999's Minimal Code Editor

<!DOCTYPE html>
<html>
<head>
<style>
body { 
    font-family: Arial; 
    text-align: center; 
    margin: 0;
    padding: 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    min-height: 100vh;
}
h1 { 
    font-size: 3rem; 
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}
button { 
    padding: 15px 30px; 
    background: #ff6b6b; 
    color: white; 
    border: none;
    border-radius: 25px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}
button:hover {
    background: #ff5252;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}
</style>
</head>
<body>
<h1>Hello World!</h1>
<p>Welcome to 999's Code Editor!</p>
<button onclick="changeColor()">Change Color</button>