/* ══════════════════════════════════════════════════════════════════════
   CSS Variables — Light (default) & Dark override
   ══════════════════════════════════════════════════════════════════════ */
:root {
    /* Sidebar */
    --sb-bg: #ffffff;
    --sb-hover: #f3f5f8;
    --sb-active: #eef2f7;
    --sb-active-border: #dbe2ea;
    --sb-border: #e5e7eb;

    /* Surfaces */
    --bg: #f8fafc;
    --surface: #ffffff;
    --surface-2: #f8f9ff;
    --surface-3: #f3f4f6;

    /* Text */
    --text: #111827;
    --text-2: #374151;
    --text-3: #6b7280;
    --text-4: #9ca3af;
    --placeholder: #9ca3af;

    /* Borders */
    --line: #e5e7eb;
    --line-2: #d1d5db;

    /* Accent */
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-light: rgba(99,102,241,0.12);

    /* Semantic */
    --rose: #ef4444;
    --green: #22c55e;
    --amber: #f59e0b;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.07);
    --shadow: 0 4px 20px rgba(0,0,0,0.09);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.14);

    --radius-xl: 28px;
    --radius-lg: 20px;
    --radius-md: 14px;
}

[data-theme="dark"] {
    --sb-bg: rgba(255,255,255,0.06);
    --sb-hover: rgba(255,255,255,0.07);
    --sb-active: rgba(255,255,255,0.10);
    --sb-active-border: rgba(255,255,255,0.14);
    --sb-border: rgba(255,255,255,0.08);

    --bg: #0d0f1a;
    --surface: rgba(255,255,255,0.07);
    --surface-2: rgba(255,255,255,0.06);
    --surface-3: rgba(255,255,255,0.10);

    --text: rgba(255,255,255,0.88);
    --text-2: rgba(255,255,255,0.65);
    --text-3: rgba(255,255,255,0.38);
    --text-4: rgba(255,255,255,0.25);
    --placeholder: rgba(255,255,255,0.22);

    --line: rgba(255,255,255,0.08);
    --line-2: rgba(255,255,255,0.14);

    --accent: #7c6ffa;
    --accent-hover: #6d60f0;
    --accent-light: rgba(124,111,250,0.15);

    --rose: #f87171;
    --green: #34d399;
    --amber: #fbbf24;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.35);
    --shadow: 0 4px 20px rgba(0,0,0,0.45);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.55);
}

/* ══════════════════════════════════════════════════════════════════════
   Base
   ══════════════════════════════════════════════════════════════════════ */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; margin: 0; }
body {
    background: linear-gradient(180deg, #ffffff 0%, #f6f8fb 100%);
    color: var(--text);
    font-family: -apple-system, "SF Pro Display", "Inter", "Manrope", "Segoe UI", sans-serif;
    font-size: 15px; line-height: 1.6;
    display: flex; align-items: stretch; padding: 0;
    -webkit-font-smoothing: antialiased;
    transition: background 0.2s;
}
button, input, textarea, select { font: inherit; }

[data-theme="dark"] body {
    background: #080808;
    background-image:
        radial-gradient(ellipse 80% 60% at 15% -5%, rgba(120,80,255,0.32) 0%, transparent 60%),
        radial-gradient(ellipse 60% 50% at 85% 105%, rgba(0,100,255,0.20) 0%, transparent 60%);
}

.shell {
    display: flex; flex: 1; overflow: hidden;
    border-radius: 0;
    box-shadow: none;
}

/* ── Sidebar ──────────────────────────────────────────────────────────── */
.sidebar {
    width: 260px; flex-shrink: 0;
    background: var(--sb-bg);
    color: var(--text);
    display: flex; flex-direction: column;
    padding: 16px 12px; overflow-y: auto; overflow-x: hidden;
    border-right: 1px solid var(--sb-border);
    transition: background 0.2s, border-color 0.2s;
}
[data-theme="dark"] .sidebar {
    border-right-width: 0.5px;
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
}

.brand-block {
    display: flex; align-items: center; gap: 10px; padding: 6px 8px 16px;
    border-bottom: 1px solid var(--sb-border); margin-bottom: 14px;
}
[data-theme="dark"] .brand-block { border-bottom-width: 0.5px; }

.brand-mark {
    width: 34px; height: 34px; border-radius: 10px;
    background: linear-gradient(145deg, #a78bfa, #6366f1 55%, #4f46e5);
    display: grid; place-items: center; font-size: 1rem; color: white;
    flex-shrink: 0;
    box-shadow: 0 4px 12px rgba(99,102,241,0.3), inset 0 1px 0 rgba(255,255,255,0.2);
}
[data-theme="dark"] .brand-mark { box-shadow: 0 4px 14px rgba(99,102,241,0.45), inset 0 1px 0 rgba(255,255,255,0.25); }

.brand-name { font-weight: 600; font-size: 0.92rem; color: var(--text); letter-spacing: -0.2px; }
.brand-sub  { font-size: 0.68rem; color: var(--text-3); margin-top: 1px; }

/* New chat button — gradient in light, glass in dark */
.new-chat-button {
    display: flex; align-items: center; justify-content: center; gap: 8px;
    width: 100%; padding: 10px 14px; border-radius: 12px;
    border: 1px solid transparent;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: white; font-weight: 600; font-size: 0.88rem; cursor: pointer;
    letter-spacing: -0.1px; margin-bottom: 16px;
    box-shadow: 0 4px 14px rgba(99,102,241,0.28);
    transition: all 0.18s ease;
}
.new-chat-button:hover { opacity: 0.9; transform: translateY(-1px); box-shadow: 0 6px 18px rgba(99,102,241,0.36); }
.new-chat-button:active { transform: scale(0.98); }

[data-theme="dark"] .new-chat-button {
    background: rgba(255,255,255,0.10);
    border: 0.5px solid rgba(255,255,255,0.18);
    color: rgba(255,255,255,0.88);
    box-shadow: 0 1px 0 rgba(255,255,255,0.08) inset, 0 2px 8px rgba(0,0,0,0.25);
    backdrop-filter: blur(10px);
}
[data-theme="dark"] .new-chat-button:hover {
    opacity: 1;
    background: rgba(255,255,255,0.15);
    border-color: rgba(255,255,255,0.26);
    box-shadow: 0 1px 0 rgba(255,255,255,0.12) inset, 0 6px 16px rgba(0,0,0,0.3);
}

.sidebar-section { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.section-head {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 6px; margin-bottom: 8px;
}
.section-label {
    font-size: 0.68rem; font-weight: 700; letter-spacing: 0.09em;
    text-transform: uppercase; color: var(--text-3);
}
.ghost-icon {
    background: transparent; border: 0; border-radius: 8px; padding: 3px 8px;
    color: var(--text-3); font-size: 0.76rem; cursor: pointer; transition: color 0.15s;
}
.ghost-icon:hover { color: var(--text); }

.session-list {
    display: flex; flex-direction: column; gap: 1px;
    overflow-y: auto; flex: 1; padding-right: 2px;
}
.session-item {
    display: flex; flex-direction: column; gap: 3px; width: 100%; text-align: left;
    padding: 9px 10px; border-radius: 10px; border: 1px solid transparent;
    background: transparent; color: var(--text); cursor: pointer; transition: background 0.15s;
}
.session-item:hover { background: var(--sb-hover); }
.session-item.active { background: var(--sb-active); border-color: var(--sb-active-border); }
[data-theme="dark"] .session-item { border-width: 0.5px; }
.session-item-title {
    display: flex; align-items: center; justify-content: space-between;
    gap: 8px; font-size: 0.84rem; font-weight: 500; overflow: hidden;
    color: var(--text-2);
}
.session-item.active .session-item-title { color: var(--text); }
.session-item-title > span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.session-meta { font-size: 0.70rem; color: var(--text-3); }

.sidebar-footer {
    border-top: 1px solid var(--sb-border); padding-top: 12px;
    margin-top: 12px; display: flex; flex-direction: column; gap: 10px;
}
[data-theme="dark"] .sidebar-footer { border-top-width: 0.5px; }

.sidebar-status {
    display: flex; align-items: center; flex-wrap: wrap;
    column-gap: 8px; row-gap: 2px; padding: 0 6px;
    font-size: 0.73rem; color: var(--text-3);
}
.status-label { font-weight: 500; color: var(--text-3); }
.status-value { font-weight: 700; font-size: 0.73rem; }

.sidebar-user {
    display: flex; align-items: center; gap: 8px; padding: 8px 10px;
    border-radius: 10px; transition: background 0.15s;
}
.sidebar-user:hover { background: var(--sb-hover); }

.user-avatar-circle {
    width: 28px; height: 28px; border-radius: 8px;
    background: linear-gradient(135deg, #38bdf8, #818cf8);
    display: grid; place-items: center; font-weight: 700;
    font-size: 0.78rem; color: white; flex-shrink: 0;
}
.user-name {
    font-size: 0.84rem; font-weight: 500; color: var(--text-2);
    flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.theme-toggle-btn {
    background: none; border: none; cursor: pointer;
    font-size: 0.88rem; padding: 4px 5px; border-radius: 6px; flex-shrink: 0;
    color: var(--text-3); transition: background 0.15s, color 0.15s;
    line-height: 1;
}
.theme-toggle-btn:hover { background: var(--sb-hover); color: var(--text); }

.lang-switcher {
    display: flex; align-items: center; flex-shrink: 0;
    border: 1px solid var(--line); border-radius: 8px; overflow: hidden;
}
.lang-btn {
    background: none; border: none; border-left: 1px solid var(--line); cursor: pointer;
    font-size: 0.73rem; font-weight: 600; padding: 5px 10px; line-height: 1;
    color: var(--text-3); transition: background 0.15s, color 0.15s;
    letter-spacing: 0.03em;
}
.lang-btn:first-child { border-left: none; }
.lang-btn:hover { background: var(--sb-hover); color: var(--text); }
.lang-btn.active { background: var(--accent); color: #fff; }

.logout-btn {
    background: none; border: none; color: var(--text-3); cursor: pointer;
    font-size: 1rem; padding: 4px 6px; border-radius: 6px; flex-shrink: 0;
    transition: color 0.15s, background 0.15s;
}
.logout-btn:hover { color: var(--text); background: var(--sb-hover); }

/* ── Main Panel ──────────────────────────────────────────────────────── */
.main-panel { flex: 1; min-width: 0; display: flex; flex-direction: column; background: var(--bg); overflow: hidden; }

.topbar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 14px 22px; background: var(--surface);
    border-bottom: 1px solid var(--line); gap: 16px; flex-shrink: 0;
    box-shadow: var(--shadow-sm);
}
[data-theme="dark"] .topbar {
    background: rgba(255,255,255,0.025);
    border-bottom-width: 0.5px;
    box-shadow: none;
    backdrop-filter: blur(30px);
    -webkit-backdrop-filter: blur(30px);
}

.topbar-title h2 { margin: 0; font-size: 0.96rem; font-weight: 600; color: var(--text); line-height: 1.3; letter-spacing: -0.2px; }
.topbar-actions { display: flex; align-items: center; gap: 8px; }

.stats-bar {
    display: flex; align-items: center; gap: 20px; padding: 5px 22px;
    background: var(--surface); border-bottom: 1px solid var(--line); flex-shrink: 0;
    opacity: 0.72;
}
[data-theme="dark"] .stats-bar {
    background: rgba(255,255,255,0.015);
    border-bottom-width: 0.5px;
}
.stat-item { display: flex; align-items: center; gap: 5px; font-size: 0.72rem; color: var(--text-3); }
.stat-item strong { font-weight: 600; font-size: 0.72rem; color: var(--text-2); }
.stat-label { font-weight: 500; }

/* ── Buttons ─────────────────────────────────────────────────────────── */
.primary-button, .soft-button, .tab-button {
    border: 0; border-radius: 12px; cursor: pointer; font-weight: 600;
    transition: transform 0.12s, background 0.15s, box-shadow 0.15s, opacity 0.15s;
}
.primary-button {
    padding: 11px 16px; color: white;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    box-shadow: 0 4px 14px rgba(99,102,241,0.28);
}
.primary-button:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(99,102,241,0.38); }
[data-theme="dark"] .primary-button {
    box-shadow: 0 4px 14px rgba(99,102,241,0.4), inset 0 1px 0 rgba(255,255,255,0.2);
    border: 0.5px solid rgba(255,255,255,0.1);
}
.primary-button:disabled {
    background: var(--surface-3); color: var(--text-3);
    cursor: not-allowed; box-shadow: none; transform: none; opacity: 1;
}
.primary-button:disabled:hover { transform: none; box-shadow: none; }

.soft-button {
    padding: 7px 14px; border-radius: 980px;
    background: var(--surface); color: var(--text-2);
    border: 1px solid var(--line) !important;
    font-size: 0.82rem;
    box-shadow: var(--shadow-sm);
}
.soft-button:hover { background: var(--surface-3); color: var(--text); transform: translateY(-1px); }
[data-theme="dark"] .soft-button {
    background: rgba(255,255,255,0.07);
    border: 0.5px solid rgba(255,255,255,0.13) !important;
    color: rgba(255,255,255,0.6);
    box-shadow: none;
    backdrop-filter: blur(10px);
}
[data-theme="dark"] .soft-button:hover { background: rgba(255,255,255,0.12); color: rgba(255,255,255,0.88); }

.soft-button.danger { color: var(--rose); border-color: rgba(239,68,68,0.3) !important; }
.soft-button.danger:hover { background: rgba(239,68,68,0.06); }
[data-theme="dark"] .soft-button.danger {
    background: rgba(255,59,48,0.10);
    border-color: rgba(255,59,48,0.22) !important;
    color: rgba(255,100,90,0.9);
}
[data-theme="dark"] .soft-button.danger:hover { background: rgba(255,59,48,0.18); }

.soft-button.accent { background: var(--accent-light); color: var(--accent); border-color: rgba(99,102,241,0.26) !important; }
.soft-button.accent:hover { background: rgba(99,102,241,0.2); }
[data-theme="dark"] .soft-button.accent {
    background: rgba(124,111,250,0.12);
    border-color: rgba(124,111,250,0.28) !important;
    color: rgba(165,180,252,0.9);
}
[data-theme="dark"] .soft-button.accent:hover { background: rgba(124,111,250,0.2); }

.wide { width: 100%; }

/* ── Message Stream ──────────────────────────────────────────────────── */
.message-stream { flex: 1; overflow-y: auto; padding: 28px 32px; }
.message-stream.empty-state { display: flex; align-items: center; justify-content: center; }
.empty-card { text-align: center; max-width: 380px; padding: 36px 24px; }
.empty-icon { font-size: 2.8rem; margin-bottom: 16px; opacity: 0.25; }
.empty-card h3 { margin: 0 0 10px; font-size: 1.02rem; font-weight: 600; color: var(--text); }
.empty-card p  { margin: 0; color: var(--text-3); font-size: 0.86rem; }
.eyebrow { margin: 0 0 8px; text-transform: uppercase; letter-spacing: 0.14em; font-size: 0.65rem; color: var(--text-3); }
.message-stack { display: flex; flex-direction: column; gap: 28px; width: 100%; }
.message { display: flex; flex-direction: column; gap: 5px; animation: rise 0.2s ease; }
.message.user { align-items: flex-end; }
.message.assistant { align-items: flex-start; }
.message-meta { font-size: 0.70rem; color: var(--text-4); padding: 0 4px; }
.message-card {
    padding: 13px 17px; border-radius: 18px; line-height: 1.7;
    white-space: pre-wrap; word-break: break-word; font-size: 0.92rem; max-width: 80%;
}

/* User bubble — flat accent in light, gradient+glow in dark */
.message.user .message-card {
    background: var(--accent); color: #f8fafc;
    border-bottom-right-radius: 5px;
    box-shadow: 0 2px 12px rgba(99,102,241,0.25);
}
[data-theme="dark"] .message.user .message-card {
    background: linear-gradient(145deg, #7c6ffa, #5b5ff5, #6d4fd6);
    color: rgba(255,255,255,0.95);
    box-shadow: 0 4px 20px rgba(99,102,241,0.4), inset 0 1px 0 rgba(255,255,255,0.2);
    border: 0.5px solid rgba(255,255,255,0.12);
}

/* AI bubble — subtle card */
.message.assistant .message-card {
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--line);
    border-bottom-left-radius: 5px;
    box-shadow: var(--shadow-sm);
}
[data-theme="dark"] .message.assistant .message-card {
    background: rgba(255,255,255,0.055);
    border: 0.5px solid rgba(255,255,255,0.10);
    box-shadow: 0 2px 12px rgba(0,0,0,0.25);
}

/* ── Markdown ────────────────────────────────────────────────────────── */
.message-card h1,.message-card h2,.message-card h3,
.message-card h4,.message-card h5,.message-card h6 {
    margin: 0.8em 0 0.5em; font-weight: 700; line-height: 1.3; color: var(--text);
}
.message.user .message-card h1,.message.user .message-card h2,.message.user .message-card h3,
.message.user .message-card h4,.message.user .message-card h5,.message.user .message-card h6 { color: #fff; }
.message-card h1:first-child,.message-card h2:first-child,.message-card h3:first-child,
.message-card h4:first-child,.message-card h5:first-child,.message-card h6:first-child { margin-top: 0; }
.message-card h1{font-size:1.5em}.message-card h2{font-size:1.3em}.message-card h3{font-size:1.15em}
.message-card h4{font-size:1.05em}.message-card h5{font-size:0.95em}
.message-card h6{font-size:0.88em;color:var(--text-3)}
.message.user .message-card h6 { color: rgba(255,255,255,0.7); }

.message-card p { margin: 0.6em 0; }
.message-card p:first-child { margin-top: 0; }
.message-card p:last-child  { margin-bottom: 0; }
.message-card ul,.message-card ol { margin: 0.8em 0; padding-left: 1.8em; }
.message-card ul:first-child,.message-card ol:first-child { margin-top: 0; }
.message-card ul:last-child,.message-card ol:last-child   { margin-bottom: 0; }
.message-card li { margin: 0.3em 0; line-height: 1.6; }
.message-card li > p { margin: 0.2em 0; }
.message-card ul ul,.message-card ol ul,.message-card ul ol,.message-card ol ol { margin: 0.3em 0; }

.message-card blockquote {
    margin: 0.8em 0; padding: 0.5em 0 0.5em 1em;
    border-left: 3px solid var(--accent); background: var(--accent-light);
    border-radius: 0 8px 8px 0; color: var(--text);
}
.message-card blockquote p { margin: 0.3em 0; }

.message-card code {
    padding: 0.15em 0.4em; background: rgba(15,23,42,0.08);
    border-radius: 4px; font-size: 0.88em;
    font-family: "Menlo","Consolas","Monaco",monospace;
    color: #1f2937; border: 1px solid rgba(15,23,42,0.12);
}
[data-theme="dark"] .message.assistant .message-card code {
    background: rgba(255,255,255,0.10); color: rgba(200,190,255,0.9);
    border: 0.5px solid rgba(255,255,255,0.12);
}
.message.user .message-card code {
    background: rgba(255,255,255,0.18); color: #fff;
    border-color: rgba(255,255,255,0.25);
}

.message-card pre {
    margin: 0.8em 0; padding: 0.9em 1em; background: var(--surface-2);
    border: 1px solid var(--line); border-radius: 12px; overflow-x: auto; font-size: 0.85em;
}
[data-theme="dark"] .message.assistant .message-card pre {
    background: rgba(0,0,0,0.35); border: 0.5px solid rgba(255,255,255,0.10);
}
.message-card pre code {
    padding: 0; background: transparent; border: 0; color: var(--text); font-size: 1em;
}
[data-theme="dark"] .message.assistant .message-card pre code { color: rgba(220,215,255,0.88); }

.message-card hr { margin: 1.2em 0; border: 0; height: 1px; background: var(--line); }
.message-card a { color: var(--accent); text-decoration: none; border-bottom: 1px solid rgba(99,102,241,0.3); transition: border-color 0.15s; }
[data-theme="dark"] .message.assistant .message-card a { color: #a5b4fc; border-bottom-color: rgba(165,180,252,0.35); }
.message-card a:hover { border-bottom-color: var(--accent); }
.message-card strong { font-weight: 700; color: var(--text); }
.message.user .message-card strong { color: #fff; }
.message-card em { font-style: italic; }

.message-card table { margin: 0.8em 0; border-collapse: collapse; width: 100%; font-size: 0.9em; }
.message-card th,.message-card td { padding: 0.5em 0.8em; border: 1px solid var(--line); text-align: left; }
[data-theme="dark"] .message-card th,[data-theme="dark"] .message-card td { border-width: 0.5px; }
.message-card th { background: var(--accent-light); font-weight: 600; color: var(--accent); }
.message-card tr:nth-child(even) { background: var(--surface-2); }

/* ── Composer ─────────────────────────────────────────────────────────── */
.composer { flex-shrink: 0; padding: 7px 22px 10px; background: var(--bg); border-top: 1px solid var(--line); }
[data-theme="dark"] .composer {
    border-top: 0.5px solid rgba(255,255,255,0.07);
    background: rgba(255,255,255,0.02);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.composer-inner {
    display: flex; flex-direction: column; background: var(--surface);
    border: none; border-radius: 14px; padding: 9px 14px 7px;
    box-shadow: 0 2px 14px rgba(15,23,42,0.09), 0 1px 4px rgba(0,0,0,0.05);
    transition: box-shadow 0.15s;
}
.composer-inner:focus-within { box-shadow: 0 4px 22px rgba(15,23,42,0.14), 0 1px 6px rgba(0,0,0,0.07); }

[data-theme="dark"] .composer-inner {
    background: rgba(255,255,255,0.07);
    border: 0.5px solid rgba(255,255,255,0.13);
    box-shadow: 0 4px 24px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.08);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}
[data-theme="dark"] .composer-inner:focus-within {
    border-color: rgba(124,111,250,0.5);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.12), 0 4px 24px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.08);
}

.composer textarea {
    width: 100%; resize: none; border: 0; background: transparent; outline: none;
    padding: 2px 4px 6px; min-height: 64px; max-height: 200px;
    font-size: 0.88rem; line-height: 1.55; color: var(--text);
}
.composer textarea::placeholder { color: var(--placeholder); }

.composer-bottom {
    display: flex; align-items: center; justify-content: space-between;
    padding-top: 4px; border-top: 1px solid rgba(26,28,46,0.06); gap: 6px;
}
[data-theme="dark"] .composer-bottom { border-top: 0.5px solid rgba(255,255,255,0.07); }

.composer-selects { display: flex; align-items: center; gap: 6px; flex: 1; min-width: 0; }
.composer-select {
    font-size: 0.72rem; font-weight: 500;
    border: 1px solid var(--line-2); border-radius: 999px;
    padding: 5px 28px 5px 10px; background-color: var(--surface-3); color: var(--text-3);
    cursor: pointer; transition: color 0.15s, background-color 0.15s, border-color 0.15s;
    -webkit-appearance: none; appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='9' height='5' viewBox='0 0 9 5'%3E%3Cpath d='M1 1l3.5 3L8 1' stroke='%2394a3b8' stroke-width='1.4' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat; background-position: right 10px center;
    max-width: 160px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.composer-select:hover { color: var(--text); background-color: var(--surface-2); border-color: var(--line); }
.composer-select:focus { outline: none; color: var(--text); }
.composer-select option { color: #111827; background: #fff; }

[data-theme="dark"] .composer-select {
    background-color: rgba(255,255,255,0.07);
    border: 0.5px solid rgba(255,255,255,0.12);
    color: rgba(255,255,255,0.48);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='9' height='5' viewBox='0 0 9 5'%3E%3Cpath d='M1 1l3.5 3L8 1' stroke='%23ffffff60' stroke-width='1.4' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
}
[data-theme="dark"] .composer-select:hover { color: rgba(255,255,255,0.75); background-color: rgba(255,255,255,0.11); border-color: rgba(255,255,255,0.2); }
[data-theme="dark"] .composer-select option { color: #1a1a2e; background: #ececff; }

.composer-actions { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.stream-hint { font-size: 0.7rem; color: var(--text-3); }

.send-button {
    width: 36px; height: 36px; border-radius: 50%; border: 0;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: white; font-size: 1rem; font-weight: 700; cursor: pointer;
    display: grid; place-items: center;
    transition: transform 0.12s, box-shadow 0.12s;
    flex-shrink: 0;
    box-shadow: 0 3px 10px rgba(99,102,241,0.32);
}
.send-button:hover { transform: scale(1.07); box-shadow: 0 5px 16px rgba(99,102,241,0.42); }
[data-theme="dark"] .send-button {
    box-shadow: 0 4px 14px rgba(99,102,241,0.5), inset 0 1px 0 rgba(255,255,255,0.25);
}
[data-theme="dark"] .send-button:hover { box-shadow: 0 6px 20px rgba(99,102,241,0.6), inset 0 1px 0 rgba(255,255,255,0.25); }

/* ── Inspector ────────────────────────────────────────────────────────── */
.inspector {
    position: fixed; top: 0; right: 0; bottom: 0; width: 400px;
    background: var(--surface); border-left: 1px solid var(--line);
    border-radius: 0;
    z-index: 200; transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex; flex-direction: column; overflow: hidden;
}
.inspector.open { transform: translateX(0); box-shadow: -12px 0 52px rgba(0,0,0,0.14); border-radius: 24px 0 0 24px; }
/* Select：強制 Chrome 以 light mode 渲染原生 dropdown popup，
   否則 OS 深色模式下 dropdown 會用系統 dark 渲染，option 顏色 CSS 失效 */
[data-theme="dark"] select { color-scheme: light; }

/* main-panel 略透明讓 body 光暈穿透 */
[data-theme="dark"] .main-panel { background: rgba(13,15,26,0.88); }

[data-theme="dark"] .inspector {
    background: rgba(10,12,22,0.97);
    border-left: 0.5px solid rgba(255,255,255,0.10);
    border-radius: 0;
    backdrop-filter: blur(40px) saturate(160%);
    -webkit-backdrop-filter: blur(40px) saturate(160%);
}
[data-theme="dark"] .inspector.open { box-shadow: -16px 0 56px rgba(0,0,0,0.62); border-radius: 24px 0 0 24px; }

.inspector-backdrop {
    display: none; position: fixed; inset: 0;
    background: rgba(20,22,50,0.35); z-index: 199; backdrop-filter: blur(4px);
}
.inspector-backdrop.visible { display: block; }
[data-theme="dark"] .inspector-backdrop { background: rgba(0,0,0,0.5); }

.tabs {
    display: flex; border-bottom: 1px solid var(--line); padding: 8px 10px;
    background: var(--surface); flex-shrink: 0; flex-wrap: wrap; gap: 2px;
}
[data-theme="dark"] .tabs { background: rgba(255,255,255,0.02); border-bottom-width: 0.5px; }
.tab-button {
    padding: 7px 13px; background: transparent; color: var(--text-3);
    border-radius: 9px; border-bottom: none;
    font-size: 0.83rem; font-weight: 600;
    transition: color 0.15s, background 0.15s; white-space: nowrap;
}
.tab-button:hover { color: var(--text); background: var(--surface-3); transform: none; }
.tab-button.active { color: var(--accent); background: var(--accent-light); border-bottom: none; transform: none; }
[data-theme="dark"] .tab-button.active { background: rgba(124,111,250,0.15); color: rgba(165,180,252,0.95); }
.tab-panel { display: none; overflow-y: auto; padding: 18px; }
.tab-panel.active { display: grid; gap: 14px; align-content: start; }

/* Cards & forms */
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 20px; padding: 16px; }
[data-theme="dark"] .card { background: rgba(255,255,255,0.05); border: 0.5px solid rgba(255,255,255,0.09); border-radius: 16px; }
.compact-card,.list-card { display: grid; gap: 12px; }
.stack-form { display: grid; gap: 9px; }
.field { display: grid; gap: 5px; }
.field span { font-size: 0.82rem; font-weight: 600; color: var(--text-3); }
.inline-toggle { grid-template-columns: 1fr auto; align-items: center; }
.subtle-toggle { padding: 2px 0; }
.two-col { display: flex; gap: 8px; }
.two-col > * { flex: 1; }

.stack-form textarea,.field input,.field select,.stack-form input,.stack-form select {
    width: 100%; border: 1px solid var(--line); background: var(--surface-2);
    border-radius: 12px; padding: 9px 11px; outline: none;
    font-size: 0.88rem; color: var(--text); transition: border-color 0.15s, box-shadow 0.15s;
}
[data-theme="dark"] .stack-form textarea,[data-theme="dark"] .field input,
[data-theme="dark"] .field select,[data-theme="dark"] .stack-form input,
[data-theme="dark"] .stack-form select {
    background: rgba(255,255,255,0.06); border: 0.5px solid rgba(255,255,255,0.12);
    color: rgba(255,255,255,0.88); border-radius: 10px;
}
.stack-form input::placeholder,.stack-form textarea::placeholder,.field input::placeholder { color: var(--placeholder); }
.field input:focus,.field select:focus,.stack-form textarea:focus,
.stack-form input:focus,.stack-form select:focus {
    border-color: rgba(15,23,42,0.30); box-shadow: 0 0 0 3px rgba(15,23,42,0.08); background: var(--surface);
}
[data-theme="dark"] .field input:focus,[data-theme="dark"] .field select:focus,
[data-theme="dark"] .stack-form textarea:focus,[data-theme="dark"] .stack-form input:focus,
[data-theme="dark"] .stack-form select:focus {
    border-color: rgba(124,111,250,0.5);
    box-shadow: 0 0 0 3px rgba(99,102,241,0.12);
    background: rgba(255,255,255,0.09);
}
.stack-form select option,.field select option { color: #111827; background: #fff; }
[data-theme="dark"] .stack-form select option,[data-theme="dark"] .field select option { color: #1a1a2e; background: #ececff; }

.entity-list,.knowledge-list { display: grid; gap: 8px; max-height: 300px; overflow-y: auto; }
.entity-item,.knowledge-item {
    padding: 11px 13px; border-radius: 16px; background: var(--surface-2);
    border: 1px solid var(--line); animation: rise 0.2s ease;
}
[data-theme="dark"] .entity-item,[data-theme="dark"] .knowledge-item {
    background: rgba(255,255,255,0.04); border: 0.5px solid rgba(255,255,255,0.09); border-radius: 12px;
}
.entity-top,.knowledge-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 4px; }
.entity-actions { margin-top: 8px; display: flex; gap: 7px; }
.entity-meta,.muted-copy,#streamHint { color: var(--text-3); font-size: 0.8rem; }
.action-btn { padding: 7px 11px; border-radius: 10px; font-size: 0.8rem; }

.pill {
    display: inline-flex; align-items: center; gap: 4px; padding: 3px 9px;
    border-radius: 999px; background: var(--accent-light); color: var(--accent);
    font-size: 0.74rem; font-weight: 700;
    border: 1px solid rgba(99,102,241,0.2);
}
[data-theme="dark"] .pill { border: 0.5px solid rgba(124,111,250,0.25); }
.pill.warm { background: rgba(245,158,11,0.12); color: #b45309; border-color: rgba(245,158,11,0.2); }
[data-theme="dark"] .pill.warm { color: rgba(251,191,36,0.9); border-color: rgba(251,191,36,0.25); }
.pill.danger,.pill-danger { background: rgba(239,68,68,0.12); color: #dc2626; border-color: rgba(239,68,68,0.2); }
[data-theme="dark"] .pill.danger,[data-theme="dark"] .pill-danger { color: rgba(248,113,113,0.9); border-color: rgba(248,113,113,0.25); }

.knowledge-filter-bar { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 8px; }
.category-tag {
    padding: 4px 11px; border-radius: 999px; border: 1px solid var(--line);
    background: var(--surface); font-size: 0.78rem; cursor: pointer; color: var(--text-3);
    transition: background 0.15s, color 0.15s;
}
[data-theme="dark"] .category-tag { background: rgba(255,255,255,0.05); border: 0.5px solid rgba(255,255,255,0.12); color: rgba(255,255,255,0.45); }
.category-tag.active { background: var(--accent); color: white; border-color: var(--accent); }

.kb-category-group { display: grid; gap: 5px; margin-bottom: 8px; }
.kb-category-header { display: flex; align-items: center; justify-content: space-between; font-size: 0.78rem; font-weight: 600; color: var(--text-3); padding: 2px 4px; }
.select-category-btn {
    padding: 3px 9px; border-radius: 10px; font-size: 0.74rem;
    border: 1px solid var(--line); background: var(--surface); color: var(--text-3);
    cursor: pointer; transition: background 0.15s;
}
.select-category-btn:hover { background: var(--accent-light); color: var(--accent); }
[data-theme="dark"] .select-category-btn { background: rgba(255,255,255,0.05); border: 0.5px solid rgba(255,255,255,0.12); color: rgba(255,255,255,0.5); }
[data-theme="dark"] .select-category-btn:hover { background: var(--accent-light); color: rgba(165,180,252,0.9); }

.file-drop-zone {
    display: block; border: 2px dashed rgba(15,23,42,0.18); border-radius: 20px; padding: 22px;
    cursor: pointer; transition: border-color 0.15s, background 0.15s; text-align: center; background: var(--surface-2);
}
.file-drop-zone:hover,.file-drop-zone.drag-over { border-color: var(--accent); background: var(--accent-light); }
[data-theme="dark"] .file-drop-zone { border: 1.5px dashed rgba(255,255,255,0.15); background: rgba(255,255,255,0.03); }
input[type="file"] { display: none; }
.file-drop-inner { display: flex; flex-direction: column; align-items: center; gap: 5px; pointer-events: none; }
.file-drop-icon { font-size: 1.5rem; }
.file-drop-hint { font-weight: 600; font-size: 0.85rem; color: var(--text); }
.file-drop-types { font-size: 0.73rem; color: var(--text-3); }

.file-queue { display: grid; gap: 5px; }
.file-queue-item {
    display: flex; align-items: flex-start; flex-wrap: wrap; gap: 8px; padding: 8px 11px;
    border-radius: 14px; background: var(--surface-2); border: 1px solid var(--line); font-size: 0.82rem;
}
[data-theme="dark"] .file-queue-item { background: rgba(255,255,255,0.04); border: 0.5px solid rgba(255,255,255,0.09); border-radius: 12px; }
.file-queue-item.done { border-color: rgba(34,197,94,0.3); background: rgba(34,197,94,0.05); }
.file-queue-item.error { border-color: rgba(239,68,68,0.3); background: rgba(239,68,68,0.05); }
[data-theme="dark"] .file-queue-item.done { border-color: rgba(52,211,153,0.3); }
[data-theme="dark"] .file-queue-item.error { border-color: rgba(248,113,113,0.3); }
.file-queue-icon { flex: 0 0 18px; line-height: 1.2; margin-top: 2px; }
.file-queue-name,.file-queue-name-input {
    flex: 1; min-width: 0; padding: 2px 8px; border: 1px solid var(--line);
    border-radius: 8px; font-size: 0.8rem; background: var(--surface); color: var(--text);
}
[data-theme="dark"] .file-queue-name-input { background: rgba(255,255,255,0.06); border: 0.5px solid rgba(255,255,255,0.12); color: rgba(255,255,255,0.88); }
.file-queue-name { padding: 2px 0; border: 0; background: transparent; overflow-wrap: anywhere; word-break: break-word; }
.file-queue-size { flex: 0 0 auto; color: var(--text-3); white-space: nowrap; line-height: 1.6; }
.file-queue-remove { margin-left: auto; }
.file-queue-msg { flex: 1 0 calc(100% - 26px); margin-left: 26px; max-height: 96px; overflow: auto; white-space: pre-wrap; overflow-wrap: anywhere; word-break: break-word; line-height: 1.45; color: var(--text); }

.details-block { border: 1px solid var(--line); border-radius: 16px; padding: 11px 13px; background: var(--surface-2); }
[data-theme="dark"] .details-block { background: rgba(255,255,255,0.04); border: 0.5px solid rgba(255,255,255,0.09); border-radius: 12px; }
.details-block summary { cursor: pointer; font-weight: 600; color: var(--text); font-size: 0.85rem; }
.details-block[open] summary { margin-bottom: 9px; }
.field-row { display: flex; gap: 8px; }
.field-row > * { flex: 1; }
.knowledge-context { width: 100%; min-height: 180px; resize: vertical; font-size: 0.8rem; font-family: "Menlo","Consolas",monospace; line-height: 1.5; }

h1,h2,h3 { margin: 0; line-height: 1.2; font-family: -apple-system,"SF Pro Display","Inter","Manrope",sans-serif; }
h3 { font-size: 0.95rem; font-weight: 600; color: var(--text); }
.status-ok  { color: var(--green) !important; }
.status-error { color: var(--rose) !important; }

/* ── Toast ────────────────────────────────────────────────────────────── */
.toast-host { position: fixed; right: 16px; bottom: 16px; display: grid; gap: 8px; z-index: 9999; }
.toast {
    min-width: 220px; max-width: 340px; padding: 12px 16px; border-radius: 14px;
    color: white; background: rgba(15,23,42,0.95); box-shadow: var(--shadow);
    font-size: 0.86rem; backdrop-filter: blur(8px);
}
.toast.error { background: rgba(220,38,38,0.96); }
[data-theme="dark"] .toast { background: rgba(20,22,40,0.96); border: 0.5px solid rgba(255,255,255,0.12); box-shadow: 0 8px 32px rgba(0,0,0,0.5); }

@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }
.typing-dots { display: inline-flex; align-items: center; gap: 5px; padding: 4px 2px; }
.typing-dots span { width: 7px; height: 7px; border-radius: 50%; background: var(--text-3); animation: typing-bounce 1.2s ease-in-out infinite; }
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes typing-bounce { 0%,60%,100% { transform: translateY(0); opacity: 0.4; } 30% { transform: translateY(-5px); opacity: 1; } }

::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.15); border-radius: 4px; }
[data-theme="dark"] ::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.10); }
::-webkit-scrollbar-thumb:hover { background: rgba(0,0,0,0.25); }
[data-theme="dark"] ::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.18); }

/* ── Hamburger ────────────────────────────────────────────────────────── */
.hamburger-button {
    display: none; width: 36px; height: 36px; border: 0; border-radius: 10px;
    background: transparent; color: var(--text-2); font-size: 1.2rem; cursor: pointer;
    flex-shrink: 0; transition: background 0.15s;
}
.hamburger-button:hover { background: var(--accent-light); color: var(--accent); }

.sidebar-backdrop { display: none; position: fixed; inset: 0; background: rgba(20,22,50,0.45); z-index: 149; backdrop-filter: blur(3px); }
.sidebar-backdrop.visible { display: block; }
[data-theme="dark"] .sidebar-backdrop { background: rgba(0,0,0,0.55); }

@media (max-width: 960px) { .sidebar { width: 220px; } }
@media (max-width: 660px) {
    .hamburger-button { display: grid; place-items: center; }
    .sidebar { position: fixed; top: 0; left: 0; bottom: 0; z-index: 150; transform: translateX(-100%); transition: transform 0.3s cubic-bezier(0.4,0,0.2,1); border-radius: 0 20px 20px 0; box-shadow: 4px 0 24px rgba(0,0,0,0.18); }
    .sidebar.open { transform: translateX(0); }
    .inspector { width: 100%; border-radius: 0; }
    .message-card { max-width: 94%; }
    .message-stream { padding: 16px 14px; }
    .composer { padding: 10px 12px 14px; }
}

/* ── Modal ────────────────────────────────────────────────────────────── */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.35); display: flex; align-items: center; justify-content: center; z-index: 10000; backdrop-filter: blur(2px); }
[data-theme="dark"] .modal-overlay { background: rgba(0,0,0,0.55); backdrop-filter: blur(8px); }
.modal-box { background: var(--surface); border-radius: 20px; padding: 24px; min-width: 280px; max-width: 380px; width: 90%; box-shadow: 0 24px 64px rgba(0,0,0,0.18); border: 1px solid var(--line); }
[data-theme="dark"] .modal-box { background: rgba(14,16,28,0.98); border: 0.5px solid rgba(255,255,255,0.12); box-shadow: 0 24px 64px rgba(0,0,0,0.6); backdrop-filter: blur(40px); -webkit-backdrop-filter: blur(40px); }
.modal-box select { width: 100%; border: 1px solid var(--line); background: var(--surface-2); border-radius: 12px; padding: 9px 11px; font-size: 0.88rem; color: var(--text); outline: none; }
[data-theme="dark"] .modal-box select { background: rgba(255,255,255,0.07); border: 0.5px solid rgba(255,255,255,0.12); color: rgba(255,255,255,0.88); }
[data-theme="dark"] .modal-box select option { color: #1a1a2e; background: #ececff; }
.modal-box select:focus { border-color: rgba(15,23,42,0.30); box-shadow: 0 0 0 3px rgba(15,23,42,0.08); }
[data-theme="dark"] .modal-box select:focus { border-color: rgba(124,111,250,0.5); box-shadow: 0 0 0 3px rgba(99,102,241,0.12); }
.modal-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 14px; }

.field-row select { width: 100%; border: 1px solid var(--line); background: var(--surface-2); border-radius: 12px; padding: 9px 11px; font-size: 0.88rem; color: var(--text); outline: none; transition: border-color 0.15s; }
[data-theme="dark"] .field-row select { background: rgba(255,255,255,0.06); border: 0.5px solid rgba(255,255,255,0.12); color: rgba(255,255,255,0.88); }
[data-theme="dark"] .field-row select option { color: #1a1a2e; background: #ececff; }
.field-row select:focus { border-color: rgba(15,23,42,0.30); box-shadow: 0 0 0 3px rgba(15,23,42,0.08); }
[data-theme="dark"] .field-row select:focus { border-color: rgba(124,111,250,0.5); box-shadow: 0 0 0 3px rgba(99,102,241,0.12); }

/* ── Phase 3 ──────────────────────────────────────────────────────────── */
.phase3-list { display: grid; gap: 6px; max-height: 220px; overflow-y: auto; margin-bottom: 4px; padding-right: 2px; }
.phase3-row { display: flex; align-items: center; gap: 8px; padding: 6px 10px; background: var(--surface-2); border-radius: 10px; }
[data-theme="dark"] .phase3-row { background: rgba(255,255,255,0.04); }
.phase3-row span:first-child { flex: 1; font-size: 0.87rem; color: var(--text-2); }
.phase3-perm-badges { display: flex; gap: 4px; }
.phase3-add-row { display: flex; align-items: center; gap: 8px; }
.phase3-check { display: flex; align-items: center; gap: 4px; font-size: 0.83rem; white-space: nowrap; cursor: pointer; color: var(--text-2); }
.muted-copy { color: var(--text-3); font-size: 0.83rem; }