* {
margin: 0;
padding: 0;
box-sizing: border-box;
}

body {
font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
background-color: #ffffff;
color: #222;
line-height: 1.7;
padding: 20px;
max-width: 1100px;
margin: auto;
}

header {
margin-bottom: 30px;
}

h1 {
font-size: 2.2rem;
margin-bottom: 20px;
text-align: center;
color: #111;
}

h2 {
font-size: 1.6rem;
margin-top: 40px;
margin-bottom: 10px;
color: #2c3e50;
}

h3 {
font-size: 1.3rem;
margin-top: 25px;
color: #34495e;
}

p {
margin-bottom: 15px;
font-size: 1rem;
}

ul, ol {
margin-left: 20px;
margin-bottom: 15px;
}

ul li, ol li {
margin-bottom: 8px;
}

img {
border-radius: 12px;
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
margin-bottom: 20px;
}

section {
margin-bottom: 40px;
}

strong {
color: #000;
}

details {
margin-bottom: 15px;
background: #f2f2f2;
padding: 12px 16px;
border-left: 4px solid #3498db;
border-radius: 4px;
}

summary {
font-weight: bold;
cursor: pointer;
color: #2c3e50;
}

a {
color: #0077cc;
text-decoration: underline;
}

a:hover {
color: #005999;
}

footer {
text-align: center;
font-size: 0.9rem;
color: #555;
border-top: 1px solid #ccc;
margin-top: 40px;
padding-top: 20px;
}