:root {
    --primary-color: #2c3e50;
    --accent-color: #e67e22;
    --text-dark: #333;
    --text-light: #fff;
    --bg-color: #f9f9f9;
    --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Helvetica Neue', Arial, sans-serif; }
body { background-color: var(--bg-color); color: var(--text-dark); line-height: 1.6; }

/* Header & Nav */
header { background: #fff; box-shadow: 0 2px 5px rgba(0,0,0,0.1); position: sticky; top: 0; z-index: 1000; }
.header-container { display: flex; flex-direction: column; align-items: center; padding: 1rem; }
.logo { font-size: 1.8rem; font-weight: bold; margin-bottom: 1rem; }
.logo a { text-decoration: none; color: var(--primary-color); }

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    align-items: center;
    flex-wrap: wrap;           /* 2行レイアウト対応 */
    max-width: 900px;          /* ナビゲーション全体の最大幅制限 */
    justify-content: center;   /* メニュー項目を中央配置 */
}

.nav-item a {
    font-weight: 500;
    color: var(--text-dark);
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    transition: var(--transition);
    font-size: 0.9rem;         /* 適切なフォントサイズ */
    white-space: nowrap;       /* 項目内の改行を防止 */
    text-decoration: none;
}

.nav-item a:hover {
    background-color: var(--primary-color);
    color: var(--text-light);
}

/* Hero Section */
.hero {
    position: relative;
    width: 100%;
    height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-size: cover;
    background-position: center;
}
.hero::before {
    content: '';
    position: absolute;
    top:0; left:0; width:100%; height:100%;
    background: rgba(0,0,0,0.3);
}
.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: #fff;
    padding: 2rem;
}
.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    text-shadow: 2px 2px 8px rgba(0,0,0,0.8);
    -webkit-text-stroke: 1px #000;
    margin-bottom: 1rem;
    color: #fff;
}

/* Main Content Area */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}
.two-column {
    display: flex;
    gap: 2rem;
    margin-top: 2rem;
}
.main-content {
    flex: 3;
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.sidebar {
    flex: 1;
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    align-self: flex-start;
    position: sticky;
    top: 150px;
}

.sidebar h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 0.5rem;
}

.sidebar ul {
    list-style: none;
    margin-bottom: 2rem;
}
.sidebar li {
    margin-bottom: 0.8rem;
}
.sidebar a {
    text-decoration: none;
    color: var(--text-dark);
    font-size: 0.95rem;
    transition: color 0.2s;
}
.sidebar a:hover {
    color: var(--accent-color);
}

.ad-space {
    margin: 1rem 0;
    padding: 0;
    text-align: center;
}
.ad-space img {
    max-width: 100%;
    height: auto;
}

h2 { margin-bottom: 1rem; color: var(--primary-color); border-bottom: 2px solid var(--accent-color); padding-bottom: 0.5rem; }
h3 { margin-top: 1.5rem; margin-bottom: 0.8rem; color: #444; }
p { margin-bottom: 1.5rem; font-size: 1.05rem; }

/* News Section on Top Page */
.news-section {
    background: #fff;
    padding: 2rem;
    border-radius: 8px;
    margin-top: 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.news-list {
    list-style: none;
}
.news-list li {
    padding: 1rem 0;
    border-bottom: 1px solid #eee;
}
.news-date {
    font-weight: bold;
    color: var(--accent-color);
    margin-right: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .two-column {
        flex-direction: column;
    }
    .hero-title {
        font-size: 2.5rem;
    }
}

footer { background: var(--primary-color); color: #fff; text-align: center; padding: 2rem 1rem; margin-top: 4rem; }
.footer-links a { color: #fff; text-decoration: none; margin: 0 0.5rem; }
.footer-links a:hover { text-decoration: underline; }