header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 15px;
    background-color: rgba(26, 60, 52, 0.95);
    color: var(--text-white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px var(--shadow);
    transition: background-color 0.3s ease;
    width: 100%;
    max-width: 100vw;
    box-sizing: border-box;
}

header.scrolled {
    background-color: #1A3C34;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--text-white);
}

.logo-img {
    height: 130px;
    margin-right: 15px;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.tagline {
    font-size: 14px;
    color: var(--text-white);
    margin-top: 5px;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-white);
    font-size: 28px;
    cursor: pointer;
    z-index: 1100;
}

.nav-menu {
    display: flex;
    gap: 35px;
}

.nav-menu > li {
    position: relative;
}

.nav-menu > li > a {
    color: var(--text-white);
    text-decoration: none;
    font-size: 16px;
    font-family: 'Poppins', sans-serif;
    font-weight: 600;
    text-transform: uppercase;
    padding: 10px 15px;
    transition: color 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease;
}

.nav-menu a[href="#bitcoin-sales"], .nav-menu a[href="#development-services"], .nav-menu a[href="#community"] {
    font-weight: 700;
    color: var(--accent-blue);
}

.nav-menu > li > a:hover {
    color: var(--secondary-green);
    box-shadow: 0 0 12px rgba(46, 107, 71, 0.6);
    transform: translateY(-2px);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #2C4A44;
    min-width: 200px;
    border-radius: 8px;
    box-shadow: 0 6px 12px var(--shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.dropdown:hover .dropdown-menu,
.dropdown-toggle:focus + .dropdown-menu,
.dropdown-menu:focus-within {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li a {
    color: var(--text-white);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    padding: 12px 20px;
    display: block;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.dropdown-menu li a:hover {
    background-color: #375651;
    box-shadow: 0 0 8px rgba(74, 144, 226, 0.5);
}

@media (max-width: 768px) {
    header {
        padding: 15px 20px;
        flex-direction: column;
        align-items: flex-start;
    }

    .logo-img {
        height: 100px;
    }

    .nav-toggle {
        display: block;
        position: absolute;
        right: 20px;
        top: 20px;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        width: 100%;
        margin-top: 20px;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu > li {
        width: 100%;
    }

    .nav-menu > li > a {
        display: block;
        padding: 15px;
        text-align: left;
    }

    .dropdown-menu {
        position: static;
        width: 100%;
        box-shadow: none;
        border-radius: 0;
        transform: none;
        opacity: 1;
        visibility: visible;
        display: none;
    }

    .dropdown:hover .dropdown-menu,
    .dropdown-toggle:focus + .dropdown-menu,
    .dropdown-menu:focus-within {
        display: block;
    }
}