/* ===================================
   ヘッダー
   =================================== */
.site-header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    background: rgba(14, 14, 24, 0.9);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    display: flex;
    align-items: baseline;
    font-size: 2.2rem;
    font-weight: 900;
    letter-spacing: -1px;
    text-decoration: none;
}

.logo-aap {
    background: linear-gradient(135deg, #e91e63, #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-gz {
    color: #ffd700;
    text-shadow: 0 0 12px rgba(255, 215, 0, 0.3);
}

.site-tagline {
    font-size: 0.65rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
}


.main-nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: var(--radius);
    transition: var(--transition);
    position: relative;
}

.main-nav a:hover {
    color: var(--text-primary);
    background: var(--bg-card);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
    transform: translateX(-50%);
    border-radius: 2px;
}

.main-nav a:hover::after {
    width: 60%;
}

/* ハンバーガーボタン */
.hamburger-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    padding: 10px;
    z-index: 10000 !important;
}

.hamburger-btn span {
    display: block;
    width: 24px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

.hamburger-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger-btn.active span:nth-child(2) {
    opacity: 0;
}

.hamburger-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* PC幅でもナビが折り返し可能に */
.main-nav {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    /* ヘッダー配置: ハンバーガー左、ロゴ中央 */
    .header-inner {
        position: relative;
    }

    .hamburger-btn {
        display: flex !important;
        order: -1;
        position: absolute;
        left: 0;
        top: 50%;
        transform: translateY(-50%);
    }

    .hamburger-btn span {
        background: #ffffff !important;
    }

    .header-inner > div:first-of-type {
        flex: 1;
        display: flex;
        justify-content: center;
    }

    /* スライドメニュー: 左からスライドイン */
    .main-nav {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: 280px;
        box-sizing: border-box;
        background-color: #1a1a2e !important;
        padding: 80px 0 40px;
        z-index: 9999 !important;
        overflow-x: hidden;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        box-shadow: 4px 0 20px rgba(0, 0, 0, 0.3);
    }

    body.menu-open {
        overflow: hidden;
        position: fixed;
        width: 100%;
    }

    .main-nav.mobile-open {
        display: block;
    }

    .main-nav a {
        display: block;
        width: 100%;
        box-sizing: border-box;
        font-size: clamp(20px, 5vh, 28px);
        padding: 20px;
        margin-bottom: 5px;
        border-radius: var(--radius);
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        color: #ffffff !important;
        text-align: center;
        font-weight: bold;
        text-decoration: none;
    }

    .main-nav a:hover,
    .main-nav a.nav-active {
        background: rgba(255, 255, 255, 0.1);
        color: #ffffff !important;
    }

    /* オーバーレイ */
    .nav-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 99;
    }

    .nav-overlay.active {
        display: block;
    }
}

/* ===================================