/* ========================================
   ヘッダー専用スタイル
   ======================================== */
.site-header {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

/* ロゴエリア */
.header-logo {
    flex-shrink: 0;
}

.header-logo .custom-logo {
    max-height: 60px;
    width: auto;
    height: auto;
    display: block;
}

.site-title-link {
    text-decoration: none;
    color: var(--text-color-2);
    font-size: 1.5rem;
    font-weight: bold;
    transition: color 0.3s ease;
}

.site-title-link:hover {
    color: var(--primary-color);
}

.site-title {
    display: block;
}

/* ナビゲーション */
.main-navigation {
    position: relative;
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 0;
}

.nav-menu li {
    margin: 0;
}

.nav-menu a {
    display: block;
    padding: 10px 20px;
    color: var(--text-color-2);
    text-decoration: none;
    font-weight: var(--font-weight);
    transition: color 0.3s ease, background-color 0.3s ease;
    border-radius: 4px;
}

.nav-menu a:hover,
.nav-menu a:focus {
    color: var(--text-color-1);
    background-color: var(--primary-color);
}

/* ハンバーガーメニューボタン */
.menu-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 10px;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    color: var(--text-color-2);
    transition: color 0.3s ease;
}

.menu-toggle:hover {
    color: var(--primary-color);
}

.menu-toggle-icon {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 24px;
    height: 18px;
    position: relative;
}

.menu-toggle-icon span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: currentColor;
    transition: transform 0.3s ease, opacity 0.3s ease;
    border-radius: 2px;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.menu-toggle-text {
    font-size: 0.9rem;
    font-weight: var(--font-weight);
}

/* レスポンシブ対応（スマホ） */
@media (max-width: 768px) {
    .header-container {
        padding: 10px 15px;
    }
    
    .header-logo .custom-logo {
        max-height: 50px;
    }
    
    .site-title-link {
        font-size: 1.3rem;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .main-navigation {
        position: static;
    }
    
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        width: 100%;
        background: var(--white);
        flex-direction: column;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        padding: 10px 0;
        margin-top: 0;
        border-radius: 0;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-menu li {
        width: 100%;
    }
    
    .nav-menu a {
        padding: 15px 20px;
        border-radius: 0;
    }
    
    .nav-menu a:hover,
    .nav-menu a:focus {
        background-color: var(--primary-color);
        color: var(--text-color-1);
    }
}