:root {
    --bg-dark: #0b132b;
    --card-bg: #1c2541;
    --input-bg: #0f172a;
    --gold: #f59e0b;
    --cyan: #06b6d4;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --success: #10b981;
    --danger: #ef4444;
}

.da-arrear-page,
.da-arrear-page * {
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, sans-serif;
}

.da-arrear-page {
    min-height: 100vh;
    padding: 16px;
    background: var(--bg-dark);
    color: var(--text-main);
}

.da-arrear-page .container {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
}

.da-arrear-page .top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    background: linear-gradient(135deg, #1e293b, #0f172a);
    padding: 12px 16px;
    border-radius: 14px;
    border: 1px solid rgba(245, 158, 11, .3);
    margin-bottom: 16px;
}

.da-arrear-page .app-brand h1 {
    font-size: 18px;
    color: var(--gold);
    letter-spacing: .5px;
    margin: 0;
}

.da-arrear-page .app-brand span {
    font-size: 11px;
    color: var(--cyan);
}

.da-arrear-page .founder-badge {
    text-align: right;
    background: rgba(245, 158, 11, .12);
    padding: 6px 10px;
    border-radius: 8px;
    border: 1px solid rgba(245, 158, 11, .4);
}

.da-arrear-page .founder-badge strong {
    display: block;
    font-size: 12px;
    color: var(--gold);
}

.da-arrear-page .founder-badge small {
    font-size: 10px;
    color: var(--text-muted);
}

.da-arrear-page .card {
    background-color: var(--card-bg);
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, .4);
    border: 1px solid rgba(255, 255, 255, .08);
}

.da-arrear-page .card-title {
    font-size: 17px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 4px;
}

.da-arrear-page .card-subtitle {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 18px;
}

.da-arrear-page .form-group {
    margin-bottom: 14px;
}

.da-arrear-page label {
    display: block;
    font-size: 13px;
    color: #cbd5e1;
    margin-bottom: 6px;
    font-weight: 500;
}

.da-arrear-page select,
.da-arrear-page input[type="number"] {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: 1px solid #334155;
    background-color: var(--input-bg);
    color: #fff;
    font-size: 15px;
    outline: none;
}

.da-arrear-page select:focus,
.da-arrear-page input:focus {
    border-color: var(--cyan);
}

.da-arrear-page .row-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.da-arrear-page .checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--input-bg);
    padding: 12px;
    border-radius: 10px;
    border: 1px solid #334155;
    margin-bottom: 16px;
    cursor: pointer;
}

.da-arrear-page .checkbox-group input {
    width: 18px;
    height: 18px;
    accent-color: var(--gold);
}

.da-arrear-page .btn-calc {
    width: 100%;
    padding: 14px;
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--gold), #d97706);
    color: #0b132b;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
}

.da-arrear-page .btn-calc:active {
    transform: scale(.98);
}

.da-arrear-page .result-box {
    display: none;
    margin-top: 20px;
    background: #0f172a;
    border-radius: 14px;
    padding: 16px;
    border: 1px solid rgba(6, 182, 212, .4);
}

.da-arrear-page .net-pay-banner {
    background: linear-gradient(
        135deg,
        rgba(16, 185, 129, .2),
        rgba(6, 182, 212, .2)
    );
    border: 1px solid var(--success);
    border-radius: 12px;
    padding: 14px;
    text-align: center;
    margin-bottom: 14px;
}

.da-arrear-page .net-pay-banner span {
    font-size: 12px;
    color: #a7f3d0;
    display: block;
}

.da-arrear-page .net-pay-banner h2 {
    font-size: 28px;
    color: #34d399;
    margin-top: 4px;
}

.da-arrear-page .breakdown-row {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    padding: 8px 0;
    border-bottom: 1px dashed #334155;
    font-size: 13px;
}

.da-arrear-page .breakdown-row strong {
    text-align: right;
}

.da-arrear-page .breakdown-row:last-child {
    border-bottom: none;
}

.da-arrear-page .rule-note {
    font-size: 11px;
    color: var(--cyan);
    margin-top: 4px;
    line-height: 1.5;
}

@media (max-width: 380px) {
    .da-arrear-page {
        padding: 10px;
    }

    .da-arrear-page .card {
        padding: 15px;
    }

    .da-arrear-page .row-2 {
        gap: 8px;
    }

    .da-arrear-page .breakdown-row {
        font-size: 12px;
    }
}