header {
    position: fixed;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 50px 20px 20px;
    height: 10vh;
    background-color: white;
    min-width: 100vw;
    z-index: 3;
}

.header {
    height: 10vh;
}

header nav a {
    position: relative;
    text-decoration: none;
    color: black;
    transition: color 0.3s ease;
}

header nav a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 0;
    height: 2px;
    background-color: black;
    transition: width 0.3s ease;
}

header nav a:hover::after {
    width: 100%;
}

header nav a:hover::after {
    width: 100%;
}

header h1 {
    color: red;
}

header h1 span {
    color: blue;
}

.nav-links-mobile {
    visibility: hidden;
}

@media (max-width: 768px) {
    header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 1rem;
        position: relative;
    }

    .header {
        height: 0;
    }

    .menu-toggle {
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        width: 30px;
        height: 24px;
        background: none;
        border: none;
        cursor: pointer;
        z-index: 100;
        padding: 0;
    }

    .hamburger-line {
        display: block;
        height: 3px;
        width: 100%;
        background: #333;
        transition: all 0.3s ease;
    }

    nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: white;
        box-shadow: -2px 0 10px rgba(0,0,0,0.1);
        transition: right 0.3s ease;
        z-index: 90;
        padding-top: 70px;
        overflow-y: auto;
    }

    nav.active {
        right: 0;
    }

    .nav-links {
        visibility: hidden;
    }

    .nav-links-mobile {
        display: flex;
        flex-direction: column;
        padding: 1rem;
        visibility: revert;
    }

    .nav-links-mobile a {
        padding: 1rem 0;
        border-bottom: 1px solid #eee;
        margin: 0;
        display: block;
    }

    .nav-links-mobile a::after {
        display: none;
    }

    .menu-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0,0,0,0.5);
        z-index: 80;
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .menu-overlay.active {
        opacity: 1;
        visibility: visible;
    }

    .menu-toggle.active .hamburger-line:nth-child(1) {
        transform: translateY(10px) rotate(45deg);
    }

    .menu-toggle.active .hamburger-line:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active .hamburger-line:nth-child(3) {
        transform: translateY(-10px) rotate(-45deg);
    }
}