/* Performance Optimizations */
* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

/* Lazy Loading Images */
img.lazy {
    opacity: 0;
    transition: opacity 0.3s ease;
}

img.loaded {
    opacity: 1;
}

/* CSS Custom Properties */
:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
}



body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    font-size: 16px;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 768px) {
    .container {
        padding: 0 2rem;
    }
}

/* Header */
.header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    margin-right: 0.5rem;
}

.nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav a:hover {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav ul {
        gap: 1rem;
    }
    
    .logo h1 {
        font-size: 1.25rem;
        text-align: center;
    }
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, #1d4ed8 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-content p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .hero {
        padding: 3rem 0;
    }
    
    .hero-content h2 {
        font-size: 2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: all 0.2s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: #d97706;
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border-color: white;
}

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

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

/* Calculator Section */
.calculator-section {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.calculator-wrapper {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.calculator-wrapper h3 {
    font-size: 1.875rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

/* Popular Calculators Grid */
.popular-calculators {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.popular-calculators h3 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.calculators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .calculators-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.calculator-card {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.calculator-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.card-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.calculator-card h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.calculator-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

/* Features Section */
.features {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.features h3 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.features-grid-three {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .features-grid-three {
        grid-template-columns: 1fr;
    }
}

.feature-card {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.feature-icon {
    font-size: 2.5rem;
    color: var(--success-color);
    margin-bottom: 1rem;
}

.feature-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Footer */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: white;
}

.footer-section p {
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-section a:hover {
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    border-radius: 50%;
    color: white;
    font-size: 1.125rem;
    transition: background-color 0.2s ease;
}

.social-links a:hover {
    background-color: var(--accent-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
    text-align: center;
    color: var(--text-light);
}

/* Enhanced Mobile Responsive Design */
@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .social-links {
        justify-content: center;
    }

    /* Mobile Calculator Grid */
    .calculators-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .calculator-card {
        padding: 1.5rem;
    }

    /* Mobile Features Grid */
    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    /* Mobile Typography */
    .hero-content h2 {
        font-size: 1.75rem;
        line-height: 1.2;
    }

    .calculator-wrapper h3 {
        font-size: 1.5rem;
    }

    .popular-calculators h3,
    .features h3 {
        font-size: 1.75rem;
    }

    /* Mobile Padding Adjustments */
    .calculator-section,
    .popular-calculators,
    .features {
        padding: 3rem 0;
    }

    .calculator-wrapper {
        padding: 1.5rem;
    }
}

/* Extra Small Mobile Devices */
@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero-content h2 {
        font-size: 1.5rem;
    }

    .hero-content p {
        font-size: 0.9rem;
    }

    .btn {
        padding: 0.625rem 1.25rem;
        font-size: 0.9rem;
    }

    .calculator-wrapper {
        padding: 1rem;
        margin: 0 0.5rem;
    }

    .calculator-card,
    .feature-card {
        padding: 1.25rem;
    }

    .card-icon,
    .feature-icon {
        font-size: 2rem;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-5 { margin-bottom: 1.25rem; }
.mb-6 { margin-bottom: 1.5rem; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-5 { margin-top: 1.25rem; }
.mt-6 { margin-top: 1.5rem; }

/* Additional Styles for Enhanced Design */

/* Header Scrolled State */
.header.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

/* Field Error Styles */
.field-error {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* Info Section Styles */
.info-section {
    padding: 4rem 0;
    background-color: var(--bg-tertiary);
}

.info-content h3 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (max-width: 768px) {
    .info-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

.info-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
}

.info-card h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.info-card h4 i {
    color: var(--primary-color);
}

.info-card ul {
    list-style: none;
    padding-left: 0;
}

.info-card ul li {
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
}

.info-card ul li::before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Formula Section */
.formula-section {
    margin: 3rem 0;
}

.formula-section h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.formula-section h4 i {
    color: var(--accent-color);
}

.formula-box {
    background-color: var(--bg-secondary);
    border: 2px solid var(--primary-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.formula-box p {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    text-align: center;
}

.formula-breakdown {
    background-color: var(--bg-primary);
    border-radius: var(--radius-sm);
    padding: 1rem;
}

.formula-breakdown p {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.formula-breakdown ul {
    list-style: none;
    padding-left: 0;
}

.formula-breakdown ul li {
    margin-bottom: 0.25rem;
    padding-left: 1rem;
    position: relative;
    font-size: 0.9rem;
}

.formula-breakdown ul li::before {
    content: "→";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Practical Application Section */
.practical-application {
    margin-top: 3rem;
}

.practical-application h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.practical-application h4 i {
    color: var(--success-color);
}

.application-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

@media (max-width: 768px) {
    .application-grid {
        grid-template-columns: 1fr;
    }
}

.application-item {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease;
}

.application-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.application-item h5 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--primary-color);
}

.application-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* FAQ Section - Accordion Style */
.faq-section {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.faq-section h3,
.faq-section h4 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.faq-container {
    max-width: 80%;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    overflow: hidden;
    transition: all 0.2s ease;
}

.faq-item:hover {
    box-shadow: var(--shadow-md);
}

.faq-question {
    padding: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-primary);
    transition: background-color 0.2s ease;
    border: none;
    width: 100%;
    text-align: left;
}

.faq-question:hover {
    background-color: var(--bg-secondary);
}

.faq-question h4,
.faq-question h5 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
    flex: 1;
}

.faq-question i {
    color: var(--primary-color);
    transition: transform 0.3s ease;
    font-size: 1.25rem;
    margin-left: 1rem;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    background-color: var(--bg-primary);
}

.faq-item.active .faq-answer {
    padding: 1.5rem;
    max-height: 300px;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* Mobile FAQ Adjustments */
@media (max-width: 768px) {
    .faq-container {
        max-width: 95%;
    }

    .faq-question {
        padding: 1rem;
    }

    .faq-question h4,
    .faq-question h5 {
        font-size: 1rem;
    }

    .faq-item.active .faq-answer {
        padding: 1rem;
    }
}
}

.field-error::before {
    content: "⚠";
    font-size: 0.75rem;
}

input.error,
select.error {
    border-color: var(--error-color);
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

/* Tooltip Styles */
.tooltip {
    position: absolute;
    background-color: var(--text-primary);
    color: white;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.2s ease;
    pointer-events: none;
    max-width: 200px;
    text-align: center;
}

.tooltip.show {
    opacity: 1;
}

.tooltip::after {
    content: "";
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 5px solid transparent;
    border-top-color: var(--text-primary);
}

/* Privacy Notice Banner */
.privacy-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background-color: var(--text-primary);
    color: white;
    padding: 1rem;
    z-index: 1000;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.privacy-banner.show {
    transform: translateY(0);
}

.privacy-banner-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.privacy-banner p {
    margin: 0;
    font-size: 0.875rem;
}

.privacy-banner a {
    color: var(--primary-color);
    text-decoration: underline;
}

.privacy-banner .btn {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    white-space: nowrap;
}

@media (max-width: 768px) {
    .privacy-banner-content {
        flex-direction: column;
        text-align: center;
    }
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}

/* Focus Styles for Accessibility */
button:focus,
input:focus,
select:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .privacy-banner,
    .hero-buttons,
    .calculate-btn {
        display: none !important;
    }

    .hero {
        background: none !important;
        color: var(--text-primary) !important;
        padding: 1rem 0 !important;
    }

    .calculator-wrapper,
    .results-section {
        box-shadow: none !important;
        border: 1px solid #000 !important;
    }
}

/* Information Section Styles */
.info-section {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.info-section h3 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (max-width: 768px) {
    .info-grid {
        grid-template-columns: 1fr;
    }
}

.info-card {
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
}

.info-card h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.info-card h4 i {
    color: var(--primary-color);
}

.info-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.info-card ul {
    list-style: none;
    padding-left: 0;
}

.info-card ul li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.5;
}

.info-card ul li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

/* Formula Section */
.formula-section {
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 3rem;
    box-shadow: var(--shadow-sm);
}

.formula-section h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.formula-section h4 i {
    color: var(--primary-color);
}

.formula-box {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    font-family: 'Courier New', monospace;
}

.formula-box p {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    text-align: center;
}

.formula-breakdown {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.formula-breakdown p {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    text-align: left;
}

.formula-breakdown ul {
    list-style: none;
    padding-left: 0;
}

.formula-breakdown ul li {
    margin-bottom: 0.5rem;
    padding-left: 1rem;
    position: relative;
    font-size: 0.875rem;
    line-height: 1.4;
}

.formula-breakdown ul li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Practical Application Section */
.practical-application {
    margin-top: 3rem;
}

.practical-application h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.practical-application h4 i {
    color: var(--primary-color);
}

.application-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.application-item {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.application-item h5 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.application-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.5;
    margin: 0;
}

/* FAQ Section */
.faq-section {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
}

.faq-section h3 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    margin-bottom: 1rem;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    padding: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.2s ease;
}

.faq-question:hover {
    background-color: var(--bg-secondary);
}

.faq-question h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.faq-question i {
    color: var(--primary-color);
    transition: transform 0.2s ease;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
    padding: 0 1.5rem 1.5rem;
    max-height: 500px;
}

.faq-answer p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}



/* Mobile Responsive Adjustments */
@media (max-width: 768px) {
    .info-section,
    .faq-section,
    .related-calculators {
        padding: 3rem 0;
    }

    .info-section h3,
    .faq-section h3,
    .related-calculators h3 {
        font-size: 1.75rem;
        margin-bottom: 2rem;
    }

    .info-card,
    .formula-section {
        padding: 1.5rem;
    }

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

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

    .faq-question {
        padding: 1rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 1rem 1rem;
    }
}