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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
}

.info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

#turn {
    font-size: 18px;
    font-weight: bold;
    color: #555;
}

#resetBtn {
    padding: 10px 20px;
    background-color: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}

#resetBtn:hover {
    background-color: #764ba2;
}

#chessboard {
    display: grid;
    grid-template-columns: repeat(8, 70px);
    grid-template-rows: repeat(8, 70px);
    border: 3px solid #333;
    margin: 0 auto;
}

.square {
    width: 70px;
    height: 70px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 40px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.white {
    background-color: #f0d9b5;
}

.black {
    background-color: #b58863;
}

.square.selected {
    background-color: #7fc97f !important;
}

.square.valid-move {
    background-color: #90ee90 !important;
}

.square:hover {
    opacity: 0.8;
}

#message {
    text-align: center;
    margin-top: 20px;
    font-size: 20px;
    font-weight: bold;
    color: #333;
}

@media (max-width: 768px) {
    #chessboard {
        grid-template-columns: repeat(8, 45px);
        grid-template-rows: repeat(8, 45px);
    }
    
    .square {
        width: 45px;
        height: 45px;
        font-size: 28px;
    }
}