/* ============================================================
   On-device AI assistant for the Chanma Invest reading library.
   (Gemma 4 / WebGPU via transformers.js v4)

   Self-contained palette: the reading library's portal (dark cyan
   glass) and book pages (light/dark serif) use different design
   tokens, so the assistant defines its own cohesive dark theme here
   and looks identical on every page.
   ============================================================ */

:root {
    /* Self-contained design tokens — do not inherit from the host page. */
    --chat-bg: #0b1220;
    --chat-surface: #131c2e;
    --chat-surface-2: #1b263e;
    --chat-text: #e8edf4;
    --chat-muted: #93a1b8;
    --chat-heading: #f3f6fb;
    --chat-accent: #22d3ee;          /* cyan */
    --chat-accent-hover: #67e8f9;
    --chat-gold: #f5b042;            /* warm gold */
    --chat-border: rgba(255, 255, 255, 0.10);
    --chat-code-bg: rgba(255, 255, 255, 0.05);
    --chat-shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.45);
    --chat-scrollbar-thumb: rgba(255, 255, 255, 0.18);
    --chat-scrollbar-track: transparent;

    --chat-fab-size: 56px;
    --chat-panel-width: 380px;
    --chat-panel-height: 560px;
}

.chat-fab {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: var(--chat-fab-size);
    height: var(--chat-fab-size);
    border-radius: 50%;
    background: var(--chat-accent);
    color: #06141c;
    border: 2px solid var(--chat-gold);
    box-shadow: var(--chat-shadow-lg);
    cursor: pointer;
    z-index: 90;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.18s ease, background 0.18s ease;
    font-family: 'Segoe UI', Helvetica, Arial, sans-serif;
}
.chat-fab:hover { transform: translateY(-2px); background: var(--chat-accent-hover); }
.chat-fab svg { width: 26px; height: 26px; }
.chat-fab .badge {
    position: absolute;
    top: -4px; right: -4px;
    background: var(--chat-gold);
    color: #06141c;
    font-size: 0.62rem;
    font-weight: 700;
    padding: 2px 6px;
    border-radius: 10px;
    letter-spacing: 0.4px;
}

/* Hide FAB while the panel is open (panel has its own close button) */
.chat-panel.open ~ .chat-fab,
body.chat-open .chat-fab { display: none; }

/* --- Slide-out panel --- */
.chat-panel {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: var(--chat-panel-width);
    max-width: calc(100vw - 32px);
    height: var(--chat-panel-height);
    max-height: calc(100vh - 80px);
    background: var(--chat-surface);
    color: var(--chat-text);
    border: 1px solid var(--chat-border);
    border-radius: 14px;
    box-shadow: var(--chat-shadow-lg);
    transform: translateY(20px) scale(0.96);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.2s ease, opacity 0.2s ease;
    z-index: 95;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    font-family: 'Segoe UI', Helvetica, Arial, sans-serif;
}
.chat-panel.open {
    transform: translateY(0) scale(1);
    opacity: 1;
    pointer-events: auto;
}

.chat-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 14px;
    background: var(--chat-accent);
    color: #06141c;
    border-bottom: 1px solid var(--chat-border);
}
.chat-header .chat-title {
    flex: 1;
    font-weight: 700;
    font-size: 0.95rem;
    line-height: 1.2;
    display: flex;
    flex-direction: column;
}
.chat-header .chat-subtitle {
    font-size: 0.7rem;
    font-weight: 400;
    opacity: 0.85;
    margin-top: 1px;
}
.chat-header button {
    background: rgba(255,255,255,0.18);
    border: none;
    color: inherit;
    cursor: pointer;
    border-radius: 6px;
    padding: 4px 8px;
    font-size: 0.85rem;
    line-height: 1;
    transition: background 0.15s;
}
.chat-header button:hover { background: rgba(255,255,255,0.30); }

.chat-body {
    flex: 1;
    overflow-y: auto;
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    background: var(--chat-bg);
    scrollbar-width: thin;
    scrollbar-color: var(--chat-scrollbar-thumb) var(--chat-scrollbar-track);
}
.chat-body::-webkit-scrollbar { width: 8px; }
.chat-body::-webkit-scrollbar-track { background: var(--chat-scrollbar-track); }
.chat-body::-webkit-scrollbar-thumb {
    background: var(--chat-scrollbar-thumb);
    border-radius: 6px;
    border: 2px solid var(--chat-scrollbar-track);
}

.chat-msg {
    max-width: 85%;
    padding: 9px 12px;
    border-radius: 12px;
    font-size: 0.88rem;
    line-height: 1.45;
    white-space: pre-wrap;
    word-break: break-word;
}
.chat-msg.user {
    align-self: flex-end;
    background: var(--chat-accent);
    color: #06141c;
    border-bottom-right-radius: 4px;
}
.chat-msg.bot {
    align-self: flex-start;
    background: var(--chat-surface-2);
    color: var(--chat-text);
    border: 1px solid var(--chat-border);
    border-bottom-left-radius: 4px;
}
.chat-msg.bot.markdown-rendered {
    white-space: normal;
    overflow-wrap: anywhere;
}
.chat-msg.bot.markdown-rendered > :first-child { margin-top: 0; }
.chat-msg.bot.markdown-rendered > :last-child { margin-bottom: 0; }
.chat-msg.bot.markdown-rendered p,
.chat-msg.bot.markdown-rendered ul,
.chat-msg.bot.markdown-rendered ol,
.chat-msg.bot.markdown-rendered pre,
.chat-msg.bot.markdown-rendered blockquote,
.chat-msg.bot.markdown-rendered hr,
.chat-msg.bot.markdown-rendered h1,
.chat-msg.bot.markdown-rendered h2,
.chat-msg.bot.markdown-rendered h3,
.chat-msg.bot.markdown-rendered h4,
.chat-msg.bot.markdown-rendered h5,
.chat-msg.bot.markdown-rendered h6 {
    margin: 0.55rem 0;
}
.chat-msg.bot.markdown-rendered ul,
.chat-msg.bot.markdown-rendered ol {
    padding-left: 1.25rem;
}
.chat-msg.bot.markdown-rendered li + li {
    margin-top: 0.25rem;
}
.chat-msg.bot.markdown-rendered a {
    color: var(--chat-accent-hover);
}
.chat-msg.bot.markdown-rendered a:hover {
    color: #ffffff;
}
/* Book-citation links the assistant emits as "[Book: The Big Short]". Render
   with a subtle underline + tiny arrow so they read as clickable
   cross-references rather than inline prose. */
.chat-msg.bot.markdown-rendered a.chat-citation {
    text-decoration: underline;
    text-decoration-style: dotted;
    text-underline-offset: 2px;
    white-space: nowrap;
}
.chat-msg.bot.markdown-rendered a.chat-citation::after {
    content: " ↗";
    font-size: 0.8em;
    opacity: 0.8;
}
.chat-msg.bot.markdown-rendered code {
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.84em;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--chat-border);
    border-radius: 5px;
    padding: 0.08rem 0.34rem;
}
.chat-msg.bot.markdown-rendered .chat-code-block {
    margin: 0.65rem 0;
    padding: 0.8rem 0.95rem;
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--chat-border);
    border-radius: 10px;
    overflow-x: auto;
}
.chat-msg.bot.markdown-rendered .chat-code-block code {
    display: block;
    padding: 0;
    border: none;
    border-radius: 0;
    background: transparent;
    white-space: pre;
}
.chat-msg.bot.markdown-rendered blockquote {
    margin-left: 0;
    margin-right: 0;
    padding: 0.75rem 0.9rem;
    border-left: 3px solid var(--chat-gold);
    background: rgba(245, 176, 66, 0.10);
    border-radius: 0 10px 10px 0;
}
.chat-msg.bot.markdown-rendered hr {
    border: 0;
    border-top: 1px solid var(--chat-border);
}

.chat-mermaid-block {
    position: relative;
    margin: 0.75rem 0;
    padding: 0.7rem;
    border: 1px solid var(--chat-border);
    border-radius: 12px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.02));
}
.chat-mermaid-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.6rem;
    margin-bottom: 0.7rem;
}
.chat-mermaid-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.22rem;
    padding: 0.2rem;
    background: var(--chat-bg);
    border: 1px solid var(--chat-border);
    border-radius: 999px;
}
.chat-mermaid-toggle button {
    border: none;
    background: transparent;
    color: var(--chat-muted);
    border-radius: 999px;
    padding: 0.28rem 0.72rem;
    font-size: 0.76rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s ease, color 0.15s ease, transform 0.15s ease;
}
.chat-mermaid-toggle button:hover {
    color: var(--chat-text);
}
.chat-mermaid-toggle button.active {
    background: var(--chat-accent);
    color: #06141c;
}
.chat-mermaid-selection-status {
    min-height: 1.1rem;
    font-size: 0.72rem;
    color: var(--chat-muted);
    text-align: right;
}
.chat-mermaid-selection-status.has-selection {
    color: var(--chat-accent);
}
.chat-mermaid-diagram,
.chat-mermaid-source {
    margin: 0;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 10px;
    background: rgba(0, 0, 0, 0.20);
}
.chat-mermaid-diagram {
    padding: 0.85rem;
    overflow-x: auto;
    text-align: center;
    cursor: cell;
}
.chat-mermaid-diagram svg {
    max-width: 100%;
    height: auto;
}
.chat-mermaid-source {
    display: none;
    overflow: auto;
    padding: 0.85rem 0.9rem;
}
.chat-mermaid-block[data-view="source"] .chat-mermaid-diagram {
    display: none;
}
.chat-mermaid-block[data-view="source"] .chat-mermaid-source {
    display: block;
}
.chat-mermaid-source code {
    display: block;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.79rem;
    line-height: 1.45;
}
.chat-mermaid-source-line {
    position: relative;
    display: block;
    min-height: 1.45em;
    padding-left: 2.8rem;
    white-space: pre-wrap;
    word-break: break-word;
}
.chat-mermaid-source-line::before {
    content: attr(data-line-number);
    position: absolute;
    left: 0;
    width: 2rem;
    text-align: right;
    color: var(--chat-muted);
    user-select: none;
}
.chat-mermaid-diagram:focus,
.chat-mermaid-source:focus {
    outline: 1px solid var(--chat-accent);
    outline-offset: 2px;
}
.chat-mermaid-selection-proxy {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}
.chat-msg.system {
    align-self: center;
    background: transparent;
    color: var(--chat-muted);
    font-size: 0.78rem;
    font-style: italic;
    max-width: 100%;
    text-align: center;
}
.chat-msg.error {
    align-self: stretch;
    background: rgba(220, 50, 50, 0.14);
    color: #ff9a9a;
    border: 1px solid rgba(220, 50, 50, 0.45);
    font-size: 0.82rem;
}

/* --- Intro / capability screen --- */
.chat-intro {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    background: var(--chat-bg);
}
.chat-intro h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--chat-heading);
}
.chat-intro p {
    margin: 0;
    font-size: 0.85rem;
    line-height: 1.55;
    color: var(--chat-text);
}
.chat-intro ul {
    margin: 0;
    padding-left: 18px;
    font-size: 0.82rem;
    color: var(--chat-muted);
}
.chat-intro li { margin-bottom: 4px; }
.chat-intro .muted {
    font-size: 0.75rem;
    color: var(--chat-muted);
}

.chat-load-btn {
    background: var(--chat-accent);
    color: #06141c;
    border: 1px solid var(--chat-gold);
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
    font-family: inherit;
}
.chat-load-btn:hover { background: var(--chat-accent-hover); }
.chat-load-btn:active { transform: scale(0.98); }
.chat-load-btn:disabled {
    background: var(--chat-surface-2);
    color: var(--chat-muted);
    cursor: not-allowed;
    border-color: var(--chat-border);
}

.chat-progress {
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 0.8rem;
    color: var(--chat-muted);
}
.chat-progress-bar {
    height: 8px;
    background: var(--chat-code-bg);
    border-radius: 4px;
    overflow: hidden;
    border: 1px solid var(--chat-border);
}
.chat-progress-fill {
    height: 100%;
    background: var(--chat-gold);
    width: 0%;
    transition: width 0.2s ease;
}
.chat-progress-label {
    display: flex;
    justify-content: space-between;
    font-variant-numeric: tabular-nums;
}

/* --- Composer --- */
.chat-composer {
    display: flex;
    gap: 8px;
    padding: 10px 12px;
    border-top: 1px solid var(--chat-border);
    background: var(--chat-surface);
}
.chat-composer textarea {
    flex: 1;
    border: 1px solid var(--chat-border);
    border-radius: 8px;
    padding: 8px 10px;
    font-size: 0.88rem;
    font-family: inherit;
    background: var(--chat-bg);
    color: var(--chat-text);
    resize: none;
    max-height: 120px;
    min-height: 36px;
    line-height: 1.4;
    outline: none;
    transition: border-color 0.15s;
}
.chat-composer textarea:focus { border-color: var(--chat-accent); }
.chat-composer textarea::placeholder { color: var(--chat-muted); }
.chat-composer button {
    background: var(--chat-accent);
    color: #06141c;
    border: none;
    border-radius: 8px;
    padding: 0 14px;
    cursor: pointer;
    font-weight: 600;
    font-family: inherit;
    transition: background 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.chat-composer button:hover { background: var(--chat-accent-hover); }
.chat-composer button:disabled {
    background: var(--chat-surface-2);
    color: var(--chat-muted);
    cursor: not-allowed;
}
.chat-composer button svg { width: 18px; height: 18px; }

/* --- Scope toggle (This chapter / This book / All books) --- */
.chat-scope-toggle {
    display: flex;
    gap: 2px;
    flex: 1 1 auto;
    min-width: 0;
    padding: 3px;
    background: color-mix(in srgb, var(--chat-surface) 85%, #000 15%);
    border: 1px solid var(--chat-border);
    border-radius: 8px;
}
.chat-scope-btn {
    flex: 1 1 0;
    min-width: 0;
    padding: 5px 6px;
    border: none;
    border-radius: 6px;
    background: transparent;
    color: var(--chat-muted);
    font-size: 0.72rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.chat-scope-btn:hover:not(:disabled) {
    color: var(--chat-text);
    background: color-mix(in srgb, var(--chat-surface) 70%, var(--chat-accent) 12%);
}
.chat-scope-btn.active {
    background: var(--chat-accent);
    color: #0b1120;
    font-weight: 600;
}
.chat-scope-btn:disabled {
    opacity: 0.35;
    cursor: not-allowed;
}

/* --- Cross-book index controls --- */
.chat-index-options {
    margin: 14px 0 4px;
    padding: 12px;
    border: 1px solid var(--chat-border);
    border-radius: 8px;
    background: color-mix(in srgb, var(--chat-surface) 92%, var(--chat-accent) 8%);
}
.chat-index-label {
    margin: 0 0 4px;
    font-weight: 600;
    font-size: 0.92rem;
}
.chat-index-help {
    margin: 0 0 10px;
    font-size: 0.82rem;
    line-height: 1.4;
    color: var(--chat-muted);
}
.chat-index-checkbox {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
    font-size: 0.88rem;
    cursor: pointer;
    user-select: none;
}
.chat-index-checkbox input[type="checkbox"] {
    cursor: pointer;
    accent-color: var(--chat-accent);
}
.chat-index-checkbox input[type="checkbox"]:disabled {
    cursor: default;
}
.chat-index-checkbox input[type="checkbox"]:disabled + span {
    color: var(--chat-muted);
}

/* --- Status bar with scope selector --- */
.chat-status-bar {
    display: flex;
    justify-content: stretch;
    align-items: center;
    padding: 6px 10px;
    border-bottom: 1px solid var(--chat-border);
    background: color-mix(in srgb, var(--chat-surface) 96%, var(--chat-accent) 4%);
    flex-shrink: 0;
}
/* Scope bar: "Search:" label + segmented buttons + unavailable message.
 * Lives in the status bar; replaces the old single index chip. Uses the
 * same font stack as the rest of the chatbot panel. */
.chat-scope-bar {
    display: flex;
    align-items: center;
    gap: 6px;
    width: 100%;
    font-family: 'Segoe UI', Helvetica, Arial, sans-serif;
}
.chat-scope-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--chat-muted);
    white-space: nowrap;
    flex-shrink: 0;
}
/* The segmented button group fills available width. */
.chat-scope-bar .chat-scope-toggle {
    flex: 1 1 auto;
    margin: 0;
}
/* "Search not available" / indexing / error message. Hidden when the index
 * is ready; otherwise replaces the button row visually. */
.chat-scope-unavailable {
    display: none;
    flex: 1 1 auto;
    font-size: 0.74rem;
    color: var(--chat-muted);
    font-style: italic;
    cursor: pointer;
}
.chat-scope-bar.unavailable .chat-scope-toggle { display: none; }
.chat-scope-bar.unavailable .chat-scope-unavailable { display: block; }
.chat-scope-bar.unavailable .chat-scope-unavailable:empty {
    cursor: default;
}
.chat-scope-bar.indexing .chat-scope-unavailable {
    color: #ffd98a;
    font-style: normal;
    cursor: default;
}

/* --- Mobile --- */
@media (max-width: 640px) {
    .chat-panel {
        right: 10px;
        bottom: 10px;
        left: 10px;
        width: auto;
        max-width: none;
        height: 70vh;
    }
    .chat-fab { right: 14px; bottom: 14px; }
}