/* Material Design Color Palette */
:root {
    --primary: #2196F3;
    --primary-dark: #1976D2;
    --primary-light: #BBDEFB;
    --secondary: #FF9800;
    --success: #4CAF50;
    --danger: #F44336;
    --warning: #FF9800;
    --info: #00BCD4;
    --light: #F5F5F5;
    --dark: #212121;
    --grey: #757575;
    --white: #FFFFFF;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 8px rgba(0,0,0,0.15);
    --shadow-xl: 0 8px 16px rgba(0,0,0,0.2);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #f5f5f5;
    color: #212121;
    line-height: 1.6;
    font-size: 14px;
}

/* Material Icons */
.material-icons {
    font-family: 'Material Icons';
    font-weight: normal;
    font-style: normal;
    font-size: 24px;
    line-height: 1;
    letter-spacing: normal;
    text-transform: none;
    display: inline-block;
    white-space: nowrap;
    word-wrap: normal;
    direction: ltr;
    vertical-align: middle;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    line-height: 1.5;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: #757575;
    color: white;
}

.btn-secondary:hover {
    background: #616161;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #D32F2F;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: 50%;
    background: transparent;
    color: var(--grey);
    transition: var(--transition);
}

.btn-icon:hover {
    background: rgba(0,0,0,0.05);
    color: var(--primary);
}

.btn-icon.btn-danger:hover {
    background: rgba(244,67,54,0.1);
    color: var(--danger);
}

/* Inputs */
.input-field {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 14px;
    transition: var(--transition);
    background: white;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(33,150,243,0.1);
}

.input-group {
    position: relative;
    margin-bottom: 20px;
}

.input-group .material-icons {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--grey);
}

.input-group input {
    padding-left: 44px;
}

/* Cards */
.card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 24px;
}

.card-header {
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid #eee;
}

.card-header h2 {
    font-size: 20px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--dark);
}

.card-body {
    padding: 0;
}

/* Alerts */
.alert {
    padding: 16px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.alert-success {
    background: #E8F5E9;
    color: #2E7D32;
    border-left: 4px solid var(--success);
}

.alert-error {
    background: #FFEBEE;
    color: #C62828;
    border-left: 4px solid var(--danger);
}

.alert-warning {
    background: #FFF3E0;
    color: #E65100;
    border-left: 4px solid var(--warning);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.badge-green {
    background: #E8F5E9;
    color: #2E7D32;
}

.badge-red {
    background: #FFEBEE;
    color: #C62828;
}

.badge-orange {
    background: #FFF3E0;
    color: #E65100;
}

.badge-warning {
    background: #FFF3E0;
    color: #E65100;
}

.badge-danger {
    background: #FFEBEE;
    color: #C62828;
}

.badge-grey {
    background: #F5F5F5;
    color: #616161;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

.data-table thead {
    background: #f5f5f5;
}

.data-table th {
    padding: 16px;
    text-align: left;
    font-weight: 500;
    color: var(--dark);
    border-bottom: 2px solid #ddd;
}

.data-table td {
    padding: 16px;
    border-bottom: 1px solid #eee;
}

.data-table tbody tr:hover {
    background: #f9f9f9;
}

.data-table tbody tr.overdue {
    background: #FFEBEE;
}

.data-table tbody tr.warning {
    background: #FFF3E0;
}

/* Sidebar */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 260px;
    height: 100vh;
    background: white;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.sidebar-header {
    padding: 24px;
    border-bottom: 1px solid #eee;
}

.sidebar-header h2 {
    font-size: 20px;
    font-weight: 500;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.sidebar-nav {
    flex: 1;
    padding: 16px 0;
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    color: var(--grey);
    text-decoration: none;
    transition: var(--transition);
}

.nav-item:hover {
    background: #f5f5f5;
    color: var(--primary);
}

.nav-item.active {
    background: var(--primary-light);
    color: var(--primary);
    border-right: 3px solid var(--primary);
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid #eee;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    margin-bottom: 12px;
    background: #f5f5f5;
    border-radius: var(--border-radius);
}

.user-info .material-icons {
    font-size: 40px;
    color: var(--primary);
}

.user-info strong {
    display: block;
    font-size: 14px;
}

.user-info small {
    display: block;
    font-size: 12px;
    color: var(--grey);
}

.btn-logout {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 10px;
    background: var(--danger);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition);
}

.btn-logout:hover {
    background: #D32F2F;
}

/* Main Content */
.main-content {
    margin-left: 260px;
    padding: 24px;
    min-height: 100vh;
    transition: margin-left 0.3s ease;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 1001;
    width: 48px;
    height: 48px;
    border: none;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    align-items: center;
    justify-content: center;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
}

/* Responsive */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .sidebar-overlay.open {
        display: block;
    }
    
    .main-content {
        margin-left: 0;
        padding: 16px;
        padding-top: 80px;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    padding: 20px;
}

.login-card {
    width: 100%;
    max-width: 400px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    padding: 40px;
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-header h1 {
    font-size: 28px;
    color: var(--primary);
    margin-bottom: 8px;
}

.login-header p {
    color: var(--grey);
    font-size: 14px;
}

.login-form {
    margin-bottom: 24px;
}

.login-footer {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid #eee;
    font-size: 12px;
    color: var(--grey);
}

/* Page Header */
.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 16px;
}

.page-header h1 {
    font-size: 24px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--dark);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: var(--transition);
}

.stat-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: white;
}

.stat-card.blue .stat-icon {
    background: var(--primary);
}

.stat-card.green .stat-icon {
    background: var(--success);
}

.stat-card.red .stat-icon {
    background: var(--danger);
}

.stat-card.orange .stat-icon {
    background: var(--warning);
}

.stat-card.purple .stat-icon {
    background: #9C27B0;
}

.stat-card.teal .stat-icon {
    background: var(--info);
}

.stat-content h3 {
    font-size: 24px;
    font-weight: 500;
    margin-bottom: 4px;
}

.stat-content p {
    font-size: 14px;
    color: var(--grey);
}

/* Filter Card */
.filter-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 20px;
    margin-bottom: 24px;
}

.filter-form {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: flex-end;
}

.filter-group {
    flex: 1;
    min-width: 200px;
}

/* Table Card */
.table-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 24px;
    overflow: hidden;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--grey);
}

.empty-state .material-icons {
    font-size: 64px;
    color: #ddd;
    margin-bottom: 16px;
}

.empty-state-small {
    text-align: center;
    padding: 40px 20px;
    color: var(--grey);
}

.empty-state-small .material-icons {
    font-size: 48px;
    color: #ddd;
    margin-bottom: 12px;
}

/* Form Card */
.form-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.form {
    margin-top: 24px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark);
}

.form-group .required {
    color: var(--danger);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.form-actions {
    display: flex;
    gap: 12px;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid #eee;
}

/* Detail Grid */
.detail-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.detail-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    padding: 16px;
    border-bottom: 1px solid #eee;
}

.detail-row:last-child {
    border-bottom: none;
}

.detail-row .label {
    font-weight: 500;
    color: var(--grey);
}

.detail-row .value {
    text-align: right;
    color: var(--dark);
}

.detail-row .value.amount {
    font-size: 18px;
    font-weight: 500;
    color: var(--primary);
}

/* Payment History */
.payment-history {
    padding: 16px;
}

.payment-item {
    padding: 16px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.payment-item:last-child {
    border-bottom: none;
}

.payment-date {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--grey);
}

.payment-amount {
    font-size: 18px;
    font-weight: 500;
    color: var(--success);
}

.payment-desc {
    width: 100%;
    font-size: 12px;
    color: var(--grey);
    margin-top: 8px;
}

/* Modern Payment History */
.payment-history-badge {
    display: inline-flex;
    align-items: center;
    padding: 6px 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-left: 12px;
}

.payment-history-modern {
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.payment-item-modern {
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-radius: 16px;
    padding: 20px;
    border: 2px solid #e9ecef;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.payment-item-modern::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0;
    transition: opacity 0.3s;
}

.payment-item-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.15);
    border-color: #667eea;
}

.payment-item-modern:hover::before {
    opacity: 1;
}

.payment-item-latest {
    background: linear-gradient(135deg, #E8F5E9 0%, #ffffff 100%);
    border-color: #4CAF50;
    box-shadow: 0 4px 16px rgba(76, 175, 80, 0.1);
}

.payment-item-latest::before {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    opacity: 1;
}

.payment-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    flex-wrap: wrap;
    gap: 12px;
}

.payment-date-modern {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #424242;
}

.payment-date-modern .material-icons {
    color: #667eea;
    font-size: 22px;
}

.payment-date-text {
    font-size: 15px;
    font-weight: 600;
    color: #212121;
}

.payment-amount-modern {
    display: flex;
    align-items: baseline;
    gap: 4px;
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    padding: 10px 18px;
    border-radius: 12px;
    color: white;
    box-shadow: 0 4px 12px rgba(76, 175, 80, 0.3);
}

.payment-amount-icon {
    font-size: 16px;
    font-weight: 700;
    opacity: 0.9;
}

.payment-amount-value {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.payment-desc-modern {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 12px;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 10px;
    margin-top: 12px;
    border-left: 3px solid #667eea;
}

.payment-desc-modern .material-icons {
    color: #667eea;
    font-size: 18px;
    margin-top: 2px;
    flex-shrink: 0;
}

.payment-desc-modern span {
    font-size: 13px;
    color: #616161;
    line-height: 1.6;
}

.payment-badge-latest {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 12px;
    box-shadow: 0 2px 8px rgba(76, 175, 80, 0.3);
}

.payment-badge-latest .material-icons {
    font-size: 16px;
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}

/* Pagination */
.pagination {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid #eee;
    flex-wrap: wrap;
    gap: 12px;
}

.page-info {
    color: var(--grey);
    font-size: 14px;
}

/* Actions Column */
.actions {
    white-space: nowrap;
    display: flex;
    gap: 4px;
}

/* Utilities */
.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }