:root {
    --bg: #ffffff;
    --bg-soft: #f6f8fa;
    --text: #1f2328;
    --muted: #59636e;
    --line: #d1d9e0;
    --link: #0969da;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0d1117;
        --bg-soft: #151b23;
        --text: #e6edf3;
        --muted: #9198a1;
        --line: #3d444d;
        --link: #4493f8;
    }
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 16px;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Segoe UI", Meiryo, sans-serif;
    font-size: 16px;
    line-height: 1.8;
}

a {
    color: var(--link);
    overflow-wrap: anywhere;
}

/* ヘッダー */
.site-header {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 16px;
    align-items: center;
    justify-content: space-between;
    max-width: 1120px;
    margin: 0 auto;
    padding: 16px;
    border-bottom: 1px solid var(--line);
}

.site-name {
    font-weight: 700;
}

.lang-nav {
    display: flex;
    gap: 16px;
}

/* レイアウト: PC はサイドバー+本文、スマホは目次が上 */
.layout {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 16px;
}

main {
    min-width: 0;
    padding-bottom: 64px;
}

@media (min-width: 900px) {
    .layout {
        display: grid;
        grid-template-columns: 260px minmax(0, 1fr);
        gap: 40px;
    }

    .toc {
        position: sticky;
        top: 0;
        align-self: start;
        max-height: 100vh;
        overflow-y: auto;
        padding: 8px 0 24px;
    }

    .toc summary {
        pointer-events: none;
        list-style: none;
    }

    .toc summary::-webkit-details-marker {
        display: none;
    }
}

/* 目次 */
.toc details {
    margin: 16px 0;
    padding: 12px 16px;
    background: var(--bg-soft);
    border: 1px solid var(--line);
    border-radius: 8px;
}

.toc summary {
    font-weight: 700;
    cursor: pointer;
}

.toc ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.toc ul ul {
    margin: 4px 0 12px;
    padding-left: 12px;
    border-left: 2px solid var(--line);
}

.toc li {
    margin: 2px 0;
    font-size: 0.92rem;
    line-height: 1.5;
}

.toc a {
    display: block;
    padding: 4px 0;
    text-decoration: none;
}

.toc .toc-lang {
    margin-top: 8px;
    color: var(--text);
    font-weight: 700;
}

/* 本文 */
.lang + .lang {
    margin-top: 64px;
    border-top: 2px solid var(--line);
}

.lang-label {
    margin: 24px 0 0;
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.doc {
    padding-top: 8px;
}

.doc + .doc {
    margin-top: 40px;
    border-top: 1px solid var(--line);
}

h2 {
    font-size: 1.5rem;
    line-height: 1.4;
    margin: 24px 0 16px;
}

h3 {
    font-size: 1.05rem;
    line-height: 1.5;
    margin: 24px 0 8px;
}

p {
    margin: 0 0 8px;
}

.sub {
    padding-left: 1.5em;
}

.operator {
    margin-top: 24px;
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 8px;
}

.operator p {
    margin: 0;
}

/* 表(特商法表記) */
.info-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0;
}

.info-table th,
.info-table td {
    padding: 12px 8px;
    border-bottom: 1px solid var(--line);
    text-align: left;
    vertical-align: top;
}

.info-table th {
    width: 32%;
    font-weight: 700;
}

@media (max-width: 560px) {
    .info-table th,
    .info-table td {
        display: block;
        width: 100%;
    }

    .info-table th {
        border-bottom: none;
        padding-bottom: 0;
    }
}