/* Header Styles */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--bg-secondary);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.header.scroll-down {
    transform: translateY(-100%);
}

.header.scroll-up {
    transform: translateY(0);
}

.navbar {
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
}

.logo img {
    height: 40px;
    width: auto;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-buttons {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--hover-color);
}

.sun-icon,
.moon-icon {
    width: 24px;
    height: 24px;
    fill: var(--text-color);
}

.hidden {
    display: none;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-color);
    transition: all 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Dark Theme */
.dark-theme .header {
    background: var(--dark-bg-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--bg-color);
        padding: 1rem;
        flex-direction: column;
        gap: 1rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .dark-theme .nav-links {
        background: var(--dark-bg-color);
    }
}