/* CSS Variables for Colors */
:root {
    --primary-yellow: #FFD700;
    --dark-navy: #1a237e;
    --light-navy: #3949ab;
    --white: #ffffff;
    --light-gray: #f5f5f5;
    --dark-gray: #666666;
    --success: #4caf50;
    --error: #f44336;
    --warning: #ff9800;
    --shadow: rgba(26, 35, 126, 0.1);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: var(--dark-navy);
    background-color: var(--light-gray);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, var(--dark-navy) 0%, var(--light-navy) 100%);
    color: var(--white);
    padding: 1rem;
    box-shadow: 0 2px 10px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-yellow);
    text-decoration: none;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    font-weight: 500;
    font-size: 0.9rem;
}

.logout-btn {
    background: var(--primary-yellow);
    color: var(--dark-navy);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    font-size: 0.8rem;
}

.logout-btn:hover {
    background: #ffed4e;
    transform: translateY(-1px);
}

/* Navigation */
.nav-container {
    background: var(--white);
    padding: 1rem;
    box-shadow: 0 2px 5px var(--shadow);
    margin-bottom: 1rem;
}

.nav-menu {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 0.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-item {
    display: block;
    text-align: center;
    padding: 0.8rem 0.5rem;
    background: var(--light-gray);
    color: var(--dark-navy);
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.85rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.nav-item:hover,
.nav-item.active {
    background: var(--primary-yellow);
    color: var(--dark-navy);
    border-color: var(--dark-navy);
    transform: translateY(-2px);
}

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

.page-header {
    margin-bottom: 2rem;
    text-align: center;
}

.page-title {
    font-size: 2rem;
    color: var(--dark-navy);
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: var(--dark-gray);
    font-size: 1rem;
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 15px var(--shadow);
    border: 1px solid #e0e0e0;
}

.card-header {
    border-bottom: 2px solid var(--primary-yellow);
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}

.card-title {
    color: var(--dark-navy);
    font-size: 1.2rem;
    font-weight: 600;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--dark-navy);
    font-size: 0.9rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: var(--white);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-yellow);
    box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.1);
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    font-size: 0.9rem;
    text-align: center;
    min-width: 100px;
}

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

.btn-primary:hover {
    background: var(--light-navy);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--primary-yellow);
    color: var(--dark-navy);
}

.btn-secondary:hover {
    background: #ffed4e;
    transform: translateY(-1px);
}

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

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

.btn-full {
    width: 100%;
}

/* Tables */
.table-container {
    overflow-x: auto;
    margin-bottom: 1rem;
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px var(--shadow);
}

.table th,
.table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}

.table th {
    background: var(--dark-navy);
    color: var(--white);
    font-weight: 600;
    font-size: 0.9rem;
}

.table tr:hover {
    background: #f9f9f9;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-weight: 500;
    border-left: 4px solid;
}

.alert-success {
    background: #e8f5e8;
    color: #2d5932;
    border-left-color: var(--success);
}

.alert-error {
    background: #fdeaea;
    color: #721c24;
    border-left-color: var(--error);
}

.alert-warning {
    background: #fff8e1;
    color: #663c00;
    border-left-color: var(--warning);
}

/* Loading Spinner */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid var(--primary-yellow);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Footer */
.footer {
    background: var(--dark-navy);
    color: var(--white);
    text-align: center;
    padding: 1rem;
    margin-top: auto;
}

/* Login Page Specific */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--dark-navy) 0%, var(--light-navy) 100%);
    padding: 1rem;
}

.login-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 400px;
}

.login-logo {
    text-align: center;
    margin-bottom: 2rem;
}

.login-logo h1 {
    color: var(--dark-navy);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.login-logo p {
    color: var(--dark-gray);
    font-size: 0.9rem;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-yellow) 0%, #ffed4e 100%);
    color: var(--dark-navy);
    padding: 1.5rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(255, 215, 0, 0.3);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-weight: 600;
    opacity: 0.8;
}

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

.empty-state h3 {
    margin-bottom: 1rem;
    color: var(--dark-navy);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 0.5rem;
    }

    .user-info {
        justify-content: center;
    }

    .nav-menu {
        grid-template-columns: repeat(2, 1fr);
    }

    .page-title {
        font-size: 1.5rem;
    }

    .card {
        padding: 1rem;
    }

    .table th,
    .table td {
        padding: 0.5rem;
        font-size: 0.8rem;
    }

    .btn {
        padding: 0.7rem 1rem;
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        grid-template-columns: 1fr;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}

/* Sales Line Items Styling */
.line-item-form {
    background: var(--light-gray);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.line-items-table {
    margin-top: 1rem;
}

.line-items-table .table tfoot td {
    background: linear-gradient(135deg, var(--primary-yellow) 0%, #ffed4e 100%);
    color: var(--dark-navy);
    font-weight: 700;
    border-top: 3px solid var(--dark-navy);
}

.bill-section-divider {
    border-bottom: 2px solid var(--light-gray);
    padding-bottom: 1rem;
    margin-bottom: 2rem;
}

.payment-section-divider {
    border-top: 2px solid var(--light-gray);
    padding-top: 1rem;
    margin-top: 2rem;
}

/* Editable line total inputs */
.line-total-input {
    width: 100px;
    display: inline-block;
    padding: 0.4rem;
    font-size: 0.9rem;
    border: 2px solid var(--primary-yellow);
    border-radius: 4px;
    font-weight: bold;
}

.line-total-input:focus {
    outline: none;
    border-color: var(--dark-navy);
    box-shadow: 0 0 0 2px rgba(26, 35, 126, 0.1);
}

/* Sales history improvements */
.sales-item-details {
    font-size: 0.85rem;
    line-height: 1.3;
}

.sales-item-details > div {
    margin-bottom: 0.25rem;
    padding: 0.25rem 0;
    border-bottom: 1px dotted #e0e0e0;
}

.sales-item-details > div:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

/* Button group for actions */
.btn-group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .btn-group {
        flex-direction: column;
    }
    
    .line-total-input {
        width: 80px;
        font-size: 0.8rem;
    }
    
    .sales-item-details {
        font-size: 0.8rem;
    }
}
.text-right { text-align: right; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }