/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --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;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-800);
    background: var(--gray-100);
    min-height: 100vh;
}

/* Landing Page */
.landing {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.landing-header {
    text-align: center;
    color: white;
    margin-bottom: 60px;
}

.landing-header h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.tagline {
    font-size: 1.5rem;
    opacity: 0.9;
}

.landing-main {
    max-width: 900px;
    width: 100%;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-bottom: 48px;
}

.feature {
    background: white;
    padding: 32px;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 16px;
}

.feature h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
    color: var(--gray-800);
}

.feature p {
    color: var(--gray-600);
}

.cta-button {
    display: block;
    width: fit-content;
    margin: 0 auto;
    padding: 18px 48px;
    background: white;
    color: var(--primary);
    font-size: 1.25rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 50px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    transition: transform 0.2s, box-shadow 0.2s;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(0,0,0,0.3);
}

.landing-footer {
    margin-top: 48px;
    color: rgba(255,255,255,0.8);
}

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

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-bottom: none;
}

.app-header .logo {
    color: white;
}

.app-header .btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.app-header .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-800);
    text-decoration: none;
}

.header-actions {
    display: flex;
    gap: 12px;
}

.btn {
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
}

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

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

.btn-secondary {
    background: var(--gray-100);
    color: var(--gray-700);
}

.btn-secondary:hover {
    background: var(--gray-200);
}

/* Form Container */
.form-container {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 32px;
    width: 100%;
}

.form-container h1 {
    font-size: 2rem;
    margin-bottom: 32px;
    color: var(--gray-800);
}

/* Clone Options */
.clone-options {
    background: var(--gray-50);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 32px;
    border: 1px solid var(--gray-200);
}

.clone-options h3 {
    font-size: 1rem;
    margin-bottom: 12px;
    color: var(--gray-700);
}

.clone-options label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    cursor: pointer;
}

.clone-options input[type="checkbox"] {
    width: 18px;
    height: 18px;
}

/* Form Grid */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 32px;
    margin-bottom: 32px;
}

.form-section {
    background: white;
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--gray-200);
}

.form-section.full-width {
    grid-column: 1 / -1;
    margin-bottom: 32px;
}

.form-section h2 {
    font-size: 1.125rem;
    color: var(--gray-700);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--gray-200);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--gray-300);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-row.four-col {
    grid-template-columns: repeat(4, 1fr);
}

.form-row.four-col .three-col-span {
    grid-column: span 3;
}

.form-row.two-col {
    grid-template-columns: 1fr 2fr;
}

/* Line Items */
.line-items-container {
    overflow-x: auto;
}

.line-items-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

.line-items-table th {
    text-align: left;
    padding: 12px 8px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--gray-500);
    background: var(--gray-50);
    border-bottom: 2px solid var(--gray-200);
}

.line-items-table td {
    padding: 8px;
    border-bottom: 1px solid var(--gray-200);
}

.line-items-table input,
.line-items-table select {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    font-size: 0.875rem;
}

.col-type { width: 120px; }
.col-desc { min-width: 200px; }
.col-qty, .col-rate { width: 100px; }
.col-amount { width: 120px; }
.col-action { width: 40px; }

.add-item-btn {
    margin-top: 16px;
    padding: 10px 20px;
    background: var(--gray-100);
    border: 1px dashed var(--gray-300);
    border-radius: 8px;
    color: var(--gray-600);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.add-item-btn:hover {
    background: var(--gray-200);
    border-color: var(--gray-400);
}

.remove-btn {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--gray-100);
    border-radius: 6px;
    color: var(--gray-500);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all 0.2s;
}

.remove-btn:hover {
    background: #fee2e2;
    color: #dc2626;
}

/* Invoice Summary */
.invoice-summary {
    background: white;
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--gray-200);
    max-width: 350px;
    margin-left: auto;
    margin-bottom: 32px;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--gray-200);
}

.summary-row.total {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    border-bottom: none;
    padding-top: 16px;
}

/* Form Actions */
.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
}

.submit-btn {
    padding: 14px 32px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.submit-btn:hover {
    background: var(--primary-dark);
}

/* Invoice Preview */
.invoice-preview {
    flex: 1;
    padding: 32px;
    display: flex;
    justify-content: center;
}

.invoice-document {
    background: white;
    padding: 48px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    max-width: 800px;
    width: 100%;
}

.invoice-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 48px;
    padding-bottom: 24px;
    border-bottom: 3px solid var(--primary);
}

.invoice-title h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -1px;
}

.invoice-number {
    font-size: 1rem;
    color: var(--gray-500);
    margin-top: 8px;
}

.invoice-parties {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-bottom: 32px;
}

.invoice-parties h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--gray-500);
    margin-bottom: 12px;
}

.party-name {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
}

.party-address,
.party-contact,
.party-tax {
    color: var(--gray-600);
    font-size: 0.875rem;
    margin-bottom: 4px;
}

.invoice-meta {
    display: flex;
    gap: 48px;
    margin-bottom: 32px;
    padding: 16px 24px;
    background: var(--gray-50);
    border-radius: 8px;
}

.meta-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--gray-500);
}

.meta-value {
    font-weight: 600;
    color: var(--gray-800);
}

.invoice-items {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 32px;
}

.invoice-items th {
    text-align: left;
    padding: 14px 12px;
    background: var(--gray-100);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--gray-600);
    border-bottom: 2px solid var(--gray-200);
}

.invoice-items td {
    padding: 14px 12px;
    border-bottom: 1px solid var(--gray-200);
}

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

.invoice-items th.col-qty,
.invoice-items th.col-rate,
.invoice-items th.col-amount {
    text-align: right;
}

.invoice-totals {
    width: 300px;
    margin-left: auto;
    margin-bottom: 32px;
}

.total-row {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--gray-200);
}

.grand-total {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
    border-bottom: 3px solid var(--primary);
}

.invoice-notes {
    margin-top: 48px;
    padding: 24px;
    background: var(--gray-50);
    border-radius: 8px;
}

.invoice-notes h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--gray-500);
    margin-bottom: 12px;
}

.invoice-notes p {
    color: var(--gray-700);
}

/* Footer */
.app-footer {
    padding: 16px 32px;
    text-align: center;
    color: var(--gray-500);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .landing-header h1 {
        font-size: 2.5rem;
    }

    .tagline {
        font-size: 1.125rem;
    }

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

    .form-row,
    .form-row.four-col,
    .form-row.two-col {
        grid-template-columns: 1fr;
    }

    .invoice-parties {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .invoice-meta {
        flex-direction: column;
        gap: 16px;
    }

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

    .invoice-document {
        padding: 24px;
    }
}