:root{
    --pitch:        #07080A;
    --pitch-2:      #0C0E12;
    --pitch-raised: #11141A;
    --line:         rgba(237,234,228,0.10);
    --line-strong:  rgba(237,234,228,0.22);
    --ink:          #EFEAE0;
    --ink-soft:     rgba(239,234,224,0.62);
    --ink-faint:    rgba(239,234,224,0.32);
    --signal:       #FF5945;
    --signal-deep:  #C8351F;
    --ember:        #FFB077;
    --cool:         #5A9BFF;
  }
  *{ box-sizing: border-box; }
  html, body{ margin: 0; padding: 0; }
  html{ background: var(--pitch); }
  body{
    background: var(--pitch);
    color: var(--ink);
    font-family: var(--font-sans);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
  }

  .stage{
    width: min(1100px, 100%);
    margin: 0 auto;
    padding: 20px clamp(28px, 3.4vw, 56px) 56px;
  }

  /* ---------- topstrip ---------- */
  .topstrip{
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .12em;
    text-transform: uppercase;
    color: var(--ink-soft);
    margin-bottom: clamp(40px, 5vw, 64px);
  }
  .brand{
    display: inline-flex; align-items: center; gap: 10px;
    color: var(--ink);
    font-family: var(--font-sans);
    font-weight: 600;
    letter-spacing: 0.005em;
    text-transform: none;
    font-size: 14px;
    text-decoration: none;
  }
  .brand:hover{ text-decoration: none; color: var(--ink); }
  .brand .back{ color: var(--ink-soft); }
  .brand svg{ width: 22px; height: 22px; color: var(--ink); }
  .topstrip .right{ display: flex; gap: 22px; align-items: center; }

  /* ---------- hero ---------- */
  .hero{
    margin-bottom: clamp(40px, 5vw, 72px);
    padding-bottom: clamp(32px, 4vw, 48px);
    border-bottom: 1px solid var(--line);
  }
  .eyebrow{
    display: inline-flex; align-items: center; gap: 14px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .18em;
    text-transform: uppercase;
    color: var(--ink-soft);
    margin-bottom: 24px;
  }
  .eyebrow .num{
    color: var(--signal);
    border: 1px solid rgba(255,89,69,.4);
    background: rgba(255,89,69,.08);
    border-radius: 4px;
    padding: 3px 8px;
    font-size: 10px;
  }
  h1.display{
    font-family: var(--font-sans);
    font-weight: 600;
    color: var(--ink);
    letter-spacing: -0.03em;
    line-height: 1;
    font-size: clamp(44px, 7vw, 96px);
    margin: 0 0 28px 0;
  }
  .lede{
    margin: 0;
    max-width: 60ch;
    font-size: clamp(16px, 1.2vw, 19px);
    line-height: 1.55;
    color: var(--ink-soft);
  }
  .lede b{ color: var(--ink); font-weight: 600; }

  /* ---------- section ---------- */
  .section{
    margin-bottom: clamp(48px, 5vw, 72px);
  }
  .section-head{
    display: flex;
    align-items: baseline;
    gap: 16px;
    margin-bottom: clamp(20px, 2.4vw, 28px);
    padding-bottom: 14px;
    border-bottom: 1px solid var(--line);
    flex-wrap: wrap;
  }
  .section-num{
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: .2em;
    color: var(--signal);
    padding: 4px 9px;
    border: 1px solid rgba(255,89,69,.35);
    background: rgba(255,89,69,.06);
    border-radius: 4px;
    flex: 0 0 auto;
  }
  .section h2{
    margin: 0;
    font-size: clamp(24px, 3vw, 36px);
    font-weight: 600;
    letter-spacing: -0.022em;
    color: var(--ink);
    line-height: 1.15;
  }
  .section p{
    margin: 0 0 18px 0;
    font-size: clamp(15px, 1.1vw, 17px);
    line-height: 1.6;
    color: var(--ink-soft);
    max-width: 68ch;
  }
  .section p b{ color: var(--ink); font-weight: 600; }
  .section p a, .section a{
    color: var(--ink);
    text-decoration: underline;
    text-underline-offset: 3px;
    text-decoration-color: var(--ink-faint);
  }
  .section a:hover{ text-decoration-color: var(--signal); }

  /* ---------- special session ---------- */
  .special-session{
    scroll-margin-top: 24px;
    border: 1px solid rgba(255,89,69,.28);
    background: rgba(255,89,69,.035);
    border-radius: 14px;
    padding: clamp(20px, 2.6vw, 32px);
  }
  .special-session .section-head{ margin-top: 0; }
  .ss-chair{
    font-family: var(--font-mono);
    font-size: 12.5px !important;
    letter-spacing: .03em;
    color: var(--ink-soft);
    margin-top: -6px !important;
  }
  .ss-chair b{ color: var(--ink); }
  .ss-topics{
    margin: 4px 0 18px;
    padding-left: 0;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-width: 68ch;
  }
  .ss-topics li{
    font-size: clamp(14px, 1.05vw, 16px);
    line-height: 1.55;
    color: var(--ink-soft);
    padding-left: 20px;
    position: relative;
  }
  .ss-topics li::before{ content: "▸"; position: absolute; left: 0; color: var(--signal); }
  .ss-topics b{ color: var(--ink); font-weight: 600; }
  .ss-note{ font-size: 13.5px !important; color: var(--ink-faint) !important; }

  /* ---------- prompt block ---------- */
  .prompt-wrap{
    margin-top: clamp(20px, 2.4vw, 28px);
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--pitch-raised);
    overflow: hidden;
  }
  .prompt-toolbar{
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 12px 14px;
    background: rgba(255,255,255,.02);
    border-bottom: 1px solid var(--line);
  }
  .prompt-label{
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: .2em;
    text-transform: uppercase;
    color: var(--ink-soft);
  }
  .prompt-label b{ color: var(--ink); font-weight: 600; }
  .copy-btn{
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    background: var(--ink);
    color: var(--pitch);
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 12px;
    letter-spacing: -0.005em;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background var(--dur-base) var(--ease-out-soft),
                transform var(--dur-micro) var(--ease-out-soft);
  }
  .copy-btn:hover{ background: #fff; transform: translateY(-1px); }
  .copy-btn.copied{ background: var(--cool); color: var(--pitch); }
  .copy-btn::before{
    content: "";
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--signal);
    box-shadow: 0 0 8px var(--signal);
  }
  .copy-btn.copied::before{ background: var(--pitch); box-shadow: none; }
  .prompt-textarea{
    width: 100%;
    background: transparent;
    color: var(--ink);
    font-family: var(--font-mono);
    font-size: 12.5px;
    line-height: 1.6;
    border: 0;
    padding: 16px 18px;
    resize: vertical;
    min-height: 320px;
    outline: none;
    display: block;
    white-space: pre;
    overflow-x: auto;
  }
  .prompt-textarea:focus{ outline: none; }