/* ============================================
   CSS Variables & Reset
   ============================================ */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius: 8px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-logo i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 8px 0;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-dropdown {
    position: relative;
}

/* Desktop: Show on hover */
.nav-dropdown:hover .dropdown-content {
    display: block;
}

/* Mobile: Show when active class is added */
.nav-dropdown.active .dropdown-content {
    display: block;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--bg-white);
    min-width: 200px;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius);
    padding: 10px 0;
    margin-top: 10px;
    border: 1px solid var(--border-color);
    z-index: 1001;
}

.dropdown-content a {
    display: block;
    padding: 12px 20px;
    color: var(--text-dark);
    text-decoration: none;
    transition: var(--transition);
}

.dropdown-content a:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

.nav-search {
    position: relative;
    display: flex;
    align-items: center;
}

.nav-search input {
    padding: 8px 35px 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    width: 250px;
    font-size: 0.9rem;
}

.nav-search i {
    position: absolute;
    right: 12px;
    color: var(--text-light);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.search-box {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    gap: 10px;
}

.search-box input {
    flex: 1;
    padding: 15px 20px;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
}

.search-box button {
    padding: 15px 25px;
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition);
}

.search-box button:hover {
    background: #059669;
}

/* ============================================
   Categories Section
   ============================================ */
.categories {
    padding: 60px 20px;
    background: var(--bg-light);
}

.categories h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 40px;
    color: var(--text-dark);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.category-card {
    background: var(--bg-white);
    padding: 30px;
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text-dark);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    text-align: center;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.category-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
}

.category-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.category-card p {
    color: var(--text-light);
    margin-bottom: 15px;
}

.count {
    display: inline-block;
    padding: 5px 15px;
    background: var(--bg-light);
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 600;
}

/* ============================================
   Popular Calculators
   ============================================ */
.popular-calculators {
    padding: 60px 20px;
}

.popular-calculators h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 40px;
    color: var(--text-dark);
}

.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.calc-card {
    background: var(--bg-white);
    padding: 30px;
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text-dark);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 2px solid transparent;
}

.calc-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.calc-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
    display: block;
}

.calc-card h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.calc-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ============================================
   FAQ Section
   ============================================ */
.faq-section {
    padding: 60px 20px;
    background: var(--bg-light);
}

.faq-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 40px;
    color: var(--text-dark);
}

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

.faq-item {
    background: var(--bg-white);
    border-radius: var(--radius);
    margin-bottom: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    width: 100%;
    padding: 20px;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
    transition: var(--transition);
}

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

.faq-question i {
    transition: var(--transition);
    color: var(--primary-color);
}

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

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

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 20px 20px;
    color: var(--text-light);
    line-height: 1.8;
}

/* ============================================
   Calculator Page Styles
   ============================================ */
.calculator-page {
    padding: 40px 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.calculator-header {
    text-align: center;
    margin-bottom: 40px;
}

.calculator-header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.calculator-header p {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto;
}

.calculator-container {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow-md);
    margin-bottom: 30px;
}

.calc-form {
    display: grid;
    gap: 25px;
}

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

.form-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-dark);
}

.form-group input,
.form-group select {
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group small {
    margin-top: 5px;
    color: var(--text-light);
    font-size: 0.9rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.btn-group {
    display: flex;
    gap: 15px;
    margin-top: 10px;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

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

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

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

.result-section {
    margin-top: 30px;
    padding: 25px;
    background: var(--bg-light);
    border-radius: var(--radius);
    display: none;
}

.result-section.active {
    display: block;
}

.result-section h3 {
    margin-bottom: 20px;
    color: var(--text-dark);
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.result-item:last-child {
    border-bottom: none;
}

.result-label {
    font-weight: 600;
    color: var(--text-dark);
}

.result-value {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.1rem;
}

.error-message {
    background: #fee2e2;
    color: #991b1b;
    padding: 12px 15px;
    border-radius: var(--radius);
    margin-top: 10px;
    display: none;
}

.error-message.active {
    display: block;
}

.disclaimer {
    background: var(--bg-light);
    padding: 20px;
    border-radius: var(--radius);
    border-left: 4px solid var(--primary-color);
    margin-top: 30px;
}

.disclaimer h4 {
    margin-bottom: 10px;
    color: var(--text-dark);
}

.disclaimer p {
    color: var(--text-light);
    font-size: 0.9rem;
    line-height: 1.6;
}

.related-calculators {
    margin-top: 40px;
    padding: 30px;
    background: var(--bg-light);
    border-radius: var(--radius);
}

.related-calculators h3 {
    margin-bottom: 20px;
    color: var(--text-dark);
}

.related-links {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.related-links a {
    padding: 8px 15px;
    background: var(--bg-white);
    color: var(--primary-color);
    text-decoration: none;
    border-radius: var(--radius);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.related-links a:hover {
    background: var(--primary-color);
    color: white;
}

/* Chart Container */
.chart-container {
    margin-top: 30px;
    padding: 20px;
    background: var(--bg-white);
    border-radius: var(--radius);
}

.chart-container canvas {
    max-height: 400px;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 50px 20px 20px;
    margin-top: 60px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* ============================================
    Calculator SEO Content Section
   ============================================ */

   /* ============================================
   Calculator SEO Content Section
   ============================================ */

.calculator-content {
    margin-top: 40px;
    padding: 35px;
    background: var(--bg-white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.calculator-content h2 {
    font-size: 1.6rem;
    margin-bottom: 12px;
    color: var(--text-dark);
    position: relative;
    padding-left: 14px;
}

.calculator-content h2::before {
    content: "";
    position: absolute;
    left: 0;
    top: 6px;
    width: 4px;
    height: 70%;
    background: var(--primary-color);
    border-radius: 2px;
}

.calculator-content h3 {
    font-size: 1.25rem;
    margin-top: 25px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

.calculator-content p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 16px;
    line-height: 1.75;
}

.calculator-content ul,
.calculator-content ol {
    margin-left: 20px;
    margin-bottom: 18px;
}

.calculator-content li {
    margin-bottom: 8px;
    color: var(--text-light);
    font-size: 0.95rem;
}

/* FAQ-style blocks */
.calculator-content .faq-block {
    background: var(--bg-light);
    padding: 18px 20px;
    border-radius: var(--radius);
    margin-bottom: 15px;
    border-left: 3px solid var(--primary-color);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
    .calculator-content {
        padding: 25px;
    }

    .calculator-content h2 {
        font-size: 1.4rem;
    }

    .calculator-content h3 {
        font-size: 1.1rem;
    }

    .calculator-content p,
    .calculator-content li {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .calculator-content {
        padding: 20px;
    }

    .calculator-content h2 {
        font-size: 1.25rem;
    }
}


/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--bg-white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 20px 0;
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        width: 100%;
        padding: 10px 0;
    }

    .nav-dropdown .dropdown-content {
        position: static;
        display: none;
        box-shadow: none;
        border: none;
        background: var(--bg-light);
        margin-top: 0;
        padding-left: 20px;
    }

    .nav-dropdown.active .dropdown-content {
        display: block;
    }
    
    .nav-dropdown .nav-link i {
        transition: transform 0.3s ease;
    }
    
    .nav-dropdown.active .nav-link i {
        transform: rotate(180deg);
    }

    .nav-toggle {
        display: flex;
    }

    .nav-search {
        display: none;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .categories h2,
    .popular-calculators h2,
    .faq-section h2 {
        font-size: 2rem;
    }

    .calculator-header h1 {
        font-size: 2rem;
    }

    .calculator-container {
        padding: 25px;
    }

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

    .btn-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .category-grid,
    .calculator-grid {
        grid-template-columns: 1fr;
    }

    .search-box {
        flex-direction: column;
    }

    .search-box button {
        width: 100%;
    }
}