.site-footer {
    background: #f8faff;
    border-top: 1px solid rgba(12, 108, 254, 0.09);
    margin-top: auto;
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--ds-space-16) var(--ds-space-6) var(--ds-space-10);
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--ds-space-10);
}

.footer-logo {
    display: inline-flex;
    align-items: center;
    gap: var(--ds-space-2);
    font-size: 1.2rem;
    font-weight: var(--ds-font-black);
    color: var(--primary-color);
    text-decoration: none;
    margin-bottom: var(--ds-space-3);
}

.footer-logo i {
    animation: ds-spin 4s linear infinite;
}

.footer-desc {
    color: var(--ds-color-text-muted);
    font-size: var(--ds-text-sm);
    line-height: var(--ds-leading-relaxed);
    margin-bottom: var(--ds-space-5);
    max-width: 260px;
}

.footer-social {
    display: flex;
    gap: var(--ds-space-2);
}

.footer-social a {
    width: 38px;
    height: 38px;
    background: var(--ds-color-surface);
    border: 1px solid rgba(12, 108, 254, 0.14);
    border-radius: var(--ds-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1rem;
    text-decoration: none;
    transition: background var(--ds-transition-base), color var(--ds-transition-base), transform var(--ds-transition-base);
}

.footer-social a:hover {
    background: var(--primary-color);
    color: var(--ds-color-text-inverse);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.footer-col-title {
    font-size: var(--ds-text-xs);
    font-weight: var(--ds-font-bold);
    text-transform: uppercase;
    letter-spacing: var(--ds-tracking-wider);
    color: var(--ds-color-text-muted);
    margin-bottom: var(--ds-space-3);
}

.footer-col ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--ds-space-2);
}

.footer-col ul li a {
    color: var(--ds-color-text-secondary);
    text-decoration: none;
    font-size: var(--ds-text-sm);
    transition: color var(--ds-transition-fast);
}

.footer-col ul li a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    padding: var(--ds-space-4) var(--ds-space-6);
    text-align: center;
    color: var(--ds-color-text-muted);
    font-size: 0.8rem;
}

.scroll-to-top {
    position: fixed;
    bottom: 90px;
    right: var(--ds-space-5);
    width: 44px;
    height: 44px;
    background: var(--primary-color);
    color: var(--ds-color-text-inverse);
    border: none;
    border-radius: var(--ds-radius-lg);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--ds-transition-medium), visibility var(--ds-transition-medium), transform var(--ds-transition-base);
    z-index: var(--ds-z-toast);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 14px rgba(12, 108, 254, 0.35);
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-3px);
}

.scroll-to-top svg {
    width: 20px;
    height: 20px;
}

@media (max-width: 960px) {
    .footer-inner {
        grid-template-columns: 1fr 1fr;
        gap: var(--ds-space-8);
    }

    .footer-brand {
        grid-column: 1 / -1;
    }

    .footer-desc {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    .scroll-to-top {
        bottom: 80px;
        right: var(--ds-space-4);
        width: 40px;
        height: 40px;
    }
}

@media (max-width: 576px) {
    .footer-inner {
        padding: var(--ds-space-8) var(--ds-space-4) var(--ds-space-6);
        gap: var(--ds-space-6);
    }
}