:root{
  --navy:#14203a;--navy2:#1f3157;--ink:#1b2438;--ink2:#36415a;--muted:#667089;--cream:#fbf8f1;--paper:#fffdf8;--line:#e9e2d2;--line2:#ddd3bd;
  --amber:#f2b707;--amber2:#ffe08a;--amber-ink:#8a5d00;--hl:rgba(255,214,74,.55);--ok:#168a4a;--ok-bg:#e8f6ee;--bad:#c93c3c;--bad-bg:#fbecec;
  --blue:#2f6fd0;--r:14px;--shadow:0 1px 2px rgba(20,32,58,.05),0 10px 30px rgba(20,32,58,.07);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{background:var(--cream);color:var(--ink);font:400 16px/1.7 Poppins,"Segoe UI",system-ui,sans-serif;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:var(--blue)}
button{font:inherit;color:inherit}
img{max-width:100%}
:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.hand{font-family:Caveat,"Segoe Print","Comic Sans MS",cursive}
.mark{background:linear-gradient(104deg,transparent .9%,var(--hl) 2.4%,var(--hl) 97%,transparent 99%);padding:0 .15em;border-radius:3px}
code{font-family:"Cascadia Code",Consolas,"SFMono-Regular",monospace;font-size:.88em;background:#f3eee2;border:1px solid var(--line);border-radius:5px;padding:0 .3em}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;border-radius:11px;border:0;background:var(--amber);color:#1f1600;font-weight:700;padding:10px 18px;cursor:pointer;text-decoration:none;box-shadow:0 6px 16px rgba(180,130,0,.22);text-align:center}
.btn:hover{filter:brightness(1.03);transform:translateY(-1px)}
.btn.ghost{background:#fff;border:1.5px solid var(--line2);box-shadow:none;color:var(--ink)}
.btn.navy{background:var(--navy);color:#fff;box-shadow:none}
.btn.sm{min-height:38px;padding:7px 12px;font-size:.86rem}
.chip{display:inline-flex;align-items:center;gap:5px;font-size:.72rem;font-weight:600;padding:2px 9px;border-radius:99px;background:#f1ebdc;color:var(--ink2);white-space:nowrap}
.k{font-size:.7rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--muted)}
.meter{height:7px;border-radius:99px;background:#ece5d3;overflow:hidden}
.meter i{display:block;height:100%;width:0;background:var(--amber);border-radius:99px;transition:width .5s}

/* brand bar */
.brand{background:var(--navy);color:#fff}
.brand .in{max-width:1320px;margin:auto;padding:10px 20px;display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand b{letter-spacing:.18em;font-size:.82rem}
.brand span{font-size:.8rem;color:#c8d1e4}
.brand a{color:#fff;text-decoration:none;font-size:.82rem;font-weight:600}
.brand a:hover{color:var(--amber2)}
.foot{text-align:center;color:var(--muted);font-size:.8rem;padding:26px 16px 34px;border-top:1px solid var(--line)}
.foot b{color:var(--navy)}

/* library */
.lib{max-width:1180px;margin:auto;padding:26px 20px 40px}
.lib-hero{display:grid;grid-template-columns:1.4fr 1fr;gap:22px;align-items:center;margin-bottom:22px}
.lib-hero h1{font-size:clamp(1.7rem,4vw,2.6rem);line-height:1.12;font-weight:800;letter-spacing:-.02em}
.lib-hero p{color:var(--ink2);margin-top:8px;max-width:620px}
.journey-note{background:var(--paper);border:1px solid var(--line);border-radius:var(--r);padding:16px 18px;box-shadow:var(--shadow);position:relative}
.journey-note ol{list-style:none;display:flex;flex-wrap:wrap;gap:4px 6px;font-size:.78rem;font-weight:700;letter-spacing:.06em;color:var(--navy)}
.journey-note li:not(:last-child):after{content:" ↓";color:var(--amber-ink)}
.journey-note .big{font-size:1.9rem;font-weight:800;line-height:1;margin:6px 0}
.access{background:var(--paper);border:1.5px dashed var(--line2);border-radius:var(--r);padding:14px 16px;margin-bottom:22px;display:flex;flex-wrap:wrap;gap:10px 16px;align-items:center}
.access p{flex:1 1 300px;font-size:.92rem;color:var(--ink2)}
.access form{display:flex;flex-wrap:wrap;gap:8px;flex:1 1 300px}
.access input{flex:1 1 160px;min-width:0;min-height:44px;border:1.5px solid var(--line2);border-radius:10px;padding:8px 12px;font:inherit;text-transform:uppercase;background:#fff}
.access .err{color:var(--bad);font-size:.82rem;width:100%;display:none}
.lib h2{font-size:1.25rem;font-weight:800;margin:26px 0 12px;display:flex;align-items:center;gap:8px}
.lib h2 small{font-size:.82rem;font-weight:500;color:var(--muted)}
.books{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:14px}
.book{position:relative;background:var(--paper);border:1px solid var(--line);border-radius:16px;padding:18px 18px 16px 24px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:8px;overflow:hidden}
.book:before{content:"";position:absolute;left:0;top:0;bottom:0;width:8px;background:var(--navy)}
.book.open:before{background:linear-gradient(var(--amber),#e3a400)}
.book.lock{background:#faf7ef}
.book .no{font-size:.72rem;font-weight:800;letter-spacing:.14em;color:var(--amber-ink)}
.book h3{font-size:1.06rem;line-height:1.3}
.book .days{font-size:.8rem;color:var(--muted)}
.book .st{font-size:.8rem;font-weight:700}
.book.open .st{color:var(--ok)}
.book.lock .st{color:var(--muted)}
.book ul{list-style:none;display:flex;flex-wrap:wrap;gap:4px}
.book .acts{margin-top:auto;display:flex;flex-wrap:wrap;gap:8px;padding-top:6px}
.shelf{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:10px}
.shelf a,.shelf span.off{display:flex;align-items:center;gap:10px;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:10px 12px;text-decoration:none;color:var(--ink);font-size:.88rem;font-weight:600;min-height:52px}
.shelf a:hover{border-color:var(--amber)}
.shelf span.off{color:#a39a86;font-weight:500}
.shelf b{font-size:.7rem;color:var(--amber-ink);letter-spacing:.08em}
.revlist{list-style:none;display:grid;gap:8px}
.revlist li{display:flex;align-items:center;gap:10px;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:10px 12px}
.revlist a{flex:1;color:var(--ink);font-weight:600;text-decoration:none;font-size:.9rem}
.revlist small{color:var(--muted);font-weight:500}
.empty{color:var(--muted);font-size:.9rem;background:var(--paper);border:1px dashed var(--line2);border-radius:12px;padding:14px}

/* search */
.search{position:relative}
.search input{width:100%;min-height:44px;border:1.5px solid var(--line2);border-radius:11px;padding:8px 12px 8px 36px;font:inherit;background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='none' stroke='%23667089' stroke-width='2'%3E%3Ccircle cx='7' cy='7' r='5'/%3E%3Cpath d='m11 11 4 4'/%3E%3C/svg%3E") 12px 50% no-repeat}
.search input:focus{outline:0;border-color:var(--amber);box-shadow:0 0 0 3px rgba(242,183,7,.25)}
.results{list-style:none;margin-top:8px;display:grid;gap:6px;max-height:60vh;overflow:auto}
.results li a{display:block;text-decoration:none;color:var(--ink);background:#fff;border:1px solid var(--line);border-radius:10px;padding:8px 10px;font-size:.84rem;line-height:1.45}
.results li a:hover{border-color:var(--amber)}
.results a>b{display:block;font-size:.86rem}
.results small{color:var(--muted);display:block}
.results mark{background:var(--hl);color:inherit;border-radius:2px}
.results .none{color:var(--muted);font-size:.84rem;padding:6px 2px}

/* reader */
.reader{max-width:1320px;margin:auto;display:grid;grid-template-columns:270px minmax(0,1fr) 250px;gap:28px;padding:0 20px}
.side{position:sticky;top:0;align-self:start;height:100vh;overflow-y:auto;padding:22px 0 30px;scrollbar-width:thin}
.side .back{font-size:.84rem;font-weight:600;text-decoration:none;color:var(--ink2)}
.side h2{font-size:1rem;line-height:1.3;margin:10px 0 2px}
.side .d{font-size:.8rem;color:var(--muted)}
.side .prog{margin:12px 0 14px}
.side .prog span{font-size:.76rem;color:var(--muted);display:block;margin-bottom:4px}
.toc{list-style:none;display:grid;gap:2px}
.toc a{display:flex;align-items:center;gap:8px;padding:7px 10px;border-radius:9px;text-decoration:none;color:var(--ink2);font-size:.88rem;font-weight:500;line-height:1.3}
.toc a:hover{background:#f3ecdb}
.toc a.on{background:var(--navy);color:#fff}
.toc a .ck{margin-left:auto;font-size:.72rem;color:var(--ok)}
.toc a.on .ck{color:var(--amber2)}
.tools{position:sticky;top:0;align-self:start;max-height:100vh;overflow-y:auto;padding:22px 0;display:flex;flex-direction:column;gap:18px}
.tools h3{font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:6px}
.tools ul{list-style:none;display:grid;gap:2px}
.tools ul a{font-size:.82rem;text-decoration:none;color:var(--ink2);display:block;padding:4px 6px;border-radius:6px;line-height:1.35}
.tools ul a:hover{background:#f3ecdb}
.main{padding:22px 0 40px;min-width:0}
.topbar{display:none}

.cover{background:var(--navy);color:#fff;border-radius:22px;padding:34px 32px 30px;position:relative;overflow:hidden;margin-bottom:26px}
.cover:after{content:"";position:absolute;right:-60px;top:-60px;width:240px;height:240px;border-radius:50%;background:radial-gradient(circle,rgba(242,183,7,.35),transparent 70%)}
.cover .k{color:var(--amber2)}
.cover h1{font-size:clamp(1.6rem,3.6vw,2.4rem);line-height:1.15;margin:8px 0 6px;font-weight:800;letter-spacing:-.015em;position:relative}
.cover .sub{color:#d5dcec;font-size:1.02rem;position:relative}
.cover .meta{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px;position:relative}
.cover .meta span{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.18);border-radius:99px;padding:3px 11px;font-size:.78rem}
.cover .unl{display:inline-flex;gap:8px;align-items:center;margin-top:16px;background:rgba(22,138,74,.18);border:1px solid rgba(126,214,164,.5);color:#bff0d2;border-radius:10px;padding:6px 12px;font-size:.82rem;font-weight:700;position:relative}
.intro{font-size:1.03rem;color:var(--ink2);background:var(--paper);border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;margin-bottom:10px;position:relative}
.intro:before{content:"";position:absolute;left:0;top:14px;bottom:14px;width:4px;border-radius:0 4px 4px 0;background:var(--amber)}

.chapter{padding-top:30px;scroll-margin-top:10px}
.ch-head{display:flex;align-items:flex-end;gap:12px;margin-bottom:14px;border-bottom:2px solid var(--navy);padding-bottom:8px}
.ch-head .n{font-size:2.2rem;font-weight:800;color:var(--amber);line-height:.9}
.ch-head h2{font-size:clamp(1.25rem,2.6vw,1.6rem);line-height:1.2;font-weight:800}
.ch-head p{font-size:.86rem;color:var(--muted)}
.ch-lead{color:var(--ink2);margin-bottom:12px}

.card{background:var(--paper);border:1px solid var(--line);border-radius:var(--r);padding:18px 20px;margin-bottom:16px;box-shadow:var(--shadow);scroll-margin-top:14px;position:relative}
.card h3{font-size:1.14rem;line-height:1.3;padding-right:44px}
.card .days{display:flex;flex-wrap:wrap;gap:4px;margin:6px 0 10px}
.star{position:absolute;right:12px;top:12px;width:40px;height:40px;border-radius:50%;border:1.5px solid var(--line2);background:#fff;cursor:pointer;font-size:1.05rem;line-height:1;color:#b5ab95}
.star[aria-pressed="true"]{background:#fff3c4;border-color:var(--amber);color:#b07a00}
.flash{animation:flash 1.6s ease-out}
@keyframes flash{0%,30%{box-shadow:0 0 0 4px rgba(242,183,7,.7)}100%{box-shadow:var(--shadow)}}
.qa{display:grid;grid-template-columns:150px minmax(0,1fr);gap:6px 16px;margin-top:6px}
.qa dd,.qa dt{min-width:0}
.main p,.main li,.main dd,.main summary,.main .a,.note,.learned p,.results a{overflow-wrap:anywhere}
.main :not(pre)>code{overflow-wrap:anywhere;word-break:break-word}
.qa dt{font-size:.74rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:var(--navy);padding-top:3px}
.qa dd{color:var(--ink2)}
.qa ol{margin-left:18px}
.qa li{margin:2px 0}
.note{position:relative;border-radius:10px;padding:12px 14px 12px 16px;margin-top:12px;font-size:.93rem}
.note b.t{display:block;font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;margin-bottom:2px}
.note.mist{background:#fff6cc;box-shadow:2px 3px 0 rgba(0,0,0,.06);transform:rotate(-.25deg)}
.note.mist b.t{color:#8a5d00}
.note.intv{background:#eef3fc;border-left:4px solid var(--blue)}
.note.intv b.t{color:#2551a0}
.note.exam{background:#f4f1ea;border-left:4px solid var(--navy)}
.note.exam b.t{color:var(--navy)}
.note.res{background:var(--ok-bg);border-left:4px solid var(--ok)}
.note.res b.t{color:var(--ok)}
pre.code{background:#16213a;color:#f3f5fa;border-radius:12px;padding:14px 16px;overflow-x:auto;font:400 .84rem/1.55 "Cascadia Code",Consolas,monospace;margin-top:12px;white-space:pre}
pre.code .lang{display:block;font-size:.66rem;letter-spacing:.14em;color:var(--amber2);margin-bottom:6px;font-family:Poppins,sans-serif;font-weight:700}
.tbl{overflow-x:auto;margin-top:12px;border-radius:10px;border:1px solid var(--line)}
.tbl table{width:100%;border-collapse:collapse;font-size:.86rem;background:#fff}
.tbl th{background:var(--navy);color:#fff;text-align:left;font-weight:600;padding:8px 10px}
.tbl td{padding:8px 10px;border-top:1px solid var(--line);vertical-align:top}
.tbl tr:nth-child(even) td{background:#fcfaf4}
.dg{margin-top:14px;display:flex;flex-wrap:wrap;align-items:center;gap:6px}
.dg .box{background:#fff;border:2px solid var(--navy);border-radius:10px;padding:7px 12px;font-size:.84rem;font-weight:600;box-shadow:3px 3px 0 var(--amber2)}
.dg .arr{width:38px;height:22px;flex:0 0 auto}
.dg.cmp{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px}
.dg.cmp .box{box-shadow:none;border-color:var(--line2)}
.star-dg{margin-top:14px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;align-items:center;justify-items:center;max-width:520px}
.star-dg .box{background:#fff;border:2px solid var(--line2);border-radius:10px;padding:8px 10px;font-size:.8rem;font-weight:600;text-align:center;width:100%}
.star-dg .fact{grid-column:2;grid-row:2;background:var(--navy);color:#fff;border-color:var(--navy);box-shadow:4px 4px 0 var(--amber)}
.steps{counter-reset:s;list-style:none;margin-top:8px}
.steps li{counter-increment:s;position:relative;padding:8px 0 8px 40px;border-bottom:1px dashed var(--line)}
.steps li:last-child{border:0}
.steps li:before{content:counter(s);position:absolute;left:0;top:7px;width:28px;height:28px;border-radius:50%;background:var(--navy);color:#fff;font-size:.78rem;font-weight:700;display:grid;place-items:center}
.goal{font-weight:600;color:var(--ink)}
.learned{list-style:none;display:grid;gap:10px}
.learned li{display:grid;grid-template-columns:64px 1fr;gap:12px;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.learned .dn{font-weight:800;color:var(--amber-ink);font-size:.78rem;letter-spacing:.1em;padding-top:2px}
.learned li>div>b{display:block;line-height:1.35}
.learned p{color:var(--ink2);font-size:.92rem;margin-top:2px}
.mistake{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border-radius:var(--r);overflow:hidden;border:1px solid var(--line);margin-bottom:12px;background:var(--paper)}
.mistake>div{padding:12px 14px;font-size:.9rem;position:relative}
.mistake>div+div{border-left:1px solid var(--line)}
.mistake .k{display:block;margin-bottom:4px}
.mistake .w .k{color:var(--bad)}
.mistake .f{background:#f3fbf6}
.mistake .f .k{color:var(--ok)}
.filters{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:12px}
.filters button{border:1.5px solid var(--line2);background:#fff;border-radius:99px;padding:5px 12px;font-size:.82rem;font-weight:600;cursor:pointer;min-height:36px}
.filters button[aria-pressed="true"]{background:var(--navy);color:#fff;border-color:var(--navy)}
details.iq{background:var(--paper);border:1px solid var(--line);border-radius:12px;margin-bottom:8px}
details.iq summary{cursor:pointer;padding:12px 44px 12px 14px;font-weight:600;list-style:none;position:relative;line-height:1.45}
details.iq summary::-webkit-details-marker{display:none}
details.iq summary:after{content:"+";position:absolute;right:14px;top:10px;font-size:1.3rem;color:var(--muted)}
details.iq[open] summary:after{content:"–"}
details.iq .a{padding:0 14px 14px;color:var(--ink2)}
.lvl{font-size:.68rem;font-weight:800;letter-spacing:.08em;margin-right:6px;text-transform:uppercase}
.exam-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.exam-grid ul{margin-left:18px}
.exam-grid li{margin:4px 0;color:var(--ink2);font-size:.92rem}
.terms{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:8px}
.terms div{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 12px;font-size:.88rem}
.terms div>b:first-child{display:block;color:var(--navy)}
.disclaim{font-size:.8rem;color:var(--muted);margin-top:10px}
.kc{background:var(--paper);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;margin-bottom:10px}
.kc p.q{font-weight:600;margin-bottom:8px}
.kc .opt{display:flex;width:100%;text-align:left;gap:10px;align-items:flex-start;background:#fff;border:1.5px solid var(--line);border-radius:10px;padding:9px 12px;margin:6px 0;cursor:pointer;line-height:1.45;min-height:44px}
.kc .opt:hover{border-color:var(--line2)}
.kc .opt.right{border-color:var(--ok);background:var(--ok-bg)}
.kc .opt.wrong{border-color:var(--bad);background:var(--bad-bg)}
.kc .why{display:none;margin-top:8px;font-size:.9rem;color:var(--ink2);border-left:3px solid var(--amber);padding-left:10px}
.kc.done .why{display:block}
.kc .verdict{font-weight:700;font-size:.84rem;margin-top:6px}
.kc-score{position:sticky;top:8px;z-index:2;display:inline-flex;gap:8px;background:var(--navy);color:#fff;border-radius:99px;padding:6px 14px;font-size:.84rem;font-weight:600;margin-bottom:10px}
.sheet{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px;background:#fff;border:2px dashed var(--line2);border-radius:18px;padding:16px}
.sheet section{background:#fffbe9;border-radius:12px;padding:12px 14px}
.sheet h4{font-size:.9rem;margin-bottom:6px;color:var(--navy)}
.sheet ul{margin-left:18px;font-size:.88rem;color:var(--ink2)}
.sheet li{margin:3px 0}
.fc-wrap{display:flex;flex-direction:column;align-items:center;gap:12px}
.fc{width:min(560px,100%);aspect-ratio:16/10;perspective:1200px;cursor:pointer;border:0;background:none;padding:0}
.fc .in{position:relative;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d}
.fc.flip .in{transform:rotateY(180deg)}
.fc .face{position:absolute;inset:0;backface-visibility:hidden;border-radius:18px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:22px;text-align:center;font-size:1.08rem;line-height:1.5;box-shadow:var(--shadow)}
.fc .front{background:var(--navy);color:#fff;font-weight:700;font-size:1.2rem}
.fc .back{background:#fffbe9;border:2px solid var(--amber2);transform:rotateY(180deg);color:var(--ink)}
.fc .face small{position:absolute;top:12px;left:16px;font-size:.66rem;letter-spacing:.14em;text-transform:uppercase;opacity:.7;font-weight:700}
.fc-ctl{display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:center}
.fc-ctl .cnt{font-size:.86rem;color:var(--muted);min-width:70px;text-align:center}
.print-only{display:none}
.unlock-box{background:var(--paper);border:1.5px dashed var(--line2);border-radius:18px;padding:22px;margin-top:10px}
.unlock-box h3{font-size:1.15rem;margin-bottom:6px}
.unlock-box p{color:var(--ink2)}
.unlock-box .acts{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}
.toc-preview{list-style:none;display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:6px;margin-top:12px}
.toc-preview li{background:#fff;border:1px solid var(--line);border-radius:10px;padding:8px 10px;font-size:.86rem;color:#8a8273}
.loading{padding:40px 0;color:var(--muted)}

/* drawer (mobile) */
.drawer-bg{display:none}

@media (max-width:1180px){
  .chapter,.card,.kc,.mistake,details.iq{scroll-margin-top:72px}
  .reader{grid-template-columns:250px minmax(0,1fr);gap:22px}
  .tools{display:none}
  .tools.open{display:flex;position:fixed;inset:0 0 0 auto;width:min(340px,90vw);background:var(--cream);z-index:40;padding:18px;box-shadow:-10px 0 40px rgba(0,0,0,.2);height:100vh;max-height:none}
  .topbar{display:flex}
}
@media (max-width:860px){
  .lib-hero{grid-template-columns:1fr}
  .reader{display:block;padding:0 16px}
  .side{display:none}
  .side.open{display:block;position:fixed;inset:0 auto 0 0;width:min(320px,88vw);background:var(--cream);z-index:40;padding:18px;box-shadow:10px 0 40px rgba(0,0,0,.2);height:100vh}
  .drawer-bg.on{display:block;position:fixed;inset:0;background:rgba(15,24,44,.45);z-index:35}
  .qa{grid-template-columns:minmax(0,1fr);gap:2px}
  .qa dd{margin-bottom:8px}
  .mistake{grid-template-columns:1fr}
  .mistake>div+div{border-left:0;border-top:1px solid var(--line)}
  .exam-grid{grid-template-columns:1fr}
  .cover{padding:26px 20px 22px;border-radius:18px}
  .card{padding:16px}
  .learned li{grid-template-columns:1fr;gap:2px}
  .brand .in{padding:9px 16px}
  .brand span{display:none}
  .lib{padding:20px 16px 32px}
}
.topbar{position:sticky;top:0;z-index:30;background:rgba(251,248,241,.96);backdrop-filter:blur(6px);border-bottom:1px solid var(--line);gap:6px;align-items:center;padding:8px 0;margin:0 -2px}
.topbar .t{flex:1;min-width:0;font-size:.82rem;font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar button{min-height:42px;min-width:42px;border-radius:10px;border:1.5px solid var(--line2);background:#fff;cursor:pointer;font-size:.84rem;font-weight:600;padding:0 10px}
@media (min-width:861px){.topbar .menu{display:none}}

@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}html{scroll-behavior:auto}}

@media print{
  @page{size:A4;margin:16mm 14mm 18mm}
  body{background:#fff;font-size:10.5pt;line-height:1.5;color:#000}
  .brand,.side,.tools,.topbar,.drawer-bg,.star,.filters,.fc-wrap,.kc-score,.no-print,.foot .no-print,.btn{display:none!important}
  .reader{display:block;max-width:none;padding:0}
  .main{padding:0}
  .cover{background:#fff;color:#000;border:2px solid #14203a;border-radius:0;padding:14mm 12mm;margin-bottom:6mm}
  .cover:after{display:none}
  .cover .k,.cover .sub{color:#333}
  .cover .meta span{border-color:#999;background:none}
  .cover .unl{display:none}
  .chapter{page-break-before:always;padding-top:0}
  .card,.kc,.mistake,details.iq,.learned li,.sheet section,.tbl,pre.code,.note{break-inside:avoid;box-shadow:none}
  .card{border-color:#bbb}
  pre.code{background:#f5f5f5;color:#000;border:1px solid #ccc;white-space:pre-wrap}
  pre.code .lang{color:#555}
  .tbl th{background:#e9e9e9;color:#000}
  details.iq .a{display:block}
  .kc .why{display:block}
  .kc .opt{border:0;padding:1px 0;min-height:0;margin:0}
  .kc .opt.ans{font-weight:700}
  .print-only{display:block}
  .fc-list{columns:2;column-gap:8mm;font-size:9.5pt}
  .fc-list div{break-inside:avoid;border-bottom:1px solid #ddd;padding:3px 0}
  .note.mist{transform:none}
  a{color:#000;text-decoration:none}
  .foot{border:0;padding-top:6mm}
}