/* ヘッダースタイル */
header {
    background: linear-gradient(180deg, var(--black) 0%, #0a0a0a 100%);
    box-shadow: 
        0 2px 20px rgba(0, 0, 0, 0.8),
        0 0 0 1px var(--gray),
        inset 0 1px 0 rgba(57, 255, 20, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--gray);
    backdrop-filter: blur(10px);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 85px;
    position: relative;
}

.header-container::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--neon-green), transparent);
    opacity: 0.3;
}

.logo {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
    font-family: 'Orbitron', 'Rajdhani', 'Noto Sans JP', sans-serif;
    letter-spacing: 0.15em;
    text-shadow: 
        0 0 10px rgba(57, 255, 20, 0.3),
        0 0 20px rgba(57, 255, 20, 0.1);
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    text-transform: uppercase;
    position: relative;
}

.logo::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--neon-green);
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 0 10px rgba(57, 255, 20, 0.5);
}

.logo:hover {
    color: var(--neon-green);
    text-shadow: 
        0 0 20px rgba(57, 255, 20, 0.6),
        0 0 40px rgba(57, 255, 20, 0.3);
    transform: translateY(-2px);
}

.logo:hover::after {
    width: 100%;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 35px;
    align-items: center;
    flex-wrap: wrap;
}

.nav-menu a {
    color: var(--lighter-gray);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 11px;
    font-family: 'Rajdhani', 'Noto Sans JP', sans-serif;
    padding: 8px 0;
}

.nav-menu a::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--neon-green), rgba(57, 255, 20, 0.5));
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 0 10px rgba(57, 255, 20, 0.5);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    height: 100%;
    background: linear-gradient(90deg, rgba(57, 255, 20, 0.05), transparent);
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: -1;
}

.nav-menu a:hover {
    color: var(--white);
    text-shadow: 0 0 8px rgba(57, 255, 20, 0.3);
    transform: translateY(-2px);
}

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

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

.nav-menu a.active {
    color: var(--neon-green);
    text-shadow: 
        0 0 10px rgba(57, 255, 20, 0.5),
        0 0 20px rgba(57, 255, 20, 0.2);
}

.nav-menu a.active::before {
    width: 100%;
    box-shadow: 0 0 15px rgba(57, 255, 20, 0.8);
}

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

/* ハンバーガーメニュー */
.menu-toggle {
    display: none;
    background: transparent;
    border: 2px solid var(--neon-green);
    font-size: 1.3rem;
    cursor: pointer;
    color: var(--neon-green);
    padding: 10px 14px;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    font-family: 'Rajdhani', sans-serif;
    letter-spacing: 0.1em;
    position: relative;
    overflow: hidden;
}

.menu-toggle::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(57, 255, 20, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.menu-toggle:hover::before {
    width: 200px;
    height: 200px;
}

.menu-toggle:hover {
    background-color: var(--neon-green);
    color: var(--black);
    box-shadow: 
        0 0 20px rgba(57, 255, 20, 0.6),
        0 0 40px rgba(57, 255, 20, 0.3);
    transform: scale(1.05);
}

/* 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;
    }
}