/* Reset และ 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, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* Header */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 60px 20px;
}

header h1 {
    font-size: 3em;
    margin-bottom: 10px;
    animation: fadeInDown 1s ease;
}

.subtitle {
    font-size: 1.5em;
    opacity: 0.9;
    animation: fadeInUp 1s ease;
}

/* Main Content */
main {
    padding: 60px 20px;
}

.hero {
    text-align: center;
    margin-bottom: 60px;
}

.hero h2 {
    font-size: 2.5em;
    color: #667eea;
    margin-bottom: 20px;
}

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

/* Features Section */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.feature-card {
    background: #f8f9fa;
    padding: 40px 30px;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
}

.icon {
    font-size: 3em;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.5em;
    color: #667eea;
    margin-bottom: 15px;
}

.feature-card p {
    color: #666;
}

/* Call to Action */
.cta {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #667eea15 0%, #764ba215 100%);
    border-radius: 15px;
}

button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 1.2em;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

button:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.4);
}

button:active {
    transform: scale(0.98);
}

#message {
    margin-top: 20px;
    font-size: 1.2em;
    color: #667eea;
    font-weight: bold;
    min-height: 30px;
}

/* Footer */
footer {
    background: #2d3748;
    color: white;
    text-align: center;
    padding: 30px 20px;
}

/* Animations */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2em;
    }
    
    .subtitle {
        font-size: 1.2em;
    }
    
    .hero h2 {
        font-size: 2em;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
}