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

body {
font-family: system-ui, sans-serif;
font-size: 18px;
line-height: 1.7;
background: #fefefe;
color: #111;
padding: 1rem;
max-width: 800px;
margin: auto;
}

img {
max-width: 100%;
height: auto;
border-radius: 12px;
margin: 1.5rem 0;
}

h1, h2, h3 {
color: #002244;
margin: 2rem 0 1rem 0;
}

h1 {
font-size: 2.2rem;
text-align: center;
}

h2 {
font-size: 1.6rem;
}

h3 {
font-size: 1.3rem;
}

p {
margin-bottom: 1.5rem;
}

strong {
color: #000;
}

ul, ol {
padding-left: 1.5rem;
margin-bottom: 1.5rem;
}

li {
margin-bottom: 0.5rem;
}

a {
color: #0066cc;
text-decoration: underline;
}

a:visited {
color: #004488;
}

a:focus, a:hover {
outline: 2px solid #004488;
background: #eef6ff;
}

header {
text-align: center;
padding-bottom: 2rem;
}

section {
padding-bottom: 2rem;
border-bottom: 1px solid #ddd;
}

section:last-child {
border-bottom: none;
}

.faq-item {
margin-bottom: 1.5rem;
}

.faq-question {
font-weight: bold;
color: #333;
}

.faq-answer {
margin-top: 0.5rem;
color: #444;
}

.common-mistakes {
background-color: #fff8f8;
padding: 1rem;
border-left: 4px solid #cc0000;
margin-bottom: 2rem;
}

.product-box {
background-color: #f4faff;
padding: 1rem;
border: 1px solid #cce0f0;
border-radius: 12px;
margin-bottom: 2rem;
}

.product-box img {
max-width: 180px;
float: left;
margin-right: 1rem;
}

.product-box h3 {
margin-top: 0;
font-size: 1.2rem;
}

.product-box p {
overflow: hidden;
}

@media screen and (max-width: 600px) {
.product-box img {
    float: none;
    display: block;
    margin: 0 auto 1rem auto;
}
}