* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang HK", sans-serif; background: #ede7f6; color: #222; padding: 10px; max-width: 420px; margin: 0 auto; text-align: center; }
header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; }
h1 { font-size: 1.6rem; }
.big-btn { background: #673ab7; color: white; border: none; border-radius: 12px; padding: 14px 22px; font-size: 1.2rem; min-height: 50px; cursor: pointer; }
#grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 20px 0; }
.cell { font-size: 2.5rem; padding: 15px; background: white; border-radius: 12px; border: 3px solid #d1c4e9; cursor: pointer; }