:root{font-family:system-ui,sans-serif;line-height:1.5}body{margin:0;background:#f5f7fb;color:#18202a}header{background:#fff;padding:18px 24px;border-bottom:1px solid #ddd}nav{display:flex;gap:16px;flex-wrap:wrap}nav a{color:#164e63;text-decoration:none}.card{max-width:760px;margin:28px auto;padding:24px;background:#fff;border-radius:14px;box-shadow:0 3px 16px #0001}input,select,button{display:block;width:100%;box-sizing:border-box;margin:10px 0;padding:10px;border:1px solid #bbb;border-radius:8px}button,.button{cursor:pointer;background:#164e63;color:#fff;text-decoration:none;text-align:center}.good{color:#147a3c}.bad,.error{color:#b42318}.row{display:grid;grid-template-columns:1fr 1fr 1fr;gap:8px;padding:10px 0;border-bottom:1px solid #eee}code{word-break:break-all}