@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

:root{
    --bg:#0D1117;
    --surface:#161B22;
    --surface-hover:#21262D;
    --text:#F0F6FC;
    --muted:#8B949E;
    --accent:#10B981;
    --border:#30363D;
    --radius:20px;
}

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

body{
    background:var(--bg);
    color:var(--text);
    font-family:"Inter",sans-serif;
    min-height:100vh;
    display:flex;
    flex-direction:column;
    align-items:center;
    justify-content:center;
    overflow:hidden;
}

.back-btn{
    position:absolute;
    top:30px;
    left:30px;
    display:inline-flex;
    justify-content:center;
    align-items:center;
    padding:12px 24px;
    border-radius:999px;
    text-decoration:none;
    font-weight:600;
    font-size:0.9rem;
    background:var(--surface);
    color:var(--text);
    border:1px solid var(--border);
    transition:.25s;
    z-index:1000;
}

.back-btn:hover{
    background:var(--surface-hover);
    border-color:var(--accent);
    transform:translateY(-2px);
    color:white;
}

canvas{
    display:block;
    border-radius:var(--radius);
    border:1px solid var(--border);
    box-shadow:0 20px 40px rgba(0,0,0,0.5);
    background:var(--surface);
}

html, body {
  margin: 0;
  padding: 0;
}
canvas {
  display: block;
}