/* Center-aligns all text and elements inside the body */
body {
    text-align: center;
}

/* Common button styling */
.btn {
    height: 200px;                  /* Fixed height for buttons */
    width: 200px;                   /* Fixed width for buttons */
    border: 10px solid black;       /* Thick black border */
    border-radius: 20%;             /* Rounded corners */
    margin: 2rem;                   /* Space around each button */
}

/* Container that holds all buttons */
.btn-container {
    display: flex;                  /* Arrange buttons in a row */
    justify-content: center;        /* Center buttons horizontally */
}

/* Button color variants */
.red {
    background-color: #d95980;      /* Soft red/pink shade */
}

.yellow {
    background-color: #f99b45;      /* Warm yellow/orange shade */
}

.green {
    background-color: #63aac0;      /* Light teal shade */
}

.purple {
    background-color: #819ff9;      /* Soft purple/blue shade */
}

/* Special effect: flash animation background color */
.flash {
    background-color: white;        /* White background when flashing */
}

/* Special effect: user interaction flash color */
.userFlash {
    background-color: aqua;         /* Aqua background for user flash */
}

#startBtn {
    padding: 10px 20px;
    font-size: 18px;
    margin-top: 15px;
    cursor: pointer;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 8px;
}

#startBtn:hover {
    background-color: #45a049;
}