:root {
    /* Color Palette - Alegra Inspired */
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f3f5;
    --bg-glass: rgba(255, 255, 255, 0.95);

    --accent-primary: #28a745;
    --accent-secondary: #5cb3ff;
    --accent-gradient: linear-gradient(135deg, #28a745 0%, #20873a 100%);

    --success: #28a745;
    --warning: #ffc107;
    --danger: #ff6b6b;
    --info: #17a2b8;

    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-muted: #adb5bd;

    --border-color: #dee2e6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 20px rgba(40, 167, 69, 0.15);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl);
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.header-content {
    animation: fadeInDown 0.6s ease-out;
}

.app-title {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.logo-icon {
    font-size: 3rem;
    filter: drop-shadow(0 4px 8px rgba(99, 102, 241, 0.4));
}

.app-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* Main Content */
.main-content {
    animation: fadeIn 0.8s ease-out;
}

/* Control Bar */
.control-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.search-section {
    flex: 1;
    min-width: 250px;
}

.search-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-base);
}

.search-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.1);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.action-buttons {
    display: flex;
    gap: var(--spacing-md);
}

/* Buttons */
.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-family: var(--font-family);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-icon {
    font-size: 1.2rem;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-primary);
}

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

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 20px rgba(239, 68, 68, 0.4);
}

.btn-small {
    padding: 0.375rem 0.75rem;
    font-size: 0.875rem;
}

/* Table Container */
.table-container {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    min-height: 400px;
    position: relative;
}

/* Customer Table */
.customer-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}

.customer-table thead {
    background: var(--bg-secondary);
}

.customer-table th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    border-bottom: 2px solid var(--border-color);
    white-space: nowrap;
}

.customer-table th.sortable {
    cursor: pointer;
    user-select: none;
    transition: color var(--transition-fast);
}

.customer-table th.sortable:hover {
    color: var(--accent-primary);
}

.sort-icon {
    opacity: 0.5;
    margin-left: 0.25rem;
    font-size: 0.875rem;
}

.customer-table th.sorted .sort-icon {
    opacity: 1;
    color: var(--accent-primary);
}

.customer-table tbody tr {
    transition: all var(--transition-fast);
    border-bottom: 1px solid var(--border-color);
}

.customer-table tbody tr:hover {
    background: rgba(92, 179, 255, 0.08);
}

.customer-table td {
    padding: var(--spacing-md);
    color: var(--text-primary);
}

.customer-name {
    font-weight: 600;
}

.customer-credit {
    color: var(--success);
    font-weight: 600;
}

.actions-header {
    text-align: center !important;
}

.table-actions {
    display: flex;
    gap: var(--spacing-xs);
    justify-content: center;
}

/* Loading, Error, Empty States */
.loading-state,
.error-state,
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-secondary);
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--spacing-md);
}

.spinner-small {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    display: inline-block;
    animation: spin 0.8s linear infinite;
}

.error-icon,
.empty-icon,
.warning-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
}

.error-state h3,
.empty-state h3 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    z-index: 1000;
    animation: fadeIn var(--transition-fast);
}

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

.modal-content {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease-out;
}

.modal-small {
    max-width: 450px;
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 2rem;
    cursor: pointer;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.close-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* Form Styles */
.customer-form {
    padding: var(--spacing-lg);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.875rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: var(--font-family);
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.1);
}

.modal-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-lg);
}

.credit-info {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.credit-info p {
    margin-bottom: var(--spacing-xs);
}

.delete-content {
    padding: var(--spacing-lg);
    text-align: center;
}

.warning-text {
    color: var(--danger);
    font-weight: 500;
    margin-top: var(--spacing-md);
}

.btn-loading {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    transform: translateY(150%);
    transition: transform var(--transition-base);
    z-index: 2000;
    max-width: 400px;
}

.toast.show {
    transform: translateY(0);
}

.toast.success {
    border-color: var(--success);
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.2) 0%, var(--bg-secondary) 100%);
}

.toast.error {
    border-color: var(--danger);
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.2) 0%, var(--bg-secondary) 100%);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .app-title {
        font-size: 1.75rem;
    }

    .control-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .action-buttons {
        justify-content: stretch;
    }

    .action-buttons .btn {
        flex: 1;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .customer-table {
        font-size: 0.875rem;
    }

    .customer-table th,
    .customer-table td {
        padding: var(--spacing-sm);
    }

    .table-actions {
        flex-direction: column;
    }

    .toast {
        right: var(--spacing-md);
        left: var(--spacing-md);
        max-width: none;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}