*, *::before, *::after { box-sizing: border-box; }
  [hidden] { display: none !important; }
  img { max-width: 100%; }

  :root {
    color-scheme: light dark;
    --ink:        #17202e;
    --ink-soft:   #4a5668;
    --ink-faint:  #7b8697;
    --paper:      #f4f3ef;
    --card:       #ffffff;
    --rule:       #dedbd3;
    --brass:      #9a6a2c;
    --brass-soft: #f0e4d2;
    --open:       #2f6b4f;

    --font-display: "Source Serif 4", Georgia, "Times New Roman", serif;
    --font-body: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
    --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
  }

  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --ink:        #eceef2;
      --ink-soft:   #a8b1c0;
      --ink-faint:  #7d8798;
      --paper:      #12161d;
      --card:       #1a1f28;
      --rule:       #2c3340;
      --brass:      #d3a55e;
      --brass-soft: #2e2519;
      --open:       #6fb890;
    }
  }

  :root[data-theme="dark"] {
    --ink:        #eceef2;
    --ink-soft:   #a8b1c0;
    --ink-faint:  #7d8798;
    --paper:      #12161d;
    --card:       #1a1f28;
    --rule:       #2c3340;
    --brass:      #d3a55e;
    --brass-soft: #2e2519;
    --open:       #6fb890;
  }

  body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    padding-inline: 20px;
    padding-block: 48px 64px;
    -webkit-font-smoothing: antialiased;
  }

  .sheet {
    max-width: 560px;
    margin-inline: auto;
    display: flex;
    flex-direction: column;
    gap: 32px;
  }

  /* ---- door plate ---- */

  .plate {
    background: var(--card);
    border: 1px solid var(--rule);
    border-top: 3px solid var(--brass);
    border-radius: 3px;
    overflow: hidden;
  }

  .brandmark {
    display: block;
    width: 100%;
    height: auto;
    border-bottom: 1px solid var(--rule);
  }

  .plate-body {
    padding: 32px;
    display: flex;
    flex-direction: column;
    gap: 24px;
  }

  .eyebrow {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--ink-faint);
    margin: 0;
  }

  h1 {
    font-family: var(--font-display);
    font-size: clamp(28px, 7vw, 38px);
    font-weight: 600;
    line-height: 1.14;
    letter-spacing: -0.015em;
    text-wrap: balance;
    margin: 0;
  }

  .org {
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.5;
    color: var(--ink-soft);
    margin: 4px 0 0;
  }

  .plate-head {
    display: flex;
    flex-direction: column;
    gap: 8px;
  }

  .status {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--ink-soft);
  }

  .status::before {
    content: "";
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--open);
    flex: none;
  }

  /* ---- join ---- */

  .join {
    display: block;
    text-align: center;
    text-decoration: none;
    background: var(--ink);
    color: var(--paper);
    font-family: var(--font-body);
    font-size: 17px;
    font-weight: 600;
    padding: 18px 24px;
    border-radius: 3px;
    transition: opacity 0.15s ease;
  }

  .join:hover { opacity: 0.88; }

  .join:focus-visible {
    outline: 2px solid var(--brass);
    outline-offset: 3px;
  }

  .join-note {
    font-size: 13.5px;
    color: var(--ink-faint);
    text-align: center;
    margin: -12px 0 0;
  }

  /* ---- device guidance ---- */

  .guidance {
    border: 1px solid var(--rule);
    border-left: 3px solid var(--brass);
    background: var(--brass-soft);
    border-radius: 3px;
    padding: 20px 22px;
    display: flex;
    flex-direction: column;
    gap: 10px;
  }

  .guidance h2 {
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.01em;
    margin: 0;
    color: var(--ink);
  }

  .guidance p {
    margin: 0;
    font-size: 14.5px;
    color: var(--ink-soft);
  }

  .guidance a {
    color: var(--brass);
    font-weight: 500;
    text-underline-offset: 3px;
  }

  kbd {
    font-family: var(--font-mono);
    font-size: 12px;
    background: var(--card);
    border: 1px solid var(--rule);
    border-radius: 3px;
    padding: 1px 5px;
    color: var(--ink);
  }

  /* ---- steps ---- */

  .steps h2 {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--ink-faint);
    font-weight: 400;
    margin: 0 0 16px;
  }

  ol {
    list-style: none;
    margin: 0;
    padding: 0;
    counter-reset: step;
    background: var(--card);
    border: 1px solid var(--rule);
    border-radius: 3px;
  }

  ol li {
    counter-increment: step;
    display: grid;
    grid-template-columns: 30px 1fr;
    column-gap: 14px;
    row-gap: 4px;
    align-items: start;
    padding: 18px 22px;
    border-top: 1px solid var(--rule);
  }

  ol li:first-child { border-top: 0; }

  ol li::before {
    content: counter(step);
    grid-row: span 2;
    font-family: var(--font-mono);
    font-size: 12px;
    line-height: 26px;
    text-align: center;
    color: var(--brass);
    background: var(--brass-soft);
    border-radius: 50%;
    width: 26px;
    height: 26px;
    font-variant-numeric: tabular-nums;
  }

  ol li b {
    display: block;
    font-size: 15.5px;
    font-weight: 600;
    line-height: 1.45;
    color: var(--ink);
  }

  ol li span {
    display: block;
    font-size: 14.5px;
    line-height: 1.55;
    color: var(--ink-soft);
  }

  /* ---- footer ---- */

  footer {
    border-top: 1px solid var(--rule);
    padding-top: 20px;
    font-size: 13px;
    color: var(--ink-faint);
    display: flex;
    flex-direction: column;
    gap: 6px;
  }

  footer a { color: var(--ink-soft); text-underline-offset: 3px; }

  .disclosure {
    line-height: 1.5;
  }

  @media (prefers-reduced-motion: reduce) {
    * { transition: none !important; animation: none !important; }
  }

  @media (max-width: 420px) {
    .plate-body { padding: 26px 22px; }
    ol li { padding: 16px 18px; }
  }

  /* ---- shared page furniture ---- */

  .intro {
    font-size: 16.5px;
    color: var(--ink-soft);
    margin: 0;
  }

  .cta {
    display: block;
    text-align: center;
    text-decoration: none;
    background: var(--ink);
    color: var(--paper);
    font-size: 17px;
    font-weight: 600;
    padding: 18px 24px;
    border-radius: 3px;
    transition: opacity 0.15s ease;
  }

  .cta:hover { opacity: 0.88; }

  .cta:focus-visible {
    outline: 2px solid var(--brass);
    outline-offset: 3px;
  }

  /* ---- agent directory ---- */

  .agent-list {
    list-style: none;
    margin: 0;
    padding: 0;
    background: var(--card);
    border: 1px solid var(--rule);
    border-radius: 3px;
  }

  .agent-list li { border-top: 1px solid var(--rule); }
  .agent-list li:first-child { border-top: 0; }

  .agent-list a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 18px 22px;
    text-decoration: none;
    color: var(--ink);
    font-size: 16px;
    font-weight: 600;
    transition: background 0.15s ease;
  }

  .agent-list a:hover { background: var(--brass-soft); }

  .agent-list a::after {
    content: "\2192";
    color: var(--brass);
    font-weight: 400;
    flex: none;
  }

  .back {
    font-size: 13.5px;
    color: var(--ink-faint);
    text-decoration: none;
    text-underline-offset: 3px;
  }

  .back:hover { text-decoration: underline; }

  @media (max-width: 420px) {
    .agent-list a { padding: 16px 18px; }
  }