:root {
  color-scheme: light;
  --bg: #f6f5f2;
  --surface: #fcfcfb;
  --surface-2: #f0efec;
  --border: #e2e0da;
  --text: #0b0b0b;
  --text-2: #52514e;
  --text-3: #7a7974;
  --accent: #2a78d6;
  --accent-ink: #ffffff;
  --accent-soft: #e6f0fc;
  --danger: #c13434;
  --danger-soft: #fbeaea;
  --good: #0f7a0f;
  --warn-soft: #fdf3dc;
  --series-1: #2a78d6;
  --series-2: #eb6834;
  --series-3: #1baf7a;
  --user-bubble: #e9eef6;
  --code-bg: #f0efec;
  --shadow: 0 1px 2px rgba(0,0,0,.06), 0 4px 16px rgba(0,0,0,.05);
  --radius: 10px;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #131312; --surface: #1a1a19; --surface-2: #232321; --border: #33332f;
    --text: #f0efec; --text-2: #c3c2b7; --text-3: #8f8e86;
    --accent: #3987e5; --accent-soft: #1b2b40; --danger: #e66767; --danger-soft: #3a1f1f;
    --good: #3fbf3f; --warn-soft: #3a3020;
    --series-1: #3987e5; --series-2: #d95926; --series-3: #199e70;
    --user-bubble: #22303f; --code-bg: #232321;
    --shadow: 0 1px 2px rgba(0,0,0,.4);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #131312; --surface: #1a1a19; --surface-2: #232321; --border: #33332f;
  --text: #f0efec; --text-2: #c3c2b7; --text-3: #8f8e86;
  --accent: #3987e5; --accent-soft: #1b2b40; --danger: #e66767; --danger-soft: #3a1f1f;
  --good: #3fbf3f; --warn-soft: #3a3020;
  --series-1: #3987e5; --series-2: #d95926; --series-3: #199e70;
  --user-bubble: #22303f; --code-bg: #232321;
  --shadow: 0 1px 2px rgba(0,0,0,.4);
}

* { box-sizing: border-box; }
html, body, #app { height: 100%; margin: 0; }
body { overflow: hidden; }
.login-wrap { overflow-y: auto; height: 100%; }
body { background: var(--bg); color: var(--text); font: 15px/1.6 var(--sans); -webkit-font-smoothing: antialiased; }
button, input, select, textarea { font: inherit; color: inherit; }
a { color: var(--accent); }
.hidden { display: none !important; }
.muted { color: var(--text-3); }
.small { font-size: 13px; }
.mono { font-family: var(--mono); font-size: 13px; }
.num { font-variant-numeric: tabular-nums; }

/* ---------- controls */
.btn { display: inline-flex; align-items: center; gap: 6px; border: 1px solid var(--border); background: var(--surface);
  border-radius: 8px; padding: 6px 12px; cursor: pointer; white-space: nowrap; }
.btn:hover { background: var(--surface-2); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.07); }
.btn.danger { color: var(--danger); }
.btn.ghost { border-color: transparent; background: transparent; }
.btn.ghost:hover { background: var(--surface-2); }
.btn.sm { padding: 3px 9px; font-size: 13px; }
.btn:disabled { opacity: .5; cursor: default; }
input[type=text], input[type=password], input[type=number], select, textarea {
  border: 1px solid var(--border); background: var(--surface); border-radius: 8px; padding: 7px 10px; outline: none; min-width: 0; }
input:focus, select:focus, textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
label.field { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--text-2); }
label.check { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; cursor: pointer; }
.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.grid2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.badge { display: inline-block; font-size: 12px; padding: 1px 8px; border-radius: 99px; background: var(--surface-2); color: var(--text-2); }
.badge.ok { background: color-mix(in srgb, var(--good) 15%, transparent); color: var(--good); }
.badge.bad { background: var(--danger-soft); color: var(--danger); }
.badge.warn { background: var(--warn-soft); color: var(--text-2); }

/* ---------- login */
.login-wrap { min-height: 100%; display: grid; place-items: center; padding: 16px; }
.login { width: 100%; max-width: 360px; display: flex; flex-direction: column; gap: 14px; padding: 28px; box-shadow: var(--shadow); }
.login h1 { margin: 0 0 4px; font-size: 22px; }
.err { color: var(--danger); font-size: 14px; min-height: 1.2em; }

/* ---------- shell */
.shell { display: grid; grid-template-columns: 270px 1fr; height: 100%; }
.side { background: var(--surface); border-right: 1px solid var(--border); display: flex; flex-direction: column; min-height: 0; }
.side-head { padding: 14px 14px 8px; display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.brand { font-weight: 650; font-size: 16px; letter-spacing: .2px; }
.side .new { margin: 4px 14px 10px; justify-content: center; }
.conv-list { flex: 1; overflow-y: auto; padding: 0 8px; }
.conv { display: flex; align-items: center; gap: 6px; padding: 7px 10px; border-radius: 8px; cursor: pointer; color: var(--text-2); }
.conv:hover { background: var(--surface-2); }
.conv.active { background: var(--accent-soft); color: var(--text); }
.conv .t { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; font-size: 14px; }
.conv .c { font-size: 12px; color: var(--text-3); font-variant-numeric: tabular-nums; }
.side-nav { border-top: 1px solid var(--border); padding: 8px; display: flex; flex-direction: column; gap: 2px; }
.side-nav a { text-decoration: none; color: var(--text-2); padding: 7px 10px; border-radius: 8px; display: flex; justify-content: space-between; }
.side-nav a:hover { background: var(--surface-2); }
.side-nav a.active { background: var(--surface-2); color: var(--text); font-weight: 550; }
.side-user { padding: 10px 14px; border-top: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--text-2); }
.main { min-width: 0; min-height: 0; display: flex; flex-direction: column; }
.menu-btn { display: none; }
.scrim { display: none; }

/* ---------- chat */
.topbar { display: flex; align-items: center; gap: 10px; padding: 10px 16px; border-bottom: 1px solid var(--border); background: var(--surface); flex-wrap: wrap; }
.topbar .title { font-weight: 600; flex: 1; min-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.topbar select { max-width: 280px; }
.spend-chip { font-size: 13px; color: var(--text-2); background: var(--surface-2); padding: 3px 10px; border-radius: 99px; white-space: nowrap; }
.chat-scroll { flex: 1; overflow-y: auto; }
.thread { max-width: 860px; margin: 0 auto; padding: 20px 16px 8px; display: flex; flex-direction: column; gap: 18px; }
.empty-hint { max-width: 560px; margin: 12vh auto 0; text-align: center; color: var(--text-2); padding: 0 16px; }
.empty-hint h2 { color: var(--text); font-size: 22px; margin-bottom: 6px; }
.msg.user { align-self: flex-end; max-width: 85%; background: var(--user-bubble); padding: 9px 14px; border-radius: 14px 14px 4px 14px; white-space: pre-wrap; word-wrap: break-word; }
.msg.user.excluded { opacity: .55; }
.msg.assistant { min-width: 0; }
.msg .who { font-size: 13px; color: var(--text-3); margin-bottom: 2px; }
.msg .meta { font-size: 12px; color: var(--text-3); margin-top: 6px; display: flex; gap: 4px 12px; flex-wrap: wrap; font-variant-numeric: tabular-nums; }
.msg .meta .cost { color: var(--text-2); font-weight: 550; }
.msg .notice { font-size: 13px; background: var(--warn-soft); border-radius: 8px; padding: 6px 10px; margin: 6px 0; }
.msg .error { color: var(--danger); background: var(--danger-soft); border-radius: 8px; padding: 8px 12px; }
details.thinking { border-left: 3px solid var(--border); padding: 2px 0 2px 12px; margin: 4px 0 8px; color: var(--text-2); font-size: 14px; }
details.thinking summary { cursor: pointer; color: var(--text-3); font-size: 13px; }
details.thinking .body { white-space: pre-wrap; margin-top: 6px; }
.cursor::after { content: "▍"; animation: blink 1s steps(2) infinite; color: var(--text-3); }
@keyframes blink { 50% { opacity: 0; } }

.md { overflow-wrap: anywhere; }
.md > :first-child { margin-top: 0; }
.md > :last-child { margin-bottom: 0; }
.md p { margin: .6em 0; }
.md pre { background: var(--code-bg); padding: 12px 14px; border-radius: 8px; overflow-x: auto; font-size: 13px; line-height: 1.5; position: relative; }
.md code { font-family: var(--mono); font-size: .9em; }
.md :not(pre) > code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; }
.md table { border-collapse: collapse; display: block; overflow-x: auto; }
.md th, .md td { border: 1px solid var(--border); padding: 5px 10px; }
.md blockquote { margin: .6em 0; padding-left: 12px; border-left: 3px solid var(--border); color: var(--text-2); }
.md .katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
.copy-btn { position: absolute; top: 6px; right: 6px; font-size: 12px; padding: 1px 7px; opacity: .7; }

.composer { border-top: 1px solid var(--border); background: var(--surface); padding: 10px 16px 14px; }
.composer-inner { max-width: 860px; margin: 0 auto; display: flex; gap: 10px; align-items: flex-end; }
.composer textarea { flex: 1; resize: none; max-height: 40vh; min-height: 46px; padding: 11px 12px; line-height: 1.5; }
.composer .hint { max-width: 860px; margin: 4px auto 0; font-size: 12px; color: var(--text-3); }

/* ---------- pages */
.page { flex: 1; overflow-y: auto; }
.page-inner { max-width: 1100px; margin: 0 auto; padding: 20px 16px 40px; display: flex; flex-direction: column; gap: 16px; }
.page h2 { margin: 0; font-size: 20px; }
.page h3 { margin: 0 0 10px; font-size: 16px; }
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; }
.tile .label { font-size: 13px; color: var(--text-2); }
.tile .value { font-size: 26px; font-weight: 650; font-variant-numeric: tabular-nums; line-height: 1.3; }
.tile .sub { font-size: 12px; color: var(--text-3); }
.budget { display: flex; flex-direction: column; gap: 6px; }
.bar { height: 8px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 99px; }
.bar.over > i { background: var(--danger); }
.table-wrap { overflow-x: auto; }
table.data { border-collapse: collapse; width: 100%; font-size: 14px; }
table.data th { text-align: left; font-weight: 550; color: var(--text-2); font-size: 13px; border-bottom: 1px solid var(--border); padding: 7px 10px; white-space: nowrap; }
table.data td { border-bottom: 1px solid var(--border); padding: 7px 10px; vertical-align: middle; }
table.data td.r, table.data th.r { text-align: right; font-variant-numeric: tabular-nums; }
table.data tr:last-child td { border-bottom: none; }
table.data td .mono, table.data td:last-child { white-space: nowrap; }
table.data td { padding: 7px 8px; }
table.data input[type=text], table.data input[type=number], table.data select { padding: 4px 7px; font-size: 13px; }
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); overflow-x: auto; }
.tabs a { padding: 8px 14px; text-decoration: none; color: var(--text-2); border-bottom: 2px solid transparent; margin-bottom: -1px; white-space: nowrap; }
.tabs a.active { color: var(--text); border-bottom-color: var(--accent); font-weight: 550; }

/* chart */
.chart { position: relative; }
.chart svg { display: block; width: 100%; height: 220px; overflow: visible; }
.chart .grid line { stroke: var(--border); stroke-width: 1; }
.chart .axis text { fill: var(--text-3); font-size: 11px; }
.chart .hit { fill: transparent; cursor: default; }
.chart .hit:hover { fill: color-mix(in srgb, var(--text) 5%, transparent); }
.legend { display: flex; gap: 14px; font-size: 13px; color: var(--text-2); flex-wrap: wrap; margin-bottom: 8px; }
.legend i { display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }
.tooltip { position: absolute; pointer-events: none; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow);
  border-radius: 8px; padding: 8px 10px; font-size: 13px; min-width: 150px; z-index: 5; }
.tooltip .tt-row { display: flex; justify-content: space-between; gap: 12px; font-variant-numeric: tabular-nums; }
.tooltip i { display: inline-block; width: 8px; height: 8px; border-radius: 2px; margin-right: 6px; }

/* modal */
.modal-bg { position: fixed; inset: 0; background: rgba(0,0,0,.35); display: grid; place-items: center; z-index: 50; padding: 16px; }
.modal { background: var(--surface); border-radius: 12px; box-shadow: var(--shadow); width: 100%; max-width: 640px; max-height: 85vh; display: flex; flex-direction: column; }
.modal header { padding: 14px 16px; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; font-weight: 600; }
.modal .body { padding: 16px; overflow-y: auto; display: flex; flex-direction: column; gap: 12px; }
.modal footer { padding: 12px 16px; border-top: 1px solid var(--border); display: flex; justify-content: flex-end; gap: 8px; }

.toast { position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%); background: var(--text); color: var(--bg); padding: 8px 16px; border-radius: 8px; font-size: 14px; z-index: 60; max-width: calc(100% - 32px); }

/* ---------- mobile */
@media (max-width: 820px) {
  .shell { grid-template-columns: 1fr; }
  .side { position: fixed; inset: 0 auto 0 0; width: 280px; max-width: 85vw; z-index: 40; transform: translateX(-100%); transition: transform .2s; }
  .shell.side-open .side { transform: none; }
  .shell.side-open .scrim { display: block; position: fixed; inset: 0; background: rgba(0,0,0,.3); z-index: 30; }
  .menu-btn { display: inline-flex; }
  .topbar { padding: 8px 12px; gap: 8px; }
  .topbar .title { flex: 1 1 0; }
  .topbar select { order: 5; flex: 1 1 40%; max-width: none; }
  .topbar .spend-chip { display: none; }
  .thread { padding: 14px 12px 6px; }
  .msg.user { max-width: 92%; }
  .composer { padding: 8px 12px 12px; }
  .page-inner { padding: 14px 12px 32px; }
}