/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #2d3748;
    background-color: #f7fafc;
}

/* CSS Variables */
:root {
    --primary-navy: #1a365d;
    --secondary-navy: #2c5282;
    --primary-green: #38a169;
    --secondary-green: #48bb78;
    --accent-green: #68d391;
    --light-gray: #f7fafc;
    --medium-gray: #e2e8f0;
    --dark-gray: #4a5568;
    --white: #ffffff;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--primary-navy);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
}

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

/* Header */
.header {
    background: var(--white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo-image {
    height: 50px;
    width: auto;
    transition: var(--transition);
}

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

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark-gray);
    font-weight: 500;
    transition: var(--transition);
}

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

.cta-link {
    background: var(--primary-green);
    color: var(--white) !important;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.cta-link:hover {
    background: var(--secondary-green);
    transform: translateY(-1px);
}

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

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 1rem;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--white);
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.9;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-green);
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.8;
}

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

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2.5rem;
}

.calculator-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.calculator-inputs {
    background: var(--light-gray);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.form-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--primary-navy);
}

.form-group input,
.form-group select {
    padding: 0.75rem;
    border: 2px solid var(--medium-gray);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-green);
    box-shadow: 0 0 0 3px rgba(56, 161, 105, 0.1);
}

.calculate-btn {
    background: var(--primary-green);
    color: var(--white);
    padding: 1rem 2rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 1rem;
}

.calculate-btn:hover {
    background: var(--secondary-green);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.quick-results {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.result-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
}

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

.result-card.highlight {
    background: linear-gradient(135deg, var(--primary-green), var(--secondary-green));
    color: var(--white);
}

.result-card h3 {
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.result-card.highlight h3 {
    color: var(--white);
}

.result-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-navy);
}

.result-card.highlight .result-value {
    color: var(--white);
}

/* Comparison Section */
.comparison-section {
    padding: 4rem 0;
    background: var(--light-gray);
}

.scenario-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.scenario-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.scenario-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.scenario-card h3 {
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--medium-gray);
}

.scenario-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.scenario-stat {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.scenario-stat .stat-label {
    font-weight: 500;
    color: var(--dark-gray);
}

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

/* Results Section */
.results-section {
    padding: 4rem 0;
    background: var(--white);
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.chart-container {
    background: var(--light-gray);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.chart-container h3 {
    margin-bottom: 1rem;
    text-align: center;
}

.amortization-container {
    background: var(--light-gray);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.table-container {
    overflow-x: auto;
    margin-top: 1rem;
}

.amortization-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

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

.amortization-table th {
    background: var(--primary-navy);
    color: var(--white);
    font-weight: 600;
}

.amortization-table tbody tr:hover {
    background: var(--light-gray);
}

/* CTA Section */
.cta-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-navy) 0%, var(--secondary-navy) 100%);
    color: var(--white);
    text-align: center;
}

.cta-content h2 {
    color: var(--white);
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

.btn-primary,
.btn-secondary,
.btn-outline {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--secondary-green);
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background: var(--light-gray);
    transform: translateY(-2px);
}

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

.btn-outline:hover {
    background: var(--white);
    color: var(--primary-navy);
    transform: translateY(-2px);
}

/* Footer */
.footer {
    background: var(--primary-navy);
    color: var(--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 h3,
.footer-section h4 {
    color: var(--white);
    margin-bottom: 1rem;
}

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

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

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

.footer-section ul li a:hover {
    color: var(--accent-green);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: 1rem;
    text-align: center;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .calculator-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .quick-results {
        grid-template-columns: 1fr;
    }
    
    .scenario-cards {
        grid-template-columns: 1fr;
    }
    
    .results-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .nav-links a {
        font-size: 0.875rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .container {
        padding: 0 0.5rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 2rem 0;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .calculator-inputs,
    .scenario-card,
    .chart-container,
    .amortization-container {
        padding: 1rem;
    }
    
    .nav-container {
        padding: 0.5rem;
    }
    
    .logo h1 {
        font-size: 1.25rem;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s ease forwards;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-30px);
    animation: slideInLeft 0.6s ease forwards;
}

@keyframes slideInLeft {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in-right {
    opacity: 0;
    transform: translateX(30px);
    animation: slideInRight 0.6s ease forwards;
}

@keyframes slideInRight {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.spinner {
    border: 2px solid var(--medium-gray);
    border-top: 2px solid var(--primary-green);
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1s linear infinite;
    display: inline-block;
    margin-right: 0.5rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}