/* ── App header ── */
header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    background: #1a1a1a;
    border-bottom: 1px solid #2a2a2a;
}

.header-logo {
    height: 30px;
    width: auto;
    max-width: 160px;
}

header button {
    width: auto;
    padding: 0.5rem 1rem;
    background: #2a2a2a;
    font-size: 0.9rem;
}

header button:hover {
    background: #333;
}

/* ── Main content area ── */
main {
    padding: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

/* ── App nav ── */
#app-nav {
    display: flex;
    gap: 0.5rem;
}

.nav-btn {
    width: auto;
    padding: 0.4rem 0.9rem;
    font-size: 0.85rem;
    background: #2a2a2a;
}

.nav-btn:hover {
    background: #333;
}

.nav-btn.active {
    background: #2563eb;
}

.nav-btn.active:hover {
    background: #1d4ed8;
}