body {
font-family: Arial, sans-serif;
line-height: 1.7;
margin: 0;
padding: 0;
background-color: #f5f5f5;
color: #222;
}

header, footer {
background-color: #ffffff;
padding: 15px 20px;
text-align: center;
box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

main {
max-width: 900px;
margin: 25px auto;
background-color: #ffffff;
padding: 25px 30px;
box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

h1, h2 {
color: #153e75;
margin-bottom: 15px;
}

p {
margin-bottom: 16px;
}

a {
color: #1a73e8;
font-weight: 600;
text-decoration: none;
}

a:hover, a:focus {
text-decoration: underline;
}

ul {
margin-left: 20px;
margin-bottom: 16px;
}

details {
margin-bottom: 20px;
background-color: #e8f0fe;
border-left: 5px solid #1a73e8;
padding: 10px 15px;
}

summary {
cursor: pointer;
font-weight: 700;
color: #1a73e8;
outline-offset: 2px;
}

summary:focus {
outline: 2px dashed #1a73e8;
}

img {
max-width: 100%;
height: auto;
display: block;
margin: 20px 0;
border-radius: 5px;
}

@media (prefers-color-scheme: dark) {
body {
    background-color: #121212;
    color: #e0e0e0;
}

header, footer, main {
    background-color: #1e1e1e;
    box-shadow: none;
}

a {
    color: #8ab4f8;
}

details {
    background-color: #2c2c2c;
    border-left-color: #8ab4f8;
}

summary {
    color: #8ab4f8;
}
}