/* Studio v2: uses tokens from ../theme.css */
:root{--sf2:var(--sf-2)}
body{padding-bottom:env(safe-area-inset-bottom)}
.top{position:sticky;top:0;z-index:30;display:flex;gap:16px;align-items:center;padding:calc(10px + env(safe-area-inset-top)) 24px 10px;border-bottom:1px solid var(--bd);background:color-mix(in srgb,var(--bg) 85%,transparent);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
.brand{display:inline-flex;align-items:center;gap:8px;font-weight:750;letter-spacing:-.02em;color:var(--tx);text-decoration:none;min-height:44px}
.logo-m{display:grid;place-items:center;width:28px;height:28px;border-radius:8px;background:linear-gradient(135deg,var(--ac),#7c5cd6);color:#fff;font-size:15px}
.top-nav{flex:1;display:flex;gap:4px;align-items:center}.top-nav a,.top-nav b{padding:8px 12px;border-radius:999px;font-size:14px;font-weight:500;color:var(--mu);text-decoration:none;min-height:36px;display:inline-flex;align-items:center}
.top-nav b{background:var(--sf);color:var(--tx);box-shadow:var(--sh1);font-weight:600}.top-nav a:hover{color:var(--tx)}
.setpick select{width:auto;max-width:260px}
.tabs{display:flex;gap:4px;padding:12px 24px 0;max-width:1000px;margin:0 auto}
.tabs button{display:inline-flex;align-items:center;gap:8px;border:0;background:transparent;color:var(--mu);border-radius:999px;padding:8px 14px;min-height:44px;cursor:pointer;font:500 15px/1 var(--font);transition:background var(--fast),color var(--fast)}
.tabs button svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.tabs button:hover{background:var(--sf-2);color:var(--tx)}
.tabs button[aria-selected=true]{background:var(--sf);color:var(--ac-tx);box-shadow:var(--sh1);font-weight:650}
.tl-short{display:none}
main{max-width:1000px;margin:0 auto;padding:8px 24px 80px}
.card{margin:14px 0}
.card h2{font-size:24px}
.opt{display:block;width:100%;text-align:left;background:var(--sf);color:var(--tx);border:1.5px solid var(--bd);border-radius:12px;padding:14px 16px;margin:8px 0;min-height:52px;cursor:pointer;font:16px/1.4 var(--font);transition:border-color var(--fast),background var(--fast)}
.opt:hover:not(:disabled){border-color:var(--ac);background:var(--ac-s)}
.opt.ok{border-color:var(--ok);background:var(--ok-s);outline:0}.opt.bad{border-color:var(--bad);background:var(--bad-s);outline:0}
select{width:auto}textarea{min-height:240px;font-family:var(--mono);font-size:15px;line-height:1.55}
.muted{color:var(--mu);font-size:15px}.bar{height:10px;background:var(--sf-2);border-radius:99px;overflow:hidden}.bar>i{display:block;height:100%;background:var(--ok);border-radius:99px;transition:width .6s var(--ease)}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px}@media (max-width:760px){.grid2{grid-template-columns:1fr}}
.chip{padding:2px 10px;font-size:14px;border-color:var(--ac);color:var(--ac-tx);background:transparent}
.msg{white-space:pre-wrap;border-radius:14px;padding:12px 14px;margin:8px 0;max-width:88%}.msg.u{background:var(--ac);color:var(--ac-fg);margin-left:auto;border-bottom-right-radius:4px}.msg.a{background:var(--sf-2);border-bottom-left-radius:4px}
.ok{color:var(--ok);font-weight:600}.bad{color:var(--bad);font-weight:600}.pv h1,.pv h2,.pv h3{margin:.6em 0 .3em}.pv h1{font-size:28px}.pv code{background:var(--sf-2);padding:0 4px;border-radius:4px}
.ai-flag{font-size:12px;color:var(--mu);border:1px dashed var(--bd-s);border-radius:6px;padding:2px 6px;display:inline-block}
.ink canvas{width:100%;max-width:1000px;aspect-ratio:14/9;border:1px solid var(--bd-s);border-radius:14px;background:#fff;touch-action:none;display:block}
.row{display:flex;flex-wrap:wrap;gap:6px;margin:8px 0}
.drop{border:2px dashed color-mix(in srgb,var(--ac) 45%,var(--bd));background:color-mix(in srgb,var(--ac-s) 40%,var(--sf))}
.chip.cite{font-size:.72em;padding:0 6px;margin:0 2px;vertical-align:super;min-height:0!important;min-width:0!important}
.cite-pop{margin-top:6px;border-left:3px solid var(--ac);padding-left:10px}
progress{width:100%;accent-color:var(--ac)}
.src{padding:14px 16px}
details summary{cursor:pointer;min-height:44px;display:flex;align-items:center;font-weight:600}
/* Learn header */
.lhead{display:flex;gap:20px;align-items:center}.lhead .lt{flex:1;min-width:0}.lhead h2{margin:0 0 4px}
.lvl{display:flex;gap:16px;flex-wrap:wrap;margin:14px 0 6px;font-size:14px;color:var(--mu)}.lvl b{color:var(--tx);font-size:18px;margin-right:4px}
.qkind{display:inline-block;font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--ac-tx);background:var(--ac-s);border-radius:999px;padding:4px 10px;margin-bottom:10px}
#lq h3{font-size:22px;margin:4px 0 14px}
.empty{text-align:center;padding:36px 20px}.empty .e{font-size:44px;margin-bottom:8px}.empty ol{display:inline-block;text-align:left;color:var(--mu);margin:8px 0 16px}
/* mobile: bottom tab bar */
@media (max-width:760px){
  .top{padding:calc(8px + env(safe-area-inset-top)) 14px 8px;gap:10px}.brand-t{display:none}.top-nav a,.top-nav b{padding:6px 10px;font-size:13px}.setpick select{max-width:44vw}
  #streak{display:none}
  .tabs{position:fixed;left:0;right:0;bottom:0;z-index:40;margin:0;max-width:none;padding:4px 4px calc(4px + env(safe-area-inset-bottom));gap:0;background:color-mix(in srgb,var(--sf) 92%,transparent);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-top:1px solid var(--bd);overflow:visible!important;flex-wrap:nowrap}
  .tabs button{flex:1 1 0!important;min-width:0;flex-direction:column;gap:3px;padding:6px 0 4px;min-height:54px;font-size:11px;border-radius:12px;box-shadow:none!important}
  .tabs button[aria-selected=true]{background:transparent;color:var(--ac-tx)}
  .tabs button svg{width:22px;height:22px}
  .tl-full{display:none}.tl-short{display:block}
  main{padding:4px 14px calc(96px + env(safe-area-inset-bottom))}
  .card{padding:16px}.lhead{gap:14px}
  .msg{max-width:94%}
}
@media (max-width:760px){html{scroll-padding-bottom:calc(100px + env(safe-area-inset-bottom));scroll-padding-top:70px}}
.brand{min-width:44px}
@media (max-width:760px){.top-nav{min-width:0;overflow:hidden}.setpick{min-width:0}.setpick select{max-width:40vw;text-overflow:ellipsis}}
@media (max-width:380px){.top-nav a{display:none}}