/* ============================================================
   layout.css — header, navigation, footer
   ============================================================ */

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--header-height);
    background: rgba(9, 13, 18, 0.35);
    transition: background 0.25s ease, border-color 0.25s ease;
    border-bottom: 1px solid transparent;
}
.site-header.scrolled {
    background: rgba(9, 13, 18, 0.86);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom-color: var(--border);
}

.header-inner {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    color: var(--text-primary);
    font-weight: 750;
    font-size: 1.15rem;
    letter-spacing: -0.01em;
    white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--accent); }

.site-nav {
    display: flex;
    align-items: center;
    gap: 28px;
}
.site-nav a {
    color: var(--text-secondary);
    font-size: 0.98rem;
    font-weight: 550;
    white-space: nowrap;
}
.site-nav a:hover { color: var(--text-primary); text-decoration: none; }
.site-nav a.active { color: var(--accent); }

/* Language switcher */
.lang-switch {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-left: 8px;
    padding-left: 20px;
    border-left: 1px solid var(--border);
    font-size: 0.9rem;
    font-weight: 650;
}
.lang-switch a { color: var(--text-muted); }
.lang-switch a:hover { color: var(--text-primary); }
.lang-switch a.active { color: var(--accent); }
.lang-sep { color: var(--text-muted); }

/* Mobile toggle: checkbox hack (no JS required) */
.nav-toggle-input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}
.nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-primary);
}
.nav-toggle:hover { background: var(--surface-hover); }
.nav-toggle-icon { display: inline-flex; }
.nav-toggle-icon svg { width: 24px; height: 24px; }
.nav-toggle-close { display: none; }

/* Footer */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 28px 0;
}
.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
}
.footer-copy { margin: 0; color: var(--text-muted); font-size: 0.92rem; }
.footer-nav { display: flex; gap: 24px; }
.footer-nav a { color: var(--text-secondary); font-size: 0.92rem; }
.footer-nav a:hover { color: var(--accent); }