* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    min-height: 100vh;
    background-color: #222222;
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    justify-content: center;
}

/* Gabbia orizzontale: bloccata a max 1024px, centrata, altezza dinamica */
#frame-container {
    width: 100%;
    max-width: 1024px;
    min-height: 100vh;
    background-color: #ffffff;
    display: flex;
    flex-direction: column;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.4);
}

/* Top */
#box-top {
    flex-shrink: 0;
    background-color: #e5e5e5;
    border-bottom: 2px solid #ccc;
    padding: 20px;
}

/* Corpo centrale */
#box-middle {
    flex: 1;
    display: flex;
    flex-direction: row;
}

/* Area contenuti: fluida, si allunga col contenuto */
#area-pagina {
    flex: 1;
    min-width: 0;
    padding: 30px;
}

/* Menu: larghezza orizzontale statica a 260px */
#box-menu {
    width: 260px;
    flex: 0 0 260px;
    background-color: #f7f7f7;
    border-left: 2px solid #ccc;
    padding: 25px;
}

/* Bottom: spinto in fondo anche su pagine corte */
#box-bottom {
    flex-shrink: 0;
    background-color: #e5e5e5;
    border-top: 2px solid #ccc;
    padding: 15px 20px;
}

/* Comportamento responsivo su schermi ridotti / mobile */
@media (max-width: 768px) {
    #box-middle {
        flex-direction: column;
    }

    #box-menu {
        width: 100%;
        flex: 1 1 auto;
        border-left: none;
        border-top: 2px solid #ccc;
    }
}