.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-light);
    width: 100%;
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 24px;
}

.header-logo img {
    height: 28px;
    width: auto;
    display: block;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-link {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    text-decoration: none;
}

.nav-link:hover {
    text-decoration: underline;
}

.header-lang {
    display: flex;
    align-items: center;
    gap: 6px;
}

.header-lang .lang-label {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.header-lang .lang-select {
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 6px 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-surface);
    color: var(--text-primary);
    cursor: pointer;
    outline: none;
}

.header-lang .lang-select:hover {
    border-color: var(--text-muted);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    padding: 4px 10px;
    font-size: 1.1rem;
    line-height: 1;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    border-color: var(--text-muted);
}

.hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: 0.2s;
}

.hamburger.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger.open span:nth-child(2) {
    opacity: 0;
}

.hamburger.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 860px) {
    .hamburger {
        display: flex;
    }

    .header-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-surface);
        border-bottom: 1px solid var(--border-light);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        box-shadow: 0 4px 8px var(--shadow-sm);
    }

    .header-nav.open {
        display: flex;
    }

    .nav-link {
        font-size: 1rem;
        padding: 4px 0;
    }
}