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

:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #64748b;
    --background: #f8fafc;
    --surface: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 12px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, var(--background) 0%, #e0e7ff 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
}

/* Header */
.header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.header .icon {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
    animation: bounce 2s infinite;
}

.header h1 {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

/* Main Content */
.main {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
}

.card {
    background: var(--surface);
    padding: var(--spacing-xl);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    text-align: center;
    max-width: 500px;
    width: 100%;
    border: 1px solid var(--border);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

.card-icon {
    width: 32px;
    height: 32px;
    color: #ef4444;
    margin-bottom: var(--spacing-md);
    animation: pulse 2s infinite;
}

.card h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.card p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-size: 1.1rem;
}

/* Button */
.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    box-shadow: var(--shadow);
}

.btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 12px -2px rgba(59, 130, 246, 0.3);
}

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

.btn i {
    width: 18px;
    height: 18px;
}

/* Message */
.message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: #dcfce7;
    border: 1px solid #bbf7d0;
    border-radius: var(--border-radius);
    color: #166534;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    justify-content: center;
    transition: all 0.3s ease;
    animation: slideIn 0.5s ease;
}

.message.hidden {
    display: none;
}

.message i {
    width: 18px;
    height: 18px;
    color: #16a34a;
}

/* Footer */
.footer {
    text-align: center;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.9rem;
}

.footer-icon {
    width: 16px;
    height: 16px;
    color: var(--primary-color);
}

/* Animations */
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(1.1);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-sm);
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .card {
        padding: var(--spacing-lg);
    }
    
    .card h2 {
        font-size: 1.25rem;
    }
}

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