* {
    text-align: center;
    box-sizing: border-box;
}
body {
    font-family: 'Roboto', sans-serif;
    background-image: url("image.jpg");
    background-size: cover;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    backdrop-filter: blur(10px);
    color: white;
    transition: background-color 0.3s;
}

.main {
    display: flex;
    flex-direction: column;
    background-color: rgba(0,0,0,0.8);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 0 25px rgba(255,255,255,0.5);
}

h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 8px white;
}

h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    text-shadow: 1px 1px 6px white;
}

.instruction {
    color: white;
    font-size: 18px;
    margin-bottom: 20px;
    opacity: 0.9;
}

.btn-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}
.btn {
    height: 150px;
    width: 150px;
    border: 8px solid white;
    border-radius: 24px;
    margin: 1rem;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.2s;
}
.btn:hover {
    transform: scale(1.05);
    box-shadow: 0 0 20px white;
}

.pink { background-color:#FF004D; }
.green { background-color:#CCFF00; }
.teal  { background-color:#00FFB2; }
.blue  { background-color:#3300FF; }

/* Add animation for flashing */
@keyframes flash {
    0% { opacity: 1; transform: scale(1); box-shadow: none; background-color: white; }
    50% { opacity: 0.7; transform: scale(1.1); box-shadow: 0 0 40px white, 0 0 80px white; background-color: white; }
    100% { opacity: 1; transform: scale(1); box-shadow: none; background-color: white;}
}

.sliver {
    animation: flash 0.4s ease;
}