/* Modern Bill Helper Styles */
:root {
    --primary: #3B82F6;
    --primary-dark: #2563EB;
    --secondary: #6B7280;
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;
    --info: #06B6D4;
    --light: #F8FAFC;
    --dark: #1E293B;
    --white: #FFFFFF;
    --gray-50: #F8FAFC;
    --gray-100: #F1F5F9;
    --gray-200: #E2E8F0;
    --gray-300: #CBD5E1;
    --gray-400: #94A3B8;
    --gray-500: #64748B;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1E293B;
    --gray-900: #0F172A;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Layout */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.header-actions {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-700);
    border: 1px solid var(--gray-300);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--gray-200);
    border-color: var(--gray-400);
}

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

.btn-success:hover:not(:disabled) {
    background: #059669;
}

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

.btn-warning:hover:not(:disabled) {
    background: #D97706;
}

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

.btn-danger:hover:not(:disabled) {
    background: #DC2626;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
}

.btn-icon {
    padding: 0.5rem;
    border-radius: 50%;
    width: 2.5rem;
    height: 2.5rem;
    justify-content: center;
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    width: 100%;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.card-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
}

/* Grid */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 0.875rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 100px;
}

.form-help {
    font-size: 0.75rem;
    color: var(--gray-500);
    margin-top: 0.25rem;
}

.form-error {
    font-size: 0.75rem;
    color: var(--danger);
    margin-top: 0.25rem;
}

/* Checkbox */
.checkbox {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.checkbox input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
    accent-color: var(--primary);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--gray-400);
    cursor: pointer;
    padding: 0.25rem;
    border-radius: var(--radius);
    transition: color 0.2s;
}

.modal-close:hover {
    color: var(--gray-600);
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--gray-200);
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
}

/* Lists */
.list {
    list-style: none;
}

.list-item {
    padding: 1rem;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: background-color 0.2s;
}

.list-item:hover {
    background: var(--gray-50);
}

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

.list-item-content {
    flex: 1;
}

.list-item-title {
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.25rem;
}

.list-item-subtitle {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.list-item-actions {
    display: flex;
    gap: 0.5rem;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 9999px;
    background: var(--gray-100);
    color: var(--gray-700);
}

.badge-primary { background: rgba(59, 130, 246, 0.1); color: var(--primary); }
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--gray-500);
}

.empty-state i {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 0.5rem;
}

.empty-state p {
    font-size: 0.875rem;
}

/* Notifications */
.notification {
    position: fixed;
    top: 1rem;
    right: 1rem;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    z-index: 1001;
    max-width: 400px;
    animation: slideIn 0.3s ease-out;
}

.notification-success {
    border-left: 4px solid var(--success);
}

.notification-error {
    border-left: 4px solid var(--danger);
}

.notification-warning {
    border-left: 4px solid var(--warning);
}

.notification-info {
    border-left: 4px solid var(--info);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Tab Navigation */
.tab-buttons {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tab-button {
    padding: 0.75rem 1.5rem;
    border: 1px solid #e5e7eb;
    background: #f9fafb;
    color: #6b7280;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}

.tab-button:hover {
    background: #f3f4f6;
    color: #374151;
}

.tab-button.active {
    background: #3b82f6;
    color: white;
    border-color: #3b82f6;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Month Navigation */
.month-navigation {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 0.25rem;
    margin-top: 0.5rem;
}

/* Account Cards */
.account-card {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 0.5rem;
    padding: 1rem;
    text-align: center;
    transition: all 0.2s;
}

.account-card:hover {
    background: #f1f5f9;
    border-color: #cbd5e1;
}

.account-name {
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 0.25rem;
}

.account-type {
    font-size: 0.875rem;
    color: #64748b;
    text-transform: capitalize;
    margin-bottom: 0.5rem;
}

.account-balance {
    font-size: 1.25rem;
    font-weight: 700;
}

.account-balance.positive {
    color: #059669;
}

.account-balance.negative {
    color: #dc2626;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        padding: 1rem;
        flex-direction: column;
        gap: 1rem;
    }
    
    .header-actions {
        width: 100%;
        justify-content: center;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .grid-cols-2,
    .grid-cols-3,
    .grid-cols-4 {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 1rem;
        max-width: none;
    }
    
    .list-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .list-item-actions {
        width: 100%;
        justify-content: flex-end;
    }
}

@media (max-width: 480px) {
    .btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.75rem;
    }
    
    .card-header,
    .card-body {
        padding: 1rem;
    }
    
    .modal-header,
    .modal-body,
    .modal-footer {
        padding: 1rem;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-sm { font-size: 0.875rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-2xl { font-size: 1.5rem; }

.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-gray-500 { color: var(--gray-500); }
.text-gray-600 { color: var(--gray-600); }
.text-gray-700 { color: var(--gray-700); }
.text-gray-900 { color: var(--gray-900); }

.text-green-600 { color: var(--success); }
.text-red-600 { color: var(--danger); }
.text-yellow-600 { color: var(--warning); }
.text-blue-600 { color: var(--primary); }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }

.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-6 { padding: 1.5rem; }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }

.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.w-full { width: 100%; }
.h-full { height: 100%; }

.rounded { border-radius: var(--radius); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: 9999px; }

.shadow { box-shadow: var(--shadow); }
.shadow-lg { box-shadow: var(--shadow-lg); }