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

body{
    font-family:Arial,sans-serif;
    background:#f4f6f9;
    color:#222;
}

#app{
    display:flex;
    min-height:100vh;
}

.sidebar{
    width:260px;
    background:#1f2937;
    color:white;
    padding:20px;
    display:flex;
    flex-direction:column;
    gap:10px;
}

.sidebar h2{
    margin-bottom:20px;
}

.sidebar button{
    border:none;
    background:#374151;
    color:white;
    padding:12px;
    border-radius:8px;
    text-align:left;
    cursor:pointer;
}

.sidebar button:hover{
    background:#4b5563;
}

.content{
    flex:1;
    padding:20px;
}

.page.hidden{
    display:none;
}

.card{
    background:white;
    border-radius:12px;
    padding:16px;
    margin-bottom:16px;
    box-shadow:0 2px 8px rgba(0,0,0,.08);
}

.customer-list{
    display:grid;
    gap:12px;
}

.customer-list .card{
    cursor:pointer;
}

.customer-list .card:hover{
    transform:translateY(-2px);
}

input,
select,
textarea{
    width:100%;
    padding:10px;
    border:1px solid #d1d5db;
    border-radius:8px;
    margin-top:5px;
    margin-bottom:10px;
}

button.primary{
    background:#2563eb;
    color:white;
    border:none;
    padding:12px;
    border-radius:8px;
}

button.primary:hover{
    background:#1d4ed8;
}