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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --accent: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --text: #1f2937;
    --text-light: #6b7280;
    --bg: #f9fafb;
    --white: #ffffff;
    --border: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text);
}

.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    width: 100%;
    display: block !important;
    visibility: visible !important;
    opacity: 1 !important;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.nav-logo:hover {
    transform: scale(1.05);
}

.nav-logo i {
    font-size: 1.8rem;
    color: var(--primary);
}

.nav-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.5px;
}

.nav-actions {
    display: flex;
    gap: 15px;
    align-items: center;
}

.btn-premium {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 30px 20px;
}

.header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
    display: block !important;
    visibility: visible !important;
    opacity: 1 !important;
    width: 100%;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.hero-subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    font-weight: 400;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

.invoice-builder {
    background: var(--white);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
}

.builder-section {
    margin-bottom: 40px;
    padding-bottom: 30px;
    border-bottom: 2px solid var(--border);
}

.builder-section:last-child {
    border-bottom: none;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 25px;
}

.section-header h2 {
    font-size: 1.5rem;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 10px;
}

.section-header h2 i {
    color: var(--primary);
}

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

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-group.full-width {
    grid-column: 1 / -1;
}

.input-group label {
    font-weight: 600;
    color: var(--text);
    font-size: 0.9rem;
}

.input-group input,
.input-group textarea,
.input-group select {
    padding: 12px 15px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
}

.input-group input:focus,
.input-group textarea:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input-group textarea {
    resize: vertical;
    min-height: 80px;
}

.btn-add-item {
    background: var(--success);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
}

.btn-add-item:hover {
    background: #059669;
    transform: translateY(-2px);
}

.item-row {
    display: grid;
    grid-template-columns: 2fr 120px 80px 100px 100px 40px;
    gap: 10px;
    align-items: center;
    padding: 15px;
    background: var(--bg);
    border-radius: 8px;
    margin-bottom: 10px;
}

.item-row.with-hsn {
    grid-template-columns: 1.5fr 120px 80px 100px 80px 100px 40px;
}

.item-row.with-hsn .item-hsn,
.item-row.with-hsn .item-tax-rate {
    display: block !important;
}

.item-row input {
    padding: 10px;
    border: 2px solid var(--border);
    border-radius: 6px;
    font-size: 0.95rem;
}

.item-row input:focus {
    outline: none;
    border-color: var(--primary);
}

.item-total {
    font-weight: 600;
    color: var(--text);
    text-align: right;
}

.btn-remove-item {
    background: var(--danger);
    color: white;
    border: none;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.btn-remove-item:hover {
    background: #dc2626;
    transform: scale(1.1);
}

.invoice-summary {
    margin-top: 30px;
    padding: 20px;
    background: var(--bg);
    border-radius: 12px;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

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

.summary-row label {
    font-weight: 600;
    margin-right: 15px;
}

.summary-row input {
    padding: 8px 12px;
    border: 2px solid var(--border);
    border-radius: 6px;
    width: 100px;
}

.total-row {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 2px solid var(--primary);
    font-size: 1.2rem;
}

.action-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 30px;
}

.btn-primary,
.btn-secondary {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 10px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    flex: 1;
    justify-content: center;
}

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

.btn-secondary {
    background: var(--white);
    color: var(--text);
    border: 2px solid var(--border);
}

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

.preview-section {
    background: var(--white);
    border-radius: 20px;
    padding: 30px;
    box-shadow: var(--shadow-lg);
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--border);
}

.btn-close {
    background: var(--danger);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
}

.invoice-preview {
    background: var(--white);
    padding: 40px;
    border: 2px solid var(--border);
    border-radius: 12px;
    max-width: 800px;
    margin: 0 auto;
}

.footer {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    margin-top: 50px;
    text-align: center;
    color: white;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.footer-links a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer-links a:hover {
    opacity: 1;
}

/* Modal */
.modal {
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--white);
    border-radius: 20px;
    padding: 40px;
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
}

.close-modal {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-light);
}

.pricing-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.pricing-card {
    background: var(--bg);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    position: relative;
    border: 2px solid var(--border);
}

.pricing-card.featured {
    border-color: var(--primary);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
}

.badge {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 5px 20px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.price {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 20px;
}

.price span {
    font-size: 1rem;
    color: var(--text-light);
}

.pricing-card ul {
    list-style: none;
    text-align: left;
    margin: 20px 0;
}

.pricing-card ul li {
    padding: 10px 0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.pricing-card ul li i.fa-check {
    color: var(--success);
}

.pricing-card ul li i.fa-times {
    color: var(--text-light);
}

.btn-premium-subscribe {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    margin-top: 20px;
    transition: all 0.3s ease;
}

.btn-premium-subscribe:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

@media (max-width: 768px) {
    .nav-container {
        padding: 0 15px;
        flex-wrap: nowrap;
    }
    
    .nav-logo {
        flex: 0 0 auto;
        min-width: 0;
    }
    
    .nav-text {
        font-size: 1.1rem !important;
        display: block !important;
        white-space: nowrap;
    }
    
    .nav-actions {
        gap: 6px;
        flex-wrap: nowrap;
        flex: 0 0 auto;
        justify-content: flex-end;
        min-width: 0;
    }
    
    .nav-actions a {
        font-size: 0.75rem;
        padding: 6px 8px;
        white-space: nowrap;
        margin-right: 0 !important;
    }
    
    .nav-actions span {
        display: flex;
        flex-wrap: nowrap;
        gap: 6px;
    }
    
    .nav-actions span a {
        font-size: 0.75rem;
        margin-right: 0 !important;
        white-space: nowrap;
    }
    
    .nav-actions span button {
        margin-right: 0 !important;
    }
    
    .nav-actions button {
        font-size: 0.75rem;
        padding: 6px 10px;
        white-space: nowrap;
    }
    
    .btn-premium {
        padding: 6px 12px;
        font-size: 0.75rem;
    }
    
    .btn-premium i {
        font-size: 0.8rem;
    }
    
    /* Back button text handling on mobile - shorten text */
    .nav-back-btn {
        display: flex;
        align-items: center;
        gap: 4px;
    }
    
    .nav-back-btn .back-text {
        white-space: nowrap;
    }
    
    @media (max-width: 600px) {
        .nav-back-btn {
            font-size: 0.7rem;
        }
    }
    
    @media (max-width: 480px) {
        .nav-back-btn .back-text {
            display: none;
        }
        .nav-back-btn::after {
            content: 'Back';
            margin-left: 4px;
        }
    }
    
    @media (max-width: 400px) {
        .nav-back-btn::after {
            content: '';
        }
        .nav-back-btn {
            padding: 5px !important;
        }
    }
    
    .container {
        padding: 20px 15px;
    }
    
    .header {
        margin-bottom: 30px;
        padding: 20px 0;
    }
    
    .hero-title {
        font-size: 2rem;
        line-height: 1.3;
    }
    
    .hero-subtitle {
        font-size: 1rem;
        padding: 0 10px;
    }
    
    .invoice-builder {
        padding: 25px 20px;
    }
    
    .builder-section {
        margin-bottom: 30px;
        padding-bottom: 20px;
    }
    
    .section-header {
        margin-bottom: 20px;
    }
    
    .section-header h2 {
        font-size: 1.2rem;
        flex-wrap: wrap;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .input-group input,
    .input-group textarea,
    .input-group select {
        padding: 12px;
        font-size: 16px; /* Prevents zoom on iOS */
    }
    
    .item-row {
        grid-template-columns: 1fr;
        gap: 10px;
        padding: 12px;
    }
    
    .item-row.with-hsn {
        grid-template-columns: 1fr;
    }
    
    .item-row input {
        width: 100%;
    }
    
    .item-total {
        text-align: left;
        margin-top: 10px;
    }
    
    .btn-remove-item {
        width: 36px;
        height: 36px;
        margin-top: 5px;
    }
    
    .action-buttons {
        flex-direction: column;
        gap: 10px;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
    }
    
    .invoice-summary {
        padding: 20px;
    }
    
    .summary-row {
        flex-direction: column;
        gap: 10px;
        align-items: flex-start;
    }
    
    .summary-row input {
        width: 100%;
        max-width: 200px;
    }
    
    .summary-row .label {
        font-size: 0.9rem;
    }
    
    .summary-row .value {
        font-size: 1rem;
    }
    
    .footer {
        padding: 25px 15px;
        margin-top: 30px;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
        flex-wrap: wrap;
        gap: 15px;
    }
    
    .modal-content {
        padding: 25px 20px;
        margin: 10% auto;
        width: 90%;
    }
    
    .pricing-cards {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .invoice-preview {
        padding: 25px 15px;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 8px;
        flex-direction: row;
        align-items: center;
        gap: 4px;
        flex-wrap: nowrap;
    }
    
    .nav-logo {
        flex: 0 0 auto;
        min-width: 0;
    }
    
    .nav-logo i {
        font-size: 1.2rem;
    }
    
    .nav-text {
        font-size: 0.95rem !important;
        display: block !important;
        white-space: nowrap;
    }
    
    .nav-actions {
        flex: 0 0 auto;
        gap: 4px;
        justify-content: flex-end;
        flex-wrap: nowrap;
        min-width: 0;
    }
    
    .nav-actions a {
        font-size: 0.7rem;
        padding: 5px 6px;
        white-space: nowrap;
        margin-right: 0 !important;
    }
    
    /* Back button styling for very small screens */
    .nav-back-btn {
        font-size: 0.65rem;
    }
    
    .nav-back-btn .back-text {
        display: none;
    }
    
    .nav-back-btn::after {
        content: 'Back';
        margin-left: 4px;
    }
    
    /* On very small screens, show only icon */
    @media (max-width: 360px) {
        .nav-back-btn::after {
            content: '';
        }
        .nav-back-btn {
            padding: 5px !important;
        }
    }
    
    .nav-actions span {
        display: flex;
        flex-wrap: nowrap;
        gap: 4px;
    }
    
    .nav-actions span a {
        font-size: 0.7rem;
        margin-right: 0 !important;
        white-space: nowrap;
    }
    
    .nav-actions span button {
        margin-right: 0 !important;
    }
    
    .nav-actions button {
        font-size: 0.7rem;
        padding: 5px 8px;
        margin-right: 0 !important;
        white-space: nowrap;
    }
    
    .btn-premium {
        padding: 5px 10px;
        font-size: 0.7rem;
    }
    
    .btn-premium i {
        font-size: 0.75rem;
    }
    
    .nav-actions a i,
    .nav-actions button i {
        font-size: 0.7rem;
    }
    
    .container {
        padding: 15px 10px;
    }
    
    .header {
        padding: 20px 0 15px;
        margin-bottom: 20px;
    }
    
    .hero-title {
        font-size: 1.5rem;
        line-height: 1.3;
        padding: 0 5px;
    }
    
    .hero-subtitle {
        font-size: 0.9rem;
        padding: 0 10px;
    }
    
    .main-content {
        padding: 0;
    }
    
    .invoice-builder {
        padding: 20px 15px;
        border-radius: 15px;
    }
    
    .builder-section {
        margin-bottom: 25px;
        padding-bottom: 15px;
    }
    
    .section-header {
        margin-bottom: 15px;
    }
    
    .section-header h2 {
        font-size: 1.1rem;
        flex-wrap: wrap;
    }
    
    .section-header h2 i {
        font-size: 1rem;
    }
    
    .form-grid {
        gap: 12px;
    }
    
    .input-group label {
        font-size: 0.85rem;
    }
    
    .input-group input,
    .input-group select,
    .input-group textarea {
        padding: 10px;
        font-size: 16px; /* Prevents zoom on iOS */
    }
    
    .input-group textarea {
        min-height: 60px;
    }
    
    .item-row {
        gap: 8px;
        padding: 12px;
    }
    
    .item-row.with-hsn {
        grid-template-columns: 1fr;
    }
    
    .item-row input {
        width: 100%;
    }
    
    .btn-add-item {
        padding: 10px 15px;
        font-size: 0.85rem;
        width: 100%;
        justify-content: center;
    }
    
    .btn-remove-item {
        padding: 8px;
        width: 32px;
        height: 32px;
        margin-top: 5px;
    }
    
    .btn-primary,
    .btn-secondary {
        padding: 12px 20px;
        font-size: 0.9rem;
    }
    
    .invoice-summary {
        padding: 15px;
        margin-top: 20px;
    }
    
    .summary-row {
        flex-direction: column;
        gap: 8px;
        align-items: flex-start;
    }
    
    .summary-row input {
        width: 100%;
        max-width: 100%;
    }
    
    .summary-row .label {
        font-size: 0.8rem;
    }
    
    .summary-row .value {
        font-size: 0.9rem;
    }
    
    .footer {
        padding: 20px 10px;
        margin-top: 30px;
        border-radius: 15px;
    }
    
    .footer-content {
        padding: 0;
    }
    
    .footer-content p {
        font-size: 0.85rem;
    }
    
    .footer-links {
        gap: 8px;
        flex-direction: column;
    }
    
    .footer-links a {
        font-size: 0.8rem;
        padding: 5px 8px;
    }
    
    .modal-content {
        padding: 20px 15px;
        margin: 5% auto;
        width: 95%;
        max-width: 95%;
    }
    
    .modal-content h2 {
        font-size: 1.3rem;
    }
    
    .invoice-preview {
        padding: 20px 10px;
    }
    
    .pricing-card {
        padding: 20px 15px;
    }
    
    .pricing-card h3 {
        font-size: 1.2rem;
    }
    
    .price {
        font-size: 1.8rem;
    }
    
    .btn-premium-subscribe {
        padding: 12px 20px;
        font-size: 0.9rem;
    }
}

/* Additional responsive fixes for medium screens */
@media (max-width: 992px) and (min-width: 769px) {
    .nav-container {
        padding: 0 20px;
    }
    
    .container {
        padding: 25px 20px;
    }
    
    .invoice-builder {
        padding: 30px 25px;
    }
    
    .form-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .item-row {
        grid-template-columns: 2fr 100px 80px 80px 80px 40px;
        gap: 8px;
    }
    
    .item-row.with-hsn {
        grid-template-columns: 1.5fr 100px 70px 80px 70px 80px 40px;
    }
}