@font-face{font-family:"Heebo";font-style:normal;font-display:swap;font-weight:100 900;src:url(../fonts/heebo-hebrew-wght-normal.woff2) format("woff2");unicode-range:U+0307-0308,U+0590-05FF,U+200C-2010,U+20AA,U+25CC,U+FB1D-FB4F}
@font-face{font-family:"Heebo";font-style:normal;font-display:swap;font-weight:100 900;src:url(../fonts/heebo-latin-wght-normal.woff2) format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Rubik";font-style:normal;font-display:swap;font-weight:300 900;src:url(../fonts/rubik-hebrew-wght-normal.woff2) format("woff2");unicode-range:U+0307-0308,U+0590-05FF,U+200C-2010,U+20AA,U+25CC,U+FB1D-FB4F}
@font-face{font-family:"Rubik";font-style:normal;font-display:swap;font-weight:300 900;src:url(../fonts/rubik-latin-wght-normal.woff2) format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
:root{--bg:#f4f3ff;--card:#fff;--ink:#1e1b4b;--text:#27253f;--muted:#6b6a85;--line:#e4e2f3;--accent:#4f46e5;--accent2:#7c3aed;--accent-soft:#eef0ff;--good:#059669;--goodbg:#ecfdf5;--bad:#e11d48;--badbg:#fff1f3;--curve:#3730a3;--asym:#ea580c;
--l1:#059669;--l1bg:#d1fae5;--l2:#b45309;--l2bg:#fef3c7;--l3:#be123c;--l3bg:#ffe4e6;--r:20px;--shadow:0 1px 2px rgba(30,27,75,.05),0 8px 28px rgba(79,70,229,.09)}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;color:var(--text);font-family:"Heebo","Rubik","Segoe UI",Arial,sans-serif;font-size:17px;line-height:1.6;min-height:100vh;
background:radial-gradient(1200px 500px at 100% -10%,#e0e7ff 0,rgba(224,231,255,0) 60%),radial-gradient(900px 500px at -10% 30%,#fae8ff 0,rgba(250,232,255,0) 55%),var(--bg);background-attachment:fixed}
h1,h2,h3,.primary,.pill,.chip,.tab,.qnum,.ghost{font-family:"Rubik","Heebo",Arial,sans-serif}
a{color:var(--accent)}
.wrap{max-width:1040px;margin:0 auto;padding:0 16px}
.hero{background:linear-gradient(120deg,#4338ca 0%,#6d28d9 55%,#a21caf 100%);color:#fff;padding:16px 0 46px;position:relative;overflow:hidden}
.hero:after{content:"";position:absolute;inset:auto -10% -60px -10%;height:90px;background:var(--bg);border-radius:50% 50% 0 0/100% 100% 0 0}
.hero:before{content:"";position:absolute;width:340px;height:340px;left:-120px;top:-170px;border-radius:50%;background:radial-gradient(circle,rgba(255,255,255,.18),rgba(255,255,255,0) 70%)}
.hero-in{display:flex;align-items:center;gap:14px;position:relative;z-index:1}
.logo{width:46px;height:46px;flex:none;filter:drop-shadow(0 4px 10px rgba(0,0,0,.18))}
.hero h1{margin:0;font-size:1.45rem;line-height:1.2;font-weight:700}
.hero .sub{margin:3px 0 0;opacity:.88;font-size:.95rem}
.crumbs{position:relative;z-index:1;display:flex;gap:8px;flex-wrap:wrap;margin-bottom:10px;font-size:.88rem}
.crumbs a{color:#fff;opacity:.9;text-decoration:none;background:rgba(255,255,255,.14);border-radius:999px;padding:3px 12px}
.crumbs a:hover{opacity:1;background:rgba(255,255,255,.24)}
main{position:relative;margin-top:-28px;padding-bottom:30px}
.card{background:var(--card);border:1px solid rgba(228,226,243,.9);border-radius:var(--r);padding:16px 16px 18px;box-shadow:var(--shadow)}
.pill{display:inline-block;border-radius:999px;padding:2px 10px;font-size:.8rem;font-weight:600;white-space:nowrap}
.pill.l1{background:var(--l1bg);color:var(--l1)}.pill.l2{background:var(--l2bg);color:var(--l2)}.pill.l3{background:var(--l3bg);color:var(--l3)}
.pill.soon{background:#ede9fe;color:#6d28d9}.pill.vid{background:#e0f2fe;color:#0369a1}
.primary{background:linear-gradient(120deg,var(--accent),var(--accent2));color:#fff;border:0;border-radius:14px;padding:11px 22px;font-weight:600;font-size:1rem;cursor:pointer;box-shadow:0 8px 20px rgba(79,70,229,.25);transition:transform .12s}
.primary:active{transform:scale(.97)}
.ghost{background:#fff;border:1.5px solid var(--line);color:var(--ink);border-radius:12px;padding:8px 14px;font-size:.95rem;font-weight:600;cursor:pointer}
.ghost:hover{border-color:#a5b4fc}
.ghost.on{background:var(--accent-soft);border-color:#c7d2fe}
.katex{direction:ltr;unicode-bidi:isolate}
.m .katex{white-space:nowrap}
.dmath{direction:ltr;overflow-x:auto;overflow-y:hidden;text-align:center;font-size:1.15rem;background:linear-gradient(180deg,#f8f7ff,#f3f2ff);border-radius:14px;padding:0 8px;margin:8px 0}
.dmath .katex-display{margin:.5em 0}
svg{direction:ltr}
/* ---- index ---- */
.intro{margin:0 0 14px}
.intro p{margin:4px 0}
.sec-title{font-size:1.1rem;color:var(--ink);margin:22px 4px 10px;display:flex;align-items:center;gap:8px}
.grid{display:grid;grid-template-columns:1fr;gap:12px}
@media(min-width:640px){.grid{grid-template-columns:1fr 1fr}}
@media(min-width:960px){.grid{grid-template-columns:1fr 1fr 1fr}}
.tcard{display:flex;gap:12px;align-items:flex-start;text-decoration:none;color:inherit;transition:transform .12s,box-shadow .2s;animation:rise .4s ease both}
.tcard:hover{transform:translateY(-2px);box-shadow:0 2px 4px rgba(30,27,75,.05),0 14px 34px rgba(79,70,229,.16)}
.tnum{flex:none;width:44px;height:44px;border-radius:14px;display:grid;place-items:center;font:700 1.2rem "Rubik",sans-serif;color:#fff;background:linear-gradient(135deg,#6366f1,#8b5cf6)}
.tcard.soon .tnum{background:linear-gradient(135deg,#a78bfa,#f0abfc)}
.tbody{flex:1;min-width:0}
.tbody h3{margin:0 0 2px;font-size:1.06rem;color:var(--ink);line-height:1.3}
.tbody p{margin:0 0 8px;color:var(--muted);font-size:.9rem;line-height:1.4}
.tmeta{display:flex;gap:6px;flex-wrap:wrap;align-items:center;font-size:.8rem;color:var(--muted)}
.mini{height:6px;background:#e8e6f6;border-radius:99px;overflow:hidden;margin-top:8px}
.mini i{display:block;height:100%;background:linear-gradient(90deg,#34d399,#059669);border-radius:99px}
.back{display:inline-flex;align-items:center;gap:6px;margin:18px 4px 0;font-weight:600;text-decoration:none}
/* ---- topic page ---- */
.layout{display:grid;grid-template-columns:minmax(0,1fr);gap:14px}
.layout>*,#content,.card,.steps>li,.ex{min-width:0}
@media(max-width:899px){.side{display:none}}
@media(min-width:900px){.layout{grid-template-columns:280px minmax(0,1fr)}.side{position:sticky;top:12px;align-self:start;max-height:calc(100vh - 24px);overflow:auto}}
.side h3{margin:2px 4px 8px;font-size:.95rem;color:var(--muted);font-weight:600}
.plist{list-style:none;margin:0;padding:0}
.plist li a{display:flex;align-items:center;gap:8px;padding:8px 10px;border-radius:12px;color:var(--ink);text-decoration:none;font-size:.95rem}
.plist li a:hover{background:#f5f4ff}
.plist li a.on{background:var(--accent-soft);font-weight:600}
.plist .ic{flex:none;width:26px;height:26px;border-radius:8px;display:grid;place-items:center;font-size:.8rem;font-weight:700;background:#eef0f7;color:#555}
.plist .ic.l1{background:var(--l1bg);color:var(--l1)}.plist .ic.l2{background:var(--l2bg);color:var(--l2)}.plist .ic.l3{background:var(--l3bg);color:var(--l3)}
.plist .ic.lesson{background:linear-gradient(135deg,#6366f1,#8b5cf6);color:#fff}
.plist .ok{margin-inline-start:auto;color:var(--good);font-weight:700}
.plist .vd{font-size:.75rem;color:#0369a1;margin-inline-start:auto}
.plist .ok+.vd,.plist .vd+.ok{margin-inline-start:4px}
.plist .sep{font-size:.8rem;color:var(--muted);padding:10px 10px 2px}
.tabs{display:flex;gap:6px;margin:0 0 12px;background:rgba(255,255,255,.75);border:1px solid var(--line);border-radius:14px;padding:4px;position:sticky;top:6px;z-index:5;backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}
.tab{flex:1;border:0;background:transparent;border-radius:10px;padding:9px 6px;font-size:.98rem;font-weight:600;color:var(--muted);cursor:pointer}
.tab.on{background:var(--ink);color:#fff}
@media(min-width:900px){.tabs{display:none}}
.video{border-radius:16px;overflow:hidden;background:#0f0d2e;margin:0 0 14px;aspect-ratio:16/9;position:relative}
.video video{width:100%;height:100%;display:block;background:#000}
.vsoon{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;color:#c7c6e8;gap:6px;font-size:.95rem;text-align:center;padding:10px}
.vsoon svg{width:46px;height:46px;opacity:.7}
.vcap{display:flex;justify-content:space-between;color:var(--muted);font-size:.85rem;margin:-8px 4px 12px}
.lesson h2{margin:0 0 6px;font-size:1.3rem;color:var(--ink)}
.lesson h3{margin:18px 0 6px;font-size:1.08rem;color:var(--ink)}
.lesson p{margin:8px 0}
.lesson ol{margin:6px 0;padding-inline-start:22px}
.lesson li{margin:4px 0}
.rule{background:linear-gradient(135deg,#eef2ff,#faf5ff);border:1px solid #ddd6fe;border-radius:16px;padding:10px 14px;margin:12px 0}
.ex{border:1px solid var(--line);border-radius:16px;padding:12px 14px;margin:14px 0;background:#fcfcff}
.ex .et{font-weight:700;color:var(--accent);font-family:"Rubik",sans-serif;margin-bottom:2px}
.steps{list-style:none;counter-reset:s;margin:8px 0 0;padding:0}
.steps>li{counter-increment:s;position:relative;padding:4px 34px 4px 0;margin:6px 0}
.steps>li:before{content:counter(s);position:absolute;right:0;top:4px;width:24px;height:24px;border-radius:50%;background:var(--accent-soft);color:var(--accent);font:700 .8rem/24px "Rubik",sans-serif;text-align:center}
.fig{margin:10px 0;text-align:center}
.fig svg.plot{width:100%;max-width:420px;height:auto;border:1px solid var(--line);border-radius:14px}
.fig figcaption{font-size:.88rem;color:var(--muted);margin-top:4px}
.ttable{width:100%;border-collapse:separate;border-spacing:0;margin:10px 0;font-size:.93rem;border:1px solid var(--line);border-radius:14px;overflow:hidden}
.ttable th{background:var(--accent-soft);color:var(--ink);padding:8px;text-align:right}
.ttable td{padding:8px;border-top:1px solid var(--line);vertical-align:middle}
.ttable-wrap{overflow-x:auto}
.itab-wrap{direction:ltr;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:8px 0}
table.itab{border-collapse:collapse;margin:0 auto;font-size:.92rem}
table.itab th,table.itab td{border:1.5px solid #3b3a52;text-align:center;padding:4px 6px;min-width:34px;height:34px;white-space:nowrap}
table.itab th{background:#f1f0fb;font-weight:600}
table.itab td.pt{background:#fafaff}
table.itab .up,table.itab .down{font-size:1.25rem;line-height:1}
table.itab .pos{color:var(--good);font-weight:700}table.itab .neg{color:var(--bad);font-weight:700}
table.itab .na{font-size:.75rem;color:var(--muted)}
/* question */
.qnav{display:flex;gap:6px;flex-wrap:wrap;margin:0 0 12px}
.qn{width:38px;height:38px;border-radius:12px;border:2px solid transparent;font:700 .95rem "Rubik",sans-serif;cursor:pointer;position:relative}
.qn.l1{background:var(--l1bg);color:var(--l1)}.qn.l2{background:var(--l2bg);color:var(--l2)}.qn.l3{background:var(--l3bg);color:var(--l3)}
.qn.on{border-color:var(--ink)}
.qn.done:after{content:"✓";position:absolute;top:-6px;left:-6px;width:17px;height:17px;border-radius:50%;background:var(--good);color:#fff;font-size:.65rem;line-height:17px}
.qhead{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px}
.qnum{font-weight:700;color:var(--ink)}
.qprompt{font-size:1.02rem}
.qsvg{margin:10px 0;text-align:center}
.qsvg svg{width:100%;max-width:420px;height:auto;border:1px solid var(--line);border-radius:14px}
.field{margin:12px 0}
.flabel{display:block;font-weight:600;color:var(--ink);font-size:.95rem;margin-bottom:5px}
.frow{display:flex;gap:6px;align-items:center}
.frow input{flex:1;min-width:0;font:inherit;font-size:1.05rem;padding:10px 12px;border:1.5px solid var(--line);border-radius:12px;background:#fbfbff;color:var(--ink);direction:ltr;text-align:left}
.frow input:focus{outline:0;border-color:var(--accent);box-shadow:0 0 0 4px rgba(79,70,229,.15);background:#fff}
.frow input[readonly]{background:#f1f0fb;color:var(--muted)}
.none{flex:none;border:1.5px solid var(--line);background:#fff;border-radius:12px;padding:9px 12px;font:600 .9rem "Rubik",sans-serif;color:var(--muted);cursor:pointer}
.none.on{background:var(--ink);color:#fff;border-color:var(--ink)}
.mark{flex:none;width:28px;text-align:center;font-weight:800;font-size:1.1rem}
.mark.ok{color:var(--good)}.mark.no{color:var(--bad)}
.field.ok input{border-color:var(--good);background:var(--goodbg)}
.field.no input{border-color:var(--bad);background:var(--badbg)}
.choices{display:flex;gap:8px;flex-wrap:wrap}
.choices .cbtn{border:2px solid var(--line);background:#fff;border-radius:12px;padding:8px 16px;font:inherit;cursor:pointer;color:var(--ink)}
.choices.svgs{display:grid;grid-template-columns:1fr 1fr;gap:8px}
@media(min-width:760px){.choices.svgs{grid-template-columns:repeat(4,1fr)}}
.choices.svgs .cbtn{padding:4px;position:relative}
.choices.svgs .cbtn svg{width:100%;height:auto;display:block}
.choices .lab{position:absolute;top:5px;right:5px;background:var(--ink);color:#fff;border-radius:8px;min-width:22px;height:22px;display:grid;place-items:center;font:700 .85rem "Rubik",sans-serif}
.choices .cbtn.sel{border-color:var(--accent);box-shadow:0 0 0 3px rgba(79,70,229,.18)}
.field.ok .cbtn.sel{border-color:var(--good);background:var(--goodbg)}
.field.no .cbtn.sel{border-color:var(--bad);background:var(--badbg)}
.qbtns{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0 4px}
.box{border-radius:14px;padding:10px 14px;margin:10px 0;animation:rise .3s ease both}
.box.hint{background:#fffbeb;border:1px solid #fde68a}
.box.res.ok{background:var(--goodbg);border:1px solid #a7e3c9}
.box.res.no{background:var(--badbg);border:1px solid #fbb6c3}
.box.sol{background:#fff;border:1px solid var(--line)}
.box b.t{display:block;font-family:"Rubik",sans-serif;margin-bottom:2px}
.solvid{margin:6px 0 10px}
.solvid video{width:100%;border-radius:12px;background:#000;aspect-ratio:16/9}
.nextrow{display:flex;justify-content:space-between;gap:8px;margin-top:12px}
.texerr{color:red}
.foot{color:var(--muted);font-size:.84rem;text-align:center;margin:16px 0 20px}
.hidden{display:none!important}
@keyframes rise{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
@keyframes pop{0%{transform:scale(.9)}60%{transform:scale(1.04)}100%{transform:none}}
.pop{animation:pop .35s ease both}
@media (prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important}}
@media (max-width:420px){body{font-size:16px}.wrap{padding:0 10px}.hero h1{font-size:1.25rem}.card{padding:14px 12px 16px}}

.steps .m,.qprompt .m,.box .m,.lesson p .m{display:inline-block;max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle;padding:2px 0}
.steps .m .katex{white-space:nowrap}

.whobox{margin:12px 0 0;display:flex;flex-wrap:wrap;align-items:center;gap:6px 12px;font-size:.95rem}
.whobox small{color:var(--muted);flex-basis:100%}
.whobox .linkbtn{background:none;border:0;color:var(--accent);font:inherit;font-weight:600;cursor:pointer;padding:0}
.whoform{width:100%}
.whoform small{display:inline;color:var(--muted)}
.whoform .frow{margin-top:8px;flex-wrap:wrap}
.whoform input{flex:1;min-width:120px;font:inherit;padding:9px 12px;border:1.5px solid var(--line);border-radius:12px;background:#fbfbff;direction:rtl;text-align:right}
.whoform .primary{padding:9px 18px}