:root {
    --color-bg-light: #e0f2fe;
    --color-bg-dark: #bae6fd;
    --color-window-bg: #ffffff;
    --color-border: #1e293b;
    --color-text: #334155;
    --color-text-link: #0284c7;
}

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

body {
    font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
    color: var(--color-text);
    background: linear-gradient(180deg, var(--color-bg-light) 0%, var(--color-bg-dark) 100%);
    background-attachment: fixed;
    line-height: 1.8;
    padding: 40px 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--color-window-bg);
    border: 4px solid var(--color-border);
    border-radius: 8px;
    box-shadow: 4px 4px 0px #38bdf8;
    padding: 40px;
}

h1 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e2e8f0;
    text-align: center;
}

h2 {
    font-size: 1.3rem;
    margin-top: 30px;
    margin-bottom: 15px;
    color: var(--color-border);
}

p {
    margin-bottom: 15px;
}

ol {
    margin-left: 25px;
    margin-bottom: 15px;
}

li {
    margin-bottom: 8px;
}

a {
    color: var(--color-text-link);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.back-link {
    margin-top: 40px;
    text-align: center;
    font-weight: bold;
}

@media (max-width: 600px) {
    .container {
        padding: 20px;
    }
    h1 {
        font-size: 1.5rem;
    }
}