/* ========================================
   Ling.AI - 页脚组件样式
   ======================================== */

.footer {
    --footer-bg: #f8f8fb;
    --footer-surface: #ffffff;
    --footer-ink: #15151b;
    --footer-muted: #575866;
    --footer-line: rgba(21, 21, 27, 0.08);
    --footer-accent: #6768b6;
    --footer-accent-deep: #4f518f;
    --footer-accent-soft: rgba(103, 104, 182, 0.10);
    background: var(--footer-bg);
    border-top: 1px solid var(--footer-line);
    padding: 4rem 0 2rem;
}

.footer-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

.footer-main {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: 4rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid var(--footer-line);
}

.footer-brand .logo {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--footer-ink);
    text-decoration: none;
    margin-bottom: 1.25rem;
}

.footer-brand .logo-svg {
    width: 133px;
    height: auto;
    aspect-ratio: 16 / 7;
    display: block;
    color: var(--footer-ink);
}

.footer-brand-desc {
    font-size: 0.9375rem;
    color: var(--footer-muted);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    max-width: 320px;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--footer-accent-soft);
    border-radius: 50%;
    color: var(--footer-accent);
    transition: all 0.2s ease;
}

.social-link svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

.social-link:hover {
    background: var(--footer-accent);
    color: white;
    transform: translateY(-2px);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.footer-column {
    display: flex;
    flex-direction: column;
}

.footer-column-title {
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--footer-ink);
    margin-bottom: 1.25rem;
}

.footer-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer-list li {
    margin-bottom: 0.75rem;
}

.footer-list a {
    font-size: 0.9375rem;
    color: var(--footer-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-list a:hover {
    color: var(--footer-accent);
}

.footer-bottom {
    padding-top: 2rem;
}

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

.footer-copyright {
    font-size: 0.875rem;
    color: var(--footer-muted);
}

.footer-legal {
    display: flex;
    gap: 2rem;
}

.footer-legal a {
    font-size: 0.875rem;
    color: var(--footer-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-legal a:hover {
    color: var(--footer-accent);
}

.dark .footer {
    background: #1a1a1a;
    border-top-color: #333;
}

@media (max-width: 1024px) {
    .footer-main {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .footer {
        padding: 3rem 0 1.5rem;
    }
    .footer-container {
        padding: 0 1.5rem;
    }
    .footer-links {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .footer-bottom-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    .footer-legal {
        gap: 1.5rem;
    }
}