html, body {
    margin: 0;
    height: 100%;
    background-color: #f0f0f0;
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center; /* horizontal center */
    align-items: flex-start; /* top align vertically */
    padding: 20px 0;
    box-sizing: border-box;
}

.text-block {
    background: white;
    padding: 20px 30px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh; /* max height relative to viewport */
    overflow-y: auto; /* enable vertical scroll inside */
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    text-align: justify; /* JUSTIFY text */
    line-height: 1.5;
    border-radius: 8px;
    box-sizing: border-box;
}

/* Center h2 and h4 inside the block */
.text-block h2,
.text-block h4 {
    text-align: center;
}