:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --success: #059669;
    --danger: #dc2626;
    --secondary: #6b7280;
    --neutral: #4b5563;
    --background: #f8fafc;
    --surface: #ffffff;
    --text: #1e293b;
    --border: #e2e8f0;
    --input-focus: #e0e7ff;
}

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

body {
    font-family: 'Almarai', sans-serif;
    background-color: var(--background);
    color: var(--text);
    margin: 0;
    padding: 1.5rem;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    direction: rtl;
    text-align: right;
    line-height: 1.5;
}

.form-container {
    margin-top: 2rem;
}

.form-container {
    background-color: var(--surface);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    width: 100%;
    max-width: 480px;
    transition: transform 0.2s ease;
}

.form-container:hover {
    transform: translateY(-2px);
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text);
    font-weight: 700;
    font-size: 0.95rem;
}

input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: 12px;
    font-size: 1rem;
    font-family: 'Almarai', sans-serif;
    background-color: var(--surface);
    color: var(--text);
    transition: all 0.2s ease;
}

input:focus {
    outline: none;
    border-color: var(--primary);
    background-color: var(--input-focus);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

button {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: 'Almarai', sans-serif;
}

button:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

button:active {
    transform: translateY(0);
}

.message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 12px;
    font-size: 0.95rem;
    display: none;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.message.success {
    background-color: #ecfdf5;
    color: var(--success);
    border: 1px solid #a7f3d0;
}

.message.error {
    background-color: #fef2f2;
    color: var(--danger);
    border: 1px solid #fecaca;
}

.loading {
    position: relative;
    color: transparent !important;
}

.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    top: 50%;
    left: 50%;
    margin: -10px 0 0 -10px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.8s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

#installmentsSection {
    margin-top: 1rem;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border);
}

.section-header h2 {
    font-size: 1.5rem;
    color: var(--text);
    margin: 0;
}

#lateInstallmentsSum {
    font-weight: 700;
    color: var(--danger);
}
#lateInstallmentsSum:not(:empty) {
    padding: 0.5rem 1rem;
    background-color: #fef2f2;
    border-radius: 8px;
}

/* --- Sticky payment bar (total + pay button, stays at top while scrolling) --- */
.sticky-pay-bar {
    position: sticky;
    top: 0;
    z-index: 10;
    background-color: var(--surface);
    padding: 1rem 0;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.payment-total {
    display: flex;
    align-items: baseline;
    gap: 0.4rem;
    font-size: 1rem;
    color: var(--neutral);
}
.payment-total #selectedTotal {
    color: var(--primary);
    font-size: 1.35rem;
    font-weight: 700;
}
#fawryPayButton {
    padding: 0.9rem 1rem;
}
#fawryPayButton:disabled {
    background-color: var(--secondary);
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}
#fawryPayButton:disabled:hover {
    background-color: var(--secondary);
    transform: none;
}

/* --- Installment cards: one clickable block, color tells you its state --- */
.installment-item {
    position: relative;
    border: 2px solid var(--border);
    border-radius: 12px;
    margin-bottom: 0.75rem;
    padding: 1rem 1.25rem;
    transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
    background-color: var(--surface);
}
.installment-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}
.installment-header .due-date {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--text);
}
.installment-header .amount-tag {
    background-color: #f1f5f9;
    padding: 0.4rem 0.9rem;
    border-radius: 8px;
    color: var(--neutral);
    font-weight: 700;
}
.late-notice,
.late-fee-notice {
    margin-top: 0.5rem;
    padding: 0.4rem 0.6rem;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 700;
}
.late-notice {
    color: var(--danger);
    background-color: #fef2f2;
}
.late-fee-notice {
    color: #b45309;
    background-color: #fffbeb;
}

/* Paid — green background, solid border, muted type */
.installment-item.paid {
    background-color: #ecfdf5;
    border-color: #6ee7b7;
}
.installment-item.paid .due-date,
.installment-item.paid .amount-tag {
    color: var(--success);
}
.installment-item.paid .amount-tag {
    background-color: #d1fae5;
}
.installment-item.paid::after {
    content: "تم السداد";
    display: inline-block;
    margin-top: 0.5rem;
    padding: 0.25rem 0.6rem;
    background-color: var(--success);
    color: white;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 700;
}

/* Late (unpaid + overdue) — red tint */
.installment-item.late {
    background-color: #fef2f2;
    border-color: #fecaca;
}

/* Selectable cards get a hover hint */
.installment-item.selectable {
    cursor: pointer;
}
.installment-item.selectable:hover {
    border-color: var(--primary);
    transform: translateY(-1px);
}

/* Selected — strong blue, overrides paid/late tint */
.installment-item.selected {
    background-color: var(--input-focus);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}
.installment-item.selected .amount-tag {
    background-color: var(--primary);
    color: white;
}

/* Blocked from selection (predecessor not yet picked) — faded, no pointer */
.installment-item.blocked {
    opacity: 0.55;
    cursor: not-allowed;
}

@media (max-width: 480px) {
    body {
        padding: 1rem;
    }

    .form-container {
        padding: 1.5rem;
        border-radius: 12px;
    }
}