/* CHAT-UI — the conversational surface shared by zero-tvm.html (chat) and
 * share.html (remote guest): palette, chat area, message bubbles, streaming
 * markdown, actions, scroll FAB, composer. Moved VERBATIM out of
 * zero-tvm.html's inline styles so the two pages cannot drift; the page-
 * specific chrome (header, welcome, gate, overlay) stays inline per page.
 * Companion module: src/zero-tvm/chat-ui.ts. */

    /* ALIAS LAYER onto the family tokens (public/tokens.css), which must be
     * linked BEFORE this file. The chat surface kept its own palette — a green
     * accent on a different ground — so the instrument and the landing page
     * looked like two products. Only the names this file does not share with
     * tokens.css are redefined here; --bg, --border, --text, --accent and
     * --mono come straight through.
     *
     * --muted is the exception and must be restated: this file uses it for the
     * DIMMEST text, where the token set uses it for mid-tone. Letting the token
     * value through would brighten every caption on the page. */
    :root {
      --panel:       var(--surface);
      --panel-2:     var(--surface-2);
      --border-2:    var(--border-hi);
      --text-dim:    #a9b3c6;
      --muted:       var(--dim);
      --accent-2:    var(--accent-hi);
      --accent-tint: var(--accent-dim);
      --user-bubble: var(--surface-2);
      --danger:      var(--err);
      --radius:      12px;
      --composer-max: 760px;
      --msg-max:      760px;
      --font:        var(--body);
    }

    /* The browser's default focus ring is blue, which on this palette reads as
     * a second selected state next to the amber one — in the model picker two
     * chips looked chosen at once. Shared by the chat page and the rooms guest,
     * matching landing.css. */
    :focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
      border-radius: var(--radius);
    }

    /* ─────────── Chat area ─────────── */
    /* share.html's guest view is a flex column, not zero-tvm.html's auto/1fr/auto
   grid — without flex:1 this collapsed to ~56px on an empty room and the
   composer floated near the top of a blank page. Scoped: on zero-tvm.html the
   grid row sizes it and #guest-view does not exist. */
#guest-view .chat-main { flex: 1; min-height: 0; }
.chat-main {
      overflow-y: auto;
      scroll-behavior: smooth;
      position: relative;
    }
    .chat-main::-webkit-scrollbar { width: 8px; }
    .chat-main::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 4px; }
    .chat-main::-webkit-scrollbar-track { background: transparent; }

    .chat-inner {
      max-width: var(--msg-max);
      margin: 0 auto;
      padding: 1.5rem 1rem 2rem;
    }


    /* ─────────── Messages ─────────── */
    .msg { margin-bottom: 1.75rem; animation: fade-in 0.2s ease; }
    .msg:last-child { margin-bottom: 0.5rem; }
    @keyframes fade-in { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

    .msg.user {
      display: flex;
      justify-content: flex-end;
      gap: 0.5rem;
    }
    .msg.user .bubble {
      max-width: 80%;
      background: var(--user-bubble);
      border: 1px solid var(--border);
      padding: 0.65rem 0.95rem;
      border-radius: 16px 16px 4px 16px;
      white-space: pre-wrap;
      word-wrap: break-word;
      line-height: 1.55;
    }

    .msg.ai .role {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-size: 0.72rem;
      color: var(--muted);
      margin-bottom: 0.45rem;
      font-weight: 500;
    }
    .msg.ai .role .role-name { color: var(--text-dim); }
    .msg.ai .role .model-tag {
      margin-left: auto;
      font-size: 0.65rem;
      color: var(--muted);
      padding: 2px 7px;
      border: 1px solid var(--border);
      border-radius: 999px;
      background: var(--panel);
      font-variant-numeric: tabular-nums;
    }
    .msg.ai .role-dot {
      width: 22px; height: 22px; border-radius: 7px;
      /* Was a fixed violet, so every model's replies were badged in Phi-3's
         colours. Both stops come from the model's own lane now. */
      background: linear-gradient(135deg, var(--accent), var(--accent-hi));
      display: inline-flex; align-items: center; justify-content: center;
      font-size: 0.62rem; font-weight: 800; color: #000;
      letter-spacing: -0.05em;
    }
    /* One still frame of the model's mascot, captured once at boot and reused
       by every reply. The letter stays as the fallback for browsers that gave
       us no mascot to capture. */
    .has-mascot-avatar .msg.ai .role-dot {
      background: var(--mascot-avatar) center/cover no-repeat,
                  linear-gradient(135deg, var(--accent), var(--accent-hi));
      font-size: 0;
    }
    .msg.ai .body {
      color: var(--text);
      word-wrap: break-word;
      line-height: 1.65;
    }
    .msg.ai .body > *:first-child { margin-top: 0; }
    .msg.ai .body > *:last-child { margin-bottom: 0; }
    .msg.ai .body p { margin: 0 0 0.7rem; }
    .msg.ai .body ul, .msg.ai .body ol {
      margin: 0 0 0.7rem;
      padding-left: 1.4rem;
    }
    .msg.ai .body li { margin-bottom: 0.25rem; }
    .msg.ai .body li > p { margin: 0; }
    .msg.ai .body h1, .msg.ai .body h2, .msg.ai .body h3,
    .msg.ai .body h4, .msg.ai .body h5, .msg.ai .body h6 {
      font-weight: 600;
      letter-spacing: -0.01em;
      margin: 1rem 0 0.45rem;
      line-height: 1.3;
      color: #fff;
    }
    .msg.ai .body h1 { font-size: 1.25rem; }
    .msg.ai .body h2 { font-size: 1.12rem; }
    .msg.ai .body h3 { font-size: 1.02rem; }
    .msg.ai .body h4, .msg.ai .body h5, .msg.ai .body h6 { font-size: 0.95rem; }
    .msg.ai .body code {
      font-family: var(--mono);
      font-size: 0.85em;
      background: var(--panel-2);
      padding: 1px 5px;
      border-radius: 4px;
      border: 1px solid var(--border);
    }
    .msg.ai .body blockquote {
      border-left: 3px solid var(--border-2);
      padding: 0.1rem 0 0.1rem 0.85rem;
      color: var(--text-dim);
      margin: 0 0 0.7rem;
    }
    .msg.ai .body hr {
      border: 0;
      border-top: 1px solid var(--border);
      margin: 1rem 0;
    }
    .msg.ai .body a { color: var(--accent-2); text-decoration: underline; text-underline-offset: 2px; }
    .msg.ai .body strong { color: #fff; font-weight: 600; }

    /* Fenced code block — top bar with lang pill + copy button */
    .msg.ai .body .code-block {
      margin: 0.7rem 0;
      border-radius: 10px;
      border: 1px solid var(--border);
      background: var(--panel);
      overflow: hidden;
    }
    .msg.ai .body .code-head {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0.4rem 0.6rem 0.4rem 0.75rem;
      background: var(--panel-2);
      border-bottom: 1px solid var(--border);
      font-size: 0.68rem;
      color: var(--muted);
    }
    .msg.ai .body .code-lang {
      text-transform: uppercase;
      letter-spacing: 0.08em;
      font-weight: 600;
    }
    .msg.ai .body .code-copy {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 3px 8px;
      border-radius: 6px;
      color: var(--text-dim);
      font-size: 0.68rem;
      transition: background 0.15s, color 0.15s;
    }
    .msg.ai .body .code-copy:hover { background: rgba(255,255,255,0.06); color: var(--text); }
    .msg.ai .body .code-copy.copied { color: var(--accent); }
    .msg.ai .body .code-copy .icon { width: 11px; height: 11px; stroke-width: 2.3; }
    .msg.ai .body .code-block pre {
      margin: 0;
      padding: 0.75rem 0.9rem;
      overflow-x: auto;
      background: none;
      border: none;
    }
    .msg.ai .body .code-block pre code {
      background: none;
      border: none;
      padding: 0;
      font-size: 0.82rem;
      line-height: 1.5;
      color: var(--text);
    }

    .msg.ai .cursor {
      display: inline-block;
      width: 7px;
      height: 1.05em;
      background: var(--accent);
      margin-left: 2px;
      vertical-align: text-bottom;
      border-radius: 1px;
      animation: blink 1.1s steps(2) infinite;
      opacity: 0.9;
    }
    @keyframes blink { 50% { opacity: 0.1; } }

    /* Thinking indicator — 3 dots that wave while prefill runs */
    .thinking {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 2px 0;
    }
    .thinking span {
      width: 6px; height: 6px;
      border-radius: 50%;
      background: var(--muted);
      animation: wave 1.2s ease-in-out infinite;
    }
    .thinking span:nth-child(2) { animation-delay: 0.15s; }
    .thinking span:nth-child(3) { animation-delay: 0.3s; }
    @keyframes wave {
      0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
      30% { transform: translateY(-3px); opacity: 1; }
    }

    .msg .actions {
      display: flex;
      align-items: center;
      gap: 0.15rem;
      margin-top: 0.55rem;
      opacity: 0;
      transition: opacity 0.2s;
    }
    .msg:hover .actions,
    .msg:focus-within .actions,
    .msg .actions:focus-within { opacity: 1; }
    .msg.ai .actions { margin-left: -0.35rem; }
    .msg.ai .actions .msg-stats {
      margin-left: auto;
      font-size: 0.66rem;
      color: var(--muted);
      font-variant-numeric: tabular-nums;
      padding-right: 0.2rem;
    }
    .msg.user .actions { justify-content: flex-end; }

    /* Reply cut short (context window full, or the user hit Stop). Unlike
       .actions this is always visible — a truncated answer must never look
       like a finished one. */
    .msg.ai .truncation {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      flex-wrap: wrap;
      margin-top: 0.7rem;
      padding: 0.45rem 0.7rem;
      border: 1px solid var(--border-2);
      border-left: 2px solid var(--accent-2);
      border-radius: 8px;
      background: var(--panel-2);
      font-size: 0.72rem;
      line-height: 1.45;
      color: var(--text-dim);
    }
    .truncation-btn {
      padding: 3px 11px;
      border-radius: 6px;
      font-size: 0.7rem;
      font-weight: 600;
      color: #000;
      background: var(--accent);
    }
    .truncation-btn:hover { background: var(--accent-2); }
    .truncation-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
    .action-btn {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 4px 8px;
      border-radius: 6px;
      font-size: 0.7rem;
      color: var(--muted);
      transition: background 0.15s, color 0.15s;
    }
    .action-btn:hover { background: var(--panel-2); color: var(--text); }
    .action-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
    .action-btn.copied { color: var(--accent); }
    .action-btn .icon { width: 13px; height: 13px; }

    /* ─────────── Scroll-to-bottom FAB ─────────── */
    .scroll-fab {
      position: absolute;
      bottom: 1rem;
      left: 50%;
      transform: translateX(-50%);
      width: 34px;
      height: 34px;
      border-radius: 50%;
      background: var(--panel-2);
      border: 1px solid var(--border-2);
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--text-dim);
      box-shadow: 0 4px 12px rgba(0,0,0,0.3);
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.2s, transform 0.2s;
      z-index: 5;
    }
    .scroll-fab.visible { opacity: 1; pointer-events: auto; visibility: visible; }
    .scroll-fab:hover { background: var(--panel); color: var(--text); }

    /* ─────────── Composer ─────────── */
    .composer-wrap {
      padding: 0.75rem 1rem 1rem;
      border-top: 1px solid var(--border);
      background: var(--bg);
    }
    .composer {
      max-width: var(--composer-max);
      margin: 0 auto;
      display: flex;
      align-items: flex-end;
      gap: 0.5rem;
      background: var(--panel);
      border: 1px solid var(--border-2);
      border-radius: 14px;
      padding: 0.5rem 0.5rem 0.5rem 0.9rem;
      transition: border-color 0.15s, background 0.15s;
    }
    /* border-color used to restate the UNFOCUSED border — a focus style that
       cancelled itself, leaving a 1.07:1 background shift as the only cue on
       the product's main control. The accent is the ring every other control
       already uses. */
    .composer:focus-within {
      border-color: var(--accent);
      background: var(--panel-2);
    }
    .composer textarea {
      flex: 1;
      background: none;
      border: none;
      outline: none;
      color: var(--text);
      font: inherit;
      resize: none;
      padding: 0.4rem 0;
      max-height: 200px;
      line-height: 1.5;
    }
    .composer textarea::placeholder { color: var(--muted); }
    .composer textarea:disabled { cursor: not-allowed; }

    .composer-btn {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 34px;
      height: 34px;
      border-radius: 10px;
      transition: background 0.15s, color 0.15s, opacity 0.15s;
      flex-shrink: 0;
    }
    .composer-btn[hidden] { display: none; }
    .composer-btn[data-variant="send"] {
      background: var(--accent);
      color: #000;
    }
    .composer-btn[data-variant="send"]:hover:not(:disabled) { background: var(--accent-2); }
    .composer-btn[data-variant="send"]:disabled {
      background: var(--border);
      color: var(--muted);
      cursor: not-allowed;
    }
    .composer-btn[data-variant="stop"] {
      background: var(--panel-2);
      color: var(--text);
      border: 1px solid var(--border-2);
    }
    .composer-btn[data-variant="stop"]:hover { background: #222228; }

    .composer-hint {
      max-width: var(--composer-max);
      margin: 0.4rem auto 0;
      text-align: center;
      font-size: 0.68rem;
      color: var(--muted);
    }
    .composer-hint kbd {
      background: var(--panel-2);
      border: 1px solid var(--border);
      padding: 1px 5px;
      border-radius: 4px;
      font-family: var(--mono);
      font-size: 0.62rem;
    }