/* ============================================================
   platform.css — Navbar & Footer (shared across ALL pages)
   Edit here → updates everywhere automatically.
   engsim.app
   ============================================================ */

/* ── Page wrapper ───────────────────────────────────────────── */
.page-wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.page-main {
    flex: 1;
}

/* ══════════════════════════════════════════════════════════════
   NAV
   ══════════════════════════════════════════════════════════════ */
.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--nav-h);
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    transition: background var(--transition), border-color var(--transition);
}

.nav__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    gap: var(--space-lg);
}

/* Brand */
.nav__brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    text-decoration: none;
    flex-shrink: 0;
}

.nav__brand-icon {
    width: 34px;
    height: 34px;
    background: var(--brand-primary);
    color: #fff;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.nav__brand-icon svg {
    width: 18px;
    height: 18px;
}

.nav__brand-name {
    display: block;
    font-weight: 700;
    font-size: .9rem;
    color: var(--text-primary);
    line-height: 1.1;
}

.nav__brand-sub {
    display: block;
    font-size: .7rem;
    color: var(--text-muted);
    line-height: 1.1;
}

/* Links */
.nav__links {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.nav__link {
    font-size: .875rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 6px 12px;
    border-radius: var(--radius-md);
    transition: background var(--transition), color var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

.nav__link:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    text-decoration: none;
}

.nav__link.is-active {
    background: var(--bg-hover);
    color: var(--text-primary);
    font-weight: 600;
}

/* Actions */
.nav__actions {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    flex-shrink: 0;
}

.nav__icon-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    transition: background var(--transition), color var(--transition);
    background: none;
    border: none;
    cursor: pointer;
    flex-shrink: 0;
}

.nav__icon-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav__icon-btn svg {
    width: 18px;
    height: 18px;
    pointer-events: none;
}

/* Theme toggle icon visibility */
.icon-sun {
    display: none;
}

body.dark .icon-sun {
    display: block;
}

body.dark .icon-moon {
    display: none;
}

/* Hamburger (mobile only) */
.nav__hamburger {
    display: none;
}

/* Mobile nav */
@media (max-width: 640px) {
    .nav__hamburger {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 36px;
        height: 36px;
        border-radius: var(--radius-md);
        color: var(--text-secondary);
    }

    .nav__hamburger:hover {
        background: var(--bg-hover);
    }

    .nav__hamburger svg {
        width: 20px;
        height: 20px;
    }

    .nav__links {
        display: none;
        position: absolute;
        top: var(--nav-h);
        left: 0;
        right: 0;
        background: var(--bg-card);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        align-items: stretch;
        padding: var(--space-sm) var(--space-md);
        gap: var(--space-xs);
        box-shadow: var(--shadow-md);
    }

    .nav__links.is-open {
        display: flex;
    }

    .nav__link {
        padding: 10px 12px;
    }
}

/* ══════════════════════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════════════════════ */
.page-footer {
    background: var(--brand-primary);
    color: rgba(255, 255, 255, .7);
    padding: var(--space-xl) 0;
    margin-top: auto;
}

.page-footer__inner {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
}

.page-footer__brand {
    font-weight: 700;
    font-size: 1rem;
    color: #fff;
    letter-spacing: -.01em;
}

.page-footer__links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
}

.page-footer__links a {
    color: rgba(255, 255, 255, .65);
    font-size: .85rem;
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    transition: color var(--transition), background var(--transition);
    text-decoration: none;
}

.page-footer__links a:hover {
    color: #fff;
    background: rgba(255, 255, 255, .08);
    text-decoration: none;
}

.page-footer__legal {
    font-size: .78rem;
    color: rgba(255, 255, 255, .45);
}

@media (max-width: 640px) {
    .page-footer__inner {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-md);
    }
}