:root {
    --bg: #f5f8ff;
    --ink: #17233c;
    --muted: #52607c;
    --line: rgba(23, 35, 60, 0.14);
    --surface: #fff;
    --font-main: "Avenir Next", "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-main);
    color: var(--ink);
    background: var(--bg);
    line-height: 1.8;
}

.wrap {
    width: min(860px, calc(100% - 32px));
    margin: 26px auto 48px;
    padding: 22px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 16px;
}

.page-tools {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}

.back {
    color: var(--muted);
    font-size: 0.92rem;
}

.lang-switch {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
    padding: 8px 14px;
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--ink);
    background: rgba(23, 35, 60, 0.03);
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

h1 {
    margin: 0 0 4px;
    font-size: clamp(1.5rem, 3.5vw, 2rem);
}

.updated {
    margin: 0 0 18px;
    color: var(--muted);
    font-size: 0.85rem;
}

section {
    margin-bottom: 18px;
}

h2 {
    margin: 0 0 6px;
    font-size: 1.12rem;
}

p,
li {
    margin: 0;
}

ul {
    margin: 0;
    padding-left: 18px;
}

@media (max-width: 640px) {
    .page-tools {
        flex-wrap: wrap;
    }
}