* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #f0f4f8;
  font-family: 'Segoe UI', Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

#header {
  background: #06bcb7;
  color: #fff;
  padding: 28px 0 18px 0;
  box-shadow: 0 3px 10px rgba(6, 188, 183, 0.08);
  text-align: center;
}

#header h1 {
  font-size: 2.4em;
  letter-spacing: 2px;
  font-weight: 700;
}

main {
  flex: 1 0 auto;
  width: 330px;
  max-width: 94vw;
  margin: 50px auto 20px auto;
  background: #fff;
  padding: 34px 22px 24px 22px;
  border-radius: 16px;
  box-shadow: 0 6px 24px #cbe2e4;
  text-align: center;
}

.container {
  margin-bottom: 12px;
}

.buttons {
  display: grid;
  grid-template-columns: repeat(3, 80px);
  grid-gap: 12px;
  justify-content: center;
  margin-bottom: 14px;
}

.button {
  width: 80px;
  height: 80px;
  background: #eaeaea;
  font-size: 2.4em;
  color: #634caf;
  border-radius: 10px;
  cursor: pointer;
  user-select: none;
  border: none;
  font-weight: bold;
  transition: background 0.18s, color 0.15s, box-shadow 0.18s;
  box-shadow: 0 1px 4px rgba(0,0,0,0.07);
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

.button.X {
  background: #ffe96c !important;
  color: #413c00;
}

.button.O {
  background: #feb8e4 !important;
  color: #700447;
}

.button:hover:enabled {
  background: #d6feff !important;
}

.winner {
  min-height: 38px;
  font-size: 1.2em;
  font-weight: 600;
  letter-spacing: 1px;
  color: #444;
  margin-bottom: 9px;
  margin-top: 8px;
}

.resetBtn {
  background: #06bcb7;
  color: #fff;
  border: none;
  padding: 11px 32px;
  border-radius: 8px;
  font-size: 1.1em;
  cursor: pointer;
  margin-top: 8px;
  font-weight: 500;
  transition: background 0.2s;
  box-shadow: 0 3px 14px rgba(6, 188, 183, 0.03);
}

.resetBtn:hover {
  background: #03919c;
}

.footer {
  width: 100%;
  background: #1e2c33;
  color: #f2f8f9;
  text-align: center;
  padding: 16px 0 14px 0;
  font-size: 1em;
  font-weight: 500;
  letter-spacing: 1px;
  box-shadow: 0 -2px 12px rgba(30,44,51,0.07);
  position: relative;
  bottom: 0;
}

.footer-container {
  max-width: 340px;
  margin: 0 auto;
}

@media (max-width: 500px) {
  main {
    width: 98vw;
    padding: 10vw 1vw 7vw 1vw;
  }
  .buttons {
    grid-template-columns: repeat(3, 21vw);
    grid-gap: 2vw;
  }
  .button {
    width: 21vw;
    height: 21vw;
    min-width: 52px;
    min-height: 52px;
    font-size: 2em;
  }
}