body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}
header {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 1rem;
}
nav {
    background-color: #f4f4f4;
    padding: 0.5rem;
}
nav ul {
    list-style-type: none;
    padding: 0;
    display: flex;
    justify-content: center;
}
nav ul li {
    margin: 0 10px;
}
nav ul li a {
    text-decoration: none;
    color: #333;
}
main {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}
.laatikko {
    flex-basis: calc(33.333% - 20px);
    margin-bottom: 20px;
    background-color: #f9f9f9;
    padding: 15px;
    box-sizing: border-box;
}
footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 1rem;
    margin-top: 20px;
}
button {
    margin: 0 10px;
    list-style-type: none;
    padding: 0;
    justify-content: center;
    text-decoration: none;
    color: #333;
}
@media (max-width: 768px) {
    .laatikko {
        flex-basis: calc(50% - 20px);
    }
}
@media (max-width: 480px) {
    .laatikko {
        flex-basis: 100%;
    }
}