/* --- Site Header (Common) --- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.header-container {
    max-width: 80rem;
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 4.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    transition: transform 0.3s ease, opacity 0.3s ease;
}
.logo-link:hover { 
    transform: scale(1.05);
    opacity: 0.9;
}
.logo-image {
    height: 2.5rem;
    width: auto;
    object-fit: contain;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

/* Desktop Navigation */
.desktop-nav { display: none; }
@media (min-width: 1024px) {
    .desktop-nav { display: block; }
    .desktop-nav > ul {
        display: flex;
        align-items: center;
        gap: 0.5rem;
        list-style: none;
    }
    .nav-item { 
        position: relative;
    }
    .nav-link, .nav-trigger {
        display: flex;
        align-items: center;
        padding: 0.75rem 1.25rem;
        border-radius: 0.5rem;
        font-size: 0.95rem;
        font-weight: 600;
        color: var(--color-text);
        background: none;
        border: none;
        cursor: pointer;
        text-decoration: none;
        transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    
    .nav-trigger.active {
        color: var(--color-primary);
    }
    
    .nav-trigger .chevron-icon {
        margin-left: 0.5rem;
        transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        width: 16px;
        height: 16px;
    }
    .nav-trigger.active .chevron-icon { 
        transform: rotate(180deg);
    }

    .dropdown-menu {
        position: absolute;
        top: calc(100% + 10px);
        left: 50%;
        transform: translateX(-50%);
        min-width: 220px;
        background-color: white;
        border-radius: 12px;
        box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15), 0 0 0 1px rgba(0, 0, 0, 0.05);
        padding: 0.75rem;
        opacity: 0;
        visibility: hidden;
        transform: translateX(-50%) translateY(-10px) scale(0.95);
        transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 100;
    }
    
    .dropdown-menu::before {
        content: '';
        position: absolute;
        top: -6px;
        left: 50%;
        transform: translateX(-50%);
        width: 12px;
        height: 12px;
        background: white;
        border: 1px solid rgba(0, 0, 0, 0.05);
        border-bottom: none;
        border-right: none;
        transform: translateX(-50%) rotate(45deg);
    }
    
    .dropdown-menu.active {
        opacity: 1;
        visibility: visible;
        transform: translateX(-50%) translateY(0) scale(1);
    }
    
    .dropdown-menu ul { 
        list-style: none;
        display: flex;
        flex-direction: column;
        gap: 0.25rem;
    }
    
    .dropdown-link {
        display: block;
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
        font-weight: 500;
        color: var(--color-secondary-text);
        text-decoration: none;
        border-radius: 8px;
        transition: all 0.2s ease;
        white-space: nowrap;

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

/* Mobile Navigation */
.mobile-menu-button {
    display: block;
    padding: 0.75rem;
    cursor: pointer;
    background-color: transparent;
    border: 2px solid transparent;
    border-radius: 8px;
    z-index: 100;
    color: var(--color-text);
    transition: all 0.3s ease;
}

.mobile-menu-button:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
}

.mobile-menu-button.active { 
    color: var(--color-primary);
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
}

.mobile-nav {
    position: absolute;
    top: 4.5rem;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(0, 0, 0, 0.08);
    max-height: calc(100vh - 4.5rem);
    overflow-y: auto;
    transform: translateY(-100%);
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.mobile-nav.active {
    transform: translateY(0);
    visibility: visible;
}

.mobile-nav ul { 
    list-style: none; 
    padding: 1.5rem; 
}

.mobile-nav-item { 
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    margin-bottom: 0.5rem;
}

.mobile-nav-item:last-child { 
    border-bottom: none;
    margin-bottom: 0;
}

.mobile-nav-link, .mobile-nav-trigger {
    display: flex;
    width: 100%;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    background: none;
    border: none;
    cursor: pointer;
    text-align: left;
    transition: all 0.3s ease;
    border-radius: 8px;
}

.mobile-nav-link:hover, .mobile-nav-trigger:hover {
    color: var(--color-primary);
    padding-left: 0.5rem;
}

.mobile-nav-trigger .chevron-icon { 
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    width: 20px;
    height: 20px;
}

.mobile-nav-trigger.active .chevron-icon { 
    transform: rotate(180deg);
}

.mobile-dropdown-menu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    background: linear-gradient(135deg, var(--color-primary-light), rgba(255, 255, 255, 0.8));
    margin: 0 -1.5rem;
    border-radius: 12px;
    margin-top: 0.5rem;
}

.mobile-dropdown-menu ul { 
    padding: 1rem 2rem 1rem 3rem; 
}

.mobile-dropdown-menu li { 
    list-style: none;
    margin-bottom: 0.5rem;
}

.mobile-dropdown-link {
    display: block;
    padding: 0.75rem 0;
    color: var(--color-secondary-text);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border-radius: 6px;
    position: relative;
}

.mobile-dropdown-link:hover {
    color: var(--color-primary);
    padding-left: 0.5rem;
}

.mobile-dropdown-link::before {
    content: '→';
    position: absolute;
    left: -1rem;
    opacity: 0;
    transition: all 0.3s ease;
    color: var(--color-primary);
}

.mobile-dropdown-link:hover::before {
    opacity: 1;
    left: -0.5rem;
}

@media (min-width: 1024px) {
    .mobile-menu-button { display: none; }
    .mobile-nav { display: none; }
}

/* スクロール無効化 */
.no-scroll {
    overflow: hidden;
    height: 100vh;
}