/* Footer */
.openai-footer {
    background: var(--bg-footer);
    padding: 80px 40px 40px 40px;
    border-top: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
}

.footer-inner {
    max-width: 1600px;
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 80px;
}

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

.footer-label {
    color: var(--secondary-text);
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.footer-column a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
    display: inline-block;
    margin-bottom: 12px;
    width: fit-content;
    max-width: max-content;
}

.footer-column a:hover {
    color: var(--secondary-text);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    color: var(--secondary-text);
    font-size: 12px;
}

.bottom-left {
    display: flex;
    gap: 24px;
    align-items: center;
}

.bottom-left a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    transition: color 0.2s;
}

.bottom-left a:hover {
    color: var(--secondary-text);
}

.bottom-left a svg {
    fill: currentColor;
    transition: fill 0.2s;
}

/* Fix Bilibili icon vertical alignment */
.bottom-left a .fa-bilibili {
    position: relative;
    top: 2px;
}

.bottom-center {
    color: var(--secondary-text);
}

.bottom-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.lang-selector {
    color: var(--secondary-text);
    cursor: pointer;
    transition: color 0.2s;
}

.lang-selector:hover {
    color: var(--text-color);
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--secondary-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4px;
    transition: color 0.2s;
}

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

.bottom-bar { position: fixed; bottom: 40px; left: 50%; transform: translateX(-50%); z-index: 100; }

@media (max-width: 768px) {
    .openai-footer {
        padding: 48px 20px 32px;
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 32px 16px;
        margin-bottom: 48px;
    }
    
    /* Increase footer text size for mobile */
    .footer-label {
        font-size: 16px; /* Larger than desktop */
        margin-bottom: 20px;
    }
    
    .footer-column a {
        font-size: 16px; /* Larger than desktop */
        padding: 6px 0;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }

    .bottom-left {
        justify-content: center;
    }
    
    /* Increase bottom bar text size */
    .bottom-center, .lang-selector {
        font-size: 14px;
    }

    .bottom-bar {
        bottom: 24px;
    }
}