:root {
    --primary: #0B2D49;
    --accent: #1E88E5;
    --sidebar-width: 260px;
    --bg: #F0F4F8;
}

body { 
    font-family: 'Inter', sans-serif; 
    background: var(--bg); 
    margin: 0; 
    display: flex; 
    height: 100vh; 
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background: var(--primary);
    color: white;
    display: flex;
    flex-direction: column;
    padding: 20px 0;
    box-shadow: 4px 0 10px rgba(0,0,0,0.1);
}

.sidebar-header {
    padding: 0 20px 30px;
    text-align: center;
}

.sidebar-header img {
    width: 50px;
    margin-bottom: 10px;
}

.sidebar-header h2 {
    font-size: 16px;
    margin: 0;
    letter-spacing: 1px;
}

.nav-menu {
    flex: 1;
}

.nav-item {
    padding: 15px 25px;
    display: flex;
    align-items: center;
    cursor: pointer;
    transition: 0.3s;
    color: #A0AEC0;
    border-left: 4px solid transparent;
}

.nav-item:hover {
    background: rgba(255,255,255,0.05);
    color: white;
}

.nav-item.active {
    background: rgba(255,255,255,0.1);
    color: white;
    border-left-color: var(--accent);
}

.nav-item i {
    margin-right: 15px;
    font-size: 20px;
}

/* Main Content */
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 40px;
}

.form-container {
    background: white;
    max-width: 700px;
    margin: 0 auto;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.form-header {
    margin-bottom: 30px;
    border-bottom: 1px solid #E2E8F0;
    padding-bottom: 20px;
}

.form-header h1 {
    color: var(--primary);
    margin: 0;
    font-size: 24px;
}

.form-group { text-align: left; margin-bottom: 20px; }
label { font-weight: 600; font-size: 14px; margin-bottom: 8px; display: block; color: #4A5568; }
input, textarea { width: 100%; padding: 14px; border: 2px solid #E2E8F0; border-radius: 10px; box-sizing: border-box; outline: none; transition: 0.3s; }
input:focus, textarea:focus { border-color: var(--accent); }

button#submit-btn { 
    background: var(--accent); 
    color: white; 
    border: none; 
    padding: 16px; 
    border-radius: 10px; 
    width: 100%; 
    font-weight: 700; 
    cursor: pointer; 
    font-size: 16px;
    transition: 0.3s;
}

button#submit-btn:hover { background: #1565C0; }

#message { margin-top: 20px; padding: 15px; border-radius: 10px; display: none; text-align: center; }
.success { background: #C6F6D5; color: #22543D; }
.error { background: #FED7D7; color: #822727; }

/* Stile per le Combo (Select) */
select {
    width: 100%;
    padding: 14px;
    border: 2px solid #E2E8F0;
    border-radius: 10px;
    background-color: white;
    font-family: 'Inter', sans-serif;
    font-size: 15px;
    color: #1E293B;
    outline: none;
    transition: 0.3s;
    cursor: pointer;
    /* Rimuove la freccia di default per metterne una più bella */
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%234A5568' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 15px center;
    background-size: 18px;
    padding-right: 45px; /* Spazio per la freccia */
}

select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(30, 136, 229, 0.1);
}

select:disabled {
    background-color: #F8FAFC;
    cursor: not-allowed;
    color: #94A3B8;
}

/* Miglioramento per le opzioni interne */
select option {
    padding: 10px;
    font-size: 15px;
}

/* Effetto Hover sugli input e select per feedback visivo */
input:hover, textarea:hover, select:hover {
    border-color: #CBD5E1;
}