body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    margin: 0;
    padding: 20px;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

/* Navigation Menu Styles */
.nav-container {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 0;
}

.nav-menu {
    display: flex;
    justify-content: center;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-menu li {
    margin: 0;
}

.nav-menu a {
    display: block;
    padding: 20px 40px;
    color: white;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1em;
    transition: all 0.3s ease;
    position: relative;
}

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

.nav-menu a.active {
    background: rgba(255,255,255,0.2);
    font-weight: bold;
}

.nav-menu a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: white;
    border-radius: 2px;
}

/* Main Content */
.hero-section {
    text-align: center;
    padding: 60px 40px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.hero-title {
    font-size: 3em;
    font-weight: bold;
    color: #2c3e50;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

.hero-subtitle {
    font-size: 1.3em;
    color: #7f8c8d;
    margin-bottom: 40px;
    line-height: 1.6;
}

.feature-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.feature-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 5px solid;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.feature-card.chemical {
    border-left-color: #3498db;
}

.feature-card.organic {
    border-left-color: #2ecc71;
}

.feature-card.pigment {
    border-left-color: #f39c12;
}

.feature-card h3 {
    font-size: 1.4em;
    margin-bottom: 15px;
    color: #2c3e50;
}

.feature-card.chemical h3 {
    color: #3498db;
}

.feature-card.organic h3 {
    color: #2ecc71;
}

.feature-card.pigment h3 {
    color: #f39c12;
}

.feature-card p {
    color: #7f8c8d;
    line-height: 1.6;
    margin: 0;
}

.cta-section {
    text-align: center;
    padding: 50px 40px;
    background: #f8f9fa;
}

.cta-button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 18px 50px;
    font-size: 1.2em;
    font-weight: bold;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(102, 126, 234, 0.4);
}

.info-section {
    padding: 50px 40px;
    background: white;
}

.info-title {
    text-align: center;
    font-size: 2.5em;
    color: #2c3e50;
    margin-bottom: 40px;
}

.parameters-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 25px;
    margin-top: 30px;
}

.parameters-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.parameters-flexible {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.parameter-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid #667eea;
    transition: all 0.3s ease;
    height: auto;
    min-height: 120px;
}

.parameter-item.full-width {
    grid-column: 1 / -1;
    border-left: 4px solid #e74c3c;
    min-height: auto;
}

.parameter-item:hover {
    background: #e9ecef;
    transform: translateX(5px);
}

.parameter-name {
    font-weight: bold;
    color: #2c3e50;
    font-size: 1.1em;
    margin-bottom: 10px;
}

.parameter-desc {
    color: #6c757d;
    line-height: 1.5;
    font-size: 0.95em;
}

/* pH Classification Styles */
.ph-classification {
    margin-top: 15px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
}

.ph-item {
    display: flex;
    flex-direction: column;
    padding: 12px 15px;
    border-radius: 8px;
    text-align: center;
    border: 2px solid;
    transition: all 0.3s ease;
    cursor: pointer;
}

.ph-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.ph-range {
    font-weight: bold;
    font-size: 0.9em;
    margin-bottom: 5px;
}

.ph-label {
    font-size: 0.8em;
    font-weight: 500;
}

.ph-item.neutral {
    background: linear-gradient(135deg, #e8f5e8 0%, #d4edda 100%);
    border-color: #28a745;
    color: #155724;
}

.ph-item.alkaline {
    background: linear-gradient(135deg, #e2e6ff 0%, #d1ecf1 100%);
    border-color: #17a2b8;
    color: #0c5460;
}

.ph-item.acidic {
    background: linear-gradient(135deg, #fff3cd 0%, #ffeaa7 100%);
    border-color: #ffc107;
    color: #856404;
}

.ph-item.highly-acidic {
    background: linear-gradient(135deg, #ffe6e6 0%, #ffd6cc 100%);
    border-color: #fd7e14;
    color: #bd2130;
}

.ph-item.sulfate-acidic {
    background: linear-gradient(135deg, #f8d7da 0%, #f5c6cb 100%);
    border-color: #dc3545;
    color: #721c24;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2em;
    }
    
    .hero-subtitle {
        font-size: 1.1em;
    }
    
    .nav-menu a {
        padding: 15px 20px;
        font-size: 1em;
    }
    
    .parameters-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .parameters-flexible {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        gap: 20px;
    }
    
    .parameters-flexible {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .feature-cards {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .hero-section {
        padding: 40px 20px;
    }
    
    .info-section {
        padding: 40px 20px;
    }
    
    .parameter-item {
        padding: 15px;
        min-height: 100px;
    }
    
    .ph-classification {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 8px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.6em;
    }
    
    .info-title {
        font-size: 2em;
    }
    
    .cta-button {
        padding: 15px 30px;
        font-size: 1.1em;
    }
    
    .ph-classification {
        grid-template-columns: 1fr;
        gap: 6px;
    }
    
    .ph-item {
        padding: 10px 12px;
    }
    
    .ph-range {
        font-size: 0.85em;
    }
    
    .ph-label {
        font-size: 0.75em;
    }
}