:root{
    --bg: #f6f5f1;
    --panel: #ffffff;
    --ink: #17181a;
    --ink-soft: #55585d;
    --line: #d8d6cf;
    --accent: #2f5d8f;
    --accent-soft: #e7edf4;
    --mono: "IBM Plex Mono", "Courier New", monospace;
    --sans: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  }
  *{box-sizing:border-box;}
  body{
    margin:0;
    background:var(--bg);
    color:var(--ink);
    font-family:var(--sans);
    line-height:1.5;
  }
  header{
    border-bottom:1px solid var(--line);
    padding:28px 24px 22px;
    max-width:920px;
    margin:0 auto;
  }
  header h1{
    font-family:var(--mono);
    font-size:22px;
    font-weight:600;
    margin:0 0 6px;
    letter-spacing:-0.01em;
  }
  header p{
    margin:0;
    color:var(--ink-soft);
    font-size:14px;
    max-width:60ch;
  }
  main{
    max-width:920px;
    margin:0 auto;
    padding:24px;
    display:flex;
    flex-direction:column;
    gap:20px;
  }
  section{
    background:var(--panel);
    border:1px solid var(--line);
    border-radius:3px;
  }
  .section-head{
    padding:14px 18px;
    border-bottom:1px solid var(--line);
    display:flex;
    align-items:baseline;
    justify-content:space-between;
    gap:12px;
  }
  .section-head h2{
    font-size:15px;
    font-weight:600;
    margin:0;
  }
  .section-head .hint{
    font-size:12px;
    color:var(--ink-soft);
  }
  .section-body{
    padding:18px;
    display:flex;
    flex-direction:column;
    gap:14px;
  }
  textarea{
    width:100%;
    min-height:110px;
    font-family:var(--mono);
    font-size:13px;
    padding:12px;
    border:1px solid var(--line);
    border-radius:2px;
    resize:vertical;
    background:#fbfbf9;
    color:var(--ink);
  }
  textarea:focus, button:focus, select:focus{
    outline:2px solid var(--accent);
    outline-offset:1px;
  }
  .row{
    display:flex;
    gap:10px;
    flex-wrap:wrap;
    align-items:center;
  }
  button{
    font-family:var(--sans);
    font-size:13px;
    font-weight:600;
    padding:9px 16px;
    border:1px solid var(--ink);
    border-radius:2px;
    background:var(--ink);
    color:#fff;
    cursor:pointer;
  }
  button:hover{ background:#000; }
  button.secondary{
    background:transparent;
    color:var(--ink);
    border:1px solid var(--line);
    font-weight:500;
  }
  button.secondary:hover{ border-color:var(--ink); }
  button:disabled{
    opacity:0.45;
    cursor:not-allowed;
  }
  .stat-row{
    display:flex;
    gap:22px;
    flex-wrap:wrap;
  }
  .stat{
    display:flex;
    flex-direction:column;
    gap:2px;
  }
  .stat .label{
    font-size:11px;
    color:var(--ink-soft);
  }
  .stat .value{
    font-family:var(--mono);
    font-size:19px;
  }
  .suggestion{
    font-size:13px;
    padding:9px 12px;
    background:var(--accent-soft);
    border-left:3px solid var(--accent);
    border-radius:2px;
  }
  .freq-list{
    display:flex;
    flex-wrap:wrap;
    gap:6px;
    font-family:var(--mono);
    font-size:12px;
  }
  .freq-item{
    border:1px solid var(--line);
    border-radius:2px;
    padding:3px 7px;
    background:#fbfbf9;
  }
  .freq-item b{ color:var(--accent); }
  table{
    width:100%;
    border-collapse:collapse;
    font-family:var(--mono);
    font-size:12.5px;
  }
  th, td{
    text-align:left;
    padding:6px 8px;
    border-bottom:1px solid var(--line);
  }
  th{ color:var(--ink-soft); font-weight:600; }
  tr.best{ background:var(--accent-soft); }
  .output-box{
    font-family:var(--mono);
    font-size:13px;
    background:#fbfbf9;
    border:1px solid var(--line);
    border-radius:2px;
    padding:12px;
    white-space:pre-wrap;
    word-break:break-all;
    min-height:40px;
  }
  .field-row{
    display:flex;
    gap:10px;
    align-items:center;
    flex-wrap:wrap;
    font-size:13px;
  }
  .field-row label{ color:var(--ink-soft); }
  select, input[type=number]{
    font-family:var(--mono);
    font-size:13px;
    padding:6px 8px;
    border:1px solid var(--line);
    border-radius:2px;
    background:#fbfbf9;
  }
  .placeholder{
    color:var(--ink-soft);
    font-size:13px;
    font-style:normal;
  }
  .validation-row{
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:8px 0;
    border-bottom:1px solid var(--line);
    font-size:13px;
  }
  .validation-row:last-child{ border-bottom:none; }
  .badge{
    font-family:var(--mono);
    font-size:12px;
    padding:2px 8px;
    border-radius:2px;
  }
  .badge.ok{ background:#e5f2e8; color:#256a3a; }
  .badge.fail{ background:#f7e6e4; color:#a13a2e; }
  footer{
    max-width:920px;
    margin:0 auto;
    padding:10px 24px 40px;
    font-size:12px;
    color:var(--ink-soft);
  }

.topbar{
  display:flex;
  justify-content:space-between;
  align-items:center;
  background:var(--ink);
  color:#fff;
  font-size:12.5px;
  padding:8px 24px;
}
.topbar a{
  color:#fff;
  text-decoration:underline;
}
.login-wrap{
  max-width:380px;
  margin:80px auto;
  background:#fff;
  border:1px solid #d8d6cf;
  border-radius:4px;
  padding:28px;
  font-family:"IBM Plex Sans","Segoe UI",system-ui,sans-serif;
}
.login-wrap h1{
  font-family:"IBM Plex Mono","Courier New",monospace;
  font-size:19px;
  margin:0 0 18px;
}
.login-wrap label{
  display:block;
  font-size:12.5px;
  color:#55585d;
  margin-bottom:4px;
}
.login-wrap input{
  width:100%;
  padding:9px 10px;
  border:1px solid #d8d6cf;
  border-radius:2px;
  font-size:14px;
  margin-bottom:14px;
  box-sizing:border-box;
}
.login-wrap button{
  width:100%;
  padding:10px;
  border:1px solid #17181a;
  background:#17181a;
  color:#fff;
  font-weight:600;
  border-radius:2px;
  cursor:pointer;
}
.login-error{
  background:#f7e6e4;
  border-left:3px solid #a13a2e;
  color:#a13a2e;
  font-size:13px;
  padding:8px 10px;
  border-radius:2px;
  margin-bottom:14px;
}