:root {
    --bg: #0d1117; --surface: #161b22; --border: #30363d;
    --text: #e6edf3; --muted: #8b949e; --accent: #58a6ff;
    --green: #3fb950; --red: #f85149; --yellow: #d29922;
    --font: 'SF Mono', 'Fira Code', monospace;
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  body { background: var(--bg); color: var(--text); font-family: var(--font);
         min-height: 100vh; padding: 2rem 1rem; }
  .container { max-width: 780px; margin: 0 auto; }

  header { text-align: center; margin-bottom: 3rem; position: relative; }
  header h1 { font-size: 1.6rem; color: var(--accent); letter-spacing: 0.05em; }
  header p  { color: var(--muted); margin-top: 0.5rem; font-size: 0.85rem; }

  .cert-link {
    display: inline-flex; align-items: center; gap: 0.4rem;
    margin-top: 1rem; padding: 0.45rem 1rem;
    border: 1px solid var(--border); border-radius: 6px;
    color: var(--muted); font-size: 0.78rem; text-decoration: none;
    transition: border-color 0.15s, color 0.15s;
  }
  .cert-link:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
  .cert-link svg { flex-shrink: 0; }

  .card { background: var(--surface); border: 1px solid var(--border);
          border-radius: 8px; padding: 1.5rem; margin-bottom: 1.5rem; }
  .card h2 { font-size: 0.9rem; color: var(--muted); text-transform: uppercase;
             letter-spacing: 0.1em; margin-bottom: 1rem; }

  label { display: block; font-size: 0.8rem; color: var(--muted);
          margin-bottom: 0.35rem; }
  input[type=text], textarea {
    width: 100%; background: var(--bg); border: 1px solid var(--border);
    border-radius: 6px; color: var(--text); font-family: var(--font);
    font-size: 0.82rem; padding: 0.6rem 0.8rem; outline: none;
    transition: border-color 0.15s;
  }
  input[type=text]:focus, textarea:focus { border-color: var(--accent); }
  textarea { resize: vertical; min-height: 130px; }

  .drop-zone {
    border: 2px dashed var(--border); border-radius: 8px;
    padding: 2rem; text-align: center; cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    color: var(--muted); font-size: 0.85rem;
  }
  .drop-zone.hover  { border-color: var(--accent); background: rgba(88,166,255,0.05); }
  .drop-zone.loaded { border-color: var(--green);  color: var(--green); }

  button {
    background: var(--accent); color: #0d1117; border: none;
    border-radius: 6px; padding: 0.65rem 1.4rem; font-family: var(--font);
    font-size: 0.85rem; font-weight: 700; cursor: pointer;
    transition: opacity 0.15s; margin-top: 1rem;
  }
  button:hover { opacity: 0.85; }
  button:disabled { opacity: 0.4; cursor: not-allowed; }
  button.secondary { background: var(--surface); color: var(--accent); border: 1px solid var(--border); }
  button.danger    { background: var(--red); color: #fff; }

  .tabs { display: flex; gap: 0.5rem; margin-bottom: 1.5rem; flex-wrap: wrap; }
  .tab { padding: 0.5rem 1.1rem; border: 1px solid var(--border);
         border-radius: 6px; cursor: pointer; font-size: 0.82rem;
         color: var(--muted); background: var(--surface); transition: all 0.15s; }
  .tab.active { border-color: var(--accent); color: var(--accent); background: rgba(88,166,255,0.08); }
  .tab.highlight { border-color: var(--green); color: var(--green); }
  .tab.highlight.active { background: rgba(63,185,80,0.08); }

  .result { margin-top: 1rem; padding: 1rem 1.2rem; border-radius: 6px;
            font-size: 0.82rem; line-height: 1.7; display: none; }
  .result.ok   { background: rgba(63,185,80,0.1);  border: 1px solid var(--green); }
  .result.err  { background: rgba(248,81,73,0.1);   border: 1px solid var(--red); }
  .result.info { background: rgba(88,166,255,0.1);  border: 1px solid var(--accent); }
  .result.warn { background: rgba(210,153,34,0.1);  border: 1px solid var(--yellow); }
  .result.show { display: block; }

  .kv { display: grid; grid-template-columns: 160px 1fr; gap: 0.2rem 0.8rem; margin-top: 0.6rem; }
  .kv .k { color: var(--muted); }
  .kv .v { word-break: break-all; }

  /* Payment box */
  .payment-box {
    border: 1px solid var(--yellow); border-radius: 8px;
    padding: 1.2rem 1.4rem; margin-top: 1rem;
    background: rgba(210,153,34,0.06); font-size: 0.82rem; line-height: 1.9;
  }
  .payment-box .pb-title {
    font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase;
    color: var(--yellow); margin-bottom: 0.8rem; font-weight: 700;
  }
  .payment-box .pb-row { display: flex; gap: 0.6rem; align-items: baseline; flex-wrap: wrap; }
  .payment-box .pb-label { color: var(--muted); min-width: 130px; font-size: 0.78rem; }
  .payment-box .pb-val   { color: var(--text); word-break: break-all; }
  .payment-box .pb-tag   { color: var(--yellow); font-weight: 700; font-size: 1rem; }
  .payment-box .xaman-qr {
    margin-top: 1.2rem; padding-top: 1.2rem; border-top: 1px solid rgba(210,153,34,0.3);
    display: flex; align-items: center; gap: 1.4rem; flex-wrap: wrap;
  }
  .payment-box .xaman-qr-canvas { flex-shrink: 0; background: #fff; padding: 8px; border-radius: 6px; }
  .payment-box .xaman-qr-canvas canvas, .payment-box .xaman-qr-canvas img { display: block; }
  .payment-box .xaman-qr-info { font-size: 0.78rem; color: var(--muted); line-height: 1.7; }
  .payment-box .xaman-qr-info strong { color: var(--text); }
  .payment-box .xaman-qr-info a { color: var(--yellow); }
  .payment-box .pb-warn  {
    margin-top: 0.8rem; padding: 0.5rem 0.7rem; border-radius: 4px;
    background: rgba(210,153,34,0.12); color: var(--yellow); font-size: 0.78rem;
  }
  .payment-box .pb-timer { float: right; color: var(--muted); font-size: 0.75rem; }

  /* Nonce save reminder */
  .nonce-box {
    border: 1px solid var(--accent); border-radius: 8px;
    padding: 1rem 1.2rem; margin-bottom: 1rem;
    background: rgba(88,166,255,0.06); font-size: 0.82rem; line-height: 1.7;
  }
  .nonce-box .nb-title { color: var(--accent); font-weight: 700; font-size: 0.78rem;
                         letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 0.4rem; }
  .nonce-box code { color: var(--accent); word-break: break-all; font-size: 0.79rem; }
  .nonce-box .nb-warn { color: var(--red); font-size: 0.78rem; margin-top: 0.4rem; }

  .poll-log {
    margin-top: 0.8rem; max-height: 140px; overflow-y: auto;
    background: var(--bg); border: 1px solid var(--border);
    border-radius: 6px; padding: 0.6rem 0.8rem;
    font-size: 0.75rem; color: var(--muted); line-height: 1.8;
  }
  .poll-log .pl-ok   { color: var(--green); }
  .poll-log .pl-pay  { color: var(--yellow); }
  .poll-log .pl-wait { color: var(--muted); }
  .poll-log .pl-err  { color: var(--red); }

  .status-badge {
    display: inline-block; padding: 0.2rem 0.6rem; border-radius: 4px;
    font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
  }
  .badge-PENDING_PAYMENT { background: rgba(210,153,34,0.2);  color: var(--yellow); }
  .badge-QUEUED          { background: rgba(88,166,255,0.2);  color: var(--accent); }
  .badge-PROCESSING      { background: rgba(88,166,255,0.2);  color: var(--accent); }
  .badge-DONE            { background: rgba(63,185,80,0.2);   color: var(--green); }
  .badge-FAILED          { background: rgba(248,81,73,0.2);   color: var(--red); }
  .badge-EXPIRED         { background: rgba(139,148,158,0.2); color: var(--muted); }
  /* legacy names */
  .badge-queued    { background: rgba(210,153,34,0.2);  color: var(--yellow); }
  .badge-submitted { background: rgba(88,166,255,0.2);  color: var(--accent); }
  .badge-validated { background: rgba(63,185,80,0.2);   color: var(--green); }
  .badge-failed    { background: rgba(248,81,73,0.2);   color: var(--red); }

  .spinner { display: inline-block; width: 14px; height: 14px;
             border: 2px solid var(--border); border-top-color: var(--accent);
             border-radius: 50%; animation: spin 0.7s linear infinite;
             vertical-align: middle; margin-right: 6px; }
  @keyframes spin { to { transform: rotate(360deg); } }

  .step-row { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 0.3rem; font-size: 0.82rem; }
  .step-num {
    width: 22px; height: 22px; border-radius: 50%; border: 1px solid var(--border);
    display: flex; align-items: center; justify-content: center;
    font-size: 0.7rem; color: var(--muted); flex-shrink: 0;
  }
  .step-num.done { border-color: var(--green); color: var(--green); background: rgba(63,185,80,0.1); }
  .step-num.active { border-color: var(--accent); color: var(--accent); background: rgba(88,166,255,0.1); }

  footer { text-align: center; color: var(--muted); font-size: 0.75rem; margin-top: 3rem; }
  a { color: var(--accent); text-decoration: none; }
  a:hover { text-decoration: underline; }

  .receipt-download {
    display: inline-block; margin-top: 0.8rem; padding: 0.5rem 1rem;
    border: 1px solid var(--green); border-radius: 6px;
    color: var(--green); font-size: 0.8rem; cursor: pointer;
    background: rgba(63,185,80,0.06); transition: background 0.15s;
    font-family: var(--font); font-weight: 700;
  }
  .receipt-download:hover { background: rgba(63,185,80,0.12); }