:root {
  --navy: #14213d; --copper: #b87333; --gold: #c9a227; --paper: #faf8f3; --stone: #8a8378; --slate: #5b6b7f;
  --bg: var(--paper); --panel: #ffffff; --ink: #1b2233; --ink-soft: #4a5263; --line: #e7e2d8; --accent: var(--copper);
  --side: var(--navy); --side-ink: #e9e6df; --side-soft: #9aa5b8; --bubble: #f1ede4; --focus: #c9a22755;
  --radius: 14px; --shadow: 0 1px 2px rgba(20,33,61,.06), 0 8px 24px rgba(20,33,61,.06);
  --serif: "Fraunces", Georgia, "Times New Roman", serif; --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1626; --panel: #151e31; --ink: #ece8df; --ink-soft: #b4b9c4; --line: #26314a; --bubble: #1c2740; --side: #0b1120; --side-ink: #e9e6df; }
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: var(--accent); }
button { font: inherit; cursor: pointer; }
input, textarea, select { font: inherit; color: inherit; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }

/* layout */
.app { display: grid; grid-template-columns: 280px 1fr; height: 100vh; height: 100dvh; }
.side { background: var(--side); color: var(--side-ink); display: flex; flex-direction: column; padding: 16px 12px; gap: 12px; min-height: 0; }
.brand { display: flex; align-items: center; gap: 10px; padding: 4px 6px 8px; }
.mark { width: 34px; height: 34px; border-radius: 10px; background: linear-gradient(140deg, var(--copper), var(--gold)); color: #fff; display: grid; place-items: center; font: 600 18px var(--serif); flex: none; }
.mark img { width: 100%; height: 100%; object-fit: contain; border-radius: 10px; background: #fff; }
.brand-name { font: 600 17px/1.2 var(--serif); }
.brand-tag { font-size: 12px; color: var(--side-soft); }
.new-chat { background: transparent; border: 1px solid #ffffff2a; color: var(--side-ink); border-radius: 10px; padding: 10px 12px; text-align: left; display: flex; gap: 8px; align-items: center; }
.new-chat:hover { background: #ffffff10; }
.convs { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 2px; min-height: 0; }
.convs .label { font-size: 11px; letter-spacing: .08em; text-transform: uppercase; color: var(--side-soft); padding: 8px 8px 4px; }
.conv { background: none; border: 0; color: var(--side-ink); text-align: left; padding: 8px 10px; border-radius: 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 14px; opacity: .85; }
.conv:hover, .conv.active { background: #ffffff14; opacity: 1; }
.side-foot { border-top: 1px solid #ffffff1a; padding-top: 10px; display: flex; flex-direction: column; gap: 2px; }
.side-link { background: none; border: 0; color: var(--side-soft); text-align: left; padding: 7px 10px; border-radius: 8px; font-size: 14px; text-decoration: none; display: block; }
.side-link:hover { color: var(--side-ink); background: #ffffff10; }
.powered { font-size: 11px; color: var(--side-soft); padding: 6px 10px 0; opacity: .7; }

.main { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.topbar { display: none; align-items: center; gap: 10px; padding: 10px 16px; border-bottom: 1px solid var(--line); background: var(--panel); }
.thread { flex: 1; overflow-y: auto; padding: 24px 16px 8px; scroll-behavior: smooth; }
.inner { max-width: 820px; margin: 0 auto; }

/* welcome */
.welcome { text-align: center; padding: 8vh 8px 24px; }
.welcome h1 { font: 500 clamp(28px, 4vw, 40px)/1.15 var(--serif); margin: 0 0 10px; color: var(--ink); }
.welcome p { color: var(--ink-soft); margin: 0 auto 26px; max-width: 560px; }
.starters { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; text-align: left; }
.starter { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; color: var(--ink); text-align: left; box-shadow: var(--shadow); }
.starter:hover { border-color: var(--accent); }
.starter b { display: block; font-weight: 600; margin-bottom: 2px; }
.starter span { color: var(--ink-soft); font-size: 14px; }

/* messages */
.msg { margin: 0 0 22px; }
.msg.user { display: flex; justify-content: flex-end; }
.msg.user .bubble { background: var(--bubble); border-radius: 18px 18px 4px 18px; padding: 10px 16px; max-width: 85%; white-space: pre-wrap; }
.msg.assistant .who { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--ink-soft); margin-bottom: 6px; }
.msg.assistant .who .mark { width: 24px; height: 24px; font-size: 13px; border-radius: 7px; }
.answer { font-size: 16.5px; }
.answer h1, .answer h2, .answer h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; margin: 1.2em 0 .4em; }
.answer h1 { font-size: 1.45em; } .answer h2 { font-size: 1.25em; } .answer h3 { font-size: 1.08em; }
.answer p { margin: .6em 0; }
.answer ul, .answer ol { padding-left: 1.4em; }
.answer li { margin: .25em 0; }
.answer blockquote { margin: .8em 0; padding: .6em 1em; border-left: 3px solid var(--copper); background: var(--bubble); border-radius: 0 10px 10px 0; }
.answer code { background: var(--bubble); padding: .1em .35em; border-radius: 5px; font-size: .92em; }
.answer pre { background: #0f1626; color: #e9e6df; padding: 14px; border-radius: 10px; overflow-x: auto; }
.answer pre code { background: none; padding: 0; }
.answer table { border-collapse: collapse; width: 100%; margin: .8em 0; font-size: .95em; display: block; overflow-x: auto; }
.answer th, .answer td { border: 1px solid var(--line); padding: 7px 10px; text-align: left; vertical-align: top; }
.answer th { background: var(--bubble); }
.answer strong { font-weight: 650; }
.cursor::after { content: "▍"; color: var(--copper); animation: blink 1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

/* council at work */
.work { border: 1px solid var(--line); background: var(--panel); border-radius: var(--radius); padding: 12px 14px; margin-bottom: 12px; font-size: 14px; box-shadow: var(--shadow); }
.work .stage { display: flex; gap: 8px; align-items: center; color: var(--ink-soft); padding: 2px 0; }
.work .stage.on { color: var(--ink); }
.work .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--line); flex: none; }
.work .stage.on .dot { background: var(--gold); animation: pulse 1.2s ease-in-out infinite; }
.work .stage.done .dot { background: var(--copper); animation: none; }
@keyframes pulse { 50% { transform: scale(1.5); opacity: .6; } }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0 2px; }
.chip { font-size: 12.5px; border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px; background: var(--bg); color: var(--ink-soft); }
.chip.live { border-color: var(--gold); color: var(--ink); }
.chip.ok { border-color: var(--copper); color: var(--ink); }
.notice { font-size: 13.5px; color: var(--ink-soft); background: var(--bubble); border-radius: 10px; padding: 8px 12px; margin-bottom: 10px; }

/* after answer */
.extras { margin-top: 12px; display: flex; flex-direction: column; gap: 8px; }
.sources { display: flex; flex-wrap: wrap; gap: 6px; }
.source { font-size: 12.5px; text-decoration: none; border: 1px solid var(--line); border-radius: 8px; padding: 4px 9px; color: var(--ink-soft); max-width: 260px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; background: var(--panel); }
.source:hover { border-color: var(--accent); color: var(--ink); }
details.how { border: 1px solid var(--line); border-radius: 12px; background: var(--panel); }
details.how summary { cursor: pointer; padding: 9px 14px; font-size: 14px; color: var(--ink-soft); }
details.how .body { padding: 4px 14px 12px; font-size: 14px; }
.contrib { border-top: 1px solid var(--line); padding: 10px 0; }
.contrib h4 { margin: 0 0 4px; font: 600 14px var(--sans); }
.contrib .m { font-weight: 400; color: var(--ink-soft); }
.actions { display: flex; gap: 6px; }
.icon-btn { border: 1px solid var(--line); background: var(--panel); color: var(--ink-soft); border-radius: 8px; padding: 4px 10px; font-size: 13px; }
.icon-btn:hover { color: var(--ink); border-color: var(--accent); }
.icon-btn.on { color: var(--copper); border-color: var(--copper); }

/* mind map */
.mindmap { border: 1px solid var(--line); border-radius: 12px; background: var(--panel); padding: 8px; margin: 12px 0; overflow-x: auto; }
.mindmap svg { display: block; }
.mindmap text { font: 13px var(--sans); fill: var(--ink); }
.mindmap .root { font: 600 14px var(--serif); }

/* composer */
.composer { padding: 10px 16px 16px; }
.box { max-width: 820px; margin: 0 auto; background: var(--panel); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); padding: 10px 12px 8px; }
.box:focus-within { border-color: var(--copper); }
.box textarea { width: 100%; border: 0; outline: 0; resize: none; background: transparent; min-height: 26px; max-height: 240px; line-height: 1.5; padding: 4px 4px; }
.box .row { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 4px; }
.modes { display: flex; gap: 4px; background: var(--bg); padding: 3px; border-radius: 10px; }
.mode { border: 0; background: transparent; color: var(--ink-soft); padding: 5px 10px; border-radius: 8px; font-size: 13px; }
.mode.on { background: var(--panel); color: var(--ink); box-shadow: 0 1px 2px rgba(0,0,0,.08); }
.send { background: var(--navy); color: #fff; border: 0; border-radius: 10px; padding: 8px 16px; font-weight: 600; }
.send:disabled { opacity: .4; cursor: default; }
@media (prefers-color-scheme: dark) { .send { background: var(--copper); } }
.hint { max-width: 820px; margin: 6px auto 0; text-align: center; font-size: 12px; color: var(--stone); }

/* overlays */
.overlay { position: fixed; inset: 0; background: rgba(15,22,38,.45); display: none; align-items: flex-start; justify-content: center; padding: 5vh 16px; z-index: 50; overflow-y: auto; }
.overlay.open { display: flex; }
.sheet { background: var(--panel); border-radius: 18px; max-width: 980px; width: 100%; padding: 20px 22px 26px; box-shadow: 0 20px 60px rgba(0,0,0,.25); }
.sheet h2 { font: 600 24px var(--serif); margin: 0 0 4px; }
.sheet .sub { color: var(--ink-soft); margin: 0 0 16px; }
.sheet-head { display: flex; justify-content: space-between; align-items: start; gap: 12px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 10px; }
.card { border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; background: var(--bg); text-align: left; color: var(--ink); }
button.card:hover { border-color: var(--copper); }
.card b { display: block; } .card small { color: var(--ink-soft); }
.tag { display: inline-block; font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--copper); margin-bottom: 4px; }
.beam { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 10px; margin: 12px 0; }
.beam div { background: var(--bg); border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; }
.beam h4 { margin: 0 0 4px; font: 600 14px var(--serif); color: var(--copper); }
.beam ul { margin: 0; padding-left: 1.1em; font-size: 14px; }
.tabs { display: flex; gap: 6px; margin-bottom: 14px; }
.tab { border: 1px solid var(--line); background: var(--bg); padding: 6px 14px; border-radius: 999px; color: var(--ink-soft); }
.tab.on { background: var(--navy); color: #fff; border-color: var(--navy); }

/* auth pages */
.auth { min-height: 100vh; display: grid; place-items: center; padding: 24px 16px; background: radial-gradient(1200px 600px at 20% -10%, #c9a22722, transparent), var(--bg); }
.auth-card { width: 100%; max-width: 420px; background: var(--panel); border: 1px solid var(--line); border-radius: 20px; padding: 28px 26px; box-shadow: var(--shadow); }
.auth-card h1 { font: 500 28px/1.2 var(--serif); margin: 14px 0 6px; }
.auth-card p { color: var(--ink-soft); margin: 0 0 18px; }
.field { display: flex; flex-direction: column; gap: 5px; margin-bottom: 12px; font-size: 14px; }
.field input, .field textarea, .field select { border: 1px solid var(--line); background: var(--bg); border-radius: 10px; padding: 10px 12px; }
.field input:focus, .field textarea:focus { border-color: var(--copper); outline: none; }
.primary { width: 100%; background: var(--navy); color: #fff; border: 0; border-radius: 10px; padding: 11px; font-weight: 600; }
.err { color: #a33b2b; font-size: 14px; min-height: 20px; }

/* mobile */
@media (max-width: 860px) {
  .app { grid-template-columns: 1fr; }
  .side { position: fixed; inset: 0 auto 0 0; width: 280px; transform: translateX(-100%); transition: transform .2s ease; z-index: 40; }
  .app.nav-open .side { transform: none; }
  .topbar { display: flex; }
  .thread { padding: 16px 16px 8px; }
  .modes .mode { padding: 5px 8px; }
  .starters { grid-template-columns: 1fr; }
}