/* ヘッダースタイル */
header {
    background-color: var(--black);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--gray);
}

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

.logo {
    font-size: 1.3rem;
    font-weight: 500;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
    font-family: 'Orbitron', 'Rajdhani', 'Noto Sans JP', sans-serif;
    letter-spacing: 0.1em;
    text-shadow: 0 0 6px rgba(57, 255, 20, 0.15);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    text-transform: uppercase;
}

.logo:hover {
    color: var(--neon-green);
    text-shadow: 0 0 15px rgba(57, 255, 20, 0.4);
}

.logo img {
    height: 40px;
    margin-right: 10px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
    align-items: center;
}

.nav-menu a {
    color: var(--lighter-gray);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-size: 12px;
    font-family: 'Rajdhani', 'Noto Sans JP', sans-serif;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--neon-green);
    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 0 8px rgba(57, 255, 20, 0.3);
}

.nav-menu a:hover {
    color: var(--white);
}

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

.nav-menu a.active {
    color: var(--neon-green);
}

.nav-menu a.active::after {
    width: 100%;
}

/* ハンバーガーメニュー */
.menu-toggle {
    display: none;
    background: none;
    border: 1px solid var(--neon-green);
    font-size: 1.3rem;
    cursor: pointer;
    color: var(--neon-green);
    padding: 10px 14px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Rajdhani', sans-serif;
    letter-spacing: 0.1em;
}

.menu-toggle:hover {
    background-color: var(--neon-green);
    color: var(--black);
    box-shadow: var(--glow-subtle);
}

/* レスポンシブ */
@media (max-width: 768px) {
    .header-container {
        padding: 0 20px;
        height: 70px;
    }

    .menu-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--black);
        flex-direction: column;
        padding: 30px 20px;
        box-shadow: var(--shadow);
        transform: translateX(-100%);
        transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        gap: 0;
        align-items: stretch;
        border-top: 1px solid var(--gray);
    }

    .nav-menu.active {
        transform: translateX(0);
    }

    .nav-menu a {
        width: 100%;
        padding: 20px 0;
        border-bottom: 1px solid var(--gray);
        text-align: left;
    }

    .nav-menu a:last-child {
        border-bottom: none;
    }

    .nav-menu a.active::after {
        display: none;
    }

    .nav-menu a::after {
        display: none;
    }
}