:root{
    --bg:var(--gray-0); --bg-2:var(--gray-20); --panel:var(--gray-0);
    --text:var(--gray-750); --text-2:var(--gray-500); --text-3:var(--gray-300);
    --brand:var(--violet-400);
    --line:color-mix(in srgb, var(--gray-900) 8%, transparent); --line-strong:color-mix(in srgb, var(--gray-900) 12%, transparent);
    --hover:color-mix(in srgb, var(--gray-750) 4.5%, transparent);
    --shadow-float:0 0 0 1px color-mix(in srgb, var(--gray-900) 5%, transparent), 0 2px 6px color-mix(in srgb, var(--gray-900) 5%, transparent), 0 12px 32px color-mix(in srgb, var(--gray-900) 10%, transparent);
    --ease-exit:cubic-bezier(.215,.61,.355,1);   /* canon: hover/exit */
    --ease-out:cubic-bezier(.16,1,.3,1);          /* canon: entrances */
    --ease-spring:cubic-bezier(.34,1.26,.64,1);
    --ok:var(--green-300);
  }
  html[data-theme="dark"]{
    --bg:var(--gray-900); --bg-2:var(--gray-880); --panel:var(--gray-870);
    --text:var(--gray-20); --text-2:var(--gray-350); --text-3:var(--gray-550);
    --brand:var(--violet-450);
    --line:color-mix(in srgb, var(--gray-0) 8%, transparent); --line-strong:color-mix(in srgb, var(--gray-0) 14%, transparent);
    --hover:color-mix(in srgb, var(--gray-0) 5.5%, transparent);
    --shadow-float:0 0 0 1px color-mix(in srgb, var(--gray-0) 8%, transparent), 0 2px 6px color-mix(in srgb, var(--gray-900) 40%, transparent), 0 12px 32px color-mix(in srgb, var(--gray-900) 55%, transparent);
  }
  *{margin:0;padding:0;box-sizing:border-box}
  html{color-scheme:light dark}
  body{
    font-family:var(--font);
    font-feature-settings:"cv01","ss03";
    background:var(--bg); color:var(--text);
    -webkit-font-smoothing:antialiased;
  }
  button{font:inherit;color:inherit;background:none;border:0;cursor:default}
  ::selection{background:color-mix(in srgb, var(--brand) 25%, transparent)}
  .stage{
    height:190px;display:grid;place-items:center;
    background:
      radial-gradient(circle at 50% 120%, color-mix(in srgb, var(--brand) 4%, transparent), transparent 70%),
      var(--bg-2);
    position:relative;
  }

  /* base pill */
  .b{
    position:relative;height:46px;padding:0 26px;border-radius:9999px;
    font-size:15px;font-weight:550;letter-spacing:-.1px;
    display:inline-flex;align-items:center;gap:9px;
    user-select:none;-webkit-user-select:none;
  }
  /* ============ 6 · STATE-MORPH ============ */
  .b6{
    background:var(--brand);color:var(--gray-0);justify-content:center;
    width:150px;
    transition:width .4s var(--ease-spring), border-radius .4s var(--ease-spring), background .3s;
  }
  .b6 .lbl{white-space:nowrap;transition:opacity .15s}
  .b6 .spin, .b6 .chk{position:absolute;opacity:0}
  .b6.working{width:46px;border-radius:12px}
  .b6.working .lbl{opacity:0}
  .b6.working .spin{
    opacity:1;width:20px;height:20px;border-radius:9999px;
    background:conic-gradient(var(--gray-0) 0 25%, transparent 25% 100%);
    -webkit-mask:radial-gradient(circle, transparent 55%, var(--gray-900) 56%);
    mask:radial-gradient(circle, transparent 55%, var(--gray-900) 56%);
    animation:b6spin .7s linear infinite;
  }
  @keyframes b6spin{to{transform:rotate(360deg)}}
  .b6.done{background:var(--ok);width:150px}
  .b6.done .lbl{opacity:0}
  .b6.done .chk{opacity:1}
  .b6 .chk path{
    stroke:var(--gray-0);stroke-width:2.2;fill:none;stroke-linecap:round;stroke-linejoin:round;
    stroke-dasharray:20;stroke-dashoffset:20;
  }
  .b6.done .chk path{animation:b6draw .4s var(--ease-out) forwards}
  @keyframes b6draw{to{stroke-dashoffset:0}}

  @media (prefers-reduced-motion: reduce){
    *{transition-duration:.01ms !important;animation-duration:.01ms !important}
  }
body { font-size: 15px; line-height: normal; }
.stage { height: auto; min-height: 100vh; }
.b6.working { border-radius: 9999px; }