/**
 * ACM Chapter Theme — Header & Navigation
 */

.site-header {
    background: var(--white);
    border-bottom: 3px solid var(--blue);
    position: sticky;
    top: 0;
    z-index: 200;
    box-shadow: var(--shadow-sm);
}

.header-inner {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 var(--space-8);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

/* ── Logo ── */
.site-logo { display: flex; align-items: center; text-decoration: none; }
.site-logo img { height: 48px; display: block; width: auto; }

/* Responsive logos */
.logo-tablet { display: none; }
.logo-mobile { display: none; }

/* ── Nav ── */
.site-nav ul {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-nav a {
    color: var(--blue-dark);
    text-decoration: none;
    font-size: 14.5px;
    font-weight: 600;
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-sm);
    letter-spacing: 0.2px;
    transition: background var(--transition), color var(--transition);
}
.site-nav a:hover {
    background: var(--blue-light);
    color: var(--blue);
}

/* Join CTA in nav */
.site-nav .nav-cta {
    background: var(--gold);
    color: var(--blue-dark) !important;
    padding: var(--space-2) var(--space-5);
    border-radius: var(--radius-sm);
    font-weight: 700;
    margin-left: var(--space-2);
}
.site-nav .nav-cta:hover {
    background: var(--gold-dark);
}

/* ── Mobile Hamburger (hidden on desktop) ── */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    flex-direction: column;
    gap: 5px;
}
.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--blue-dark);
    border-radius: 2px;
    transition: transform var(--transition);
}