body {
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    font-family: 'Arial', sans-serif;
}

h1 {
    color: white;
    font-size: 3em;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

p {
    color: white;
    font-size: 1.2em;
    margin-bottom: 50px;
    text-align: center;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.square-container {
    position: relative;
    width: 300px;
    height: 300px;
}

.square {
    width: 100%;
    height: 100%;
    background: #4a90e2;
    border: 3px solid #fff;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.plasma-ball {
    position: absolute;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: radial-gradient(circle at 40% 40%, #ffff99, #ffeb3b, #ff9800);
    box-shadow:
        0 0 10px #ffeb3b,
        0 0 20px #ff9800,
        0 0 30px #ff5722,
        inset 0 0 10px rgba(255, 255, 255, 0.5);
    animation: circleSquare 4s linear infinite, pulse 0.5s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.1);
    }
}

@keyframes circleSquare {
    0% {
        top: -15px;
        left: -15px;
    }

    25% {
        top: -15px;
        left: calc(100% - 15px);
    }

    50% {
        top: calc(100% - 15px);
        left: calc(100% - 15px);
    }

    75% {
        top: calc(100% - 15px);
        left: -15px;
    }

    100% {
        top: -15px;
        left: -15px;
    }
}