body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 20px;
    background-color: #f4f7f6;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
}

nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

nav button {
    padding: 10px 15px;
    border: 1px solid #ccc;
    background: white;
    cursor: pointer;
    border-radius: 4px;
    font-size: 14px;
}

nav button.active {
    background: #007bff;
    color: white;
    border-color: #0056b3;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

th, td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: center;
}

th {
    background-color: #f8f9fa;
    font-weight: 600;
}

input[type="number"] {
    width: 60px;
    padding: 5px;
    border: 1px solid #ccc;
    border-radius: 3px;
    text-align: center;
}

.weekend {
    background-color: #FFF2CC !important;
}

.other-month {
    background-color: #e9ecef;
    color: #adb5bd;
}

.balance-positive {
    background-color: #C6EFCE !important;
}

.balance-negative {
    background-color: #FFCCCC !important;
}

.balance-zero {
    background-color: #FFFFC0 !important;
}

.total-row {
    font-weight: bold;
    background-color: #f8f9fa;
}

.summary-table {
    max-width: 800px;
    margin: 0 auto;
}