.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    box-sizing: border-box;
}

.site-header *,
.site-header *::before,
.site-header *::after {
    box-sizing: border-box;
}

.site-header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    position: relative;
}

.site-header-logo {
    display: flex;
    align-items: baseline;
    gap: 0;
    text-decoration: none;
    flex-shrink: 0;
}

.site-header-logo:hover {
    text-decoration: none;
}

.site-header-logo img {
    height: 48px;
    width: auto;
    display: block;
}

.site-header-tagline {
    font-size: 11px;
    font-style: italic;
    color: #6b7280;
    margin-left: 6px;
    white-space: nowrap;
    letter-spacing: 0.01em;
    line-height: 1;
}

.site-header-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    margin: 0;
    padding: 0;
    background: none;
    height: 100%;
}

.site-header-nav a {
    font-size: 14px;
    font-weight: 500;
    color: #24292f;
    text-decoration: none;
    white-space: nowrap;
    transition: color 0.15s ease;
    line-height: 1.5;
    padding: 0;
    margin: 0;
}

.site-header-nav a:hover {
    color: #3FBB14;
    text-decoration: none;
    background: none;
}

.site-header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.site-header-upload-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    background: #1763cb;
    color: #fff !important;
    font-size: 14px;
    font-weight: 600;
    border-radius: 8px;
    text-decoration: none;
    white-space: nowrap;
    transition: background 0.15s ease;
    line-height: 1.5;
    height: 38px;
    border: none;
}

.site-header-upload-btn:hover {
    background: #1953a9;
    color: #fff !important;
    text-decoration: none;
}

.site-header-upload-btn svg {
    flex-shrink: 0;
}

.site-header-icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    color: #24292f;
    text-decoration: none;
    transition: background 0.15s ease;
    border: 1px solid #e5e7eb;
    background: #fff;
    padding: 0;
}

.site-header-icon-btn:hover {
    background: #f3f4f6;
    text-decoration: none;
    color: #24292f;
}

@media (max-width: 900px) {
    .site-header-nav {
        display: none;
    }
}

@media (max-width: 640px) {
    .site-header-inner {
        padding: 0 16px;
        height: 60px;
    }

    .site-header-icon-btn {
        width: 36px;
        height: 36px;
    }
}