:root {
    --ink: #0A1F3C;
    --ink-soft: #4A5D78;
    --navy: #0F2A4F;
    --blue: #1170CF;
    --blue-dark: #0B58A6;
    --sky: #EAF2FC;
    --page: #F5F8FC;
    --paper: #FFFFFF;
    --line: #D5DEEA;
    --ok: #0E7C5A;
    --ok-bg: #E4F4EE;
    --err: #C42B2B;
    --err-bg: #FBEAEA;
    --font: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  }
  * { box-sizing: border-box; }
  html, body { margin: 0; }
  body { font-family: var(--font); color: var(--ink); background: var(--page); font-size: 16px; line-height: 1.5; }
  a { color: var(--blue); }
  :focus-visible { outline: 3px solid var(--blue); outline-offset: 2px; }

  header.top { background: var(--navy); color: #fff; padding: 28px 32px 30px; }
  header.top .wrap { max-width: 1240px; margin: 0 auto; }
  header.top h1 { margin: 0; font-size: 34px; font-weight: 800; letter-spacing: -0.02em; line-height: 1.1; }
  header.top p { margin: 8px 0 0; color: #C3D3EA; max-width: 60ch; }

  main { max-width: 1240px; margin: 0 auto; padding: 28px 32px 64px; display: grid; grid-template-columns: minmax(0, 1fr) 470px; gap: 32px; align-items: start; }
  @media (max-width: 1080px) { main { grid-template-columns: 1fr; } .preview-col { position: static !important; } }
  @media (max-width: 600px) { main, header.top { padding-left: 16px; padding-right: 16px; } header.top h1 { font-size: 27px; } }

  .howto { background: var(--paper); border: 2px solid var(--blue); border-radius: 14px; padding: 22px 26px; margin-bottom: 26px; }
  .howto h2 { margin: 0 0 10px; font-size: 20px; }
  .howto ol { margin: 0; padding-left: 22px; }
  .howto li { margin: 6px 0; max-width: 72ch; }
  .howto .note { margin: 14px 0 0; padding: 12px 14px; background: var(--sky); border-radius: 8px; font-size: 14px; color: var(--ink-soft); max-width: 78ch; }

  .step { background: var(--paper); border: 1px solid var(--line); border-radius: 14px; padding: 22px 26px; margin-bottom: 18px; }
  .step.locked { opacity: .55; pointer-events: none; }
  .step-head { display: flex; gap: 14px; align-items: center; margin-bottom: 14px; }
  .step-num { flex: none; width: 34px; height: 34px; border-radius: 50%; background: var(--navy); color: #fff; display: grid; place-items: center; font-weight: 800; }
  .step.done .step-num { background: var(--ok); }
  .step-head h2 { margin: 0; font-size: 20px; }
  .step-head p { margin: 0; color: var(--ink-soft); font-size: 14px; }

  label.field { display: block; font-weight: 600; font-size: 14px; margin: 12px 0 6px; }
  input[type=text], input[type=password], input[type=email], input[type=search], textarea {
    width: 100%; font: inherit; color: var(--ink); padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: #fff;
  }
  textarea { min-height: 70px; resize: vertical; }
  .row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
  .row > input { flex: 1 1 260px; }

  button { font: inherit; font-weight: 700; border-radius: 8px; padding: 10px 18px; cursor: pointer; border: 1px solid var(--blue); background: var(--blue); color: #fff; }
  button:hover { background: var(--blue-dark); }
  button.ghost { background: #fff; color: var(--blue); }
  button.ghost:hover { background: var(--sky); }
  button.small { padding: 6px 12px; font-size: 14px; }
  button:disabled { background: #B9C6D8; border-color: #B9C6D8; color: #fff; cursor: not-allowed; }
  button.big { font-size: 18px; padding: 14px 26px; }

  .msg { margin-top: 10px; font-size: 14px; padding: 10px 12px; border-radius: 8px; display: none; }
  .msg.show { display: block; }
  .msg.ok { background: var(--ok-bg); color: var(--ok); }
  .msg.err { background: var(--err-bg); color: var(--err); }

  .filters { display: flex; gap: 6px; margin: 10px 0; flex-wrap: wrap; }
  .chip { background: #fff; color: var(--ink); border: 1px solid var(--line); font-weight: 600; padding: 6px 12px; border-radius: 99px; font-size: 14px; }
  .chip:hover { background: var(--sky); }
  .chip[aria-pressed=true] { background: var(--navy); border-color: var(--navy); color: #fff; }
  .rooms { border: 1px solid var(--line); border-radius: 10px; max-height: 360px; overflow-y: auto; }
  .room { display: flex; gap: 12px; align-items: center; padding: 10px 14px; border-bottom: 1px solid var(--line); cursor: pointer; }
  .room:last-child { border-bottom: 0; }
  .room:hover { background: var(--sky); }
  .room input { width: 18px; height: 18px; accent-color: var(--blue); flex: none; }
  .room .t { font-weight: 600; }
  .room .m { font-size: 13px; color: var(--ink-soft); }
  .rooms .empty { padding: 18px; color: var(--ink-soft); }
  .count { font-size: 14px; color: var(--ink-soft); margin-left: auto; }

  .drop { margin-top: 12px; border: 2px dashed var(--line); border-radius: 10px; padding: 18px; text-align: center; color: var(--ink-soft); font-size: 14px; }
  .drop.over { border-color: var(--blue); background: var(--sky); }
  .using { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; font-size: 15px; }
  .using strong { font-weight: 700; }

  .results { margin-top: 14px; display: none; }
  .results.show { display: block; }
  .results .summary { font-weight: 700; margin-bottom: 8px; }
  .res { display: flex; justify-content: space-between; gap: 12px; padding: 8px 12px; border-radius: 8px; margin-bottom: 4px; background: var(--page); font-size: 14px; }
  .res.ok { background: var(--ok-bg); }
  .res.err { background: var(--err-bg); }
  .res .s { font-weight: 700; white-space: nowrap; }
  .res.ok .s { color: var(--ok); }
  .res.err .s { color: var(--err); }

  .preview-col { position: sticky; top: 20px; }
  .chat { background: var(--sky); border-radius: 16px; padding: 18px; border: 1px solid var(--line); }
  .chat-title { font-weight: 700; font-size: 15px; margin: 0 0 12px; color: var(--ink-soft); }
  .sender { display: flex; gap: 10px; align-items: center; margin-bottom: 8px; }
  .avatar { width: 34px; height: 34px; border-radius: 50%; background: var(--navy); color: #fff; display: grid; place-items: center; font-weight: 800; font-size: 13px; }
  .sender .n { font-weight: 700; font-size: 14px; }
  .sender .w { font-size: 12px; color: var(--ink-soft); }
  .bubble { background: #fff; border-radius: 12px; border: 1px solid var(--line); max-height: calc(100vh - 160px); overflow-y: auto; }
  .bubble .ac-adaptiveCard { border-radius: 12px; }
  .bubble a { color: var(--blue); }


  .mt-10 { margin-top: 10px; }
  .mt-18 { margin-top: 18px; }
  .help { font-size: 13px; color: var(--ink-soft); margin-top: 4px; }
  .res.detail { margin-top: -4px; font-size: 13px; }
  .pv-empty { padding: 18px; color: var(--ink-soft); font-size: 14px; }

  /* Card preview, styled to resemble a Webex card */
  .acard { padding: 14px 16px 16px; font-size: 14px; line-height: 1.4; color: #1F2933; }
  .acard .tb { margin-top: 8px; overflow-wrap: anywhere; }
  .acard .tb:first-child, .acard .box > :first-child { margin-top: 0; }
  .acard .size-small { font-size: 13px; }
  .acard .size-default { font-size: 14px; }
  .acard .size-medium { font-size: 16px; }
  .acard .size-large { font-size: 20px; line-height: 1.25; }
  .acard .size-extralarge { font-size: 24px; line-height: 1.2; }
  .acard .bold, .acard strong { font-weight: 700; }
  .acard .c-accent { color: var(--blue); }
  .acard .c-good { color: var(--ok); }
  .acard .c-attention { color: var(--err); }
  .acard .c-warning { color: #A35A00; }
  .acard .subtle { color: #637083; }
  .acard .al-center { text-align: center; }
  .acard .al-right { text-align: right; }
  .acard .sp-none { margin-top: 0 !important; }
  .acard .sp-small { margin-top: 4px; }
  .acard .sp-medium { margin-top: 12px; }
  .acard .sp-large { margin-top: 18px; }
  .acard .sp-extralarge { margin-top: 26px; }
  .acard .sep { border-top: 1px solid var(--line); padding-top: 14px; }
  .acard .box { margin-top: 8px; }
  .acard .st-emphasis { background: #F2F5F9; padding: 12px 16px; border-radius: 8px; }
  .acard .st-emphasis.bleed { margin: -14px -16px 0; border-radius: 12px 12px 0 0; padding: 16px; }
  .acard .st-accent { background: var(--sky); padding: 12px 16px; border-radius: 8px; }
  .acard .img { margin-top: 8px; }
  .acard .img img { display: block; max-width: 100%; border-radius: 6px; }
  .acard .img-stretch img { width: 100%; height: auto; }
  .acard .img-small img { width: 60px; }
  .acard .img-medium img { width: 120px; }
  .acard .facts { display: grid; grid-template-columns: max-content 1fr; gap: 4px 12px; margin: 6px 0 0; font-size: 13px; }
  .acard .facts dt { font-weight: 700; margin: 0; }
  .acard .facts dd { margin: 0; overflow-wrap: anywhere; }
  .acard .cols { display: flex; gap: 10px; margin-top: 8px; }
  .acard .col { flex: 1 1 0; min-width: 0; }
  .acard .col-auto { flex: 0 0 auto; }
  .acard .acts { display: flex; flex-direction: column; gap: 6px; margin-top: 14px; }
  .acard .act { display: block; text-align: center; padding: 8px 12px; border: 1px solid var(--blue); border-radius: 18px; color: var(--blue); font-weight: 600; text-decoration: none; }
  .acard .act:hover { background: var(--sky); }
  .acard .act-off { border-color: var(--line); color: #637083; }