/* ============================================================================
   数学画板 MathGraph —— 界面样式
   设计目标：像 GeoGebra 一样“一眼看懂什么能点、什么能拖”，但更克制清爽。
   布局：顶栏 / 工具条 / 代数区 / 画板 / 聊天面板 / 状态栏
   ========================================================================== */

:root {
    --bg: #EBF0ED;
    --panel: #F9FBF8;
    --panel-2: #EBF0ED;
    --panel-3: #F9FBF8;
    --border: #D5DCE4;
    --border-strong: #D5DCE4;
    --text: #2B3542;
    --muted: #687687;
    --accent: #276E5D;
    --accent-weak: #276E5D12;
    --accent-dark: #276E5D;
    --secondary: #C58251;
    --ok: #17a673;
    --warn: #d98324;
    --danger: #e0483f;
    --shadow-sm: 0 1px 2px rgba(23, 38, 63, .08);
    --shadow-md: 0 6px 20px rgba(23, 38, 63, .14);
    --radius: 8px;
    --radius-lg: 12px;
    --board-bg: #ffffff;
    --mono: ui-monospace, SFMono-Regular, "Cascadia Mono", Consolas, "Liberation Mono", monospace;
}

body.theme-dark {
    --bg: #161a20;
    --panel: #1f242c;
    --panel-2: #252b34;
    --panel-3: #2d343e;
    --border: #333c48;
    --border-strong: #46505e;
    --text: #e7ecf3;
    --muted: #9aa7b8;
    --accent: #5b93ff;
    --accent-weak: #22304a;
    --accent-dark: #7aa8ff;
    --board-bg: #1b2027;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, .5);
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
    background: var(--bg);
    color: var(--text);
    font: 14px/1.5 "Segoe UI", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
    -webkit-font-smoothing: antialiased;
}

button { font-family: inherit; color: inherit; }
code, .mono { font-family: var(--mono); }
.muted { color: var(--muted); }
.small { font-size: 12px; }

#app {
    display: grid;
    grid-template-rows: 38px 48px minmax(0, 1fr) 26px;
    height: calc(100vh - 24px);
}

/* ══════════════════════════ 备案信息条（工信部要求，请勿删除） ══════════════════════════ */

#site-icp {
    position: fixed; left: 0; right: 0; bottom: 0; height: 24px; z-index: 1001;
    display: flex; align-items: center; justify-content: center;
    background: var(--panel-2);
    border-top: 1px solid var(--border);
    font-size: 11px; letter-spacing: .2px; color: var(--muted);
}
#site-icp a { color: var(--muted); text-decoration: none; }
#site-icp a:hover { color: var(--accent-dark); text-decoration: underline; }

/* ══════════════════════════ 顶栏 ══════════════════════════ */

#topbar {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 0 12px;
    background: var(--panel);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    z-index: 40;
}

.brand { display: flex; align-items: center; gap: 8px; font-weight: 600; letter-spacing: .3px; }
.brand-logo { display: block; width: 26px; height: 26px; flex: 0 0 26px; color: #276E5D; }
.brand-mark {
    display: grid; place-items: center;
    width: 26px; height: 26px; border-radius: 7px;
    background: linear-gradient(135deg, var(--accent), #7b5cff);
    color: #fff; font-size: 16px; font-weight: 700;
}
.brand-text { font-size: 15px; color: #276E5D; }
body:not(.theme-dark) .brand-mark {
    background: #276E5D15; color: var(--accent); border: 1px solid #276E5D24;
}

.menus { display: flex; gap: 2px; }
.menu { position: relative; }
.menu-btn {
    border: 0; background: transparent; cursor: pointer;
    padding: 6px 11px; border-radius: 6px; font-size: 14px;
}
.menu-btn:hover { background: var(--panel-3); }
.menu.open .menu-btn { background: var(--accent-weak); color: var(--accent-dark); }
.menu-list {
    position: absolute; top: calc(100% + 6px); left: 0; min-width: 236px;
    background: var(--panel); border: 1px solid var(--border);
    border-radius: var(--radius); box-shadow: var(--shadow-md);
    padding: 5px; display: none; z-index: 60;
}
.menu.open .menu-list { display: block; }
.menu-list button {
    display: flex; width: 100%; align-items: center; justify-content: space-between;
    gap: 16px; border: 0; background: transparent; cursor: pointer;
    padding: 7px 10px; border-radius: 6px; font-size: 13.5px; text-align: left;
}
.menu-list button:hover { background: var(--accent-weak); color: var(--accent-dark); }
.menu-list hr { border: 0; border-top: 1px solid var(--border); margin: 5px 8px; }
kbd {
    font: 11px var(--mono); color: var(--muted);
    background: var(--panel-3); border: 1px solid var(--border);
    border-bottom-width: 2px; border-radius: 4px; padding: 1px 5px;
}

.topbar-right { margin-left: auto; display: flex; align-items: center; gap: 8px; }

.seg { display: flex; background: var(--panel-3); border-radius: 8px; padding: 3px; }
.seg-btn {
    border: 0; background: transparent; cursor: pointer;
    padding: 5px 13px; border-radius: 6px; font-size: 13px; color: var(--muted);
}
.seg-btn.active { background: var(--panel); color: var(--accent-dark); font-weight: 600; box-shadow: var(--shadow-sm); }

.icon-btn {
    border: 1px solid transparent; background: transparent; cursor: pointer;
    width: 32px; height: 32px; border-radius: 7px; font-size: 15px;
}
.icon-btn:hover { background: var(--panel-3); border-color: var(--border); }

/* ══════════════════════════ 绘图会话标签 ══════════════════════════ */

#sessionbar {
    position: relative;
    display: flex;
    align-items: stretch;
    min-width: 0;
    padding: 4px 10px 0;
    gap: 8px;
    background: var(--panel-2);
    border-bottom: 1px solid var(--border);
    z-index: 35;
}
.session-tabs {
    display: flex;
    align-items: stretch;
    gap: 4px;
    min-width: 0;
    overflow-x: auto;
    scrollbar-width: thin;
}
.session-tabs::-webkit-scrollbar { height: 4px; }
.session-tab {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    width: 100%; min-width: 0; height: 100%;
    padding: 0 30px 0 12px;
    border: 1px solid transparent;
    border-bottom: 0;
    border-radius: 8px 8px 0 0;
    background: transparent;
    color: var(--muted);
    cursor: pointer;
    white-space: nowrap;
    font-size: 12.5px;
}
.session-tab-wrapper { position: relative; flex: 0 0 180px; min-width: 118px; }
.session-tab:hover { background: var(--panel); color: var(--text); }
.session-tab.active {
    background: var(--panel);
    border-color: var(--border);
    color: var(--accent-dark);
    font-weight: 600;
    box-shadow: 0 -1px 2px rgba(23, 38, 63, .04);
}
.session-tab-title { overflow: hidden; text-overflow: ellipsis; }
.session-tab-close {
    position: absolute; right: 6px; top: 6px;
    flex: 0 0 auto;
    width: 20px;
    height: 20px;
    padding: 0;
    border: 0;
    border-radius: 5px;
    background: transparent;
    color: var(--muted);
    cursor: pointer;
    line-height: 1;
}
.session-tab-close:hover { background: var(--panel-3); color: var(--danger); }
.sessionbar-actions { display: flex; align-items: center; gap: 5px; margin-left: auto; flex: 0 0 auto; }
.session-history-btn, .session-new-btn {
    height: 28px;
    border: 1px solid var(--border);
    background: var(--panel);
    color: var(--muted);
    cursor: pointer;
    border-radius: 6px;
}
.session-history-btn { padding: 0 10px; font-size: 12px; }
.session-new-btn { width: 30px; padding: 0; font-size: 20px; line-height: 1; }
.session-history-btn:hover, .session-new-btn:hover { color: var(--accent-dark); border-color: var(--accent); background: var(--accent-weak); }
.session-history {
    position: absolute;
    top: 34px;
    right: 10px;
    width: min(360px, calc(100vw - 20px));
    max-height: min(64vh, 460px);
    overflow: hidden;
    padding: 10px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 9px;
    box-shadow: var(--shadow-md);
}
.session-history[hidden] { display: none; }
.session-history-head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; padding: 2px 4px 8px; border-bottom: 1px solid var(--border); }
.session-history-list { overflow-y: auto; max-height: 390px; padding-top: 6px; }
.session-history-item {
    display: flex; align-items: center; justify-content: space-between; gap: 10px;
    width: 100%; padding: 8px 9px; border: 0; border-radius: 6px;
    background: transparent; color: var(--text); cursor: pointer; text-align: left;
}
.session-history-item:hover { background: var(--accent-weak); }
.session-history-item.active { background: var(--panel-3); }
.session-history-item-main { min-width: 0; }
.session-history-item-title { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 13px; }
.session-history-item-meta { display: block; margin-top: 2px; color: var(--muted); font-size: 11px; }
.session-history-item-state { flex: 0 0 auto; color: var(--muted); font-size: 11px; }

/* ══════════════════════════ 主体骨架 ══════════════════════════ */

#main {
    display: grid;
    --left-panel-width: 306px;
    --right-panel-width: 348px;
    /* 工具条 / 聊天区 / 画板 / 代数区：两侧面板按当前工作流调换 */
    grid-template-columns: 0px var(--right-panel-width) minmax(220px, 1fr) var(--left-panel-width);
    min-height: 0;
    position: relative;
    overflow: hidden;
    transition: grid-template-columns .28s ease;
}
body.chat-collapsed #main { grid-template-columns: 0px 0px minmax(220px, 1fr) var(--left-panel-width); }
body.chat-collapsed #panel-right { transform: translateX(-100%); opacity: 0; pointer-events: none; }
body.left-collapsed #main { grid-template-columns: 0px var(--right-panel-width) minmax(220px, 1fr) 0px; }
body.left-collapsed #panel-left { transform: translateX(100%); opacity: 0; pointer-events: none; }
body.chat-collapsed.left-collapsed #main { grid-template-columns: 0px 0px minmax(220px, 1fr) 0px; }
body.chat-collapsed #btn-right-expand,
body.left-collapsed #btn-left-expand { display: grid; }

#panel-right { grid-column: 2; grid-row: 1; border-left: 0; border-right: 1px solid var(--border); }
#panel-left { grid-column: 4; grid-row: 1; border-right: 0; border-left: 1px solid var(--border); }
#panel-right .panel-resizer-right { left: auto; right: -5px; }
#panel-left .panel-resizer-left { right: auto; left: -5px; }

/* ══════════════════════════ 工具条 ══════════════════════════ */

#toolbar {
    background: var(--panel);
    border-right: 1px solid var(--border);
    padding: 6px 0;
    display: flex; flex-direction: column; align-items: center; gap: 2px;
    overflow-y: auto; overflow-x: hidden;
}
#toolbar, #btn-settings, #btn-chat-toggle { display: none; }
.tool {
    width: 34px; height: 32px;
    display: grid; place-items: center;
    border: 1px solid transparent; background: transparent; cursor: pointer;
    border-radius: 7px; font-size: 16px; line-height: 1; color: var(--text);
    flex: 0 0 auto;
}
.tool:hover { background: var(--panel-3); border-color: var(--border); }
.tool.active { background: var(--accent); border-color: var(--accent-dark); color: #fff; }
body:not(.theme-dark) .tool.active { background: #276E5D18; color: var(--accent); border-color: #276E5D40; }
.tool-sep { width: 24px; height: 1px; background: var(--border); margin: 5px 0; flex: 0 0 auto; }

/* ══════════════════════════ 通用面板 ══════════════════════════ */

#panel-left, #panel-right {
    background: var(--panel);
    display: flex; flex-direction: column;
    min-height: 0; min-width: 0; position: relative;
    transition: transform .28s ease, opacity .2s ease;
}
#panel-left { width: var(--left-panel-width); }
#panel-right { width: var(--right-panel-width); }
body.is-resizing #main { transition: none; }
#panel-right.image-drag-over { box-shadow: inset 0 0 0 3px var(--accent); }
#panel-left { border-right: 1px solid var(--border); }
#panel-right { border-left: 1px solid var(--border); }

.panel-resizer {
    position: absolute; top: 0; bottom: 0; width: 10px; z-index: 20;
    cursor: col-resize; touch-action: none;
}
.panel-resizer::after {
    content: ""; position: absolute; top: 0; bottom: 0; left: 4px; width: 2px;
    background: transparent; transition: background .12s ease;
}
.panel-resizer:hover::after, body.is-resizing .panel-resizer::after { background: var(--accent); }
.panel-resizer-left { right: -5px; }
.panel-resizer-right { left: -5px; }
body.is-resizing, body.is-resizing * { cursor: col-resize !important; user-select: none !important; }

.panel-head {
    padding: 9px 10px;
    border-bottom: 1px solid var(--border);
    background: var(--panel-2);
    flex: 0 0 auto;
}
.panel-body { flex: 1 1 auto; overflow-y: auto; overflow-x: hidden; min-height: 0; }

.section-title {
    display: flex; align-items: center; justify-content: space-between;
    padding: 9px 11px 5px; font-size: 12px; font-weight: 600;
    color: var(--muted); text-transform: none; letter-spacing: .4px;
}
.section-tools { display: flex; gap: 6px; }

.mini {
    border: 1px solid var(--border); background: var(--panel); cursor: pointer;
    border-radius: 6px; padding: 2px 7px; font-size: 12px; color: var(--muted);
}
.mini:hover { background: var(--panel-3); color: var(--text); }

/* ── 输入行 ── */
.input-row { display: flex; gap: 6px; }
#algebra-input {
    flex: 1 1 auto; min-width: 0;
    padding: 8px 10px; border: 1px solid var(--border-strong); border-radius: 7px;
    background: var(--panel); color: var(--text);
    font: 13.5px var(--mono);
}
#algebra-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-weak); }
.input-hint { margin-top: 6px; font-size: 11.5px; line-height: 1.4; color: var(--muted); overflow-wrap: anywhere; }

button.primary {
    border: 1px solid var(--accent-dark); background: var(--accent); color: #fff;
    cursor: pointer; border-radius: 7px; padding: 8px 14px; font-size: 13.5px; font-weight: 500;
}
button.primary:hover { background: var(--accent-dark); }
button.ghost {
    border: 1px solid var(--border-strong); background: var(--panel); cursor: pointer;
    border-radius: 7px; padding: 8px 14px; font-size: 13.5px;
}
button.ghost:hover { background: var(--panel-3); }

/* ── 对象列表 ── */
.element-list { list-style: none; margin: 0; padding: 0 6px 10px; }
.element-list li {
    display: flex; align-items: center; gap: 7px;
    padding: 6px 7px; border-radius: 7px; border: 1px solid transparent;
    cursor: pointer; min-width: 0;
}
.element-list li:hover { background: var(--panel-2); }
.element-list li.selected { background: var(--accent-weak); border-color: var(--accent); }
.element-list li.hidden-obj .el-name,
.element-list li.hidden-obj .el-value { opacity: .45; text-decoration: line-through; }

.el-swatch {
    width: 11px; height: 11px; border-radius: 3px; flex: 0 0 auto;
    border: 1px solid rgba(0, 0, 0, .18);
}
.el-name { font: 13px var(--mono); flex: 0 0 auto; max-width: 96px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.el-eq { color: var(--muted); font: 12px var(--mono); flex: 1 1 auto; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.el-value { font: 12px var(--mono); color: var(--accent-dark); flex: 0 0 auto; }
.el-actions { display: flex; gap: 2px; flex: 0 0 auto; opacity: 0; transition: opacity .12s; }
.element-list li:hover .el-actions, .element-list li.selected .el-actions { opacity: 1; }
.el-actions button {
    border: 0; background: transparent; cursor: pointer; border-radius: 5px;
    width: 22px; height: 22px; font-size: 12px; line-height: 1;
}
.el-actions button:hover { background: var(--panel-3); }

/* ── 参数控制台（音量条样式） ── */
.param-console { padding: 0 11px 16px; }
.param-card {
    background: var(--panel-2); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 10px 11px; margin-bottom: 9px;
}
.param-card-head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; margin-bottom: 8px; }
.param-name { font: 14px var(--mono); font-weight: 600; }
.param-value { font: 14px var(--mono); color: var(--accent-dark); font-weight: 600; }
.param-range-row { display: flex; align-items: center; gap: 8px; }
.param-range-row .edge { font: 11px var(--mono); color: var(--muted); flex: 0 0 auto; }

/* 音量条：粗轨道 + 圆形滑块，左侧已填充部分随数值增长 */
input[type="range"].vol {
    -webkit-appearance: none; appearance: none;
    flex: 1 1 auto; min-width: 0; height: 26px; background: transparent; cursor: pointer;
    --fill: 50%;
}
input[type="range"].vol::-webkit-slider-runnable-track {
    height: 12px; border-radius: 6px;
    background: linear-gradient(to right, var(--accent) 0 var(--fill), var(--panel-3) var(--fill) 100%);
    border: 1px solid var(--border-strong);
}
input[type="range"].vol::-webkit-slider-thumb {
    -webkit-appearance: none; appearance: none;
    width: 24px; height: 24px; border-radius: 50%;
    background: #fff; border: 2px solid var(--accent);
    box-shadow: 0 1px 4px rgba(0, 0, 0, .3); margin-top: -7px;
}
input[type="range"].vol::-moz-range-track {
    height: 12px; border-radius: 6px; background: var(--panel-3); border: 1px solid var(--border-strong);
}
input[type="range"].vol::-moz-range-progress { height: 12px; border-radius: 6px; background: var(--accent); }
input[type="range"].vol::-moz-range-thumb {
    width: 22px; height: 22px; border-radius: 50%; background: #fff; border: 2px solid var(--accent);
}
.param-note { font-size: 11.5px; color: var(--muted); margin-top: 7px; }
.param-number-row { display: flex; align-items: center; gap: 8px; margin-top: 8px; }
.param-number-label { flex: 0 0 auto; font-size: 11.5px; color: var(--muted); }
.param-number {
    flex: 1 1 auto; min-width: 0; width: 100%;
    padding: 5px 7px; border: 1px solid var(--border-strong); border-radius: 6px;
    background: var(--panel); color: var(--text); font: 13px var(--mono);
}
.param-number:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-weak); }

/* ══════════════════════════ 画板 ══════════════════════════ */

#board-wrap { position: relative; min-width: 0; min-height: 0; background: var(--board-bg); grid-column: 3; grid-row: 1; width: 100%; height: 100%; }
.board-host { position: absolute; inset: 0; display: none; width: 100%; height: 100%; }
.board-host.active { display: block; }
.board-host .jxgbox { width: 100% !important; height: 100% !important; border: 0 !important; }
.board-host svg { display: block; width: 100%; height: 100%; }

#board-overlay {
    position: absolute; top: 10px; left: 12px; pointer-events: none;
    display: flex; flex-direction: column; gap: 5px; z-index: 5;
}
.overlay-badge {
    align-self: flex-start;
    background: var(--panel); border: 1px solid var(--border);
    border-radius: 20px; padding: 3px 11px; font-size: 12px; color: var(--muted);
    box-shadow: var(--shadow-sm);
}
.overlay-hint {
    align-self: flex-start; max-width: 460px;
    background: var(--accent-weak); border: 1px solid var(--accent);
    color: var(--accent-dark); border-radius: 8px; padding: 5px 11px; font-size: 12.5px;
    box-shadow: var(--shadow-sm);
}
.overlay-hint:empty { display: none; }

#viewport-tools {
    position: absolute; right: 12px; bottom: 12px; z-index: 5;
    display: flex; flex-direction: column; gap: 5px;
}
.vp-btn {
    width: 32px; height: 32px; border-radius: 8px; cursor: pointer;
    border: 1px solid var(--border); background: var(--panel);
    box-shadow: var(--shadow-sm); font-size: 15px; line-height: 1;
}
.vp-btn:hover { background: var(--panel-3); }

/* ══════════════════════════ 聊天面板 ══════════════════════════ */

.chat-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.chat-title { display: flex; align-items: center; gap: 7px; font-weight: 600; }
.chat-head-tools { display: flex; gap: 5px; }
.badge {
    font-size: 11px; font-weight: 500; padding: 2px 8px; border-radius: 20px;
    background: var(--panel-3); color: var(--muted); border: 1px solid var(--border);
}
.badge.online { background: #e6f7f0; color: var(--ok); border-color: #a9e3cc; }
body.theme-dark .badge.online { background: #16302a; }

.chat-messages { flex: 1 1 auto; overflow-y: auto; padding: 12px 11px; display: flex; flex-direction: column; gap: 10px; min-height: 0; }
.msg { max-width: 100%; }
.msg-attachments { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 4px; }
.msg-attachments img { width: 92px; height: 72px; object-fit: cover; border-radius: 7px; border: 1px solid var(--border-strong); background: var(--panel); }
.msg-attachments img[role="button"] { cursor: zoom-in; }
.msg-attachments img:focus-visible { outline: 2px solid var(--accent, #237565); outline-offset: 3px; }
.chat-image-viewer { box-sizing: border-box; width: max-content; max-width: 94vw; max-height: 94dvh; padding: 0; border: 1px solid var(--border-strong); border-radius: 12px; background: var(--panel, #fff); color: var(--text); overflow: auto; box-shadow: 0 20px 80px #0006; }
.chat-image-viewer::backdrop { background: #000b; }
.chat-image-viewer-head { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 8px 12px; }
.chat-image-viewer-head span { min-width: 0; overflow-wrap: anywhere; }
.chat-image-viewer-head button { flex: none; width: 34px; height: 34px; border: 0; border-radius: 6px; font-size: 24px; cursor: pointer; background: transparent; color: inherit; }
.chat-image-viewer > img { display: block; width: auto; height: auto; max-width: calc(94vw - 2px); max-height: calc(94dvh - 60px); object-fit: contain; margin: auto; }
.msg .bubble {
    padding: 8px 11px; border-radius: 10px; font-size: 13.5px;
    white-space: pre-wrap; word-break: break-word; border: 1px solid var(--border);
    background: var(--panel-2);
}
.msg.user { align-self: flex-end; max-width: 92%; }
.msg.user .bubble { background: var(--accent); border-color: var(--accent-dark); color: #fff; }
body:not(.theme-dark) .msg.user .bubble { background: #276E5D0F; color: var(--text); border-color: #276E5D28; }
.msg.bot .bubble { background: var(--panel-2); }
.msg .meta { font-size: 11px; color: var(--muted); margin: 4px 2px 0; }
.msg.execution .bubble { background: #fff8e8; border-color: #f0d9a8; font: 12px var(--mono); color: #7a5a17; }
body:not(.theme-dark) .msg.execution .bubble { background: #C582510B; border-color: #C5825128; color: var(--secondary); }
body.theme-dark .msg.execution .bubble { background: #2e2716; border-color: #5c4a1f; color: #e2c98a; }
.msg.error .bubble { background: #fdecea; border-color: #f3b8b3; color: #9d2b23; }
body.theme-dark .msg.error .bubble { background: #3a1f1d; border-color: #6d3a35; color: #f0a9a2; }

.chat-chips { display: flex; flex-wrap: wrap; gap: 6px; padding: 24px 11px 9px; flex: 0 0 auto; position: relative; }
.chat-chips[hidden] { display: none; }
#btn-chat-chips-close { position: absolute; right: 9px; top: 1px; }
.chip {
    border: 1px solid var(--border-strong); background: var(--panel-2); cursor: pointer;
    border-radius: 20px; padding: 4px 11px; font-size: 12px; line-height: 1.35; color: var(--muted);
    max-width: 100%; overflow-wrap: anywhere; white-space: normal; text-align: left;
}
.chip:hover { background: var(--accent-weak); color: var(--accent-dark); border-color: var(--accent); }

.chat-attachments {
    display: flex; flex-wrap: wrap; gap: 7px; padding: 0 10px 8px;
    min-height: 0; background: var(--panel-2);
}
.chat-attachments:empty { display: none; }
.chat-attachment {
    position: relative; width: 58px; height: 58px; border: 1px solid var(--border-strong);
    border-radius: 7px; overflow: hidden; background: var(--panel);
}
.chat-attachment img { width: 100%; height: 100%; object-fit: cover; display: block; }
.chat-attachment button {
    position: absolute; top: 2px; right: 2px; width: 18px; height: 18px; border: 0;
    border-radius: 50%; background: rgba(0,0,0,.6); color: #fff; cursor: pointer; line-height: 1;
}
.chat-attachment span {
    position: absolute; left: 3px; right: 3px; bottom: 2px; padding: 1px 3px;
    color: #fff; background: rgba(0,0,0,.55); font-size: 9px; overflow: hidden;
    text-overflow: ellipsis; white-space: nowrap;
}

.chat-input-row { display: flex; align-items: flex-end; gap: 7px; padding: 9px 10px 11px; border-top: 1px solid var(--border); background: var(--panel-2); flex: 0 0 auto; }
.chat-actions { display: flex; flex-direction: column; gap: 6px; flex: 0 0 auto; }
.chat-actions button { width: 100%; white-space: nowrap; }
.chat-actions .image-export-entry { border: 1px solid var(--border-strong); border-radius: 7px; background: var(--panel); padding: 6px 9px; cursor: pointer; }
.chat-attach-btn { flex: 0 0 auto; width: 32px; height: 32px; padding: 0; font-size: 16px; }
.chat-attach-btn svg { width: 17px; height: 17px; display: block; margin: auto; }
#chat-input {
    flex: 1 1 auto; min-width: 0; min-height: 132px; max-height: min(40vh, 280px); resize: vertical; overflow: auto;
    border: 1px solid var(--border-strong); border-radius: 8px; padding: 7px 9px;
    background: var(--panel); color: var(--text); font: 13px/1.5 "Segoe UI", "Microsoft YaHei", sans-serif;
}
#chat-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-weak); }

.typing::after { content: "▍"; animation: blink 1s steps(2) infinite; color: var(--accent); }
@keyframes blink { 0%, 50% { opacity: 1; } 50.01%, 100% { opacity: 0; } }

/* ══════════════════════════ 状态栏 ══════════════════════════ */

#statusbar {
    display: flex; align-items: center; gap: 16px;
    padding: 0 12px; background: var(--panel-2);
    border-top: 1px solid var(--border);
    font-size: 12px; color: var(--muted);
}
#statusbar .spacer { flex: 1 1 auto; }

.panel-expand {
    display: none; position: absolute; top: 50%; transform: translateY(-50%); z-index: 35;
    width: 25px; height: 48px; padding: 0; border: 1px solid var(--border-strong);
    background: var(--panel); color: var(--accent-dark); cursor: pointer; font-size: 17px;
    box-shadow: var(--shadow-sm);
}
.panel-expand { place-items: center; line-height: 0; }
.panel-expand svg { width: 20px; height: 20px; display: block; }
.panel-expand:hover { background: var(--panel-3); color: var(--text); }
.panel-expand-left { right: 0; border-radius: 8px 0 0 8px; }
.panel-expand-right { left: 0; border-radius: 0 8px 8px 0; }
.panel-collapse-btn { min-width: 24px; padding: 1px 5px; font-size: 16px; line-height: 1; }

/* ══════════════════════════ 浮层 / 对话框 ══════════════════════════ */

.modal-mask {
    position: fixed; inset: 0; background: rgba(20, 28, 40, .42);
    display: grid; place-items: center; z-index: 200; padding: 24px;
}
.modal-mask[hidden] { display: none; }
.modal {
    background: var(--panel); border-radius: var(--radius-lg); box-shadow: var(--shadow-md);
    width: min(560px, 100%); max-height: 88vh; display: flex; flex-direction: column;
    border: 1px solid var(--border);
}
.modal.wide { width: min(860px, 100%); }
.modal-head {
    display: flex; align-items: center; justify-content: space-between;
    padding: 13px 16px; border-bottom: 1px solid var(--border);
}
.modal-head h3 { margin: 0; font-size: 15px; }
.modal-body { padding: 15px 16px; overflow-y: auto; }
.modal-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 16px; }

.field { display: block; margin-bottom: 12px; }
.field > span { display: block; font-size: 12.5px; color: var(--muted); margin-bottom: 5px; }
.field input {
    width: 100%; padding: 8px 10px; border: 1px solid var(--border-strong);
    border-radius: 7px; background: var(--panel); color: var(--text); font: 13.5px var(--mono);
}
.field input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-weak); }
.check { display: flex; align-items: flex-start; gap: 8px; margin-bottom: 10px; font-size: 13px; }
.check input { margin-top: 3px; }

.help-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 26px; }
.help-grid h4 { margin: 0 0 7px; font-size: 13.5px; color: var(--accent-dark); }
.help-grid ul { margin: 0; padding-left: 18px; }
.help-grid li { margin-bottom: 5px; font-size: 13px; }
.help-grid code {
    background: var(--panel-3); border: 1px solid var(--border); border-radius: 4px;
    padding: .5px 5px; font-size: 12.5px;
}
.demo-item {
    display: flex; gap: 12px; align-items: flex-start; width: 100%; text-align: left;
    border: 1px solid var(--border); background: var(--panel-2); cursor: pointer;
    border-radius: var(--radius); padding: 11px 13px; margin-bottom: 9px;
}
.demo-item:hover { background: var(--accent-weak); border-color: var(--accent); }
.demo-item .demo-icon { font-size: 20px; line-height: 1; }
.demo-item strong { display: block; font-size: 13.5px; margin-bottom: 3px; }
.demo-item span { font-size: 12.5px; color: var(--muted); }

.toast-host { position: fixed; left: 50%; bottom: 46px; transform: translateX(-50%); z-index: 300; display: flex; flex-direction: column; gap: 7px; align-items: center; }
.toast {
    background: #22303f; color: #fff; border-radius: 8px; padding: 8px 15px;
    font-size: 13px; box-shadow: var(--shadow-md); animation: rise .18s ease;
}
.toast.error { background: var(--danger); }
.toast.ok { background: var(--ok); }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ══════════════════════════ 小屏适配 ══════════════════════════ */

@media (max-width: 1180px) {
    #main { grid-template-columns: 0px var(--right-panel-width, 300px) minmax(220px, 1fr) var(--left-panel-width, 258px); }
}
@media (max-width: 960px) {
    #main, body.left-collapsed #main, body.chat-collapsed #main, body.chat-collapsed.left-collapsed #main {
        grid-row: 3; grid-template-columns: 0px minmax(0, 1fr); grid-template-rows: minmax(220px, 1fr) auto auto;
    }
    #toolbar { grid-column: 1; grid-row: 1 / -1; }
    body.left-collapsed #panel-left, body.chat-collapsed #panel-right { display: none; }
    .panel-resizer { display: none; }
    #panel-left { grid-row: 2; grid-column: 2; max-height: 38vh; }
    #board-wrap { grid-row: 1; grid-column: 2; }
    #panel-right { grid-column: 2; grid-row: 3; max-height: 46vh; }
    #panel-left, #panel-right { width: auto; }
}
/* 【入口布局集中设置】动画条位置；不改变原有面板和工具栏布局。 */
.animation-controls { position:absolute; z-index:9; left:50%; bottom:46px; transform:translateX(-50%); display:flex; align-items:center; gap:9px; padding:9px 12px; border:1px solid var(--border,#ccd5e0); border-radius:10px; background:var(--panel,#fff); box-shadow:0 3px 15px #0002; max-width:95%; white-space:nowrap; }
.animation-controls[hidden] { display:none; }
.animation-controls button,.animation-controls select { font:inherit; padding:4px 9px; }
.animation-controls label { display:flex; align-items:center; gap:5px; }
.ai-object-highlight { filter:drop-shadow(0 0 5px #22b8cf); }
/* 【入口布局集中设置】图片入口由 82-image-export.js 的 LAYOUT 定位。 */
.image-export-entry { font-size:12px; width:auto; padding:0 9px; }
.export-modal { width:min(850px,94vw); }
.export-options,.export-actions { display:flex; gap:16px; align-items:center; flex-wrap:wrap; padding:8px 0; }
.export-options label { display:flex; align-items:center; gap:5px; }
#export-preview { display:block; max-width:100%; max-height:55vh; margin:12px auto; border:1px solid var(--border); background:repeating-conic-gradient(#eee 0% 25%,#fff 0% 50%) 50% / 16px 16px; }
.export-actions button { padding:8px 16px; font:inherit; }
/* 【选定修改】曲线旁仅保留黑色小字，参数控件紧随公式，无面板或卡片。 */
#canvas-expressions{position:absolute;inset:0;z-index:9;pointer-events:none;background:none;border:0;box-shadow:none}
#canvas-expressions[hidden]{display:none}.canvas-expression-control{position:absolute;box-sizing:border-box;max-width:calc(100% - 16px);color:#000;font:12px Arial,sans-serif;background:none;border:0;box-shadow:none;pointer-events:auto}
.canvas-expression-control .param-card{display:flex;align-items:center;gap:5px;margin:3px 0 0;padding:0;border:0;border-radius:0;background:none;box-shadow:none;color:#000}
.canvas-expression-control .param-card-head,.canvas-expression-control .param-number-row{display:contents}.canvas-expression-control .param-name{font:12px Arial,sans-serif;color:#000}
.canvas-expression-control .param-value,.canvas-expression-control .edge,.canvas-expression-control .param-number-label,.canvas-expression-control .param-note{display:none}
.canvas-expression-control .param-range-row{display:flex;align-items:center;gap:0;min-width:0;margin:0;flex:0 1 82px}.canvas-expression-control input.vol{width:82px;min-width:40px;margin:0;height:14px}
.canvas-expression-control input.param-number{box-sizing:border-box;width:48px;min-width:0;padding:1px 3px;font:12px Arial,sans-serif;line-height:16px;color:#000;background:#ffffffd9;border:1px solid #d6dedb;border-radius:3px}
#btn-right-collapse{display:inline-flex;align-items:center;justify-content:center;box-sizing:border-box;flex:0 0 26px;width:26px;height:26px;min-width:26px;padding:0;line-height:0;border-radius:7px}
#btn-right-collapse svg{display:block;width:18px;height:18px;flex:none;pointer-events:none}

/* 分类标题左侧折叠；每个数学对象的定义、颜色、长度与附属标注纵向成组。 */
#element-list>.element-group{display:block;padding:0;border:0;background:none;cursor:default}
.element-group-toggle{display:flex;align-items:center;gap:7px;width:100%;padding:10px 6px;border:0;border-bottom:1px solid var(--border);background:var(--panel);color:var(--text);font:inherit;font-weight:600;text-align:left;cursor:pointer}
.element-group-chevron{width:14px;color:var(--accent)}.element-group-count{margin-left:auto;font-size:11px;color:var(--muted);font-weight:400}
.element-group-items{list-style:none;margin:0;padding:5px 0}.element-group-items[hidden]{display:none!important}
#element-list .element-card{display:block;margin:4px 0;padding:9px 10px;border:1px solid var(--border);border-radius:9px;background:var(--panel);overflow:hidden}
#element-list .element-card.selected{border-color:var(--accent);background:var(--accent-weak)}
.element-card-head{display:flex;align-items:center;gap:7px;min-height:24px}.element-card .el-actions{display:flex;margin-left:auto;opacity:1;position:static}
.element-card .el-name{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.element-card .el-actions{flex-shrink:0}.element-card .el-actions .copied{color:var(--accent-dark);background:var(--accent-weak)}.element-detail{margin-top:5px;font-size:12px;color:var(--muted);line-height:1.5;overflow-wrap:anywhere}
.element-owned-name{min-width:0;max-width:35%;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.element-owned-definition{flex:1;min-width:0}
.element-color{display:flex;align-items:center;gap:5px}.element-owned{display:flex;gap:7px;margin-top:6px;padding:6px 0 0 10px;border-top:1px dashed var(--border);font-size:12px;color:var(--muted);overflow-wrap:anywhere}.element-owned-name{font-weight:600;color:var(--text)}