/* =========================
   Header
========================= */
.site-header {
    height: 96px;
    border-bottom: 1px solid #e5e5e5;
    background-color: #fff;
}

.header-inner {
    height: 100%;
}

/* Logo */
.header-logo {
    align-self: start;
}

.header-logo a {
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    color: #111;
}

/* =========================
   Navigation
========================= */
.header-nav {
    align-self: end;
    /* 下寄せ */
    display: flex;
    justify-content: center;
    /* nav全体を中央へ */
}

/* ナビ全体の横幅を制御（中央寄りの肝） */
.header-nav ul {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    /* ← 等幅ボックス */
    justify-content: center;
    list-style: none;
    margin: 0;
    padding: 0 0 6px 0;
    position: relative;
}

/* 下のアクセントライン */
.header-nav ul::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: #ddd;
}

/* 各メニュー */
.header-nav li {
    text-align: center;
}

.header-nav a {
    display: block;
    padding: 10px 0;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    color: #333;
}

/* hover時 */
.header-nav a:hover {
    color: #0066cc;
}

/* hover下線（アクセント） */
.header-nav a::after {
    content: "";
    display: block;
    margin: 6px auto 0;
    width: 0;
    height: 2px;
    background-color: #0066cc;
    transition: width 0.2s ease;
}

.header-nav a:hover::after {
    width: 40%;
}


/* =========================
   Main
========================= */
.site-main {
    padding: 48px 0;
    background-color: #fafafa;
}

.main-container {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    grid-auto-flow: column;
}

/* =========================
   Sidebars
========================= */
.sidebar-toc,
.sidebar-updates {
    grid-column: span 3;
    background-color: #fff;
    border: 1px solid #e5e5e5;
    padding: 16px;
}

/* 見出し */
.sidebar-toc h3,
.sidebar-updates h3 {
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 12px;
    border-left: 4px solid #0066cc;
    padding-left: 8px;
}

/* 目次 */
.sidebar-toc ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-toc li+li {
    margin-top: 8px;
}

.sidebar-toc a {
    text-decoration: none;
    font-size: 13px;
    color: #333;
}

.sidebar-toc a:hover {
    color: #0066cc;
}

/* =========================
   Article
========================= */
.content-article {
    grid-column: span 6;
    background-color: #fff;
    padding: 32px;
    border: 1px solid #e5e5e5;
}

.content-article h1 {
    font-size: 24px;
    margin-bottom: 16px;
}

.content-article h2 {
    font-size: 18px;
    margin-top: 32px;
    margin-bottom: 12px;
    border-bottom: 1px solid #ddd;
    padding-bottom: 6px;
}

.content-article p {
    font-size: 14px;
    line-height: 1.8;
    margin-bottom: 16px;
}

/* =========================
   Updates
========================= */
.update-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.update-list li {
    margin-bottom: 12px;
}

.update-list time {
    display: block;
    font-size: 11px;
    color: #888;
}

.update-list a {
    font-size: 13px;
    text-decoration: none;
    color: #333;
}

.update-list a:hover {
    color: #0066cc;
}