:root {
  --bg: #0A0D14;
  --panel: #10141E;
  --card: #151A26;
  --card-hover: #1B2230;
  --border: #232B3A;
  --border-light: #2E3A4E;
  --primary: #7C5CFF;
  --primary-hover: #6A4DF0;
  --accent: #00D4FF;
  --text: #E8EBF2;
  --text-dim: #8A90A6;
  --success: #22C55E;
  --danger: #EF4444;
  --text-strong: #FFFFFF;   /* 高对比文字（激活状态/悬停），亮色主题会被覆盖成深色 */
  --brand1: #9B7CFF;         /* 品牌渐变起点，亮色主题会调深 */
  --brand2: var(--accent);   /* 品牌渐变终点 */
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.35);
}

/* ===== 背景主题（在 <html> 上加 data-theme 切换，只覆盖中性色，品牌紫/青不变） ===== */
:root[data-theme="light"] {
  --bg: #F5F7FA; --panel: #FFFFFF; --card: #FFFFFF; --card-hover: #EEF1F6;
  --border: #E2E6EF; --border-light: #CBD2DF; --text: #1A2233; --text-dim: #5B6472;
  --text-strong: #0F172A; --accent: #0891B2; --brand1: #5B4BD6; --brand2: #0891B2;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}
:root[data-theme="ocean"] {
  --bg: #0A1830; --panel: #0E2138; --card: #112944; --card-hover: #16334F;
  --border: #1E3A57; --border-light: #2A4A6B; --text: #DCE8F5; --text-dim: #7E93AB;
  --text-strong: #FFFFFF; --accent: #3EB6FF; --brand1: #7C5CFF; --brand2: #3EB6FF;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.40);
}
:root[data-theme="warm"] {
  --bg: #F4F1EA; --panel: #FBFAF6; --card: #FFFFFF; --card-hover: #EFEAE0;
  --border: #E4DED0; --border-light: #CEC6B6; --text: #2A2418; --text-dim: #6B634F;
  --text-strong: #0F0A00; --accent: #B4530F; --brand1: #6A4DF0; --brand2: #B4530F;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.10);
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0; background: var(--bg); color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
}
a { color: var(--accent); text-decoration: none; }

/* 顶栏 */
.topbar {
  display: flex; align-items: center; gap: 20px;
  padding: 14px 24px; border-bottom: 1px solid var(--border);
  background: var(--panel); position: sticky; top: 0; z-index: 10;
}
.topbar .brand { font-weight: 800; font-size: 1.15rem; letter-spacing: .3px;
  background: linear-gradient(90deg, var(--brand1), var(--brand2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.topbar nav { display: flex; gap: 8px; margin-left: auto; }
.topbar nav a { padding: 8px 16px; border-radius: 10px; color: var(--text-dim);
  border: 1px solid transparent; font-size: 0.9rem; }
.topbar nav a.active, .topbar nav a:hover { color: var(--text-strong); border-color: var(--border-light);
  background: rgba(124,92,255, 0.12); }

.app { display: flex; height: calc(100vh - 64px); min-height: 0; }

/* 侧栏 */
.sidebar-wrap { display: flex; min-height: 0; }
.sidebar-wrap.collapsed .sidebar { display: none; }
.rail { display: none; width: 42px; align-items: center; justify-content: center;
  background: var(--panel); border-right: 1px solid var(--border); flex-shrink: 0; transition: all .15s ease; }
.sidebar-wrap.collapsed .rail { display: flex; }
.rail .icon-btn { width: 30px; height: 30px; }
.sidebar { width: 280px; background: var(--panel); border-right: 1px solid var(--border);
  padding: 18px; display: flex; flex-direction: column; gap: 14px; overflow-y: auto; }
.side-title { font-size: 0.72rem; font-weight: 700; letter-spacing: 1.2px; color: var(--text-dim);
  text-transform: uppercase; margin-top: 4px; }
.side-head { display: flex; align-items: center; justify-content: space-between; }
.side-actions { display: flex; gap: 6px; }
.icon-btn { background: transparent; border: 1px solid var(--border-light); border-radius: 8px;
  width: 30px; height: 30px; color: var(--text-dim); cursor: pointer; font-size: 0.9rem;
  display: flex; align-items: center; justify-content: center; transition: all .15s ease; }
.icon-btn:hover { color: var(--text-strong); border-color: var(--accent); }
.search-box { margin-bottom: -6px; }
.search-box input { padding: 8px 10px; font-size: 0.85rem; }
.conv-group { font-size: 0.72rem; font-weight: 700; color: var(--text-dim); letter-spacing: .6px;
  margin: 10px 4px 2px; }
.btn { border-radius: 10px; font-weight: 600; border: 1px solid rgba(124,92,255,0.45);
  background: linear-gradient(90deg, var(--primary), var(--primary-hover)); color: #fff;
  padding: 9px 14px; cursor: pointer; transition: all .18s ease; font-size: 0.9rem; }
.btn:hover { border-color: var(--accent); box-shadow: 0 0 14px rgba(0,212,255,0.35); }
.btn.secondary { background: transparent; color: var(--text); border: 1px solid var(--border-light); }
.btn.small { padding: 6px 10px; font-size: 0.82rem; }
.btn.danger { background: transparent; border-color: rgba(239,68,68,0.4); color: var(--danger); }
.btn.danger:hover { box-shadow: 0 0 14px rgba(239,68,68,0.3); }
button:disabled { opacity: 0.5; cursor: not-allowed; }
.conv-list { display: flex; flex-direction: column; gap: 5px; }
.conv-item { padding: 8px 12px; border-radius: var(--radius-sm); cursor: pointer; font-size: 0.85rem;
  border: 1px solid transparent; color: var(--text); background: transparent; display: flex;
  align-items: center; gap: 8px; justify-content: space-between; transition: all .15s ease; }
.conv-item:hover { background: var(--card-hover); }
.conv-item.active { background: rgba(124,92,255,0.12); border-color: rgba(124,92,255,0.5); color: var(--text-strong); }
.conv-item .del { color: var(--text-dim); cursor: pointer; padding: 0 4px; }
.conv-item .del:hover { color: var(--danger); }
.stats-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.stat-box { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 10px 12px; }
.stat-box .k { font-size: 0.72rem; color: var(--text-dim); }
.stat-box .v { font-size: 1.2rem; font-weight: 800; margin-top: 2px; }

/* 主区：居中偏下的聊天列 */
.main { flex: 1; min-width: 0; height: 100%; display: flex; flex-direction: column; }
.chat-scroll { flex: 1; overflow-y: auto; padding: 24px 24px 4px; }
.chat-col { max-width: 760px; margin: 0 auto; width: 100%; display: flex; flex-direction: column; }
.hero { text-align: center; margin: 12vh auto 6px; }
.msg-row { display: flex; gap: 12px; }
.msg-row.user { justify-content: flex-end; }
.avatar { width: 34px; height: 34px; border-radius: 10px; display: flex; align-items: center;
  justify-content: center; background: rgba(124,92,255,0.15); font-size: 1rem; flex-shrink: 0; }
.bubble { max-width: 78%; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 12px 16px; box-shadow: var(--shadow); line-height: 1.65; font-size: 0.95rem; }
.msg-row.user .bubble { background: rgba(124,92,255,0.14); border-color: rgba(124,92,255,0.5); border-radius: var(--radius) var(--radius) var(--radius-sm) var(--radius); }
.cursor { display: inline-block; width: 7px; height: 1.05em; background: var(--accent);
  vertical-align: text-bottom; margin-left: 2px; animation: blink 1s steps(2) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.bubble h1, .bubble h2, .bubble h3 { margin: .4em 0 .2em; letter-spacing: .2px; }
.bubble code { background: rgba(0,212,255,0.08); padding: 1px 5px; border-radius: 5px; font-family: Consolas, monospace; font-size: 0.88em; }
.bubble pre { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 10px; overflow-x: auto; }
.bubble pre code { background: transparent; padding: 0; }
.cites { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 6px; }
.cite-chip { display: inline-flex; align-items: center; gap: 6px; padding: 3px 10px; border-radius: 999px;
  font-size: 0.74rem; color: var(--accent); background: rgba(0,212,255,0.07); border: 1px solid rgba(0,212,255,0.3); }
.fb-row { margin-top: 8px; display: flex; gap: 6px; align-items: center; }
.fb-row button { background: transparent; border: 1px solid var(--border-light); color: var(--text-dim);
  border-radius: 999px; cursor: pointer; padding: 4px 10px; font-size: 0.8rem; }
.fb-row button:hover { border-color: var(--accent); color: var(--accent); }
.fb-row button.fav.on { color: #F5A623; border-color: rgba(245,166,35,0.6); }

/* 输入：居中偏下 */
.composer-wrap { padding: 8px 24px 20px; }
.attachments { max-width: 760px; margin: 0 auto 8px; display: flex; flex-wrap: wrap; gap: 6px; }
.attach-chip { display: inline-flex; align-items: center; gap: 6px; background: var(--card);
  border: 1px solid var(--border-light); border-radius: 999px; padding: 4px 10px; font-size: 0.8rem; }
.attach-chip .attach-name { max-width: 180px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.attach-chip .attach-rm { color: var(--text-dim); cursor: pointer; padding: 0 2px; }
.attach-chip .attach-rm:hover { color: var(--danger); }
.composer { display: flex; gap: 10px; background: var(--card); max-width: 760px; margin: 0 auto;
  border: 1px solid var(--border-light); border-radius: 16px; padding: 10px; box-shadow: var(--shadow); }
.composer .icon-btn.attach { align-self: flex-end; width: 34px; height: 34px; border-radius: 10px; font-size: 1rem; margin-bottom: 4px; }
.composer textarea { flex: 1; background: transparent; border: none; color: var(--text); font-family: inherit;
  font-size: 0.95rem; resize: none; outline: none; padding: 6px; max-height: 160px; }
.composer .btn { align-self: flex-end; }

/* 通用层 */
.page { padding: 24px; max-width: 1080px; margin: 0 auto; }
.page h2 { font-size: 1.5rem; margin: 6px 0 16px; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.kv { display: flex; justify-content: space-between; padding: 6px 0; font-size: 0.88rem; border-bottom: 1px solid var(--border); }
.kv span:first-child { color: var(--text-dim); }
.kv span:last-child { font-family: Consolas, monospace; }
.grid2 { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.doc-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; }
.doc-card .name { font-weight: 600; }
.doc-card .cnt { color: var(--text-dim); font-size: 0.85rem; margin-top: 4px; }
.doc-card .ops { margin-top: 10px; display: flex; gap: 8px; }
label { display: block; font-size: 0.82rem; color: var(--text-dim); margin: 12px 0 6px; }
input[type=text], input[type=number], input[type=email], textarea {
  width: 100%; border-radius: 8px; border: 1px solid var(--border-light); background: var(--panel);
  color: var(--text); padding: 9px 12px; font-family: inherit; }
.muted { color: var(--text-dim); font-size: 0.85rem; }
.toast { position: fixed; bottom: 24px; right: 24px; background: var(--card); border: 1px solid var(--border-light);
  border-radius: var(--radius-sm); padding: 12px 18px; box-shadow: var(--shadow); z-index: 50; font-size: 0.9rem; }
.hero-title { font-size: 1.8rem; font-weight: 800; letter-spacing: -.5px;
  background: linear-gradient(90deg, var(--brand1), var(--brand2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-sub { color: var(--text-dim); margin-top: 4px; font-size: 0.9rem; }
.hidden { display: none !important; }

/* 顶栏用户区 */
.user-area { display: flex; align-items: center; gap: 10px; margin-left: 12px; }
.user-name { color: var(--text-dim); font-size: 0.88rem; white-space: nowrap; }

/* 登录/注册页 */
.auth-wrap { display: flex; align-items: center; justify-content: center; min-height: 100vh; padding: 24px; }
.auth-card { width: 100%; max-width: 380px; background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); }
.auth-brand { text-align: center; font-size: 1.4rem; margin-bottom: 4px; }
.auth-tabs { display: flex; gap: 8px; margin: 18px 0; }
.auth-tab { flex: 1; padding: 9px; background: transparent; border: 1px solid var(--border-light);
  color: var(--text-dim); border-radius: 10px; cursor: pointer; font-size: 0.9rem; transition: all .15s ease; }
.auth-tab.active { color: var(--text-strong); border-color: var(--accent); background: rgba(0,212,255,0.08); }
input[type=password] { width: 100%; border-radius: 8px; border: 1px solid var(--border-light);
  background: var(--panel); color: var(--text); padding: 9px 12px; font-family: inherit; }

/* 弹窗（修改密码等） */
.modal-mask { position: fixed; inset: 0; background: rgba(0,0,0,0.55); z-index: 60;
  display: flex; align-items: center; justify-content: center; padding: 24px; }
.modal { width: 100%; max-width: 380px; background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }

/* 会话项操作区（重命名/删除） */
.conv-item .ops { display: flex; gap: 2px; align-items: center; flex-shrink: 0; }
.conv-item .title-text { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.conv-item .op { color: var(--text-dim); cursor: pointer; padding: 0 3px; font-size: 0.8rem; }
.conv-item .op:hover { color: var(--accent); }
.conv-item .op.del:hover { color: var(--danger); }


/* ===== 引用溯源：可点击卡片（点击跳转知识库原文） ===== */
.cite-chip.link { cursor: pointer; color: var(--text); transition: color .15s, border-color .15s, background .15s; }
.cite-chip.link:hover { color: var(--accent); border-color: var(--accent); background: rgba(0, 212, 255, 0.08); }
.cites-hint { font-size: 0.75rem; color: var(--text-dim); opacity: 0.7; margin-left: 4px; }

/* 收藏页跳转定位：目标消息高亮闪烁 */
.msg-flash { animation: msgFlash 2.2s ease; }
@keyframes msgFlash { 0%, 55% { box-shadow: 0 0 0 2px var(--accent), 0 0 18px rgba(0, 212, 255, .45); } 100% { box-shadow: 0 0 0 0 rgba(0, 212, 255, 0); } }

/* ===== 背景主题切换按钮 + 色板弹层 ===== */
.theme-wrap { position: relative; display: flex; align-items: center; }
.theme-pop { position: absolute; top: calc(100% + 10px); right: 0; z-index: 80;
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 8px; display: none; min-width: 156px; }
.theme-pop.open { display: block; }
.theme-swatch { display: flex; align-items: center; gap: 10px; width: 100%;
  background: transparent; border: none; color: var(--text); cursor: pointer;
  padding: 8px 10px; border-radius: var(--radius-sm); font-size: .85rem; text-align: left; }
.theme-swatch:hover { background: var(--card-hover); }
.theme-swatch .sw { width: 18px; height: 18px; border-radius: 50%; flex: none;
  border: 2px solid var(--border-light); box-sizing: border-box; }
.theme-swatch.active { color: var(--accent); }
.theme-swatch.active .sw { border-color: var(--accent); }

/* ===== 自定义图片背景主题（面板改半透明，文字沿用暗夜配色保证可读） ===== */
:root[data-theme="custom"] {
  --bg: #0A0D14;
  --panel: rgba(13, 17, 27, 0.70);
  --card: rgba(17, 22, 34, 0.78);
  --card-hover: rgba(27, 34, 48, 0.85);
  --border: rgba(255, 255, 255, 0.10);
  --border-light: rgba(255, 255, 255, 0.17);
  --text: #E8EBF2; --text-dim: #9AA1B8;
  --text-strong: #FFFFFF;
  --accent: #00D4FF; --brand1: #9B7CFF; --brand2: #00D4FF;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.45);
}
/* body 透出 .custom-bg 图层（html 保留 --bg 作为图没加载出来时的兜底色） */
:root[data-theme="custom"] body { background: transparent; }
.custom-bg { position: fixed; inset: 0; z-index: -1; pointer-events: none; display: none;
  background-image: linear-gradient(rgba(0,0,0,var(--custom-bg-dim,.45)), rgba(0,0,0,var(--custom-bg-dim,.45))),
    var(--custom-bg-img, none);
  background-size: cover; background-position: center; background-repeat: no-repeat; }
:root[data-theme="custom"] .custom-bg { display: block; }
/* 大面板加毛玻璃；聊天气泡不加（流式渲染时逐帧模糊太费性能，靠半透明保证可读） */
:root[data-theme="custom"] .topbar,
:root[data-theme="custom"] .sidebar,
:root[data-theme="custom"] .rail,
:root[data-theme="custom"] .composer,
:root[data-theme="custom"] .theme-pop { backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); }
/* 图片背景上需要更"实"一点的表面 */
:root[data-theme="custom"] .msg-row.user .bubble { background: rgba(101, 74, 240, 0.48); border-color: rgba(124, 92, 255, 0.65); }
:root[data-theme="custom"] .bubble pre { background: rgba(8, 11, 18, 0.82); }
:root[data-theme="custom"] .modal, :root[data-theme="custom"] .para-modal,
:root[data-theme="custom"] .auth-card, :root[data-theme="custom"] .toast { background: rgba(16, 20, 30, 0.92); }
/* 自定义色板小圆（有图显示缩略图，没图显示品牌渐变）+ 弹层附加控件 */
.theme-swatch .sw-custom { background: linear-gradient(135deg, #7C5CFF, #00D4FF); background-size: cover; background-position: center; }
.theme-custom-ops { border-top: 1px solid var(--border); margin-top: 6px; padding: 10px 10px 4px;
  display: flex; flex-direction: column; gap: 10px; }
.theme-pick { width: 100%; background: transparent; border: 1px dashed var(--border-light); color: var(--text);
  border-radius: var(--radius-sm); padding: 7px 8px; cursor: pointer; font-size: .82rem; }
.theme-pick:hover { border-color: var(--accent); color: var(--accent); }
.theme-dim-row { display: flex; align-items: center; gap: 8px; font-size: .78rem; color: var(--text-dim); }
.theme-dim-row input[type=range] { flex: 1; min-width: 0; accent-color: var(--accent); }
.theme-dim-val { min-width: 34px; text-align: right; color: var(--text); }

/* ===== 自定义背景：裁剪调整弹窗 ===== */
.crop-mask { z-index: 90; }
.crop-modal { width: 94vw; max-width: 820px; }
.crop-modal h3 { margin: 0 0 4px; font-size: 1.05rem; }
.crop-hint { color: var(--text-dim); font-size: .84rem; margin-bottom: 14px; }
.crop-hint b { color: var(--accent); }
.crop-stage { position: relative; width: 100%; aspect-ratio: 16 / 9; max-height: 56vh;
  border-radius: var(--radius-sm); overflow: hidden; background: #0B0F18;
  border: 1px solid var(--border-light); touch-action: none; user-select: none;
  cursor: grab; }
.crop-stage.grabbing { cursor: grabbing; }
.crop-img { position: absolute; left: 50%; top: 50%; max-width: none; will-change: transform;
  -webkit-user-drag: none; }
.crop-frame { position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  border: 2px solid var(--accent); border-radius: 6px; pointer-events: none;
  box-shadow: 0 0 0 9999px rgba(5, 8, 14, 0.66); }
.crop-frame .gv { position: absolute; top: 0; bottom: 0; width: 1px; background: rgba(255, 255, 255, .22); }
.crop-frame .gh { position: absolute; left: 0; right: 0; height: 1px; background: rgba(255, 255, 255, .22); }
.crop-frame .c { position: absolute; width: 14px; height: 14px; border: 3px solid var(--accent); }
.crop-frame .c1 { left: -3px; top: -3px; border-right: none; border-bottom: none; border-radius: 4px 0 0 0; }
.crop-frame .c2 { right: -3px; top: -3px; border-left: none; border-bottom: none; border-radius: 0 4px 0 0; }
.crop-frame .c3 { left: -3px; bottom: -3px; border-right: none; border-top: none; border-radius: 0 0 0 4px; }
.crop-frame .c4 { right: -3px; bottom: -3px; border-left: none; border-top: none; border-radius: 0 0 4px 0; }
.crop-badge { position: absolute; left: 10px; top: 10px; pointer-events: none;
  background: rgba(0, 0, 0, .55); border: 1px solid rgba(0, 212, 255, .45); color: var(--accent);
  font-size: .74rem; padding: 3px 10px; border-radius: 999px; }
.crop-zoom-row { display: flex; align-items: center; gap: 12px; margin: 14px 2px 2px;
  font-size: .85rem; color: var(--text-dim); }
.crop-zoom-row input[type=range] { flex: 1; min-width: 0; accent-color: var(--accent); }
.crop-zoom-val { color: var(--text); min-width: 44px; text-align: right; }
.crop-btn-row { display: flex; justify-content: flex-end; gap: 10px; margin-top: 14px; }