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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    text-align: center;
    margin-bottom: 30px;
    background: rgba(255, 255, 255, 0.95);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.app-title {
    font-size: 2.5rem;
    color: #4a5568;
    margin-bottom: 10px;
    font-weight: 700;
}

.app-subtitle {
    font-size: 1.1rem;
    color: #718096;
    font-weight: 400;
}

.main-content {
    flex: 1;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.calculator-section {
    margin-bottom: 30px;
}

.input-group {
    margin-bottom: 20px;
}

.input-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #4a5568;
    font-size: 1rem;
}

.input-field {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    background: white;
}

.input-field:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.input-with-unit {
    display: flex;
    gap: 10px;
}

.input-with-unit .input-field {
    flex: 1;
}

.unit-select {
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    background: white;
    font-size: 16px;
    min-width: 100px;
}

.calculate-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.calculate-btn:active {
    transform: translateY(0);
}

.results-section {
    margin-bottom: 30px;
    padding: 20px;
    background: #f7fafc;
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

.results-title {
    color: #4a5568;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.result-card {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid #e2e8f0;
}

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

.result-label {
    font-weight: 600;
    color: #4a5568;
}

.result-value {
    font-weight: 700;
    color: #667eea;
    font-size: 1.1rem;
}

.info-section {
    background: #e6fffa;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #38b2ac;
}

.info-title {
    color: #234e52;
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.info-text {
    color: #285e61;
    line-height: 1.5;
}

.reference-section {
    background: #f0f4f8;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.reference-title {
    color: #4a5568;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.reference-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.reference-item {
    background: white;
    padding: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    font-size: 0.9rem;
    line-height: 1.4;
}

.footer {
    text-align: center;
    padding: 20px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 10px;
    color: #718096;
    font-size: 0.9rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .app-title {
        font-size: 2rem;
    }
    
    .main-content,
    .header {
        padding: 20px;
    }
    
    .input-with-unit {
        flex-direction: column;
    }
    
    .unit-select {
        min-width: auto;
    }
    
    .reference-grid {
        grid-template-columns: 1fr;
    }
    
    .result-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
}

@media (max-width: 480px) {
    .app-title {
        font-size: 1.8rem;
    }
    
    .app-subtitle {
        font-size: 1rem;
    }
    
    .container {
        padding: 10px;
    }
    
    .main-content,
    .header {
        padding: 15px;
    }
}