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

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, #2c3e50, #1a2a3a);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 0.2rem;
}

.logo p {
    font-size: 0.9rem;
    opacity: 0.8;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
}

.nav-links a:hover {
    opacity: 0.8;
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(44, 62, 80, 0.85), rgba(26, 42, 58, 0.9)), url('https://images.unsplash.com/photo-1460925895917-afdab827c52f?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=1115&q=80');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 5rem 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto 2rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.btn-primary {
    display: inline-block;
    background: #3498db;
    color: white;
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid #3498db;
}

.btn-primary:hover {
    background: transparent;
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* Calculators Section */
.calculators-section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.2rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.1rem;
    color: #7f8c8d;
    max-width: 600px;
    margin: 0 auto;
}

/* Calculator Tabs */
.calculator-tabs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tab-btn {
    padding: 12px 20px;
    background: #ecf0f1;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    margin: 0.25rem;
}

.tab-btn:hover {
    background: #bdc3c7;
}

.tab-btn.active {
    background: #3498db;
    color: white;
}

/* Calculator Content */
.calculator-content {
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.calculator-tab {
    display: none;
    padding: 2rem;
}

.calculator-tab.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

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

.calculator-tab h3 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.calculator-tab p {
    color: #7f8c8d;
    margin-bottom: 1.5rem;
}

/* Form Styles */
.calculator-form {
    margin-bottom: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #2c3e50;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.btn-calculate {
    background: #27ae60;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    width: 100%;
}

.btn-calculate:hover {
    background: #219653;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(39, 174, 96, 0.3);
}

/* Result Container */
.result-container {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid #3498db;
    margin-top: 1.5rem;
}

.result-container h4 {
    color: #2c3e50;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.result-content {
    font-size: 1.1rem;
    line-height: 1.7;
}

.result-content .success {
    color: #27ae60;
    font-weight: 600;
    font-size: 1.2rem;
}

.result-content .error {
    color: #e74c3c;
    font-weight: 600;
    font-size: 1.1rem;
}

.result-content .formula {
    background: #e3f2fd;
    padding: 1rem;
    border-radius: 8px;
    margin-top: 1rem;
    font-family: monospace;
    font-size: 0.9rem;
    border-left: 3px solid #3498db;
}

.result-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin: 1.5rem 0;
}

.result-card {
    flex: 1;
    min-width: 200px;
    background: white;
    border-radius: 8px;
    padding: 1rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    border-top: 3px solid #3498db;
}

.result-card.highlight {
    border-top-color: #27ae60;
    background: #e8f5e9;
}

.result-card-title {
    font-size: 0.9rem;
    color: #7f8c8d;
    margin-bottom: 0.5rem;
}

.result-card-value {
    font-size: 1.3rem;
    font-weight: 600;
    color: #2c3e50;
}

.chart-container {
    margin-top: 1.5rem;
    position: relative;
    height: 300px;
    width: 100%;
}

/* About Section */
.about-section {
    background: #2c3e50;
    color: white;
    padding: 5rem 0;
}

.about-content h2 {
    text-align: center;
    margin-bottom: 1rem;
    font-size: 2.2rem;
}

.about-content p {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
    font-size: 1.1rem;
    opacity: 0.9;
}

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

.feature-card {
    text-align: center;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-card i {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #3498db;
}

.feature-card h3 {
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

/* Footer */
footer {
    background: #1a2a3a;
    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-logo h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

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

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

.footer-links a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s;
}

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

.footer-disclaimer p {
    font-size: 0.9rem;
    opacity: 0.8;
    line-height: 1.6;
}

.footer-bottom {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    opacity: 0.7;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .section-header h2 {
        font-size: 1.8rem;
    }
    
    .calculator-tabs {
        flex-direction: column;
        align-items: center;
    }
    
    .tab-btn {
        width: 80%;
        margin: 0.25rem 0;
    }
    
    nav {
        flex-direction: column;
        text-align: center;
    }
    
    .nav-links {
        margin-top: 1rem;
    }
    
    .nav-links li {
        margin: 0 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        width: 95%;
    }
    
    .hero {
        padding: 3rem 0;
    }
    
    .hero h1 {
        font-size: 1.7rem;
    }
    
    .calculators-section {
        padding: 3rem 0;
    }
    
    .calculator-tab {
        padding: 1.5rem;
    }
}