:root{font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;line-height:1.5;font-weight:400;color:#1f2933;background-color:#f4f4f8}body{margin:0;min-height:100vh;display:flex;align-items:center;justify-content:center}#app{width:100%;max-width:1200px;padding:24px}.app-shell{width:100%;min-height:600px;background:#fff;border-radius:16px;box-shadow:0 10px 30px #00000014;padding:24px;display:flex;flex-direction:column;gap:16px}header{text-align:center}header h1{font-size:1.8rem;margin-bottom:4px}header p{color:#555;font-size:.95rem}.iframe-wrapper{flex:1;border-radius:12px;overflow:hidden;border:1px solid #e0e0e0}.iframe-wrapper iframe{width:100%;height:100%;min-height:600px;border:0}