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

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
}

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

/* Header Styles */
header {
    background: #2c3e50;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 1.8rem;
}

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

nav a {
    color: white;
    text-decoration: none;
    transition: color 0.3s;
}

nav a:hover {
    color: #3498db;
}


/* Header Logo Styles */
.logo-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.1);
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-main {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    line-height: 1.2;
}

.logo-tagline {
    font-size: 0.7rem;
    color: #bdc3c7;
    line-height: 1;
}

/* Navigation Icons */
.nav-icon {
    margin-right: 0.5rem;
    vertical-align: middle;
}

nav a {
    display: flex;
    align-items: center;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: all 0.3s ease;
}

nav a:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* Responsive Header */
@media (max-width: 768px) {
    .logo-container {
        gap: 0.5rem;
    }
    
    .logo-main {
        font-size: 1.2rem;
    }
    
    .logo-tagline {
        font-size: 0.6rem;
    }
    
    nav ul {
        gap: 0.5rem;
    }
    
    nav a {
        padding: 0.4rem 0.8rem;
        font-size: 0.9rem;
    }
    
    .nav-icon {
        width: 14px;
        height: 14px;
        margin-right: 0.3rem;
    }
}

@media (max-width: 480px) {
    header .container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .logo-container {
        justify-content: center;
    }
    
    nav ul {
        justify-content: center;
    }
}


/* Main Content */
main {
    min-height: calc(100vh - 140px);
    padding: 2rem 0;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 0;
    background: white;
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.hero p {
    font-size: 1.2rem;
    color: #666;
}

/* Calculators Grid */
.calculators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.calculator-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.calculator-card:hover {
    transform: translateY(-5px);
}

.calculator-card h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

/* Calculator Forms */
.calculator {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    max-width: 600px;
    margin: 0 auto;
}

.calculator h2 {
    color: #2c3e50;
    margin-bottom: 1rem;
    text-align: center;
}

.description {
    text-align: center;
    color: #666;
    margin-bottom: 2rem;
}

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

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

.input-group label {
    margin-bottom: 0.5rem;
    font-weight: bold;
    color: #555;
}

.input-group input,
.input-group select {
    padding: 0.75rem;
    border: 2px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: #3498db;
}

/* Buttons */
.btn {
    background: #3498db;
    color: white;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn:hover {
    background: #2980b9;
}

/* Results */
.result {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 5px;
    border-left: 4px solid #3498db;
}

.result h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.result-value {
    font-size: 1.5rem;
    font-weight: bold;
    color: #27ae60;
}

.classification {
    font-size: 1.2rem;
    color: #e67e22;
    margin-top: 0.5rem;
}

.error {
    border-left-color: #e74c3c;
}

.error p {
    color: #e74c3c;
}

/* BMI Info */
.bmi-info {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 5px;
}

.bmi-info h4 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.bmi-info ul {
    list-style: none;
}

.bmi-info li {
    padding: 0.25rem 0;
    border-bottom: 1px solid #ddd;
}

/* Footer */
footer {
    background: #34495e;
    color: white;
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
}

/* Responsive */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    nav ul {
        gap: 1rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .calculator {
        padding: 1rem;
    }
}