header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    color: var(--light-text);
    padding: 20px 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

.dark-mode header {
    background-color: rgba(24, 34, 45, 0.95);
    color: var(--dark-text);
}

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

.logo {
    font-size: 26px;
    font-weight: 800;
    text-decoration: none;
    color: var(--light-text);
    display: flex;
    align-items: center;
    letter-spacing: -0.03em;
}

.dark-mode .logo {
    color: var(--dark-text);
}

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

nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

nav ul li a {
    color: var(--light-text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: var(--transition);
    position: relative;
}

.dark-mode nav ul li a {
    color: var(--dark-text-secondary);
}

nav ul li a:hover {
    color: var(--primary-color);
}

nav ul li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary-color);
    transition: var(--transition);
}

nav ul li a:hover::after {
    width: 100%;
}

.header-buttons {
    display: flex;
    align-items: center;
    gap: 15px;
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--light-bg-alt);
    color: var(--light-text);
    transition: var(--transition);
}

.dark-mode .theme-toggle {
    background-color: var(--dark-bg-alt);
    color: var(--dark-text);
}

.theme-toggle:hover {
    transform: rotate(15deg);
    background-color: var(--primary-light);
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--light-text);
    font-size: 24px;
    cursor: pointer;
}

.dark-mode .mobile-menu-toggle {
    color: var(--dark-text);
}