/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header styles */
header {
    text-align: center;
    margin-bottom: 3rem;
    color: white;
}

header h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
    font-weight: 300;
    color: #e8f4f8;
}

/* Main content */
main {
    flex: 1;
}

.welcome-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    text-align: center;
}

.welcome-card h2 {
    color: #1e3c72;
    margin-bottom: 1rem;
    font-size: 2rem;
}

.welcome-card p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

/* Features grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.feature-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.feature-card h3 {
    color: #333;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.feature-card p {
    color: #666;
    margin-bottom: 1rem;
}

/* Algorithms section */
.algorithms-section {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.algorithms-section h3 {
    color: #1e3c72;
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
    text-align: center;
}

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

.algorithm-card {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid #1e3c72;
    transition: transform 0.3s ease;
}

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

.algorithm-card h4 {
    color: #1e3c72;
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.algorithm-card p {
    color: #666;
    font-size: 0.95rem;
}

/* Button styles */
.btn {
    display: inline-block;
    padding: 0.7rem 1.5rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: #1e3c72;
    color: white;
}

.btn-primary:hover {
    background: #2a5298;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
    transform: translateY(-2px);
}

.btn-warning {
    background: #ffc107;
    color: #212529;
}

.btn-warning:hover {
    background: #e0a800;
    transform: translateY(-2px);
}

.btn-info {
    background: #17a2b8;
    color: white;
}

.btn-info:hover {
    background: #138496;
    transform: translateY(-2px);
}

/* Info section */
.info-section {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.info-section h3 {
    color: #1e3c72;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.info-section ul {
    list-style: none;
    padding-left: 0;
}

.info-section li {
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    background: #f8f9fa;
    border-radius: 6px;
    border-left: 4px solid #1e3c72;
}

.info-section code {
    background: #e9ecef;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-weight: bold;
    color: #1e3c72;
}

/* Footer */
footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    color: white;
    opacity: 0.8;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .algorithms-grid {
        grid-template-columns: 1fr;
    }
    
    .welcome-card, .feature-card, .info-section, .algorithms-section {
        padding: 1.5rem;
    }
}