* {
    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;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

header h2 {
    font-size: 1.2rem;
    font-weight: 300;
    opacity: 0.9;
}

main {
    padding: 30px;
}

.input-section, .method-section {
    margin-bottom: 25px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #2c3e50;
    font-size: 1.1rem;
}

#matrix-input {
    width: 100%;
    padding: 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 16px;
    background-color: #f8f9fa;
    transition: border-color 0.3s ease;
    resize: vertical;
    min-height: 150px;
}

#matrix-input:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

#method-select {
    width: 100%;
    padding: 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    background-color: white;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

#method-select:focus {
    outline: none;
    border-color: #3498db;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.calculate-button {
    background: linear-gradient(135deg, #27ae60 0%, #2ecc71 100%);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 18px;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 4px 15px rgba(39, 174, 96, 0.3);
}

.calculate-button:hover {
    background: linear-gradient(135deg, #219a52 0%, #27ae60 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(39, 174, 96, 0.4);
}

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

.result-section {
    margin-top: 30px;
    padding: 25px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #3498db;
    display: none;
}

.result-section.show {
    display: block;
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.result-title {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 20px;
    font-weight: 600;
}

.matrix-display {
    background: white;
    padding: 20px;
    border-radius: 8px;
    margin: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.matrix-title {
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.matrix-content {
    font-family: 'Courier New', monospace;
    background: #f1f2f6;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    white-space: pre;
    border: 1px solid #ddd;
}

.error-message {
    background: #e74c3c;
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin: 15px 0;
    font-weight: 500;
}

.warning-message {
    background: #f39c12;
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin: 15px 0;
    font-weight: 500;
}

.info-message {
    background: #3498db;
    color: white;
    padding: 15px;
    border-radius: 8px;
    margin: 15px 0;
    font-weight: 500;
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    header h2 {
        font-size: 1rem;
    }
    
    main {
        padding: 20px;
    }
    
    .calculate-button {
        width: 100%;
        padding: 18px;
    }
}