:root{
  --bg:#ffffff;--panel:#ffffff;--panel2:#f4f5f7;--ink:#111827;--mute:#6b7280;--line:#e5e7eb;
  --acc:#2563eb;--acc2:#3b82f6;--acc-ink:#fff;--ok:#16a34a;--bad:#dc2626;--warn:#d97706;
  --shadow:0 1px 2px rgba(17,24,39,.05),0 4px 14px rgba(17,24,39,.05);--r:12px;
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.55 "Plus Jakarta Sans",system-ui,-apple-system,Segoe UI,Roboto,sans-serif;-webkit-font-smoothing:antialiased}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
.hidden{display:none!important}
.only-mobile{display:none}
.spacer{flex:1}

.top{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:10px;padding:10px 18px;background:#fff;border-bottom:1px solid var(--line)}
.logo{display:flex;align-items:center;gap:9px;font-size:18px}
.logo-mark{display:grid;place-items:center;width:32px;height:32px;border-radius:9px;background:var(--acc);color:#fff;font-weight:800;font-size:13px}
.chip{border:1px solid var(--line);background:var(--panel2);border-radius:99px;padding:5px 12px;font-size:13px;max-width:280px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.chip:hover{border-color:var(--acc)}
.icon{border:0;background:transparent;border-radius:8px;padding:5px 8px;font-size:16px;color:var(--mute)}
.icon:hover{background:var(--panel2);color:var(--ink)}

.btn{border:1px solid transparent;background:var(--acc);color:var(--acc-ink);border-radius:10px;padding:9px 16px;font-weight:600;transition:transform .08s,filter .15s}
.btn:hover{filter:brightness(1.07)}
.btn:active{transform:translateY(1px)}
.btn:disabled{opacity:.55;cursor:not-allowed}
.btn.small{padding:6px 12px;font-size:13px}
.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn.ghost:hover{border-color:var(--acc);background:var(--panel2)}
.btn.danger{background:var(--bad);color:#fff}
.btn.ok{background:var(--ok);color:#fff}

.layout{display:grid;grid-template-columns:270px 1fr;min-height:calc(100vh - 53px)}
#side{border-right:1px solid var(--line);background:var(--panel);padding:14px 10px;display:flex;flex-direction:column;gap:6px;position:sticky;top:53px;height:calc(100vh - 53px);overflow:auto}
.side-h{display:flex;align-items:center;justify-content:space-between;padding:0 8px;color:var(--mute);font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.06em}
#subjects{flex:1;display:flex;flex-direction:column;gap:2px}
.subj{display:flex;align-items:center;border-radius:10px}
.subj:hover{background:var(--panel2)}
.subj-t{flex:1;display:flex;align-items:center;gap:8px;border:0;background:transparent;text-align:left;padding:8px;font-weight:600;min-width:0}
.subj-t small{margin-left:auto;color:var(--mute);font-weight:500}
.subj .icon{opacity:0;font-size:13px;padding:3px 6px}
.subj:hover .icon{opacity:1}
.dot{width:10px;height:10px;border-radius:50%;flex:none}
.ses{display:block;width:calc(100% - 14px);margin:1px 0 1px 14px;text-align:left;border:0;background:transparent;padding:6px 10px;border-radius:8px;color:var(--mute);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ses:hover{background:var(--panel2);color:var(--ink)}
.ses.on{background:color-mix(in srgb,var(--acc) 16%,transparent);color:var(--ink);font-weight:600}
.ses.add{color:var(--acc);font-size:13px}
.side-f{padding:8px;border-top:1px solid var(--line)}
.side-f p{font-size:12px;color:var(--mute);margin:8px 0 0}
#scrim{display:none}

main{padding:22px clamp(14px,3vw,36px) 60px;min-width:0}
.sheet-h{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-bottom:6px}
.title-in{flex:1;min-width:200px;border:0;background:transparent;font-size:26px;font-weight:800;letter-spacing:-.02em;padding:4px 0;outline:none;border-bottom:2px solid transparent}
.title-in:focus{border-bottom-color:var(--acc)}
.crumb{color:var(--mute);font-size:13px;margin-bottom:2px}
.tabs{display:flex;gap:4px;overflow-x:auto;margin:14px 0 18px;padding-bottom:2px;border-bottom:1px solid var(--line)}
.tab{border:0;background:transparent;padding:10px 14px;border-radius:10px 10px 0 0;color:var(--mute);font-weight:600;white-space:nowrap;border-bottom:3px solid transparent;margin-bottom:-1px}
.tab:hover{color:var(--ink)}
.tab.on{color:var(--acc);border-bottom-color:var(--acc)}

.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);padding:18px;box-shadow:var(--shadow)}
.card h3{margin:0 0 4px;font-size:16px}
.card .sub{margin:0 0 12px;color:var(--mute);font-size:13px}
.grid2{display:grid;grid-template-columns:minmax(280px,380px) 1fr;gap:18px;align-items:start}
.stack{display:flex;flex-direction:column;gap:16px}
.row{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.row.sp{justify-content:space-between}
label.f{display:flex;flex-direction:column;gap:4px;font-size:13px;color:var(--mute);font-weight:600}
input[type=text],input[type=password],input[type=search],select,textarea{width:100%;border:1px solid var(--line);background:var(--panel);border-radius:10px;padding:9px 12px;outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--acc);box-shadow:0 0 0 3px color-mix(in srgb,var(--acc) 20%,transparent)}
textarea{resize:vertical;line-height:1.6}
.chk{display:flex;align-items:center;gap:8px;font-size:14px;color:var(--ink);font-weight:500}
.chk input{accent-color:var(--acc);width:16px;height:16px}

.rec-box{display:flex;flex-direction:column;align-items:center;gap:12px;padding:8px 0 2px}
.rec-btn{width:92px;height:92px;border-radius:50%;border:0;background:var(--acc);color:#fff;font-size:34px;display:grid;place-items:center;box-shadow:0 8px 24px color-mix(in srgb,var(--acc) 45%,transparent);transition:transform .15s}
.rec-btn:hover{transform:scale(1.05)}
.rec-btn.live{background:var(--bad);animation:pulse 1.4s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(220,38,38,.5)}70%{box-shadow:0 0 0 20px rgba(220,38,38,0)}100%{box-shadow:0 0 0 0 rgba(220,38,38,0)}}
.timer{font-variant-numeric:tabular-nums;font-size:28px;font-weight:700;letter-spacing:.02em}
.meter{width:100%;height:8px;border-radius:99px;background:var(--panel2);overflow:hidden}
.meter i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--ok),var(--warn));transition:width .08s}
.drop{border:2px dashed var(--line);border-radius:var(--r);padding:20px;text-align:center;color:var(--mute);transition:.15s}
.drop.over,.drop:hover{border-color:var(--acc);background:color-mix(in srgb,var(--acc) 7%,transparent);color:var(--ink)}
.drop b{display:block;color:var(--ink)}
.live-txt{max-height:90px;overflow:auto;font-size:13px;color:var(--mute);width:100%;font-style:italic}

.bar{height:8px;background:var(--panel2);border-radius:99px;overflow:hidden}
.bar i{display:block;height:100%;background:var(--acc);width:0;transition:width .3s}
.status{font-size:13px;color:var(--mute);display:flex;gap:8px;align-items:center;min-height:22px}
.spin{width:14px;height:14px;border-radius:50%;border:2px solid var(--line);border-top-color:var(--acc);animation:sp .7s linear infinite;flex:none}
@keyframes sp{to{transform:rotate(360deg)}}

.tool-grid{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:14px}
.tool{display:flex;align-items:center;gap:7px;border:1px solid var(--line);background:var(--panel);padding:8px 13px;border-radius:99px;font-weight:600;font-size:14px}
.tool:hover{border-color:var(--acc)}
.tool.on{background:var(--acc);color:var(--acc-ink);border-color:var(--acc)}
.tool.done::after{content:"●";color:var(--ok);font-size:9px}
.tool.on.done::after{color:#fff}

.md{line-height:1.7}
.md h1,.md h2,.md h3,.md h4{margin:1.1em 0 .4em;line-height:1.3;letter-spacing:-.01em}
.md h1{font-size:1.5em}.md h2{font-size:1.25em}.md h3{font-size:1.08em}
.md>*:first-child{margin-top:0}
.md p{margin:.55em 0}
.md ul,.md ol{padding-left:1.4em;margin:.4em 0}
.md li{margin:.2em 0}
.md blockquote{margin:.8em 0;padding:.4em 1em;border-left:4px solid var(--acc);background:var(--panel2);border-radius:0 10px 10px 0}
.md code{background:var(--panel2);padding:2px 6px;border-radius:6px;font-size:.9em}
.md pre{background:var(--panel2);padding:12px;border-radius:10px;overflow:auto}
.md table{border-collapse:collapse;width:100%;margin:.8em 0;display:block;overflow:auto}
.md th,.md td{border:1px solid var(--line);padding:6px 10px;text-align:left}
.md th{background:var(--panel2)}
.empty{text-align:center;color:var(--mute);padding:36px 12px}
.empty .big{font-size:42px}
.err{color:var(--bad);font-size:14px;background:color-mix(in srgb,var(--bad) 10%,transparent);padding:10px 14px;border-radius:10px;white-space:pre-wrap}

/* flashcards */
.fc-wrap{max-width:640px;margin:0 auto}
.fc{perspective:1200px;height:280px;cursor:pointer;margin:14px 0}
.fc-in{position:relative;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d}
.fc.flip .fc-in{transform:rotateY(180deg)}
.fc-f,.fc-b{position:absolute;inset:0;backface-visibility:hidden;display:grid;place-items:center;text-align:center;padding:26px;border-radius:20px;border:1px solid var(--line);background:var(--panel);box-shadow:var(--shadow);font-size:20px;font-weight:600;overflow:auto}
.fc-b{transform:rotateY(180deg);background:linear-gradient(135deg,color-mix(in srgb,var(--acc) 16%,var(--panel)),var(--panel));font-weight:500;font-size:18px}
.fc small{position:absolute;top:12px;left:16px;color:var(--mute);font-size:12px;font-weight:600;text-transform:uppercase;letter-spacing:.06em}
.prog{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--mute)}
.prog .bar{flex:1}

/* quiz */
.quiz{max-width:700px;margin:0 auto}
.q-t{font-size:19px;font-weight:700;margin:6px 0 14px}
.opt{display:flex;gap:10px;width:100%;text-align:left;border:1.5px solid var(--line);background:var(--panel);padding:12px 14px;border-radius:12px;margin-bottom:8px;font-weight:500}
.opt:hover:not(:disabled){border-color:var(--acc)}
.opt b{flex:none;width:24px;height:24px;border-radius:50%;background:var(--panel2);display:grid;place-items:center;font-size:12px}
.opt.right{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 12%,transparent)}
.opt.wrong{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 10%,transparent)}
.why{margin-top:10px;padding:10px 14px;border-radius:10px;background:var(--panel2);font-size:14px}
.score{font-size:54px;font-weight:800;text-align:center;letter-spacing:-.03em}

/* mind map */
.mm ul{list-style:none;margin:0;padding-left:26px;position:relative}
.mm>ul{padding-left:0}
.mm li{position:relative;margin:6px 0}
.mm ul ul::before{content:"";position:absolute;left:10px;top:0;bottom:14px;border-left:2px solid var(--line)}
.mm ul ul>li::before{content:"";position:absolute;left:-16px;top:15px;width:14px;border-top:2px solid var(--line)}
.node{display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border-radius:99px;font-weight:600;font-size:14px;border:1.5px solid var(--c);background:color-mix(in srgb,var(--c) 11%,var(--panel));cursor:pointer}
.node.root{font-size:17px;background:var(--c);color:#fff;padding:8px 18px}
.node.leaf{font-weight:500;cursor:default}
.node em{font-style:normal;font-size:11px;opacity:.7}

/* chat */
.chat{display:flex;flex-direction:column;height:min(66vh,640px)}
.msgs{flex:1;overflow:auto;display:flex;flex-direction:column;gap:12px;padding:4px 2px 12px}
.msg{max-width:88%;padding:10px 14px;border-radius:16px;background:var(--panel2)}
.msg.u{align-self:flex-end;background:var(--acc);color:var(--acc-ink)}
.msg small{display:block;margin-top:6px;color:var(--mute);font-size:11px}
.sugg{display:flex;flex-wrap:wrap;gap:6px;margin:8px 0}
.sugg button{border:1px solid var(--line);background:var(--panel);border-radius:99px;padding:5px 12px;font-size:13px}
.sugg button:hover{border-color:var(--acc)}

/* pomodoro */
.pomo{max-width:420px;margin:20px auto;text-align:center}
.pomo-t{font-size:84px;font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:-.03em;margin:6px 0}
.pomo-ring{width:220px;height:220px;margin:0 auto;position:relative}
.pomo-ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.pomo-ring .pomo-c{position:absolute;inset:0;display:grid;place-items:center}
.pomo-ring .pomo-t{font-size:52px;margin:0}

/* dialogs */
dialog{border:1px solid var(--line);border-radius:18px;background:var(--panel);color:var(--ink);padding:0;width:min(760px,94vw);max-height:90vh;box-shadow:0 30px 80px rgba(0,0,0,.35)}
dialog::backdrop{background:rgba(17,24,39,.45);backdrop-filter:blur(3px)}
.dlg{padding:22px;overflow:auto;max-height:90vh}
.dlg h2{margin:0 0 4px}
.dlg-h{display:flex;justify-content:space-between;align-items:start;gap:10px}
.keyrow{display:grid;grid-template-columns:130px 1fr auto;gap:8px;align-items:center;margin:8px 0}
.keyrow a{font-size:12px;color:var(--acc);white-space:nowrap}
.mrow{display:grid;grid-template-columns:auto 1fr auto;gap:8px;align-items:center;padding:6px 8px;border-radius:8px;font-size:13px}
.mrow:nth-child(odd){background:var(--panel2)}
.mrow .p{font-weight:700}
.mrow .m{color:var(--mute);overflow:hidden;text-overflow:ellipsis}
.mrow .m span{margin-left:6px}
.mlist{max-height:300px;overflow:auto;border:1px solid var(--line);border-radius:10px}
.pill{font-size:11px;padding:1px 7px;border-radius:99px;background:var(--panel2);color:var(--mute);margin-left:6px}
.pill.nokey{background:color-mix(in srgb,var(--warn) 18%,transparent);color:var(--warn)}
.log{font-size:13px;font-family:ui-monospace,Consolas,monospace;padding:4px 8px;border-radius:6px}
.log.ok{color:var(--ok)}.log.bad{color:var(--bad)}
.hint{font-size:13px;color:var(--mute)}
hr.sep{border:0;border-top:1px solid var(--line);margin:18px 0}

#toasts{position:fixed;bottom:18px;left:50%;transform:translateX(-50%);display:flex;flex-direction:column;gap:8px;z-index:100;align-items:center}
.toast{background:var(--ink);color:var(--bg);padding:10px 16px;border-radius:12px;font-size:14px;box-shadow:var(--shadow);animation:in .2s}
@keyframes in{from{opacity:0;transform:translateY(8px)}}

#print{display:none}
@media print{
  body>*:not(#print){display:none!important}
  #print{display:block;color:#000;background:#fff;padding:0}
}

@media (max-width:860px){
  .only-mobile{display:inline-block}
  .layout{grid-template-columns:1fr}
  #side{position:fixed;z-index:40;left:0;top:53px;width:290px;max-width:86vw;transform:translateX(-102%);transition:transform .2s;box-shadow:var(--shadow)}
  body.menu #side{transform:none}
  body.menu #scrim{display:block;position:fixed;inset:53px 0 0 0;background:rgba(0,0,0,.4);z-index:30}
  .grid2{grid-template-columns:1fr}
  .keyrow{grid-template-columns:1fr}
  .top .btn.small{padding:6px 9px}
  .title-in{font-size:22px}
}