* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
    background: #fff;
    color: #333;
}

.site-header {
    background: #ffffff;
    border-bottom: 2px solid #1a73e8;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

.logo {
    flex-shrink: 0;
}

.logo img {
    height: 50px;
    width: auto;
}

.logo a {
    display: block;
    line-height: 0;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
    align-items: center;
}

.main-nav a {
    color: #333;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: color 0.2s;
}

.main-nav a:hover {
    color: #1a73e8;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background: #333;
    transition: all 0.3s;
}

@media (max-width: 768px) {
    .site-header {
        padding: 1rem;
    }

    .menu-toggle {
        display: flex;
    }

    .main-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: #ffffff;
        padding: 80px 2rem 2rem;
        transition: right 0.3s;
        box-shadow: -2px 0 10px rgba(0,0,0,0.1);
    }

    body.menu-open .main-nav {
        right: 0;
    }

    .main-nav ul {
        flex-direction: column;
        align-items: flex-start;
        gap: 1.5rem;
    }

    .main-nav a {
        font-size: 1.1rem;
    }

    body.menu-open .menu-toggle span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    body.menu-open .menu-toggle span:nth-child(2) {
        opacity: 0;
    }

    body.menu-open .menu-toggle span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    body.menu-open::before {
        content: '';
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0,0,0,0.5);
        z-index: 999;
    }

    .main-nav {
        z-index: 1000;
    }
}

.logo img {
    display: block;
}