:root{--bg:#FAF7FF;--grid:#EFE9FA;--paper:#FFFFFF;--ink:#1E1633;--sub:#5F5878;--faint:#9A93B2;--line:#E6DEF4;--line2:#F0EBF9;--acc:#6D28D9;--acc-t:#F1E9FF;--red:#CF3B2C;--red-t:#FCEFED;--ok:#237A52;--ok-t:#E8F4EE;--mark:#FFE27A;--mark-s:#FFD23F;--fs:16px;
 --ease:cubic-bezier(.22,.8,.24,1);--shadow:0 1px 0 rgba(76,29,149,.05),0 12px 32px -22px rgba(76,29,149,.32);
 box-sizing:border-box;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){--bg:#120E1C;--grid:#1A1428;--paper:#1A1526;--ink:#EEE9F8;--sub:#B0A8C6;--faint:#7C7396;--line:#2E2545;--line2:#241C38;--acc:#B79BFF;--acc-t:#2A1D48;--red:#EE7D70;--red-t:#33201F;--ok:#6CC99E;--ok-t:#17302A;--mark:#6B5812;--mark-s:#8A7216;--shadow:0 12px 32px -20px rgba(0,0,0,.6)}}
:root[data-theme="dark"]{--bg:#120E1C;--grid:#1A1428;--paper:#1A1526;--ink:#EEE9F8;--sub:#B0A8C6;--faint:#7C7396;--line:#2E2545;--line2:#241C38;--acc:#B79BFF;--acc-t:#2A1D48;--red:#EE7D70;--red-t:#33201F;--ok:#6CC99E;--ok-t:#17302A;--mark:#6B5812;--mark-s:#8A7216;--shadow:0 12px 32px -20px rgba(0,0,0,.6)}
*,*::before,*::after{box-sizing:inherit}
html{scroll-padding-top:calc(env(safe-area-inset-top,0px) + 130px);height:100%}
@media (max-width:860px){html{scroll-padding-top:calc(env(safe-area-inset-top,0px) + 76px)}}
body{margin:0;color:var(--ink);font:400 var(--fs)/1.6 "Onest","Noto Sans SC",system-ui,sans-serif;-webkit-font-smoothing:antialiased;
 background-color:var(--bg);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:26px 26px;background-attachment:fixed}
.zh{font-family:"Noto Serif SC","Songti SC",serif;font-weight:500}
.serif,h1,h2{font-family:"Literata",Georgia,serif}
button{font:inherit;color:inherit;cursor:pointer}
a{color:var(--acc)}
:focus-visible{outline:2px solid var(--acc);outline-offset:2px;border-radius:6px}
svg.i{width:20px;height:20px;stroke:currentColor;fill:none;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;flex:none}
/* ---------- shell: sub-navigation inside ERA dashboard ---------- */
.shell{min-height:100vh}
.hdr{position:sticky;top:0;z-index:10;background:color-mix(in srgb,var(--paper) 92%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.hdr-in{max-width:1180px;margin:0 auto;padding:0 32px}
.hdr-top{display:flex;align-items:center;gap:18px;height:64px}
.era-home{display:inline-grid;place-items:center;width:34px;height:34px;flex:none;border-radius:10px;background:var(--acc);color:#fff;font:800 1rem system-ui,sans-serif;text-decoration:none;margin-right:-6px}
.era-home:hover{filter:brightness(1.1)}
.qpbtn{width:100%;justify-content:center}
.brand{display:flex;align-items:baseline;gap:10px;text-decoration:none;color:var(--ink);flex:none}
.brand .t{font-size:1.35rem}
.brand .era{font-size:.78rem;color:var(--faint)}
.searchbox{flex:1;max-width:420px;margin-left:auto;display:flex;align-items:center;gap:8px;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:0 12px;color:var(--faint);transition:border-color .2s,box-shadow .2s}
.searchbox input[type=search]{flex:1;min-width:0;border:0;background:none;padding:9px 0;color:var(--ink);font:inherit;outline:none}
.searchbox:focus-within{border-color:var(--acc);box-shadow:0 0 0 4px var(--acc-t)}
.langsw{position:relative;display:inline-flex;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:3px;flex:none}
.langsw .knob{position:absolute;top:3px;bottom:3px;border-radius:9px;background:var(--ink);transition:left .35s var(--ease),width .35s var(--ease)}
.langsw button{position:relative;border:0;background:none;padding:6px 12px;border-radius:9px;font-size:.87rem;color:var(--sub);font-weight:500;transition:color .25s}
.langsw button.on{color:var(--paper)}
.tabs{position:relative;display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;margin:0 -10px}
.tabs::-webkit-scrollbar{display:none}
.tabs a{display:flex;align-items:center;gap:8px;padding:10px 10px 14px;text-decoration:none;color:var(--sub);font-size:.93rem;font-weight:500;white-space:nowrap;transition:color .2s}
.tabs a:hover{color:var(--ink)}
.tabs a.on{color:var(--ink)}
.tabs .sep{width:1px;background:var(--line);margin:10px 8px 14px;flex:none}
.tabs .ind{position:absolute;bottom:0;height:3px;border-radius:3px 3px 0 0;background:var(--ink);transition:left .45s var(--ease),width .45s var(--ease)}
.tabs svg.i{width:18px;height:18px}
#view{max-width:1180px;margin:0 auto;padding:36px 32px 64px}
#view.enter{animation:enter .38s var(--ease) both}
@keyframes enter{from{opacity:0;transform:translateY(10px)}}
h1{font-size:2.3rem;line-height:1.15;margin:0 0 8px;font-weight:600;letter-spacing:-.01em}
h2{font-size:1.4rem;margin:44px 0 16px;font-weight:600}
h3{font-size:1rem;margin:0 0 10px;font-weight:600}
.sub{color:var(--sub)}.faint{color:var(--faint)}
.lead{font-size:1.06rem;color:var(--sub);max-width:60ch}
.panel,.sheet-p{background:var(--paper);border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow)}
.grid{display:grid;gap:18px}.grid>*,.rpanel>*{min-width:0}
.g2{grid-template-columns:1fr 1fr}.g3{grid-template-columns:repeat(3,1fr)}
.g5,.grid.g3:has(>.stat){display:grid;gap:0;background:var(--paper);border:1px solid var(--line);border-radius:16px;overflow:hidden;box-shadow:var(--shadow)}
.g5{grid-template-columns:repeat(5,1fr)}
.g5>.panel,.g3>.panel.stat{border:0;border-radius:0;border-right:1px dashed var(--line);padding:20px 22px;background:none;box-shadow:none}
.g5>.panel:last-child,.g3>.panel.stat:last-child{border-right:0}
.stat .v{font-family:"Literata",serif;font-size:1.8rem;font-weight:600;font-variant-numeric:tabular-nums}
.stat .l{font-size:.84rem;color:var(--sub)}
.btn{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--paper);padding:10px 18px;border-radius:12px;font-weight:550;text-decoration:none;color:var(--ink);font-size:.95rem;transition:transform .15s var(--ease),border-color .2s,background .2s,box-shadow .2s}
.btn:hover{border-color:var(--ink)}
.btn:active{transform:scale(.97)}
.btn.pri{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.btn.pri:hover{box-shadow:0 8px 20px -10px var(--ink)}
.btn.pri svg{transition:transform .25s var(--ease)}
.btn.pri:hover svg{transform:translateX(3px)}
.btn.sm{padding:6px 12px;font-size:.87rem;border-radius:10px}
.btn[disabled]{opacity:.4;cursor:default}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.chip{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:999px;padding:5px 12px;font-size:.87rem;background:var(--paper);color:var(--ink);transition:background .2s,border-color .2s,color .2s}
.chip:hover{border-color:var(--faint)}
.chip.on{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.chip.on .sub{color:inherit;opacity:.75}
.tag{font-size:.8rem;color:var(--sub)}
.tag.found{color:#8A6516}
.bar{height:6px;border-radius:99px;background:var(--line2);overflow:hidden}
.bar>i{display:block;height:100%;background:var(--acc);border-radius:99px;transform-origin:left;animation:grow .9s var(--ease) .15s both}
@keyframes grow{from{transform:scaleX(0)}}
.bar.low>i{background:var(--red)}.bar.hi>i{background:var(--ok)}
.list{list-style:none;margin:0;padding:0}
.list li{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:12px 0;border-bottom:1px dashed var(--line)}
.list li:last-child{border-bottom:0}
.empty{padding:24px;border:1.5px dashed var(--line);border-radius:16px;color:var(--sub);background:var(--paper)}
/* ---------- home ---------- */
.hero{position:relative;padding:8px 0 30px}
.hero .wm{position:absolute;right:-10px;top:-30px;font-size:13rem;line-height:1;color:var(--ink);opacity:.045;pointer-events:none;user-select:none;letter-spacing:-.05em}
.hero h1{position:relative}
.next{position:relative;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:30px 32px 30px 58px;display:grid;grid-template-columns:1fr auto;gap:24px;align-items:center;overflow:hidden}
.next::before{content:"";position:absolute;left:34px;top:0;bottom:0;width:1.5px;background:var(--red);opacity:.55}
.next .k{font-size:.85rem;color:var(--sub)}
.next .ttl{font-size:2.2rem;line-height:1.2;margin:6px 0 2px}
.home2{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:18px}
.mods .m{display:grid;grid-template-columns:1fr auto;gap:6px 12px;padding:13px 0;border-bottom:1px dashed var(--line)}
.mods .m:last-child{border-bottom:0}
.mods .m .bar{grid-column:1/-1}
.figs{display:flex;gap:32px;flex-wrap:wrap;margin-top:14px;padding-top:16px;border-top:1px dashed var(--line)}
.figs b{display:block;font-family:"Literata",serif;font-size:1.6rem;font-weight:600;font-variant-numeric:tabular-nums}
.figs span{font-size:.82rem;color:var(--sub)}
.mission li{justify-content:flex-start;gap:12px}
.mission li a{margin-left:auto;font-size:.88rem;text-decoration:none}
.ck{width:22px;height:22px;border-radius:7px;border:1.6px solid var(--line);display:grid;place-items:center;flex:none;color:#fff;transition:background .3s,border-color .3s}
.ck svg{stroke-dasharray:24;stroke-dashoffset:0;animation:draw .5s var(--ease) .3s both}
.mission li.done .ck{background:var(--ok);border-color:var(--ok)}
.mission li.done .txt{color:var(--sub);text-decoration:line-through;text-decoration-color:var(--faint)}
@keyframes draw{from{stroke-dashoffset:24}}
/* ---------- learn: textbook table of contents ---------- */
.chap{margin-top:40px}
.chap-h{display:grid;grid-template-columns:auto 1fr;gap:4px 20px;align-items:end;padding-bottom:14px;border-bottom:2px solid var(--ink)}
.chap-h .big{grid-row:span 2;font-size:3.6rem;line-height:.9}
.chap-h .no{font-size:.82rem;color:var(--sub)}
.chap-h .nm{font-size:1.35rem;font-weight:600}
.toc{background:var(--paper);border:1px solid var(--line);border-top:0;border-radius:0 0 16px 16px;box-shadow:var(--shadow);padding:6px 0}
.topic{display:flex;align-items:baseline;gap:12px;padding:12px 22px;text-decoration:none;color:inherit;transition:background .2s}
.topic:hover{background:var(--acc-t)}
.topic .n{width:22px;color:var(--faint);font-variant-numeric:tabular-nums;font-size:.86rem;flex:none}
.topic .nm .zh{font-size:1.06rem}
.topic .lead-dots{flex:1;border-bottom:1.5px dotted var(--line);transform:translateY(-4px);min-width:20px}
.topic .r{font-size:.84rem;color:var(--sub);display:flex;align-items:center;gap:6px;flex:none}
.topic .r svg{transition:transform .25s var(--ease)}
.topic:hover .r svg{transform:translateX(3px)}
.pill{font-size:.76rem;padding:2px 9px;border-radius:99px;background:var(--acc-t);color:var(--acc);font-weight:600}
.pill.ok{background:var(--ok-t);color:var(--ok)}.pill.low{background:var(--red-t);color:var(--red)}
/* ---------- question sheet ---------- */
.qcard{position:relative;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:28px 32px 26px 60px}
.qcard::before{content:"";position:absolute;left:36px;top:0;bottom:0;width:1.5px;background:var(--red);opacity:.5}
.qmeta{display:flex;gap:8px;align-items:center;margin-bottom:14px;flex-wrap:wrap;font-size:.84rem;color:var(--sub)}
.qmeta>.tag+.tag::before{content:"·";margin-right:8px;color:var(--faint)}
.stem{font-size:1.45em;line-height:1.9}
.stem:not(.zh){font-size:1.24em;line-height:1.7}
.term{border:0;padding:0 1px;font:inherit;color:inherit;border-radius:2px;background-color:transparent;background-image:linear-gradient(var(--mark),var(--mark));background-repeat:no-repeat;background-position:0 86%;background-size:100% 40%;transition:background-size .25s var(--ease)}
.term:hover{background-size:100% 78%;background-image:linear-gradient(var(--mark-s),var(--mark-s))}
.stem .term{animation:swipe .55s var(--ease) both;animation-delay:calc(var(--d,0) * 110ms + 250ms)}
@keyframes swipe{from{background-size:0% 40%}}
.chip.term{background:var(--paper);border:1px solid var(--line);border-radius:999px;padding:5px 12px;animation:none}
.chip.term:hover{background:var(--acc-t)}
.pyl{color:var(--faint);font-size:.9rem;margin-top:2px}
.mnl{margin-top:12px;font-size:.97rem;color:var(--sub);display:flex;gap:10px}
.mnl::before{content:"МН";font-size:.68rem;font-weight:700;color:var(--faint);border:1px solid var(--line);border-radius:5px;padding:1px 5px;height:fit-content;margin-top:3px;flex:none}
.hint{margin-top:10px;font-size:.88rem;color:var(--sub);display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.hint .chip{font-size:.82rem;padding:3px 10px}
.fslot:not(:empty){margin-top:10px;animation:enter .3s var(--ease) both}
.opts{display:grid;gap:9px;margin-top:22px}
.opt{display:flex;gap:14px;align-items:center;text-align:left;border:1px solid var(--line);background:var(--paper);border-radius:12px;padding:12px 16px;font-size:1.02rem;transition:border-color .2s,background .25s,transform .15s var(--ease)}
.opt:hover:not([disabled]){border-color:var(--ink);transform:translateX(3px)}
.opt:active:not([disabled]){transform:scale(.99)}
.opt .L{position:relative;width:30px;height:30px;border-radius:50%;border:1.6px solid var(--faint);display:grid;place-items:center;font-weight:600;flex:none;font-size:.86rem;color:var(--sub);transition:color .25s,border-color .25s}
.opt .L::before{content:"";position:absolute;inset:-1.6px;border-radius:50%;background:var(--ink);transform:scale(0);transition:transform .32s var(--ease),background .2s}
.opt .L>span{position:relative}
.opt.sel .L,.opt.ok .L,.opt.bad .L{color:#fff;border-color:transparent}
.opt.sel .L::before,.opt.ok .L::before,.opt.bad .L::before{transform:scale(1)}
.opt.sel{border-color:var(--ink)}
.opt.ok{border-color:var(--ok);background:var(--ok-t)}.opt.ok .L::before{background:var(--ok)}
.opt.bad{border-color:var(--red);background:var(--red-t);animation:nudge .4s var(--ease)}.opt.bad .L::before{background:var(--red)}
@keyframes nudge{20%{transform:translateX(-5px)}45%{transform:translateX(4px)}70%{transform:translateX(-2px)}}
.opt[disabled]{cursor:default}
.fb{margin-top:20px;border-radius:14px;padding:18px 20px;background:var(--ok-t);animation:enter .35s var(--ease) both}
.fb .head{font-weight:600;display:flex;align-items:center;gap:10px;margin-bottom:6px;color:var(--ok)}
.fb.bad{background:none;padding:22px 0 0;border-top:1px dashed var(--line);border-radius:0}
.fb.bad .head{color:var(--red);font-size:1.06rem;margin-bottom:16px}
.mark{width:36px;height:36px;flex:none}
.mark path{stroke-dasharray:44;stroke-dashoffset:0;animation:pen .45s var(--ease) both}
.mark path+path{animation-delay:.3s}
@keyframes pen{from{stroke-dashoffset:44}}
.step{display:grid;grid-template-columns:30px 1fr;gap:14px;padding:0 0 18px;position:relative;animation:enter .4s var(--ease) both;animation-delay:calc(var(--s,0) * 90ms + 250ms)}
.step::before{content:"";position:absolute;left:14px;top:30px;bottom:0;width:1.5px;background:var(--line)}
.step:last-child::before{display:none}
.step:nth-child(2){--s:1}.step:nth-child(3){--s:2}.step:nth-child(4){--s:3}.step:nth-child(5){--s:4}.step:nth-child(6){--s:5}.step:nth-child(7){--s:6}
.step .k{width:29px;height:29px;border-radius:50%;background:var(--paper);border:1.5px solid var(--line);display:grid;place-items:center;font-size:.8rem;font-weight:650;color:var(--sub)}
.step b{display:block;font-weight:600;margin:3px 0 4px}
.fcard{border:1px solid var(--line);border-radius:12px;padding:14px 16px;background:var(--paper);transition:border-color .2s,box-shadow .25s}
.fcard:hover{border-color:var(--faint)}
.fcard .tex{font-size:1.12rem;margin:10px 0 6px;overflow-x:auto;padding:10px 12px;background:var(--bg);border-radius:8px}
.fcard .nm{display:flex;justify-content:space-between;gap:8px;align-items:flex-start}
.fcard .d{font-size:.9rem;display:grid;gap:3px;margin-top:6px}
math{font-size:1.08em}
.star{background:none;border:0;padding:2px;color:var(--faint);display:inline-grid;place-items:center}
.star svg{width:18px;height:18px;stroke:currentColor;fill:none;stroke-width:1.7;transition:transform .3s var(--ease)}
.star.on{color:#C08A1E}.star.on svg{fill:currentColor;animation:pop .4s var(--ease)}
@keyframes pop{50%{transform:scale(1.35)}}
/* ---------- lesson ---------- */
.lesson{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:36px;align-items:start}
.lnav{display:none}
.rpanel{position:sticky;top:130px;display:grid;grid-template-columns:minmax(0,1fr);gap:10px;max-height:calc(100vh - 150px);overflow:auto;padding-bottom:10px}
.rpanel .fcard .tex{font-size:.95rem}
article h2{margin-top:48px}
.lblock{margin:0 0 18px}
p.lblock{max-width:66ch;font-size:1.03rem;line-height:1.8}
.zhblk{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:18px 20px;box-shadow:var(--shadow)}
.zhblk .stem{font-size:1.22em}
table.rules{width:100%;border-collapse:collapse;background:var(--paper);border:1px solid var(--line);border-radius:12px;overflow:hidden}
table.rules td,table.rules th{padding:12px 14px;border-bottom:1px dashed var(--line);text-align:left;vertical-align:top;font-size:.94rem}
table.rules tr:last-child td{border-bottom:0}
table.rules th{font-weight:600;color:var(--sub);font-size:.82rem}
.tw{overflow-x:auto}
/* ---------- popover ---------- */
.pop{position:fixed;z-index:50;width:min(320px,calc(100vw - 24px));background:var(--paper);border:1px solid var(--line);border-radius:16px;box-shadow:0 22px 60px -18px rgba(15,25,45,.35);padding:18px;transform-origin:var(--ox,20px) var(--oy,0);animation:popin .22s var(--ease) both}
@keyframes popin{from{opacity:0;transform:scale(.94) translateY(-4px)}}
.pop .hz{font-size:2.2rem;line-height:1.2}
.pop .py{color:var(--acc);font-size:1.02rem;margin-top:2px}
.pop .mn{font-size:1.1rem;font-weight:600;margin-top:10px}
.pop dl{display:grid;grid-template-columns:auto 1fr;gap:5px 14px;margin:10px 0 0;font-size:.9rem;padding-top:10px;border-top:1px dashed var(--line)}
.pop dt{color:var(--faint)}.pop dd{margin:0}
/* ---------- exam ---------- */
body.exam .hdr,body.exam .bottom{display:none}
body.exam #view{max-width:820px}
.exambar{display:flex;justify-content:space-between;align-items:center;gap:12px;position:sticky;top:0;background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(8px);padding:16px 0 12px;z-index:4}
.timer{font-family:"Literata",serif;font-size:1.6rem;font-weight:600;font-variant-numeric:tabular-nums}
.timer.warn{color:var(--red);animation:pulse 1s ease-in-out infinite}
@keyframes pulse{50%{opacity:.55}}
.sheet{margin-top:22px;background:var(--paper);border:1px solid var(--line);border-radius:16px;padding:16px 18px;box-shadow:var(--shadow)}
.sheet .faint{font-size:.8rem;margin-bottom:10px}
.navgrid{display:grid;grid-template-columns:repeat(12,1fr);gap:8px 6px}
.navgrid button{border:0;background:none;display:grid;justify-items:center;gap:3px;font-size:.72rem;color:var(--sub);font-variant-numeric:tabular-nums;padding:2px 0}
.navgrid button::after{content:"";width:16px;height:16px;border-radius:50%;border:1.5px solid var(--faint);transition:background .3s,border-color .3s,box-shadow .3s}
.navgrid .ans::after{background:var(--ink);border-color:var(--ink)}
.navgrid .flag{color:var(--red);font-weight:700}.navgrid .flag::after{border-color:var(--red)}
.navgrid .cur{color:var(--ink);font-weight:700}.navgrid .cur::after{box-shadow:0 0 0 4px var(--acc-t)}
dialog{border:1px solid var(--line);border-radius:16px;background:var(--paper);color:var(--ink);max-width:420px;padding:24px}
dialog[open]{animation:popin .25s var(--ease)}
dialog::backdrop{background:rgba(10,16,30,.45)}
.bottom{display:none}
.gear{display:grid;width:40px;height:40px;place-items:center;border-radius:12px;border:1px solid var(--line);color:var(--ink);background:var(--bg);flex:none;order:9;transition:border-color .2s}.gear:hover{border-color:var(--ink)}
@media (max-width:860px){.gear{display:none}}
.mob-search{display:none;margin-left:auto;width:40px;height:40px;place-items:center;border-radius:12px;border:1px solid var(--line);color:var(--ink);background:var(--bg)}
@media (max-width:860px){.mob-search{display:grid}}
.seg{display:grid;grid-template-columns:auto auto 1fr;gap:6px 18px;margin-top:14px;padding:14px 16px;background:var(--bg);border-radius:10px;animation:enter .3s var(--ease) both}
.seg .zh{font-size:1.1rem}
[data-p]:not([hidden]){animation:enter .3s var(--ease) both}
input[type=text],input[type=date],input[type=search],input[type=email],input[type=password],select{padding:9px 12px;border:1px solid var(--line);border-radius:10px;background:var(--paper);color:var(--ink);font:inherit}
details summary{cursor:pointer;color:var(--acc);font-size:.92rem}
.pmodes{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.pmode{background:var(--paper);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);padding:22px;display:flex;flex-direction:column;gap:6px;transition:transform .25s var(--ease),border-color .25s}
.pmode:hover{transform:translateY(-3px);border-color:var(--faint)}
.pmode .ic{width:40px;height:40px;border-radius:12px;background:var(--acc-t);color:var(--acc);display:grid;place-items:center;margin-bottom:6px}
.pmode .row{margin-top:auto;padding-top:10px}
.fsearch{display:flex;align-items:center;gap:10px;background:var(--paper);border:1.5px solid var(--line);border-radius:14px;padding:4px 16px;box-shadow:var(--shadow);max-width:640px;transition:border-color .2s,box-shadow .2s}
.fsearch:focus-within{border-color:var(--acc);box-shadow:0 0 0 5px var(--acc-t)}
.fsearch input{flex:1;border:0!important;background:none!important;padding:12px 0!important;font-size:1.05rem;outline:none;min-width:0}
.fres{animation:enter .25s var(--ease) both}
mark.hl{background:var(--mark);color:inherit;border-radius:2px;padding:0 1px}
/* ---------- standalone site: landing + onboarding ---------- */
.site-links,.site-cta{display:none}
body.landing .tabs,body.landing .searchbox,body.landing .gear,body.landing .mob-search,body.landing .langsw,body.landing .bottom{display:none!important}
body.landing .site-links{display:flex;gap:26px;margin-left:auto}
body.landing .site-links a{color:var(--sub);text-decoration:none;font-size:.94rem;font-weight:500;transition:color .2s}
body.landing .site-links a:hover{color:var(--ink)}
body.landing .site-cta{display:inline-flex;margin-left:18px}
body.landing #view{max-width:1180px}
.lhero{display:grid;grid-template-columns:1.05fr 1fr;gap:56px;align-items:center;padding:40px 0 20px}
.lhero h1{font-size:3.3rem;line-height:1.08;letter-spacing:-.02em;margin-bottom:18px}
.lhero .lead{font-size:1.15rem;margin-bottom:28px}
.lhero .demo-k{font-size:.85rem;color:var(--sub);margin:0 0 10px 4px;display:flex;align-items:center;gap:8px}
.lhero .demo-k::before{content:"";width:8px;height:8px;border-radius:50%;background:var(--ok);box-shadow:0 0 0 4px var(--ok-t);animation:pulse 1.6s ease-in-out infinite}
.facts{display:grid;grid-template-columns:repeat(4,1fr);margin:56px 0 0;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);overflow:hidden}
.facts>div{padding:22px 24px;border-right:1px dashed var(--line)}.facts>div:last-child{border-right:0}
.facts b{display:block;font-family:"Literata",serif;font-size:2rem;font-weight:600}
.facts span{font-size:.88rem;color:var(--sub)}
.lsec{padding-top:96px}
.lsec>h2{font-size:2.1rem;margin:0 0 10px}
.lsec>.lead{margin-bottom:30px}
.how{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;counter-reset:how}
.how>div{background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:26px;counter-increment:how;position:relative}
.how>div::before{content:counter(how);font-family:"Literata",serif;font-size:3rem;line-height:1;color:var(--line);display:block;margin-bottom:14px}
.ladder{display:grid;grid-template-columns:repeat(4,1fr);gap:0;background:var(--paper);border:1px solid var(--line);border-radius:18px;overflow:hidden;box-shadow:var(--shadow)}
.ladder>div{padding:22px;border-right:1px dashed var(--line)}.ladder>div:last-child{border-right:0}
.ladder .lv{font-size:.8rem;color:var(--sub)}
.ladder .zh{font-size:1.25rem;display:block;margin:10px 0 2px}
.ladder .py,.ladder .mnx{font-size:.85rem;color:var(--faint);display:block}
.ladder .off{text-decoration:line-through;opacity:.5}
.faq details{background:var(--paper);border:1px solid var(--line);border-radius:14px;padding:18px 22px;margin-bottom:10px;box-shadow:var(--shadow)}
.faq summary{color:var(--ink);font-size:1.02rem;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq summary::after{content:"+";font-size:1.3rem;line-height:1;color:var(--sub);transition:transform .3s var(--ease)}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{margin:12px 0 0;color:var(--sub);max-width:70ch;animation:enter .3s var(--ease) both}
.cta-end{margin-top:96px;padding:48px;text-align:center;background:var(--ink);color:var(--paper);border-radius:22px;position:relative;overflow:hidden}
.cta-end h2{color:var(--paper);font-size:2.2rem;margin:0 0 10px}
.cta-end p{opacity:.75;margin:0 0 24px}
.cta-end .btn{background:var(--paper);color:var(--ink);border-color:var(--paper)}
.cta-end .wm{position:absolute;left:-20px;bottom:-60px;font-size:14rem;opacity:.06;line-height:1;pointer-events:none}
.foot{margin-top:56px;padding-top:22px;border-top:1px solid var(--line);font-size:.85rem;color:var(--faint);display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.onb{max-width:560px;margin:10px auto 0}
.onb .panel{padding:32px}
.onb label.f{display:block;margin-top:22px;font-weight:600}
.onb label.f input{width:100%;margin-top:8px}
.choice{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:8px}
.choice button{border:1.5px solid var(--line);background:var(--paper);border-radius:12px;padding:14px;text-align:left;transition:border-color .2s,background .2s}
.choice button b{display:block;font-size:1.1rem}
.choice button span{font-size:.85rem;color:var(--sub)}
.choice button.on{border-color:var(--ink);background:var(--acc-t)}
@media (max-width:860px){
 body.landing .site-links{display:none}body.landing .site-cta{margin-left:auto}
 .lhero{grid-template-columns:1fr;gap:30px;padding-top:10px}.lhero h1{font-size:2.3rem}
 .facts,.ladder{grid-template-columns:1fr 1fr}.facts>div:nth-child(2),.ladder>div:nth-child(2){border-right:0}.facts>div:nth-child(-n+2),.ladder>div:nth-child(-n+2){border-bottom:1px dashed var(--line)}
 .how{grid-template-columns:1fr}.lsec{padding-top:64px}.lsec>h2{font-size:1.7rem}
 .cta-end{padding:32px 22px}.cta-end h2{font-size:1.7rem}
}

/* ---------- goal board ---------- */
.top2{display:grid;grid-template-columns:1.35fr 1fr;gap:18px}
.top2 .next{height:100%}
.goal{position:relative;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:24px 26px;overflow:hidden}
.goal h3{display:flex;align-items:center;gap:8px}
.goal .gtop{display:grid;grid-template-columns:auto 1fr;gap:20px;align-items:center}
.ring{width:118px;height:118px;position:relative;flex:none}
.ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:8}
.ring .bg{stroke:var(--line2)}
.ring .fg{stroke:var(--ink);stroke-linecap:round;stroke-dasharray:289;stroke-dashoffset:var(--off,289);animation:ring 1.4s var(--ease) .2s both}
@keyframes ring{from{stroke-dashoffset:289}}
.ring .c{position:absolute;inset:0;display:grid;place-items:center;text-align:center;line-height:1.05}
.ring .c b{font-family:"Literata",serif;font-size:2.1rem;font-weight:600;display:block}
.ring .c span{font-size:.74rem;color:var(--sub)}
.gauge{position:relative;margin:26px 0 8px;height:10px;border-radius:99px;background:var(--line2)}
.gauge>i{position:absolute;left:0;top:0;bottom:0;border-radius:99px;background:linear-gradient(90deg,var(--acc),var(--ok));transform-origin:left;animation:grow 1.3s var(--ease) .5s both}
.gauge .flag{position:absolute;top:-24px;transform:translateX(-50%);font-size:.74rem;font-weight:700;color:var(--red);white-space:nowrap;animation:drop .6s var(--ease) 1.2s both}
.gauge .flag::after{content:"";position:absolute;left:50%;top:18px;width:2px;height:22px;background:var(--red);transform:translateX(-50%)}
@keyframes drop{from{opacity:0;transform:translate(-50%,-10px)}}
.gauge .me{position:absolute;top:50%;width:18px;height:18px;border-radius:50%;background:var(--paper);border:3px solid var(--ink);transform:translate(-50%,-50%);animation:slide 1.3s var(--ease) .5s both}
@keyframes slide{from{left:0}}
.gl{display:flex;justify-content:space-between;font-size:.8rem;color:var(--sub)}
.today{margin-top:16px;padding-top:14px;border-top:1px dashed var(--line);display:flex;align-items:center;gap:12px;font-size:.92rem}
.today .bar{flex:1}
.gform{display:grid;gap:12px;margin-top:6px}
.gform input{width:100%}
/* ---------- landing motion ---------- */
.lhero{position:relative}
.lhero>*{position:relative;z-index:1}
.graph{position:absolute!important;z-index:0!important;left:-40px;top:-20px;width:62%;height:auto;pointer-events:none;opacity:.9}
.graph path,.graph line{fill:none;stroke-linecap:round}
.graph .ax{stroke:var(--line);stroke-width:1.5;stroke-dasharray:700;animation:pen2 1.2s var(--ease) both}
.graph .c1{stroke:var(--acc);stroke-width:2;opacity:.2;stroke-dasharray:900;animation:pen2 2.4s var(--ease) .5s both}
.graph .c2{stroke:var(--red);stroke-width:2;opacity:.16;stroke-dasharray:900;animation:pen2 2.6s var(--ease) 1s both}
.graph text{font:italic 15px "Literata",serif;fill:var(--faint);opacity:0;animation:fadein .6s ease 2.6s both}
@keyframes pen2{from{stroke-dashoffset:900}to{stroke-dashoffset:0}}
@keyframes fadein{to{opacity:1}}
.lhero h1 .w{display:inline-block;animation:rise .7s var(--ease) both;animation-delay:calc(var(--i) * 70ms + 80ms)}
@keyframes rise{from{opacity:0;transform:translateY(0.45em)}}
.lhero .lead,.lhero .row{animation:enter .7s var(--ease) both}.lhero .lead{animation-delay:.45s}.lhero .row{animation-delay:.6s}
.demo-wrap{animation:floatin 1s var(--ease) .35s both}
@keyframes floatin{from{opacity:0;transform:translate(40px,10px) rotate(2.5deg)}}
.demo-wrap .qcard{transition:transform .5s var(--ease),box-shadow .5s}
.demo-wrap:hover .qcard{transform:rotate(-.4deg) translateY(-3px);box-shadow:0 30px 60px -30px rgba(20,33,61,.4)}
.rv{opacity:0;transform:translateY(24px);transition:opacity .8s var(--ease),transform .8s var(--ease)}
.rv.in{opacity:1;transform:none}
.how>div.rv:nth-child(2){transition-delay:.12s}.how>div.rv:nth-child(3){transition-delay:.24s}
.ladder .mnx,.ladder .py{position:relative;width:fit-content}
.ladder .off{opacity:1;text-decoration:none}
.ladder .off::after{content:"";position:absolute;left:0;top:55%;height:1.5px;width:0;background:var(--red);transition:width .6s var(--ease)}
.ladder.in .off::after{width:100%}
.ladder.in .off{color:var(--line)}
.ladder>div:nth-child(3) .off::after{transition-delay:.5s}.ladder>div:nth-child(4) .py.off::after{transition-delay:.8s}.ladder>div:nth-child(4) .mnx.off::after{transition-delay:1s}
.gsec{display:grid;grid-template-columns:1.1fr 1fr;gap:48px;align-items:center}
.gsec .goal .ring .fg,.gsec .goal .gauge>i,.gsec .goal .gauge .flag,.gsec .goal .gauge .me,.gsec .bar>i{animation-play-state:paused}
.gsec.in .goal .ring .fg,.gsec.in .goal .gauge>i,.gsec.in .goal .gauge .flag,.gsec.in .goal .gauge .me,.gsec.in .bar>i{animation-play-state:running}
@media (max-width:860px){.gsec{grid-template-columns:1fr;gap:28px}}
/* ---------- v6 ---------- */
.chip.sug{border-style:dashed;border-color:var(--acc)}
.msteps{margin:8px 0 0;padding-left:22px}.msteps li{margin:5px 0;line-height:1.6}
.orig{margin-top:10px;font-size:.87rem;color:var(--sub)}
.resume{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;background:var(--ink);color:var(--paper);border-radius:14px;padding:12px 16px;margin-bottom:18px;animation:enter .4s var(--ease) both}
.resume span{display:flex;align-items:center;gap:8px}.resume .btn{background:var(--paper);color:var(--ink);border-color:var(--paper)}
#acct{display:contents}
.acct-av{width:36px;height:36px;border-radius:50%;background:var(--acc);color:#fff;display:grid;place-items:center;font-weight:700;text-decoration:none;flex:none}
body.landing #acct .btn{margin-left:10px}
/* ---------- premium ---------- */
.plan{border:1px solid var(--line);background:var(--paper);border-radius:99px;padding:5px 11px;font-size:.8rem;font-weight:600;color:var(--sub);white-space:nowrap}
button.plan:hover{border-color:var(--ink);color:var(--ink)}
.plan.prem{background:linear-gradient(135deg,#1F3A8A,#1E1633);color:#FFE27A;border-color:transparent}
.pbadge{display:inline-block;font-size:.68rem;font-weight:800;letter-spacing:.12em;padding:3px 9px;border-radius:99px;background:var(--mark);color:#5A4300;vertical-align:middle}
.paydlg{width:min(460px,calc(100vw - 24px))}
.price{font-family:"Literata",serif;font-size:2.4rem;font-weight:600;margin:14px 0 6px;display:flex;align-items:baseline;gap:10px}.price span{font-family:inherit;font-size:.85rem;color:var(--sub);font-weight:400}
.plist{list-style:none;padding:0;margin:12px 0 18px;display:grid;gap:8px}.plist li{display:flex;gap:10px;align-items:flex-start;font-size:.94rem}.plist svg{color:var(--ok);margin-top:3px;flex:none}
.pbox{border:1px solid var(--line);border-radius:12px;padding:14px;background:var(--bg)}
.prow{display:flex;align-items:center;gap:10px;padding:6px 0;border-bottom:1px dashed var(--line);font-size:.94rem}.prow:last-child{border-bottom:0}.prow span{color:var(--sub);min-width:110px}.prow b{flex:1}
.prow.hl b{background:var(--mark);padding:1px 6px;border-radius:4px;flex:none}.prow .chip{padding:2px 10px;font-size:.78rem;margin-left:auto}
.tiers{display:grid;grid-template-columns:1fr 1fr;gap:18px;max-width:820px}
.tier{background:var(--paper);border:1px solid var(--line);border-radius:18px;padding:26px;box-shadow:var(--shadow);display:flex;flex-direction:column}
.tier.hot{border:2px solid var(--ink);position:relative}
.tier .tn{font-weight:600;display:flex;align-items:center;gap:8px}
.tier .tp{font-family:"Literata",serif;font-size:2.1rem;font-weight:600;margin:8px 0 0}.tier .tp span{font-size:.9rem;color:var(--sub);font-family:inherit;font-weight:400}
.tier .plist{flex:1}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);z-index:95;display:flex;gap:12px;align-items:center;background:var(--ink);color:var(--paper);padding:12px 14px 12px 18px;border-radius:14px;box-shadow:0 18px 40px -12px rgba(0,0,0,.4);max-width:calc(100vw - 24px);animation:enter .35s var(--ease) both;transition:opacity .5s,transform .5s}
.toast.out{opacity:0;transform:translate(-50%,10px)}.toast .btn{background:var(--mark);color:#3A2B00;border-color:var(--mark);flex:none}
@media (max-width:860px){.tiers{grid-template-columns:1fr}.toast{bottom:84px}.plan{padding:4px 8px}}
/* ---------- auth ---------- */
.authdlg{width:min(420px,calc(100vw - 24px));padding:28px;position:relative}
.authdlg .x{position:absolute;right:14px;top:12px;border:0;background:none;font-size:1.1rem;color:var(--sub)}
.gbtn{width:100%;justify-content:center;margin-top:18px;gap:10px}
.or{display:flex;align-items:center;gap:10px;margin:18px 0 4px;color:var(--faint);font-size:.84rem}.or::before,.or::after{content:"";flex:1;height:1px;background:var(--line)}
.af{display:block;margin-top:12px;font-size:.9rem;font-weight:500}.af input{display:block;width:100%;margin-top:6px}
.aerr{margin-top:12px;padding:10px 12px;border-radius:10px;background:var(--red-t);color:var(--red);font-size:.9rem}
.aok{margin-top:12px;padding:10px 12px;border-radius:10px;background:var(--ok-t);color:var(--ok);font-size:.9rem}
.site-cta{white-space:nowrap}
@media (max-width:860px){#acct .btn{padding:6px 9px}#acct .btn .lbl{display:none}body.landing .site-cta{padding:6px 12px}}
.lockp{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;border:1.5px dashed var(--line);border-radius:14px;padding:14px 16px;background:var(--paper)}.lockp span{display:flex;gap:8px;align-items:center}
.alinks{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;margin-top:16px;font-size:.88rem;color:var(--sub)}
/* ---------- celebrate ---------- */
.burst{position:absolute;left:50%;top:50%;width:0;height:0;pointer-events:none}
.burst i{position:absolute;width:6px;height:6px;border-radius:50%;background:var(--ok);left:-3px;top:-3px;animation:burst .7s var(--ease) both;transform:rotate(var(--a)) translateX(0)}
.burst i:nth-child(odd){background:var(--mark-s)}
@keyframes burst{to{transform:rotate(var(--a)) translateX(26px) scale(.3);opacity:0}}
.opt.ok .L{overflow:visible}
.seal{position:fixed;inset:0;z-index:80;display:grid;place-items:center;pointer-events:none;background:radial-gradient(circle,rgba(255,255,255,.0) 40%,rgba(20,33,61,.08));animation:sealbg 2.2s ease both}
.seal .s{width:150px;height:150px;border:5px solid var(--red);border-radius:18px;color:var(--red);display:grid;place-items:center;font-family:"Noto Serif SC",serif;font-size:5.6rem;font-weight:600;line-height:1;transform:rotate(-12deg);animation:stamp 2.2s var(--ease) both;box-shadow:inset 0 0 0 3px color-mix(in srgb,var(--red) 30%,transparent);background:color-mix(in srgb,var(--paper) 70%,transparent)}
.seal .cap{position:absolute;top:calc(50% + 100px);font-weight:600;color:var(--ink);background:var(--paper);padding:8px 16px;border-radius:99px;box-shadow:var(--shadow);animation:sealcap 2.2s var(--ease) both}
@keyframes stamp{0%{opacity:0;transform:scale(2.4) rotate(-20deg)}18%{opacity:1;transform:scale(.92) rotate(-12deg)}26%{transform:scale(1) rotate(-12deg)}82%{opacity:1}100%{opacity:0;transform:scale(1) rotate(-12deg)}}
@keyframes sealcap{0%,20%{opacity:0;transform:translateY(8px)}32%{opacity:1;transform:none}82%{opacity:1}100%{opacity:0}}
@keyframes sealbg{0%,85%{opacity:1}100%{opacity:0}}
.count{position:fixed;inset:0;z-index:90;display:grid;place-items:center;background:var(--bg)}
.count b{font-family:"Literata",serif;font-size:9rem;font-weight:600;color:var(--ink);animation:cnt .8s var(--ease) both}
.count small{position:absolute;top:calc(50% + 90px);color:var(--sub)}
@keyframes cnt{0%{opacity:0;transform:scale(1.6)}30%{opacity:1;transform:scale(1)}80%{opacity:1}100%{opacity:0;transform:scale(.8)}}
@media (max-width:860px){.top2{grid-template-columns:1fr}.top2 .goal{order:-1}.graph{width:120%;left:-30%;top:-40px;opacity:.6}.ring{width:100px;height:100px}.ring .c b{font-size:1.8rem}}
@media (max-width:1000px){.lesson{grid-template-columns:1fr}.rpanel{position:static;max-height:none}}
@media (max-width:860px){
 .hdr-in{padding:0 16px}.hdr-top{height:58px;gap:10px}.brand .era{display:none}
 .searchbox{display:none}.tabs{display:none}
 #view{padding:24px 16px 110px}
 h1{font-size:1.8rem}
 .hero .wm{font-size:8rem;top:-10px}
 .g5{grid-template-columns:1fr 1fr}.g5>.panel{border-bottom:1px dashed var(--line)}.g5>.panel:first-child{grid-column:1/-1}
 .g2,.g3,.home2,.pmodes{grid-template-columns:1fr}
 .grid.g3:has(>.stat){grid-template-columns:1fr 1fr 1fr}
 .next{grid-template-columns:1fr;padding:22px 20px 22px 44px}.next::before{left:24px}.next .ttl{font-size:1.7rem}
 .qcard{padding:20px 18px 20px 38px;border-radius:16px}.qcard::before{left:22px}
 .stem{font-size:1.28em}
 .chap-h .big{font-size:2.6rem}
 .topic{padding:12px 16px}
 .bottom{display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;background:color-mix(in srgb,var(--paper) 94%,transparent);backdrop-filter:blur(10px);border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom,0px);z-index:20}
 .bottom a{position:relative;display:grid;justify-items:center;gap:3px;padding:10px 0 8px;font-size:.7rem;text-decoration:none;color:var(--faint);font-weight:500;transition:color .2s}
 .bottom a.on{color:var(--ink)}
 .bottom a.on::before{content:"";position:absolute;top:0;left:30%;right:30%;height:3px;border-radius:0 0 3px 3px;background:var(--ink);animation:grow .35s var(--ease)}
 .bottom svg.i{transition:transform .3s var(--ease)}.bottom a.on svg.i{transform:translateY(-2px)}
 .navgrid{grid-template-columns:repeat(8,1fr)}
}
@media (max-width:860px){.hs{flex-wrap:nowrap;overflow-x:auto;scrollbar-width:none;margin-left:-16px!important;margin-right:-16px!important;padding:0 16px}.hs::-webkit-scrollbar{display:none}.hs>*{flex:none}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}}

/* prerender guard: returning users skip the landing flash */
.ret #view[data-prerender]{visibility:hidden}