solid #ddd;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.panel-section + .panel-section {
  margin-top: 16px;
}

.panel h2 {
  margin: 0 0 10px 0;
  font-size: 18px;
  color: var(--accent);
}

button {
  padding: 10px 14px;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
  margin-right: 8px;
}

button:hover {
  background: var(--accent-2);
}

footer {
  margin-top: 16px;
  font-size: 14px;
  opacity: 0.8;
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 10px;
}

select {
  width: 100%;
  margin-top: 6px;
  padding: 8px;
  border-radius: 8px;
  border: 1px solid #ccc;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  display: grid;
  place-items: center;
  z-index: 10;
}

.modal.hidden {
  display: none;
}

.modal-card {
  background: #fff;
  border-radius: 12px;
  padding: 18px;
  min-width: 280px;
  border: 1px solid #ddd;
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.2);
}

.promo-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 12px;
}

@media (max-width: 900px) {
  main {
    grid-template-columns: 1fr;
  }

  .row {
    grid-template-columns: 1fr;
  }
}