/* ==========================================================================
   FOOTER — mobile-first
   Brand/tagline + Platform / Customer / Legal / Social columns + copyright
   bar, per the homepage mockup. Breakpoints match _layout.css exactly:
   mobile < 768px, tablet 768-1024px, desktop >= 1025px.
   ========================================================================== */

.du-footer {
    background-color: var(--surface);
    border-top: var(--border-width) solid var(--border);
}

.du-footer__inner {
    padding-top: var(--space-xl);
    padding-bottom: var(--space-lg);
}

/* Mobile default: single column, everything stacked */
.du-footer__grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-lg);
}

/* ---- Brand column ---- */
.du-footer__brand {
    max-width: 320px;
}

.du-footer__logo-link {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-base);
    text-decoration: none;
    margin-bottom: var(--space-xs);
}

.du-footer__logo-image-wrap {
    display: block;
    line-height: 0;
}

.du-footer__logo-image {
    display: block;
    height: 32px;
    width: auto;
}

.du-footer__logo {
    font-family: var(--font-serif);
    font-size: 1.25rem; /* see note in _header.css re: no logo token in DESIGN.md */
    font-weight: var(--headline-lg-weight);
    color: var(--on-background);
}

.du-footer__tagline {
    font-family: var(--font-sans);
    font-size: var(--caption-size);
    line-height: var(--caption-line);
    color: var(--text-body);
    margin: 0;
}

/* ---- Link columns: Platform / Customer / Legal / Social ---- */
.du-footer__heading {
    color: var(--on-surface-variant);
    margin: 0 0 var(--space-sm);
}

.du-footer__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.du-footer__list a {
    font-family: var(--font-sans);
    font-size: var(--caption-size);
    color: var(--text-body);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.du-footer__list a:hover,
.du-footer__list a:focus-visible {
    color: var(--primary-container);
}

/* ---- Social ---- */
.du-footer__social {
    display: flex;
    gap: var(--space-xs);
}

.du-footer__social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    border-radius: var(--radius-full);
    border: var(--border-width) solid var(--border);
    color: var(--on-surface-variant);
    transition: border-color var(--transition-fast), color var(--transition-fast);
}

.du-footer__social-link:hover,
.du-footer__social-link:focus-visible {
    border-color: var(--primary-container);
    color: var(--primary-container);
}

/* ---- Copyright bar ---- */
.du-footer__bottom {
    margin-top: var(--space-xl);
    padding-top: var(--space-md);
    border-top: var(--border-width) solid var(--border);
    text-align: center;
}

.du-footer__copyright {
    color: var(--text-body);
    margin: 0;
}

/* ==========================================================================
   TABLET — 768-1024px: 2 columns, brand spans the full row
   ========================================================================== */
@media (min-width: 768px) {
    .du-footer__grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .du-footer__brand {
        grid-column: 1 / -1;
        max-width: none;
    }
}

/* ==========================================================================
   DESKTOP — >= 1025px: brand column + 4 link columns
   ========================================================================== */
@media (min-width: 1025px) {
    .du-footer__grid {
        grid-template-columns: minmax(240px, 2fr) repeat(4, minmax(0, 1fr));
    }

    .du-footer__brand {
        grid-column: auto;
        max-width: 320px;
    }
}