/* Base reset and sensible defaults */
*,
*::before,
*::after {
  padding: 0;
  margin: 0;
  box-sizing: inherit;
}

html {
  font-size: 62.5%;
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: monospace;
  font-size: 1.6rem;
  color: #0f1724;
  background: linear-gradient(180deg, #e6f0ff 0%, #f7fbff 60%);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  display: flex;
  flex-direction: column;
  min-height: 100vh;
  align-items: center;
}

header {
  width: 100%;
  max-width: 1200px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 2rem 1.6rem;
}

header span {
  font-size: 2.4rem;
  font-weight: 700;
  color: #08306b;
}

main {
  width: 100%;
  max-width: 1200px;
  padding: 1.6rem;
  flex: 1 0 auto;
}

#game-container {
  display: flex;
  gap: 2.4rem;
  justify-content: center;
  align-items: flex-start;
}

.playerOne,
.playerTwo {
  background: rgba(255, 255, 255, 0.85);
  border-radius: 11px;
  padding: 1.6rem;
  box-shadow: 0 6px 18px rgba(9, 30, 66, 0.08);

  display: flex;
  flex-direction: column;
  align-items: center;
}

.playerTitle {
  font-size: 2rem;
  font-weight: 600;
  text-align: center;
  margin-bottom: 1.2rem;
  color: #0b2545;
}

.playerGrid {
  width: 34rem;
  height: 34rem;
  padding: 0.4rem;
  border: 1px solid rgba(8, 48, 107, 0.08);
  border-radius: 8px;
  background: linear-gradient(180deg, #dbeeff 0%, #ffffff 100%);

  display: grid;
  gap: 0.4rem;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
}

.playerGrid > * {
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.6),
    rgba(0, 0, 0, 0.02)
  );
  border-radius: 4px;

  display: flex;
  align-items: center;
  justify-content: center;

  cursor: pointer;
  transition:
    transform 120ms ease,
    box-shadow 120ms ease;
}

.playerGrid > *:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(9, 30, 66, 0.08);
}

.playerOneGrid {
  /* subtle tint for differentiation */
  background: linear-gradient(180deg, #e6f8ff, #f8feff);
}

.playerTwoGrid {
  background: linear-gradient(180deg, #fff0f6, #fff9fb);
}

.btnPlay {
  background: #0b5cff;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 6px 14px rgba(11, 92, 255, 0.18);
}

.btnPlay:active {
  transform: translateY(1px);
}

footer {
  width: 100%;
  max-width: 1200px;
  padding: 1.6rem;
  color: #475569;
  text-align: center;
}

@media (max-width: 820px) {
  html {
    font-size: 55%;
  }
}

@media (max-width: 740px) {
  #game-container {
    flex-direction: column;
    align-items: center;
  }
}