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

:root {
    /* Color Variables */
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #64748b;
    --background-color: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-light: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-medium: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-large: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* Header Styles */
.header {
    padding: var(--spacing-lg) 0;
    text-align: center;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.logo-icon {
    width: 2.5rem;
    height: 2.5rem;
    color: var(--primary-color);
    stroke-width: 2;
}

.title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xl);
    padding: var(--spacing-lg) 0;
}

.welcome-card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-large);
    text-align: center;
    max-width: 500px;
    width: 100%;
    border: 1px solid var(--border-color);
}

.card-icon {
    margin-bottom: var(--spacing-md);
}

.card-icon i {
    width: 3rem;
    height: 3rem;
    color: var(--primary-color);
    stroke-width: 1.5;
}

.welcome-card h2 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.welcome-card p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

/* Button Styles */
.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 0.5rem;
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all 0.2s ease;
    box-shadow: var(--shadow-medium);
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-large);
}

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

.btn-primary i {
    width: 1.25rem;
    height: 1.25rem;
    stroke-width: 2;
}

/* Greeting Message */
.greeting-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    border-radius: 0.5rem;
    font-weight: 500;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

.greeting-message.show {
    opacity: 1;
    transform: translateY(0);
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    color: var(--primary-color);
    border: 1px solid #bae6fd;
}

/* Features Section */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    width: 100%;
    max-width: 800px;
}

.feature-card {
    background: var(--card-background);
    padding: var(--spacing-lg);
    border-radius: 0.75rem;
    text-align: center;
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

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

.feature-card i {
    width: 2rem;
    height: 2rem;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
    stroke-width: 2;
}

.feature-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

/* Footer */
.footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    border-top: 1px solid var(--border-color);
    margin-top: var(--spacing-lg);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .title {
        font-size: var(--font-size-3xl);
    }
    
    .welcome-card {
        padding: var(--spacing-lg);
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .header-content {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
}

@media (max-width: 480px) {
    .title {
        font-size: var(--font-size-2xl);
    }
    
    .welcome-card h2 {
        font-size: var(--font-size-xl);
    }
    
    .welcome-card {
        padding: var(--spacing-md);
    }
}

/* Print Styles */
@media print {
    @page {
        margin: 1in;
        @top-center {
            content: "Hello World - Simple Website";
        }
        @bottom-center {
            content: "Created by Helium";
        }
    }
    
    body {
        background: white;
        color: black;
    }
    
    .container {
        max-width: none;
        padding: 0;
    }
    
    .btn-primary {
        display: none;
    }
    
    .greeting-message {
        display: none;
    }
}