:root{--ink:#171b1f;--muted:#666d73;--yellow:#f4c400;--line:#d9dde1}
*{box-sizing:border-box}
body{margin:0;background:#edf0f2;color:var(--ink);font-family:Arial,Helvetica,sans-serif}
header{min-height:88px;padding:18px max(22px,calc((100vw - 1440px)/2));display:flex;align-items:center;justify-content:space-between;gap:24px;background:var(--ink);color:white;border-bottom:8px solid var(--yellow)}
h1{margin:0;font-size:clamp(1.35rem,2.4vw,2rem)}
header p{margin:5px 0 0;color:#d9dde1;font-size:.9rem}
header strong{color:var(--yellow);text-align:right}
main{max-width:1440px;margin:24px auto;padding:0 18px 40px;display:grid;grid-template-columns:minmax(340px,560px) minmax(380px,1fr);gap:24px;align-items:start}
.panel{background:white;border:1px solid #dfe3e6;border-radius:14px;box-shadow:0 8px 28px rgba(23,27,31,.08)}
form{padding:24px}
fieldset{border:0;padding:0;margin:0 0 26px}
legend{width:100%;padding:0 0 9px;margin-bottom:14px;border-bottom:3px solid var(--yellow);font-size:1rem;font-weight:800;text-transform:uppercase;letter-spacing:.035em}
.two{display:grid;grid-template-columns:1fr 1fr;gap:14px}
label{display:block;margin:0 0 6px;font-size:.88rem;font-weight:700}
input,textarea{width:100%;margin:0 0 14px;padding:11px 12px;border:1px solid #bac1c7;border-radius:8px;background:white;color:var(--ink);font:inherit;font-size:1rem;outline:none}
input:focus,textarea:focus{border-color:#8b7000;box-shadow:0 0 0 3px rgba(244,196,0,.25)}
textarea{min-height:142px;resize:vertical;line-height:1.45}
textarea.short{min-height:82px}
small{display:block;margin:-7px 0 15px;color:var(--muted);line-height:1.35}
.actions{display:flex;gap:12px;padding-top:20px;border-top:1px solid var(--line)}
button{min-height:48px;padding:13px 18px;border:0;border-radius:8px;font:inherit;font-weight:800;cursor:pointer}
button:hover{filter:brightness(.96)}
.primary{flex:1;background:var(--yellow);color:var(--ink)}
.secondary{background:#252b31;color:white}
#status{min-height:20px;margin:12px 0 0;color:var(--muted);font-size:.88rem}
#status.error{color:#b42318;font-weight:700}
.preview{position:sticky;top:20px;min-height:760px;overflow:hidden}
.previewTitle{height:54px;padding:0 18px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}
.previewTitle span{font-size:.8rem;color:var(--muted)}
iframe{display:none;width:100%;height:760px;border:0;background:#73777a}
#empty{height:706px;display:grid;place-items:center;padding:32px;color:var(--muted);text-align:center;background:linear-gradient(135deg,#f8f9fa,#eef1f3)}
@media(max-width:900px){
  main{grid-template-columns:1fr}
  .preview{position:static;min-height:620px}
  iframe{height:620px}
  #empty{height:566px}
}
@media(max-width:560px){
  header{align-items:flex-start;flex-direction:column}
  header strong{text-align:left}
  .two{grid-template-columns:1fr}
  form{padding:18px}
  .actions{flex-direction:column}
}
@media print{header,form{display:none}.preview{box-shadow:none;border:0}}