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

/* Skip link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 0 0 4px 0;
    z-index: 100;
    font-weight: 500;
}

.skip-link:focus {
    top: 0;
}

:root {
    --primary-color: #6b8cae;
    --secondary-color: #8fa3b8;
    --background: #f5f7fa;
    --surface: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #5a6c7d;
    --border: #d5dfe8;
    --success: #7eb5a6;
    --warning: #e8a87c;
    --shadow: rgba(43, 52, 69, 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: var(--surface);
    padding: 1rem 1rem;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 2px 8px var(--shadow);
}

.header-content {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    height: 36px;
    width: auto;
    flex-shrink: 0;
}

.header-text {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.language-selector-container {
    margin-left: auto;
}

.language-selector {
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s ease;
    outline: none;
}

.language-selector:hover {
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px var(--shadow);
}

.language-selector:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(107, 140, 174, 0.1);
}

.language-selector option {
    padding: 0.5rem;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

main {
    flex: 1;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem 1rem;
}

/* SEO Intro Section */
.intro-section {
    text-align: center;
    max-width: 900px;
    margin: 0 auto 2rem;
}

.intro-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    padding: 1rem 0;
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

@media (max-width: 1024px) {
    .comparison-grid {
        grid-template-columns: 1fr;
    }
}

.option-panel {
    background: var(--surface);
    border-radius: 12px;
    padding: 1rem;
    box-shadow: 0 2px 12px var(--shadow);
    border: 1px solid var(--border);
}

.panel-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.payment-type-selector {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.35rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.payment-select,
input[type="number"],
input[type="text"],
select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.95rem;
    background: var(--background);
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.payment-select:focus,
input:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(107, 140, 174, 0.1);
}

.payment-form {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

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

@media (max-width: 640px) {
    .form-row {
        grid-template-columns: 1fr;
    }
}

.input-with-unit {
    position: relative;
}

.input-with-unit input {
    padding-right: 3rem;
}

.input-unit {
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 0.9rem;
    pointer-events: none;
}

.advanced-options {
    margin-top: 1rem;
    border-top: 1px solid var(--border);
    padding-top: 1rem;
}

.advanced-toggle {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.2s ease;
}

.advanced-toggle:hover {
    color: var(--secondary-color);
}

.advanced-toggle::before {
    content: '▶';
    display: inline-block;
    transition: transform 0.3s ease;
    font-size: 0.8rem;
}

.advanced-toggle.open::before {
    transform: rotate(90deg);
}

.advanced-content {
    display: none;
    margin-top: 1rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 8px;
    gap: 1rem;
    flex-direction: column;
}

.advanced-content.show {
    display: flex;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    cursor: pointer;
}

.checkbox-group label {
    margin-bottom: 0;
    cursor: pointer;
    font-weight: 400;
}

.compare-section {
    text-align: center;
    margin: 1rem 0;
}

.compare-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(107, 140, 174, 0.3);
}

.compare-btn:hover:not(:disabled) {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(107, 140, 174, 0.4);
}

.compare-btn:disabled {
    background: var(--border);
    cursor: not-allowed;
    box-shadow: none;
}

.results-section {
    background: var(--surface);
    border-radius: 12px;
    padding: 1.25rem;
    box-shadow: 0 2px 12px var(--shadow);
    border: 1px solid var(--border);
    margin-top: 1rem;
}

.results-section h2 {
    font-size: 1.4rem;
    color: var(--primary-color);
    margin-bottom: 0.35rem;
    text-align: center;
}

.scenarios-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

/* Winner Banner Styles */
.result-winner-banner {
    background: linear-gradient(135deg, rgba(107, 140, 174, 0.15), rgba(126, 181, 166, 0.2));
    border: 2px solid var(--primary-color);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
    text-align: center;
}

.winner-title {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.winner-option {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.15rem;
}

.winner-savings {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--success);
}

/* Result Items - Primary Info */
.result-main {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.result-option-name {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
}

.result-cost-display {
    text-align: right;
}

.result-cost-label {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.15rem;
}

.result-net-cost {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

/* Result Items - Secondary Info */
.result-details {
    margin-top: 0.5rem;
}

.result-details-toggle {
    font-size: 0.85rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem 0;
    user-select: none;
    list-style: none;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.result-details-toggle:hover {
    color: var(--primary-color);
}

.result-details-toggle::marker {
    content: '';
}

.result-details-toggle::before {
    content: '▶';
    font-size: 0.7rem;
    display: inline-block;
    transition: transform 0.2s ease;
}

.result-details[open] .result-details-toggle::before {
    transform: rotate(90deg);
}

.result-secondary {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 8px;
    margin-top: 0.5rem;
    font-size: 0.9rem;
}

.secondary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.secondary-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.secondary-value {
    color: var(--text-primary);
    font-weight: 600;
}

.secondary-note {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border);
}

.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1rem;
}

@media (max-width: 900px) {
    .scenarios-grid {
        grid-template-columns: 1fr;
    }
}

.scenario-card {
    background: var(--background);
    border-radius: 8px;
    padding: 1rem;
    border: 2px solid var(--border);
}

.scenario-card h3 {
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 0.15rem;
    text-align: center;
}

.scenario-description {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 0.75rem;
    font-style: italic;
}

.scenario-content {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.result-item {
    padding: 1rem;
    background: var(--surface);
    border-radius: 8px;
    border: 2px solid var(--border);
    position: relative;
}

.result-item.winner {
    border-color: var(--success);
    box-shadow: 0 0 0 1px var(--success);
}

.best-choice-badge {
    position: absolute;
    top: -0.65rem;
    right: 1rem;
    background: linear-gradient(135deg, var(--success), #6ba892);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 16px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    box-shadow: 0 2px 8px rgba(126, 181, 166, 0.4);
    z-index: 10;
}

.toggle-btn {
    display: block;
    margin: 1rem auto;
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.6rem 1.5rem;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.charts-section {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 8px;
}

.chart-container {
    background: var(--surface);
    padding: 0.75rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    height: 300px;
    max-width: 900px;
    margin: 0 auto;
}

.chart-container canvas {
    max-height: 100%;
}

.details-section {
    margin-top: 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--background);
}

.details-section summary {
    padding: 0.75rem;
    cursor: pointer;
    font-weight: 600;
    color: var(--primary-color);
    user-select: none;
}

.details-section summary:hover {
    background: rgba(107, 140, 174, 0.05);
}

.breakdown-content {
    padding: 0.75rem;
    border-top: 1px solid var(--border);
}

.breakdown-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.breakdown-table th,
.breakdown-table td {
    padding: 0.5rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.breakdown-table th {
    background: var(--surface);
    font-weight: 600;
    color: var(--primary-color);
}

.breakdown-table tr:hover {
    background: rgba(107, 140, 174, 0.05);
}

footer {
    text-align: center;
    padding: 1rem 1rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-top: 1px solid var(--border);
    margin-top: auto;
    max-width: 100%;
    background: var(--surface);
}

.footer-nav {
    margin-top: 0.75rem;
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.footer-nav a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.85rem;
    transition: color 0.2s ease;
}

.footer-nav a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* RTL Support for Arabic */
[dir="rtl"] {
    direction: rtl;
}

[dir="rtl"] .header-content {
    flex-direction: row-reverse;
}

[dir="rtl"] .language-selector-container {
    margin-left: 0;
    margin-right: auto;
}

[dir="rtl"] .breakdown-table th,
[dir="rtl"] .breakdown-table td {
    text-align: right;
}

[dir="rtl"] .form-row {
    flex-direction: row-reverse;
}

@media (max-width: 768px) {
    .language-selector {
        font-size: 0.85rem;
        padding: 0.4rem 0.6rem;
    }
    
    .language-selector-container {
        position: absolute;
        top: 1rem;
        right: 1rem;
    }
    
    [dir="rtl"] .language-selector-container {
        right: auto;
        left: 1rem;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-success {
    color: var(--success);
}

.text-warning {
    color: var(--warning);
}

/* Animation */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section,
.scenario-card {
    animation: fadeIn 0.4s ease;
}