* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
line-height: 1.8;
color: #333;
background-color: #f5f5f5;
}
header {
background-color: #fff;
padding: 2rem 1rem;
text-align: center;
border-bottom: 1px solid #e0e0e0;
}
h1 {
font-size: 1.8rem;
font-weight: 600;
color: #2c3e50;
}
main {
max-width: 600px;
margin: 2rem auto;
padding: 2rem 1.5rem;
background-color: #fff;
box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
h2 {
font-size: 1.6rem;
color: #34495e;
margin: 2rem 0 1rem;
padding-bottom: 0.5rem;
border-bottom: 2px solid #3498db;
}
h2:first-child {
margin-top: 0;
}
h3 {
font-size: 1.3rem;
color: #34495e;
margin: 1.5rem 0 0.8rem;
padding-left: 0.8rem;
border-left: 4px solid #3498db;
}
h4 {
font-size: 1.1rem;
color: #34495e;
margin: 1.2rem 0 0.6rem;
font-weight: 600;
}
p {
margin: 1.2rem 0;
}
img {
max-width: 100%;
height: auto;
display: block;
margin: 1.5rem auto;
}
table {
width: 100%;
border-collapse: collapse;
margin: 1.5rem 0;
}
table th,
table td {
padding: 0.8rem;
border: 1px solid #ddd;
text-align: left;
}
table th {
background-color: #f8f9fa;
font-weight: 600;
color: #2c3e50;
}
table tr:nth-child(even) {
background-color: #fafafa;
}
ul, ol {
margin: 1.2rem 0;
padding-left: 2rem;
}
li {
margin: 0.5rem 0;
}
footer {
background-color: #2c3e50;
color: #fff;
padding: 2rem 1rem;
margin-top: 3rem;
}
.footer-menu {
max-width: 600px;
margin: 0 auto;
display: flex;
flex-wrap: wrap;
justify-content: center;
gap: 1.5rem;
}
.footer-menu a {
color: #fff;
text-decoration: none;
transition: opacity 0.3s;
}
.footer-menu a:hover {
opacity: 0.7;
}
@media (max-width: 640px) {
main {
margin: 1rem;
padding: 1.5rem 1rem;
}
h1 {
font-size: 1.5rem;
}
h2 {
font-size: 1.4rem;
}
h3 {
font-size: 1.2rem;
}
table {
font-size: 0.9rem;
}
table th,
table td {
padding: 0.6rem;
}
.footer-menu {
flex-direction: column;
align-items: center;
gap: 1rem;
}
}
.copyright {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.9rem;
    opacity: 0.8;
}