body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    /* max-width: 900px; */
    margin: 0 auto;
    /* padding: 20px; */
}
h1, h2, h3 {
    color: #2c3e50;
}
h1 {
    border-bottom: 2px solid #42b983;
    padding-bottom: 10px;
}
h2 {
    margin-top: 30px;
    border-left: 4px solid #42b983;
    padding-left: 10px;
}
h3 {
    margin-top: 20px;
}
code {
    background-color: #f5f5f5;
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', Courier, monospace;
}
pre {
    background-color: #f8f8f8;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
}
.note {
    background-color: #e7f5ee;
    padding: 15px;
    border-left: 4px solid #42b983;
    margin: 20px 0;
}
.example {
    background-color: #f0f7ff;
    padding: 15px;
    border-left: 4px solid #64b5f6;
    margin: 20px 0;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}
th, td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}
th {
    background-color: #f2f2f2;
}
img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 15px 0;
    border: 1px solid #ddd;
}