/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --background: #f8fafc;
    --card-background: #ffffff;
    --border-color: #e5e7eb;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    padding: 2rem;
    width: 100%;
    max-width: 500px;
}

.card {
    background: var(--card-background);
    border-radius: 20px;
    padding: 3rem 2rem;
    text-align: center;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.icon-container {
    margin-bottom: 1.5rem;
}

.hello-icon {
    width: 64px;
    height: 64px;
    color: var(--primary-color);
    stroke-width: 1.5;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.features {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.feature {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: #f1f5f9;
    border-radius: 12px;
    transition: all 0.2s ease;
}

.feature:hover {
    background: #e2e8f0;
    transform: translateX(4px);
}

.feature i {
    width: 20px;
    height: 20px;
    color: var(--primary-color);
    stroke-width: 2;
}

.feature span {
    font-weight: 500;
    color: var(--text-primary);
}

/* Responsive Design */
@media (max-width: 640px) {
    .container {
        padding: 1rem;
    }
    
    .card {
        padding: 2rem 1.5rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    p {
        font-size: 1rem;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid #ccc;
    }
    
    @page {
        margin: 1in;
        @top-center {
            content: "Hello World";
        }
        @bottom-center {
            content: "Created by Helium";
        }
    }
}