:root {
    --bg: #e8f5e9;
    --cell-bg: #f1f8e9;
    --primary: #4caf50;
    --dark: #1b5e20;
    --cell-size: 44px;
    --gap: 2px;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}
body {
    font-family: 'Segoe UI', 'PingFang SC', system-ui, sans-serif;
    background: linear-gradient(145deg, #dcedc8 0%, #a5d6a7 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 10px;
}