/**
 * NEO Theme - ヘッダーレイアウト
 */
.neo-header {
    position: sticky;
    top: 0;
    z-index: var(--neo-z-sticky);
    background: var(--neo-glass-bg);
    border-bottom: var(--neo-glass-border);
    backdrop-filter: var(--neo-glass-blur);
    -webkit-backdrop-filter: var(--neo-glass-blur);
    transition: background var(--neo-transition-base), box-shadow var(--neo-transition-base), transform var(--neo-transition-base);
}

.neo-header.is-scrolled {
    box-shadow: var(--neo-shadow-sm);
}

.neo-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--neo-container-max);
    margin: 0 auto;
    padding: 0 var(--neo-container-padding);
    height: var(--neo-header-height);
    transition: height var(--neo-transition-base);
}

.neo-header__logo a {
    display: flex;
    align-items: center;
    font-size: var(--neo-font-size-xl);
    font-weight: var(--neo-font-weight-bold);
    color: var(--neo-color-text);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.neo-header__logo img {
    max-height: 40px;
    width: auto;
    transition: max-height var(--neo-transition-base);
}

.neo-header__nav {
    display: flex;
    align-items: center;
    gap: var(--neo-space-lg);
}

.neo-header__nav-list {
    display: flex;
    gap: var(--neo-space-lg);
    list-style: none;
    margin: 0;
    padding: 0;
}

.neo-header__nav-item a {
    font-size: var(--neo-font-size-sm);
    font-weight: var(--neo-font-weight-semibold);
    color: var(--neo-color-text-secondary);
    text-decoration: none;
    padding: 8px 0;
    transition: color var(--neo-transition-fast);
    position: relative;
}

.neo-header__nav-item a:hover,
.neo-header__nav-item.current-menu-item a {
    color: var(--neo-color-primary);
}

/* リンクの下線アニメーション (NEOオリジナル) */
.neo-header__nav-item a::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--neo-color-primary-gradient);
    border-radius: 2px;
    transition: width var(--neo-transition-base) ease-out, left var(--neo-transition-base) ease-out;
}

.neo-header__nav-item a:hover::after,
.neo-header__nav-item.current-menu-item a::after {
    width: 100%;
    left: 0;
}

.neo-header__actions {
    display: flex;
    align-items: center;
    gap: var(--neo-space-xs);
}

.neo-header__search-btn,
.neo-header__hamburger {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: none;
    background: transparent;
    color: var(--neo-color-text);
    cursor: pointer;
    transition: background var(--neo-transition-fast), color var(--neo-transition-fast), transform var(--neo-transition-spring);
}

.neo-header__search-btn:hover,
.neo-header__hamburger:hover {
    background: var(--neo-color-bg-subtle);
    color: var(--neo-color-primary);
    transform: scale(1.05);
}

/* ハンバーガーアイコン */
.neo-header__hamburger span {
    display: block;
    width: 20px;
    height: 2px;
    background: currentColor;
    border-radius: 1px;
    position: relative;
    transition: background var(--neo-transition-fast);
}

.neo-header__hamburger span::before,
.neo-header__hamburger span::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background: inherit;
    border-radius: inherit;
    transition: transform var(--neo-transition-base);
}

.neo-header__hamburger span::before {
    transform: translateY(-6px);
}

.neo-header__hamburger span::after {
    transform: translateY(6px);
}

@media (max-width: 768px) {
    .neo-header__nav-list {
        display: none;
    }
    .neo-header__inner {
        height: 60px;
    }
}