/* Common site-wide styles: header, navigation, and logo */
:root {
    --primary: #1a4d3a;
    --primary-dark: #123a2a;
    --text: #0e1116;
    --text-light: #5b6776;
    --border: #e9eef2;
    --surface: #ffffff;
    --surface-muted: #f7f9fb;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border, #e8e8e8);
    z-index: 1000;
    transition: all 0.3s ease;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 40px;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text, #1a1a1a);
    font-weight: 500;
    font-size: 18px;
}

.logo img {
    height: 44px;
    width: auto;
    margin-right: 12px;
    filter: none;
}

.nav {
    display: flex;
    gap: 40px;
    align-items: center;
}

.nav a {
    color: var(--text, #1a1a1a);
    text-decoration: none;
    font-weight: 400;
    font-size: 14px;
    letter-spacing: 0.01em;
    transition: all 0.2s ease;
    position: relative;
    padding: 8px 0;
}

.nav a:hover { color: var(--primary, #1a4d3a); }

.nav a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 1px;
    bottom: 0;
    left: 0;
    background: var(--primary, #1a4d3a);
    transition: width 0.3s ease;
}

.nav a:hover::after { width: 100%; }

@media (max-width: 768px) {
    .header-content { padding: 16px 20px; height: 70px; }
    .nav { gap: 16px; }
    .nav a { font-size: 11px; }
    .logo img { height: 36px; }
}

/* Accessibility */
.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}
.skip-link:focus {
    position: fixed;
    left: 16px;
    top: 16px;
    width: auto;
    height: auto;
    padding: 10px 14px;
    background: var(--primary, #1a4d3a);
    color: #fff;
    border-radius: 6px;
    z-index: 2000;
}


/* =============================================================
   Mobile Navigation (single row horizontal scroll)
   要件:
   1) 折り返し禁止で横一列
   2) 横スクロール可能 (overflow-x:auto)
   3) 既存 HTML を変更せず CSS のみで対応
   4) 不要なハンバーガー/メニュー系要素を強制非表示
   5) 端のフェード演出でスクロール示唆 (マスク非対応端末はそのまま)
   ------------------------------------------------------------- */
@media (max-width: 900px) {
    .header-content {
        padding: 10px 8px;
        height: 60px;
        gap: 8px;
        flex-wrap: nowrap;
    }
    
    .logo { 
        display: none;
    }
    
    .logo img {
        height: 32px;
        margin-right: 8px;
    }
    
    .nav {
        gap: 12px;
        flex-wrap: nowrap;
        overflow-x: auto;
        overflow-y: hidden;
        -webkit-overflow-scrolling: touch;
        padding: 0 4px;
        scrollbar-width: none;
        flex: 1;
        min-width: 0;
        mask: linear-gradient(90deg, transparent 0, rgba(0,0,0,1) 16px, rgba(0,0,0,1) calc(100% - 16px), transparent 100%);
        -webkit-mask: linear-gradient(90deg, transparent 0, rgba(0,0,0,1) 16px, rgba(0,0,0,1) calc(100% - 16px), transparent 100%);
    }
    
    .nav::-webkit-scrollbar { 
        display: none; 
    }
    
    .nav a {
        font-size: 11px;
        padding: 6px 8px;
        flex: 0 0 auto;
        white-space: nowrap;
        letter-spacing: -0.01em;
        border-radius: 4px;
        transition: all 0.2s ease;
    }
    
    .nav a:hover {
        background: rgba(26,77,58,0.08);
        color: var(--primary);
    }
    
    .nav a::after { 
        display: none; 
    }
    
    .hamburger, .menu-toggle, .menu-button, .nav-toggle, .mobile-menu-toggle { 
        display: none !important; 
    }
    
    .mobile-nav { 
        display: none !important; 
    }
}