/* =====================================================================================================
   «Тетрадь» · design system of shkolamarselya.ru (Design slice). Phone first: base rules are for 360-599 px,
   then @media (min-width: 600px) tablet and (min-width: 1024px) desktop. No inline styles anywhere (CSP).
   Sections: 1 tokens · 2 base · 3 type · 4 layout · 5 paper · 6 buttons · 7 header, menu, bottom nav, footer ·
   8 course card · 9 lessons · 10 price · 11 chips, tabs · 12 forms · 13 toasts, sheets, dialogs · 14 sticker,
   hints, howto · 15 progress, badges, avatars · 16 empty, table, accordion, skeleton, stepper ·
   17 trainer marks · 18 tablet · 19 desktop · 20 motion
   ===================================================================================================== */

/* ---------- 1 tokens ---------- */
:root{
  color-scheme:light;
  --paper:#f6f1e4; --paper-lo:#ece4d0; --sheet:#fffdf6; --sticker:#fff2a8;
  --ink:#1c2a4a; --ink-2:#46506a; --pencil:#5c6476; --pencil-lo:#8a90a0;
  --line:rgba(28,42,74,.15); --line-2:rgba(28,42,74,.32);
  --grid:rgba(43,79,166,.085); --grid-sheet:rgba(43,79,166,.07);
  --pen:#d6402c; --pen-ink:#b5301f; --pen-soft:rgba(214,64,44,.1);
  --blue:#2b4fa6; --blue-soft:rgba(43,79,166,.1);
  --marker:#ffd84a; --marker-soft:rgba(255,216,74,.42); --marker-hover:#ffcd24;
  --ok:#2e7350; --ok-soft:#e1efe5;
  /* subjects: --sp spine / icon, --cv cover */
  --math:#2b4fa6; --math-cv:#e2e9f7;
  --fiz:#6b4fa0; --fiz-cv:#ebe4f4;
  --him:#21766b; --him-cv:#dcede8;
  --f-text:"Golos Text","Golos Text Fallback",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;
  --f-head:"Unbounded","Unbounded Fallback","Golos Text",system-ui,sans-serif;
  --f-hand:"Caveat","Golos Text",cursive;
  --gut:16px; --wrap:1180px; --bnav-h:64px; --hdr-h:60px; --mw:20px;
  --r-s:6px; --r-m:10px; --r-l:16px;
  --r-hand:13px 17px 12px 16px/16px 12px 17px 13px;
  --sh-1:0 1px 1px rgba(28,42,74,.06),0 6px 14px -10px rgba(28,42,74,.45);
  --sh-2:0 1px 2px rgba(28,42,74,.08),0 18px 36px -22px rgba(28,42,74,.6);
  --safe-b:env(safe-area-inset-bottom,0px);
  --grid-bg:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  --grid-sheet-bg:linear-gradient(var(--grid-sheet) 1px,transparent 1px),linear-gradient(90deg,var(--grid-sheet) 1px,transparent 1px);
}

/* ---------- 2 base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-padding-top:76px}
body{margin:0;min-height:100vh;min-height:100dvh;display:flex;flex-direction:column;
  background-color:var(--paper);background-image:var(--grid-bg);background-size:30px 30px;
  color:var(--ink);font:400 17px/1.55 var(--f-text);-webkit-font-smoothing:antialiased;overflow-wrap:break-word}
main{flex:1 0 auto;display:block}
img,svg,video{max-width:100%}
img{height:auto}
a{color:var(--blue);text-decoration-thickness:1.5px;text-underline-offset:3px}
a:hover{color:var(--ink)}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
:focus-visible{outline:3px solid var(--blue);outline-offset:2px;border-radius:4px}
::selection{background:var(--marker)}
[hidden]{display:none!important}
hr{border:0;border-top:1.5px dashed var(--line-2);margin:24px 0}
.sr-only{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.skip-link{position:absolute;left:12px;top:-60px;z-index:200;padding:12px 16px;background:var(--ink);color:#fff;border-radius:8px;font-weight:600}
.skip-link:focus{top:12px;color:#fff}
.ico{width:24px;height:24px;flex:none;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;vertical-align:middle}
.ico-s{width:18px;height:18px}
.ico-l{width:32px;height:32px}
.nowrap{white-space:nowrap}
.num{font-variant-numeric:tabular-nums}

/* ---------- 3 type ---------- */
:where(h1,h2,h3,h4){margin:0 0 .45em;font-family:var(--f-head);color:var(--ink);letter-spacing:-.015em;text-wrap:balance}
:where(h1),.h1{font-weight:800;font-size:clamp(27px,5.4vw + 6px,54px);line-height:1.1}
:where(h2),.h2{font-weight:800;font-size:clamp(22px,3.2vw + 10px,38px);line-height:1.15}
:where(h3),.h3{font-weight:700;font-size:clamp(18px,.8vw + 15px,23px);line-height:1.25}
:where(h4),.h4{font-weight:700;font-size:17px;line-height:1.3}
:where(p,ul,ol,dl){margin:0 0 1em}
.lead{font-size:clamp(18px,.6vw + 16px,21px);line-height:1.5;color:var(--ink-2)}
.muted{color:var(--pencil)}
.small{font-size:16px;line-height:1.45}
.kick{display:inline-block;margin:0 0 4px;font:700 25px/1.05 var(--f-hand);color:var(--pen-ink);transform:rotate(-2deg);transform-origin:left bottom}
.kick-blue{color:var(--blue)}
.hand{font-family:var(--f-hand);font-weight:700}
.pen{color:var(--pen-ink)}
.ink{color:var(--blue)}
.mk{background:linear-gradient(transparent 52%,var(--marker-soft) 52% 92%,transparent 92%);-webkit-box-decoration-break:clone;box-decoration-break:clone;padding:0 .12em}
.ul-pen{background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 12' preserveAspectRatio='none'%3E%3Cpath d='M2 8C50 3 120 5 198 4' fill='none' stroke='%23d6402c' stroke-width='2.4' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat 0 100%/100% 8px;padding-bottom:5px}
.prose{max-width:68ch}
.t-task{font:500 17px/1.5 var(--f-text);color:var(--ink);max-width:760px}
.t-young,.t-young .t-task{font-size:20px;line-height:1.5}
.prose :where(ul,ol){padding-left:1.3em}
.prose li{margin:.3em 0}
.prose li::marker{color:var(--pen-ink)}
.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:0 8px;margin:0 0 12px;padding:0;list-style:none;font-size:16px;color:var(--pencil)}
.crumbs a{display:inline-flex;align-items:center;min-height:44px;color:var(--blue);text-decoration:none}
.crumbs a:hover{text-decoration:underline}
.crumbs li+li::before{content:"·";margin-right:8px;color:var(--pencil-lo)}

/* ---------- 4 layout ---------- */
.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding:0 var(--gut)}
.wrap-narrow{max-width:760px}
.sec{padding:32px 0}
.sec-h{margin-bottom:20px;max-width:780px}
.stack>*+*{margin-top:var(--gap,16px)}
.stack-s{--gap:8px}
.stack-l{--gap:32px}
.row{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.row-between{justify-content:space-between}
.grid-2,.grid-3{display:grid;gap:20px;grid-template-columns:minmax(0,1fr)}
.grid-cards{display:grid;gap:22px;grid-template-columns:repeat(auto-fill,minmax(min(100%,270px),1fr))}
.bleed{margin-left:calc(-1 * var(--gut));margin-right:calc(-1 * var(--gut));padding-left:var(--gut);padding-right:var(--gut)}
@media (max-width:599px){.hide-phone{display:none!important}}
@media (min-width:600px){.only-phone{display:none!important}}
@media (max-width:1023px){.only-desk{display:none!important}}
@media (min-width:1024px){.hide-desk{display:none!important}}
.photo{display:block;margin:0;background:#fff;padding:6px;box-shadow:var(--sh-1)}
.photo img{display:block;width:100%;aspect-ratio:16/9;object-fit:cover;background:var(--paper-lo)}

/* ---------- 5 paper: card, leaf (grid + margin line), spiral ---------- */
.card{position:relative;background:var(--sheet);border-radius:4px;box-shadow:var(--sh-1);padding:20px 16px}
.card-flat{box-shadow:none;border:1.5px solid var(--line-2)}
.leaf{position:relative;background-color:var(--sheet);background-image:var(--grid-sheet-bg);background-size:30px 30px;background-position:-1px -1px;
  border-radius:3px 3px 6px 6px;box-shadow:var(--sh-1);padding:22px 16px 22px calc(var(--mw) + 14px)}
.leaf::before{content:"";position:absolute;top:0;bottom:0;left:var(--mw);width:2px;background:rgba(214,64,44,.5);pointer-events:none}
.leaf-ruled{background-image:repeating-linear-gradient(transparent 0 29px,rgba(43,79,166,.16) 29px 30px);background-position:0 8px}
.leaf-plain{background-image:none}
.spiral{margin-top:18px;padding-top:40px}
.spiral::after{content:"";position:absolute;left:10px;right:10px;top:-15px;height:34px;pointer-events:none;
  background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='30' height='34'%3E%3Cellipse cx='15' cy='25' rx='4.2' ry='3.3' fill='%232a3452'/%3E%3Cpath d='M13.3 25.6C10.8 16.6 11 4.6 16.4 2.8c4.4-1.4 6.4 4.4 5 9.8' fill='none' stroke='%238a92a6' stroke-width='3' stroke-linecap='round'/%3E%3Cpath d='M14.6 22.4c-1.2-6.4-.9-14.4 2.3-15.8' fill='none' stroke='%23fff' stroke-opacity='.75' stroke-width='1' stroke-linecap='round'/%3E%3C/svg%3E") repeat-x 0 0/30px 34px}
.binder{position:relative;background:var(--sheet);border:2px solid var(--ink);border-top:0;border-radius:0 0 8px 8px;box-shadow:var(--sh-1);padding:20px 14px 24px}

/* ---------- 6 buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;padding:10px 20px;border:2px solid var(--ink);
  border-radius:var(--r-hand);background:var(--sheet);color:var(--ink);font:600 17px/1.2 var(--f-text);text-align:center;text-decoration:none;
  cursor:pointer;box-shadow:0 2px 0 var(--line-2);transition:transform .12s,box-shadow .12s,background-color .12s;touch-action:manipulation;-webkit-tap-highlight-color:transparent}
.btn:hover{color:var(--ink);background-color:var(--marker-soft)}
.btn:active{transform:translateY(1px);box-shadow:0 1px 0 var(--line-2)}
.btn .ico{width:22px;height:22px}
.btn-main{background:var(--marker)}
.btn-main:hover{background:var(--marker-hover)}
.btn-ink{background:var(--ink);color:#fff}
.btn-ink:hover{background:#2a3b63;color:#fff}
.btn-ghost{background:transparent;box-shadow:none;border-color:var(--line-2)}
.btn[aria-pressed="true"]{background:var(--ok-soft);border-color:var(--ok);color:#1f5238;box-shadow:none}
.btn[aria-pressed="true"] .ico{color:var(--ok)}
.btn-link{min-height:48px;padding:10px 6px;border:0;background:none;box-shadow:none;color:var(--blue);font-weight:600;text-decoration:underline;text-underline-offset:4px;border-radius:6px}
.btn-link:hover{background:none;color:var(--ink)}
.btn-icon{width:48px;height:48px;min-height:48px;padding:0;border-color:transparent;border-radius:50%;background:transparent;box-shadow:none}
.btn-icon:hover{background:var(--marker-soft)}
.btn-icon .ico{width:26px;height:26px}
.btn-lg{min-height:56px;padding:12px 28px;font-size:18px}
.btn-sm{min-height:48px;padding:8px 14px;font-size:16px}
.btn-block{width:100%}
.btn[disabled],.btn[aria-disabled="true"]{opacity:.5;cursor:not-allowed;transform:none;pointer-events:none}
.btn.is-loading{position:relative;color:transparent!important;pointer-events:none}
.btn.is-loading::after{content:"";position:absolute;width:22px;height:22px;border-radius:50%;border:3px solid var(--ink);border-right-color:transparent;animation:spin .7s linear infinite}
.btn-ink.is-loading::after{border-color:#fff;border-right-color:transparent}
.btn-row{display:flex;flex-wrap:wrap;gap:12px;align-items:center}
.btn-row>.btn{flex:1 1 auto}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------- 7 header ---------- */
.hdr{position:sticky;top:0;z-index:50;background:var(--paper);border-top:4px solid var(--ink);border-bottom:1.5px solid var(--line-2);transition:transform .22s ease}
.hdr.is-hidden{transform:translateY(-110%)}
.hdr-row{display:flex;align-items:center;gap:2px;min-height:var(--hdr-h)}
.hdr-logo{display:inline-flex;align-items:center;min-height:48px;margin-right:auto;padding-right:8px;border-radius:6px}
.hdr-logo img{display:block;width:auto;height:32px}
.hdr-nav,.hdr-search,.hdr-text{display:none}
.hdr-btn{position:relative;display:inline-grid;place-items:center;width:48px;height:48px;border:0;border-radius:50%;background:transparent;color:var(--ink);text-decoration:none}
.hdr-btn:hover{background:var(--marker-soft);color:var(--ink)}
.hdr-btn .ico{width:26px;height:26px}
.hdr-btn[aria-current="page"]{background:var(--marker-soft)}
.cnt{position:absolute;top:3px;right:1px;min-width:24px;height:24px;padding:0 6px;border-radius:12px;background:var(--pen-ink);color:#fff;font:700 16px/24px var(--f-text);text-align:center;box-shadow:0 0 0 2px var(--paper)}
.cnt[data-n="0"]{display:none}
.hdr-help{font:700 25px/1 var(--f-hand);color:var(--pen-ink)}
.me-chip{display:inline-flex;align-items:center;gap:8px;min-height:48px;padding:4px 14px 4px 4px;border-radius:999px;background:var(--sheet);box-shadow:var(--sh-1);color:var(--ink);text-decoration:none;font:600 16px/1 var(--f-text)}
.me-chip:hover{color:var(--ink);background:#fff}
.me-chip .ava{width:40px;height:40px}
.me-chip .streak{font-size:16px}
/* phone menu: «оглавление тетради» */
.toc{list-style:none;margin:4px 0 8px;padding:0;counter-reset:toc}
.toc li{counter-increment:toc}
.toc a{display:flex;align-items:baseline;gap:8px;min-height:52px;padding:12px 2px 4px;color:var(--ink);text-decoration:none;font:700 18px/1.2 var(--f-head)}
.toc a::after{content:counter(toc);order:3;font:700 23px/1 var(--f-hand);color:var(--pencil)}
.toc a i{order:2;flex:1;min-width:16px;border-bottom:2px dotted var(--line-2);transform:translateY(-5px)}
.toc a[aria-current="page"]{color:var(--pen-ink)}
.toc a:hover span{background:var(--marker-soft)}
.toc-sub{list-style:none;margin:10px 0 0;padding:10px 0 0;border-top:1.5px dashed var(--line-2);display:grid}
.toc-sub a{display:flex;align-items:center;min-height:48px;color:var(--ink);font:600 17px/1.2 var(--f-text);text-decoration:none}
.toc-sub a:hover{color:var(--pen-ink)}
.me-av{display:grid;place-items:center;flex:none;width:40px;height:40px;border-radius:50%;background:var(--blue);color:#fff;font:800 16px/1 var(--f-head)}
.me-av.is-parent{background:var(--ok)}
/* bottom navigation of the student and the parent (phone), tabs under the header (desktop) */
.bnav{position:fixed;left:0;right:0;bottom:0;z-index:60;background:var(--sheet);border-top:1.5px solid var(--line-2);
  padding-bottom:var(--safe-b);box-shadow:0 -10px 24px -18px rgba(28,42,74,.5)}
.bnav-in{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));max-width:640px;margin:0 auto}
.bnav a{position:relative;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;min-height:var(--bnav-h);padding:6px 2px;
  color:var(--ink-2);font:600 15px/1.1 var(--f-text);text-decoration:none;-webkit-tap-highlight-color:transparent}
.bnav a .ico{width:26px;height:26px}
.bnav a[aria-current="page"]{color:var(--ink)}
.bnav a[aria-current="page"]::before{content:"";position:absolute;top:7px;width:44px;height:30px;border-radius:15px;background:var(--marker-soft);z-index:-1}
.bnav a[aria-current="page"] span{font-weight:700}
body.has-bnav{padding-bottom:calc(var(--bnav-h) + var(--safe-b))}
/* footer: the back cover */
.ftr{margin-top:48px;background:var(--paper-lo);border-top:3px double var(--line-2);padding:32px 0 calc(28px + var(--safe-b));font-size:16px;color:var(--ink-2)}
.ftr-grid{display:grid;gap:24px}
.ftr-logo{display:inline-flex;align-items:center;min-height:48px}
.ftr-logo img{display:block;height:36px;width:auto}
.ftr p{margin:0 0 8px}
.ftr-docs{list-style:none;margin:0;padding:0;display:grid;gap:0 18px}
.ftr-docs a{display:inline-flex;align-items:center;min-height:44px;color:var(--ink);text-decoration:underline;text-decoration-color:var(--line-2)}
.ftr-docs a:hover{text-decoration-color:var(--pen)}
.ftr-note{font:700 22px/1.1 var(--f-hand);color:var(--pen-ink);margin:0}
.ftr-mail{display:inline-flex;align-items:center;gap:8px;min-height:44px}
.ftr-bottom{margin-top:20px;padding-top:6px;border-top:1.5px dashed var(--line-2);display:flex;flex-wrap:wrap;align-items:center;gap:0 18px;color:var(--pencil)}
.ftr-bottom a{display:inline-flex;align-items:center;min-height:44px;color:var(--ink-2)}

/* ---------- 8 course card: a notebook cover with a coloured spine ---------- */
.cc{--sp:var(--math);--cv:var(--math-cv);position:relative;display:flex;flex-direction:column;background:var(--cv);border-radius:4px 12px 12px 4px;
  padding:14px 14px 16px 30px;box-shadow:var(--sh-1);transition:transform .18s}
.cc::before{content:"";position:absolute;left:0;top:0;bottom:0;width:16px;border-radius:4px 0 0 4px;background:var(--sp);box-shadow:inset -3px 0 0 rgba(0,0,0,.14)}
.cc::after{content:"";position:absolute;left:7px;top:10px;bottom:10px;border-left:2px dashed rgba(255,255,255,.55)}
.cc-math{--sp:var(--math);--cv:var(--math-cv)}
.cc-fiz{--sp:var(--fiz);--cv:var(--fiz-cv)}
.cc-him{--sp:var(--him);--cv:var(--him-cv)}
.cc-cover{display:block;margin:0 0 14px;color:inherit;text-decoration:none;border-radius:3px}
.cc-photo{display:block;background:#fff;padding:5px;box-shadow:var(--sh-1)}
.cc-photo img,.cc-ph{display:block;width:100%;aspect-ratio:16/9;object-fit:cover;background:var(--paper-lo)}
.cc-ph{position:relative;display:grid;place-items:center;background-color:var(--sheet);background-image:var(--grid-sheet-bg);background-size:15px 15px;color:var(--sp)}
.cc-ph .ico{width:56px;height:56px;stroke-width:1.6}
.cc-ph b{position:absolute;right:10px;bottom:6px;font:700 30px/1 var(--f-hand);color:var(--ink-2)}
.cc-label{position:relative;flex:1;display:flex;flex-direction:column;background:var(--sheet);border:1.5px solid var(--ink);outline:1px solid rgba(28,42,74,.45);outline-offset:3px;border-radius:3px;margin:4px;padding:14px 14px 16px}
.cc-sub{display:flex;align-items:center;gap:8px;margin:0 0 4px;font:600 16px/1.2 var(--f-text);color:var(--pencil)}
.cc-sub .ico{width:22px;height:22px;color:var(--sp)}
.cc-title{margin:0 0 8px;font:700 19px/1.25 var(--f-head)}
.cc-title a{display:inline-block;padding:11px 0;margin:-11px 0;color:var(--ink);text-decoration:none}
.cc-title a:hover{text-decoration:underline;text-decoration-color:var(--pen);text-underline-offset:4px}
.cc-title a::after{content:"";position:absolute;inset:0;z-index:0}
.cc-meta{display:flex;flex-wrap:wrap;gap:2px 14px;margin:0 0 4px;font-size:16px;color:var(--ink-2)}
.cc-book{margin:0 0 12px;font-size:16px;color:var(--pencil)}
.cc-price{margin-top:auto;padding-top:10px;border-top:1.5px dashed var(--line-2)}
.cc-acts{position:relative;z-index:1;display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.cc-acts>*{flex:1 1 auto}
.cc-acts form{display:flex}
.cc-acts form .btn{flex:1}
.cc-own{position:absolute;right:14px;top:6px;z-index:2;padding:4px 12px 6px;background:var(--marker);color:var(--ink);font:700 23px/1 var(--f-hand);transform:rotate(4deg);box-shadow:var(--sh-1)}
.cc-cart{position:absolute;right:14px;top:6px;z-index:2;padding:3px 10px 5px;background:var(--sheet);color:var(--blue);font:700 22px/1 var(--f-hand);transform:rotate(-3deg);box-shadow:var(--sh-1)}
.cc-soon{opacity:.75}
@media (hover:hover){.cc:hover{transform:translateY(-3px)}}

/* ---------- 9 lesson rows ---------- */
.lessons{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.lrow{position:relative;display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:2px 12px;align-items:center;min-height:64px;padding:8px 10px 8px 6px;
  border-radius:8px;color:var(--ink);text-decoration:none;border-bottom:1px dashed var(--line)}
a.lrow:hover{background:var(--marker-soft);color:var(--ink)}
.lrow-n{grid-row:1 / span 2;align-self:center;font:700 17px/1 var(--f-head);color:var(--pencil);text-align:center;font-variant-numeric:tabular-nums}
.lrow-t{grid-column:2;font:600 17px/1.3 var(--f-text);min-width:0}
.lrow-d{grid-column:2;display:flex;flex-wrap:wrap;gap:0 12px;font-size:16px;color:var(--pencil);font-variant-numeric:tabular-nums}
.lrow-s{grid-column:3;grid-row:1 / span 2;display:grid;place-items:center;width:40px;height:40px;border-radius:50%}
.lrow-s .ico{width:26px;height:26px}
.lrow-thumb{display:none}
.lrow.is-done .lrow-s{color:var(--pen)}
.lrow.is-done .lrow-s .ico{stroke-width:2.6}
.lrow.is-open .lrow-s{color:var(--blue);background:var(--blue-soft)}
.lrow.is-locked{color:var(--ink-2)}
.lrow.is-locked .lrow-t{font-weight:500}
.lrow.is-locked .lrow-s{color:var(--pencil)}
.lrow.is-free{background:var(--marker-soft)}
.lrow-tag{display:inline-block;margin-left:6px;font:700 21px/1 var(--f-hand);color:var(--pen-ink);transform:rotate(-3deg)}
.lrow.is-current{background:var(--marker-soft);box-shadow:inset 4px 0 0 var(--pen)}
.lrow.is-current .lrow-n{color:var(--pen-ink)}
.blk{margin:0 0 24px}
.blk-h{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 14px;margin:0 0 6px;padding-bottom:6px;border-bottom:2px solid var(--ink)}
.blk-h h3,.blk-h .h3{margin:0;font-size:18px}
.blk-h small{font:700 22px/1 var(--f-hand);color:var(--pen-ink)}

/* ---------- 10 price and discount ---------- */
.price{display:flex;flex-wrap:wrap;align-items:baseline;gap:2px 12px;margin:0}
.price-now{font:800 24px/1.1 var(--f-head);font-variant-numeric:tabular-nums;white-space:nowrap}
.price-old{font:500 18px/1.1 var(--f-text);color:var(--pencil);white-space:nowrap;text-decoration:line-through;text-decoration-color:var(--pen);text-decoration-thickness:2px}
.price-off{position:relative;display:inline-block;margin-left:4px;padding:3px 12px 5px 10px;font:700 25px/1 var(--f-hand);color:var(--pen-ink);transform:rotate(-4deg);white-space:nowrap}
.price-off svg{position:absolute;left:-4px;top:-5px;width:calc(100% + 10px);height:calc(100% + 10px);overflow:visible;pointer-events:none}
.price-off path{fill:none;stroke:var(--pen);stroke-width:1.8;stroke-linecap:round}
.price-note{flex-basis:100%;margin:2px 0 0;font-size:16px;color:var(--pencil)}
.price-lg .price-now{font-size:clamp(30px,4vw + 14px,44px)}
.price-lg .price-off{font-size:28px}
.price-free{font:800 22px/1.1 var(--f-head);color:var(--ok)}

/* ---------- 11 chips and grade tabs ---------- */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:0;padding:0;border:0}
.chips-scroll{flex-wrap:nowrap;overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:none;margin-left:calc(-1 * var(--gut));margin-right:calc(-1 * var(--gut));padding:2px var(--gut) 6px}
.chips-scroll::-webkit-scrollbar{display:none}
.chips-scroll>*{flex:none}
.chip,.rchip>span{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:8px 16px;border:1.5px solid var(--line-2);border-radius:999px;
  background:var(--sheet);color:var(--ink);font:600 16px/1.2 var(--f-text);text-decoration:none;cursor:pointer;white-space:nowrap;transition:background-color .12s,border-color .12s;-webkit-tap-highlight-color:transparent}
.chip:hover,.rchip:hover>span{border-color:var(--ink);color:var(--ink)}
.chip .ico,.rchip .ico{width:20px;height:20px}
.chip[aria-pressed="true"],.chip[aria-current="page"],.chip.is-on,.rchip>input:checked+span{background:var(--marker);border:2px solid var(--ink);padding:7px 15px}
.chip-n{font:700 16px/1 var(--f-text);color:var(--pencil)}
.rchip{position:relative;display:inline-flex}
.rchip>input{position:absolute;opacity:0;inset:0;margin:0;cursor:pointer}
.rchip>input:focus-visible+span{outline:3px solid var(--blue);outline-offset:2px}
.gtabs{--tabs-in:var(--gut);display:flex;align-items:flex-end;gap:5px;overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:none;
  margin:0 calc(-1 * var(--gut));padding:6px var(--gut) 0;scroll-padding:0 var(--gut);
  background:linear-gradient(var(--ink),var(--ink)) no-repeat var(--tabs-in) 100%/calc(100% - 2 * var(--tabs-in)) 2px}
.gtabs::-webkit-scrollbar{display:none}
.gtab{flex:none;display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:52px;min-height:50px;margin-bottom:2px;padding:6px 12px;
  border:1.5px solid var(--line-2);border-bottom:0;border-radius:12px 12px 0 0;background:var(--paper-lo);color:var(--ink);font:800 19px/1 var(--f-head);text-decoration:none;transition:min-height .15s,background-color .15s}
.gtab small{display:none;margin-top:4px;font:600 16px/1 var(--f-text);color:var(--ink-2)}
.gtab:hover{background:var(--marker-soft);color:var(--ink)}
.gtab[aria-current="page"],.gtab[aria-selected="true"],.gtab.is-on{min-height:58px;margin-bottom:0;background:var(--sheet);border:2px solid var(--ink);border-bottom:0;position:relative}
.gtab[aria-current="page"]::after,.gtab[aria-selected="true"]::after,.gtab.is-on::after{content:"";position:absolute;left:8px;right:8px;bottom:7px;height:6px;
  background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 8' preserveAspectRatio='none'%3E%3Cpath d='M2 5C30 2 70 3 98 2' fill='none' stroke='%23d6402c' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat center/100% 100%}

/* ---------- 12 forms ---------- */
.field{display:grid;gap:6px;margin:0 0 18px;min-width:0}
.field-label{font:600 16px/1.35 var(--f-text);color:var(--ink)}
.field-label .opt{font-weight:400;color:var(--pencil)}
.field-hint{margin:0;font-size:16px;line-height:1.4;color:var(--pencil)}
.input,.select,.textarea{display:block;width:100%;min-height:52px;padding:12px 14px;border:2px solid var(--line-2);border-radius:10px;background:var(--sheet);
  color:var(--ink);font:500 17px/1.3 var(--f-text);transition:border-color .15s,box-shadow .15s;-webkit-appearance:none;appearance:none}
.textarea{min-height:120px;resize:vertical}
.select{padding-right:44px;background:var(--sheet) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6.3 9.3c1.9 1.9 3.8 3.8 5.7 5.7 1.9-1.9 3.8-3.8 5.7-5.7' fill='none' stroke='%231c2a4a' stroke-width='2.2' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat right 12px center/22px}
.input::placeholder,.textarea::placeholder{color:#767c8c;opacity:1}
.input:hover,.select:hover,.textarea:hover{border-color:var(--ink-2)}
.input:focus,.select:focus,.textarea:focus{outline:none;border-color:var(--blue);box-shadow:0 0 0 3px rgba(43,79,166,.22)}
.field.is-error .input,.field.is-error .select,.field.is-error .textarea,.input[aria-invalid="true"]{border-color:var(--pen)}
.field-error{display:flex;align-items:flex-start;gap:8px;margin:0;color:var(--pen-ink);font:600 16px/1.4 var(--f-text)}
.field-error .ico{width:20px;height:20px;margin-top:1px}
.input-big{min-height:56px;font-size:19px}
.check{position:relative;display:flex;align-items:flex-start;gap:12px;min-height:48px;padding:10px 0;cursor:pointer;font-size:16px;line-height:1.45}
.check>input{position:absolute;left:0;top:10px;width:28px;height:28px;margin:0;opacity:0;cursor:pointer}
.check-box{position:relative;flex:none;width:28px;height:28px;margin-top:-2px;border:2px solid var(--ink);border-radius:5px;background:var(--sheet)}
.check>input:checked+.check-box::after{content:"";position:absolute;left:-1px;top:-9px;width:34px;height:32px;
  background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 34 32'%3E%3Cpath d='M4 17c3.4 2.8 6 5.6 8.4 9.4C17 15.6 22.6 8 30.4 2.6' fill='none' stroke='%23d6402c' stroke-width='3.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") no-repeat center/contain}
.check>input:focus-visible+.check-box{outline:3px solid var(--blue);outline-offset:2px}
.check.is-error .check-box{border-color:var(--pen)}
.radio{position:relative;display:flex;align-items:flex-start;gap:12px;min-height:48px;padding:10px 0;cursor:pointer;font-size:16px;line-height:1.45}
.radio>input{position:absolute;left:0;top:10px;width:28px;height:28px;margin:0;opacity:0}
.radio-dot{flex:none;width:28px;height:28px;margin-top:-2px;border:2px solid var(--ink);border-radius:50%;background:var(--sheet);display:grid;place-items:center}
.radio>input:checked+.radio-dot::after{content:"";width:14px;height:14px;border-radius:50%;background:var(--blue)}
.radio>input:focus-visible+.radio-dot{outline:3px solid var(--blue);outline-offset:2px}
.form-acts{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-top:8px}
fieldset{margin:0 0 18px;padding:0;border:0;min-width:0}
legend{padding:0;margin-bottom:8px;font:600 16px/1.35 var(--f-text)}

/* ---------- 13 toasts, bottom sheets, dialogs ---------- */
.toasts{position:fixed;left:12px;right:12px;bottom:calc(16px + var(--safe-b));z-index:90;display:grid;gap:8px;justify-items:center;pointer-events:none}
body.has-bnav .toasts{bottom:calc(var(--bnav-h) + 12px + var(--safe-b))}
.toast{pointer-events:auto;width:100%;max-width:480px;display:flex;align-items:center;gap:12px;padding:12px 14px 12px 16px;border-radius:12px 14px 12px 16px;
  background:var(--ink);color:#fff;font:500 16px/1.4 var(--f-text);box-shadow:var(--sh-2);animation:toast-in .24s ease-out both}
.toast>span{flex:1}
.toast a,.toast .btn-link{color:var(--marker);min-height:44px;display:inline-flex;align-items:center}
.toast .ico{color:var(--marker)}
.toast-ok .ico{color:#9fe0b6}
.toast-err{background:#7a2216}
.toast-err .ico{color:#ffd0c6}
.toast-x{flex:none;display:grid;place-items:center;width:44px;height:44px;margin:-8px -8px -8px 0;border:0;border-radius:50%;background:transparent;color:#fff}
.toast.is-out{opacity:0;transform:translateY(10px);transition:opacity .2s,transform .2s}
@keyframes toast-in{from{opacity:0;transform:translateY(12px)}}
dialog{color:var(--ink)}
.bsheet,.dlg{border:0;padding:0;max-width:none;background-color:var(--sheet);background-image:var(--grid-sheet-bg);background-size:30px 30px;box-shadow:var(--sh-2);overflow:auto;overscroll-behavior:contain}
.bsheet{position:fixed;inset:auto 0 var(--kb,0px) 0;margin:0;width:100%;max-height:85vh;max-height:min(85dvh,calc(100dvh - var(--kb,0px) - 8px));border-radius:18px 18px 0 0;padding-bottom:var(--safe-b)}
.bsheet-70{max-height:70vh;max-height:min(70dvh,calc(100dvh - var(--kb,0px) - 8px))}
.bsheet[open]{animation:sheet-up .26s cubic-bezier(.2,.8,.2,1) both}
.dlg{margin:auto;width:min(520px,calc(100% - 32px));max-height:calc(100vh - 48px);max-height:calc(100dvh - 48px);border-radius:8px}
.dlg[open]{animation:dlg-in .2s ease-out both}
.bsheet::backdrop,.dlg::backdrop{background:rgba(28,42,74,.45)}
.modal-in{position:relative;padding:14px 16px 20px}
.bsheet .modal-in::before{content:"";display:block;width:44px;height:5px;margin:0 auto 10px;border-radius:3px;background:var(--line-2)}
.modal-x{position:absolute;top:4px;right:4px;z-index:2}
.modal-title{margin:4px 52px 12px 0;font:800 21px/1.25 var(--f-head)}
.modal-acts{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-top:18px}
.modal-acts>.btn:not(.btn-link){flex:1 1 auto}
.bsheet .modal-acts{position:sticky;bottom:0;z-index:1;margin-bottom:-20px;padding:10px 0 calc(16px + var(--safe-b));background:var(--sheet);box-shadow:0 -10px 14px -12px rgba(28,42,74,.35)}
html.is-locked{overflow:hidden}
@keyframes sheet-up{from{transform:translateY(40%);opacity:.4}}
@keyframes dlg-in{from{transform:translateY(12px) scale(.98);opacity:0}}

/* ---------- 14 sticker note, hint tours, howto lines ---------- */
.note{position:relative;max-width:360px;padding:16px 18px 16px;background:var(--sticker);color:var(--ink);box-shadow:var(--sh-2);border-radius:2px 2px 14px 2px;font-size:16px;line-height:1.45}
.note.tilt{transform:rotate(-1.5deg)}
.note-title{margin:0 0 4px;font:700 26px/1.05 var(--f-hand);color:var(--ink)}
.note p{margin:0 0 6px}
.note p:last-child{margin-bottom:0}
.note-arrow{position:absolute;width:64px;height:48px;overflow:visible;pointer-events:none}
.note-arrow path{fill:none;stroke:var(--ink);stroke-width:2.4;stroke-linecap:round;stroke-linejoin:round}
.note-arrow.up{left:24px;top:-44px}
.note-arrow.left{left:-58px;top:14px}
.hints-veil{position:fixed;inset:0;z-index:100;background:transparent;-webkit-tap-highlight-color:transparent}
.hints-spot{position:fixed;z-index:101;border-radius:12px;pointer-events:none;box-shadow:0 0 0 3px var(--marker),0 0 0 4000px rgba(28,42,74,.5);
  transition:left .25s,top .25s,width .25s,height .25s}
.hints-spot.is-none{box-shadow:0 0 0 4000px rgba(28,42,74,.5);width:0!important;height:0!important}
.hints-arrow{position:fixed;left:0;top:0;width:100%;height:100%;z-index:102;pointer-events:none;overflow:visible}
.hints-arrow path{fill:none;stroke:var(--marker);stroke-width:3.2;stroke-linecap:round;stroke-linejoin:round}
.hint-pop{position:fixed;z-index:103;left:12px;right:12px;bottom:calc(12px + var(--safe-b));max-width:none;padding:14px 16px 12px;outline:none}
.hint-pop-text{margin:0}
.hint-pop.is-top{bottom:auto}
.hints-on .hdr.is-hidden{transform:none}
.hint-pop .note-title{padding-right:40px}
.hint-pop-x{position:absolute;top:2px;right:2px}
.hint-pop-foot{display:flex;flex-wrap:wrap;align-items:center;gap:6px 10px;margin-top:12px}
.hint-pop-step{margin-right:auto;font:700 21px/1 var(--f-hand);color:var(--ink-2)}
.hint-pop .btn{min-height:48px}
.howto{display:flex;align-items:flex-start;gap:10px;margin:0 0 14px;padding:10px 14px;border-left:3px solid var(--blue);border-radius:0 10px 10px 0;
  background:#eaeff9;color:var(--ink-2);font:500 16px/1.45 var(--f-text);max-width:720px}
.howto .ico{flex:none;width:22px;height:22px;margin-top:1px;color:var(--blue)}
.howto b{color:var(--ink)}

/* ---------- 15 progress, badges, streak, XP, avatars ---------- */
progress.bar{display:block;width:100%;height:12px;border:0;border-radius:6px;background:rgba(28,42,74,.1);overflow:hidden;-webkit-appearance:none;appearance:none;color:var(--blue)}
progress.bar::-webkit-progress-bar{background:rgba(28,42,74,.1);border-radius:6px}
progress.bar::-webkit-progress-value{background:currentColor;border-radius:6px;transition:width .3s}
progress.bar::-moz-progress-bar{background:currentColor;border-radius:6px}
progress.bar-ok{color:var(--ok)}
progress.bar-pen{color:var(--pen)}
progress.bar-xp{height:22px;border:2px solid var(--ink);border-radius:12px;background:var(--sheet);color:var(--marker)}
progress.bar-xp::-webkit-progress-bar{background:var(--sheet)}
progress.bar-xp::-webkit-progress-value{background:repeating-linear-gradient(-45deg,var(--marker) 0 10px,#ffe37d 10px 20px)}
progress.bar-xp::-moz-progress-bar{background:repeating-linear-gradient(-45deg,var(--marker) 0 10px,#ffe37d 10px 20px)}
.meter{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:6px 12px;align-items:center;margin:0 0 12px}
.meter-label{font:600 16px/1.35 var(--f-text)}
.meter-val{font:700 16px/1 var(--f-text);color:var(--ink-2);font-variant-numeric:tabular-nums}
.meter progress{grid-column:1 / -1}
.cells{display:flex;flex-wrap:wrap;gap:3px;margin:8px 0;padding:0;list-style:none}
.cells i{display:block;width:14px;height:22px;border:1.5px solid var(--line-2);border-radius:2px;background:var(--sheet)}
.cells i.is-done{background:repeating-linear-gradient(-45deg,var(--blue) 0 2px,transparent 2px 5px);border-color:var(--blue)}
.cells i.is-cur{background:var(--marker);border:2px solid var(--pen)}
.cells i.is-err{background:var(--pen-soft);border-color:var(--pen)}
.badge{display:inline-flex;align-items:center;gap:6px;min-height:30px;padding:3px 10px;border-radius:6px;background:var(--paper-lo);color:var(--ink);font:600 16px/1.2 var(--f-text);white-space:nowrap;vertical-align:middle}
.badge .ico{width:18px;height:18px}
.badge-own{background:var(--marker)}
.badge-free{background:var(--ok-soft);color:#215a3d}
.badge-soon{background:transparent;border:1.5px dashed var(--pencil);color:var(--ink-2)}
.badge-pen{background:var(--pen-soft);color:var(--pen-ink)}
.pill{display:inline-flex;align-items:center;gap:8px;min-height:44px;padding:4px 14px;border-radius:999px;background:var(--sheet);box-shadow:var(--sh-1);font:600 16px/1 var(--f-text);color:var(--ink);white-space:nowrap}
.streak,.xp{display:inline-flex;align-items:center;gap:4px;font:800 18px/1 var(--f-head);color:var(--ink);white-space:nowrap}
.streak .ico{color:var(--pen);width:22px;height:22px}
.xp .ico{width:22px;height:22px;fill:var(--marker);stroke:var(--ink);stroke-width:1.6}
.streak small,.xp small{font:500 16px/1 var(--f-text);color:var(--pencil);margin-left:2px}
.ava{display:inline-block;flex:none;width:48px;height:48px;border-radius:50%;background:var(--paper-lo);vertical-align:middle;object-fit:cover}
.ava-s{width:32px;height:32px}
.ava-l{width:72px;height:72px}
.ava-xl{width:112px;height:112px}
.ava-pick{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:0;padding:0;border:0}
.ava-pick label{position:relative;display:grid;place-items:center;padding:6px;border-radius:50%;cursor:pointer}
.ava-pick input{position:absolute;opacity:0;inset:0;margin:0;cursor:pointer}
.ava-pick img{width:100%;max-width:72px;height:auto;aspect-ratio:1;border-radius:50%;border:3px solid transparent}
.ava-pick input:checked+img{border-color:var(--ink);box-shadow:0 0 0 4px var(--marker)}
.ava-pick input:focus-visible+img{outline:3px solid var(--blue);outline-offset:3px}

/* ---------- 16 empty state, table, accordion, skeleton, stepper ---------- */
.empty{display:grid;justify-items:center;gap:6px;max-width:440px;margin:0 auto;padding:28px 12px;text-align:center}
.empty-ico{display:grid;place-items:center;width:88px;height:88px;margin-bottom:6px;border:2px dashed var(--line-2);border-radius:50%;color:var(--blue)}
.empty-ico .ico{width:42px;height:42px;stroke-width:1.8}
.empty-title{margin:0;font:700 20px/1.3 var(--f-head)}
.empty-text{margin:0 0 10px;color:var(--ink-2)}
.tbl-wrap{overflow-x:auto;overscroll-behavior-x:contain;max-width:100%}
.tbl{width:100%;border-collapse:collapse;font-size:16px;line-height:1.4}
.tbl th,.tbl td{padding:12px 10px;text-align:left;vertical-align:top;border-bottom:1px dashed var(--line-2)}
.tbl th{font:600 16px/1.3 var(--f-text);color:var(--pencil);border-bottom:2px solid var(--ink);white-space:nowrap}
.tbl td.num,.tbl th.num{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
.tbl tbody tr:hover{background:var(--marker-soft)}
.tbl-stack thead{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.tbl-stack tr{display:block;padding:10px 0;border-bottom:1.5px dashed var(--line-2)}
.tbl-stack td{display:grid;grid-template-columns:minmax(110px,40%) minmax(0,1fr);gap:10px;padding:4px 0;border:0;text-align:left!important}
.tbl-stack td::before{content:attr(data-label);color:var(--pencil);font-size:16px}
.accs{max-width:880px}
.acc{border-bottom:1.5px dashed var(--line-2)}
.acc>summary{display:flex;align-items:center;gap:12px;min-height:60px;padding:10px 2px;cursor:pointer;list-style:none;font:700 17px/1.35 var(--f-head)}
.acc>summary::-webkit-details-marker{display:none}
.acc>summary:hover{color:var(--ink-2)}
.acc-q{flex:none;width:26px;font:700 28px/1 var(--f-hand);color:var(--pen-ink);text-align:center}
.acc>summary .ico{margin-left:auto;transition:transform .2s}
.acc[open]>summary .ico{transform:rotate(180deg)}
.acc-body{padding:0 4px 18px 40px;color:var(--ink-2)}
.acc-body>:last-child{margin-bottom:0}
.skel{display:block;border-radius:6px;background:linear-gradient(90deg,rgba(28,42,74,.07) 30%,rgba(28,42,74,.13) 50%,rgba(28,42,74,.07) 70%) 0 0/300% 100%;animation:skel 1.4s ease-in-out infinite}
.skel-line{height:16px;margin:10px 0}
.skel-line.w-60{width:60%}
.skel-line.w-40{width:40%}
.skel-title{height:26px;width:70%;margin:6px 0 14px}
.skel-thumb{width:100%;aspect-ratio:16/9}
.skel-btn{height:48px;width:160px;border-radius:12px}
@keyframes skel{from{background-position:100% 0}to{background-position:0 0}}
.stepper{display:flex;gap:6px;margin:0 0 20px;padding:0;list-style:none;counter-reset:st}
.stepper li{counter-increment:st;flex:1;display:flex;flex-direction:column;gap:6px;font:600 16px/1.2 var(--f-text);color:var(--pencil)}
.stepper li::before{content:counter(st);display:grid;place-items:center;width:34px;height:34px;border:2px solid var(--line-2);border-radius:50%;background:var(--sheet);font:700 16px/1 var(--f-head);color:var(--pencil)}
.stepper li.is-done{color:var(--ink-2)}
.stepper li.is-done::before{content:"";border-color:var(--ok);background:var(--ok-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M4.4 12.9c2.1 1.6 3.7 3.4 5.1 5.6 3.2-5.8 6.7-10.4 10.4-13.8' fill='none' stroke='%232e7350' stroke-width='2.6' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat center/20px}
.stepper li.is-cur{color:var(--ink)}
.stepper li.is-cur::before{border-color:var(--ink);background:var(--marker);color:var(--ink)}

/* ---------- 17 trainer marks: «5» and tick in red pen, wave and «?» for a slip, blue student ink ---------- */
.mark{display:inline-flex;align-items:flex-end;gap:2px;color:var(--pen);line-height:0;vertical-align:middle}
.mark svg{display:block;overflow:visible}
.mark path{fill:none;stroke:currentColor;stroke-linecap:round;stroke-linejoin:round}
.mark-ok svg{width:96px;height:58px}
.mark-ok path{stroke-width:4.4}
.mark-check svg{width:46px;height:46px}
.mark-check path{stroke-width:5}
.mark-five svg{width:38px;height:50px}
.mark-five path{stroke-width:4.6}
.mark-q svg{width:30px;height:40px}
.mark-q path{stroke-width:4.4}
.mark-cap{display:inline-block;margin-left:6px;font:700 23px/1 var(--f-hand);color:var(--pen-ink);transform:rotate(-5deg)}
.mark-wave{display:block;width:min(100%,320px);height:10px;background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='10'%3E%3Cpath d='M0 5Q4 0 8 5T16 5' fill='none' stroke='%23d6402c' stroke-width='2'/%3E%3C/svg%3E") repeat-x left center}
.draw path{stroke-dasharray:1;stroke-dashoffset:1;animation:draw .55s cubic-bezier(.55,.1,.3,1) forwards}
.draw path:nth-of-type(2){animation-delay:.42s;animation-duration:.6s}
.draw .mark-cap{animation:pop .45s ease .5s both}
@keyframes draw{to{stroke-dashoffset:0}}
@keyframes pop{from{opacity:0;transform:translateY(6px) rotate(-5deg) scale(.85)}}
.on-margin{display:flex;margin:0 0 6px}
.wavy{text-decoration:underline wavy var(--pen);text-decoration-thickness:2px;text-underline-offset:6px;text-decoration-skip-ink:none}
.ink-answer{font:700 30px/1.1 var(--f-hand);color:var(--blue)}
.input-ink{width:min(100%,240px);min-height:58px;padding:4px 8px;border:0;border-bottom:2.5px solid var(--ink);border-radius:0;background:transparent;font:700 34px/1 var(--f-hand);color:var(--blue)}
.input-ink::placeholder{color:var(--pencil-lo);font-weight:600}
.input-ink:focus{outline:none;background:var(--marker-soft);border-bottom-color:var(--blue)}
.input-ink:focus-visible{outline:3px solid var(--blue);outline-offset:2px}
.fb{display:flex;align-items:flex-start;gap:10px;margin:14px 0 0;font:600 17px/1.45 var(--f-text)}
.fb .ico{flex:none;margin-top:1px}
.fb-ok{color:var(--ok)}
.fb-bad{color:var(--ink-2);font-weight:500}
.fb-bad .ico{color:var(--pen)}
.fb-think{color:var(--ink-2)}
.fb-hand{font:700 27px/1.15 var(--f-hand)}
.xp-plus{display:inline-block;flex:none;align-self:center;padding:5px 10px;border-radius:999px;background:var(--marker);font:800 16px/1 var(--f-head);color:var(--ink);white-space:nowrap;animation:pop .6s ease .5s both}
.chem{font-family:var(--f-text);font-weight:600;font-size:.78em;letter-spacing:0}

/* the topic window «Какую тему хотите изучить?» (partials/topic_popup.html) */
.topic .modal-title{margin-bottom:14px}
.topic-q{position:relative}
.topic-q .ico{position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--pencil);pointer-events:none}
.topic-q .input{padding-left:46px}
.topic-examples{display:flex;flex-wrap:nowrap;align-items:center;gap:6px;overflow-x:auto;scrollbar-width:none;margin:8px -16px 10px;padding:0 16px;color:var(--pencil);font-size:16px}
.topic-examples::-webkit-scrollbar{display:none}
.topic-examples>*{flex:none}
.topic-examples button{min-height:44px;padding:4px 12px;border:1.5px dashed var(--line-2);border-radius:999px;background:transparent;color:var(--blue);font:600 16px/1.2 var(--f-text)}
.topic-examples button:hover{border-color:var(--blue);background:var(--blue-soft)}
.topic-subj{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin:0 0 12px}
.topic-subj .rchip>span{width:100%}
.topic-grade{display:flex;align-items:center;gap:12px;margin:0 0 4px}
.topic-grade .field-label{flex:none}
.topic-grade .select{flex:1;min-height:48px}
.topic-suggest{list-style:none;margin:6px 0 10px;padding:0;border:1.5px solid var(--line-2);border-radius:10px;background:var(--sheet);overflow:hidden}
.topic-suggest a{display:block;padding:10px 14px;min-height:48px;color:var(--ink);text-decoration:none;border-bottom:1px dashed var(--line)}
.topic-suggest li:last-child a{border-bottom:0}
.topic-suggest a:hover,.topic-suggest a:focus-visible{background:var(--marker-soft)}
.topic-suggest b{display:block;font:600 16px/1.3 var(--f-text)}
.topic-suggest small{display:block;font-size:16px;color:var(--pencil)}
.topic .modal-acts{margin-top:14px}
.topic .modal-acts .btn-main{flex:1 1 auto}
.ftr-about{max-width:40ch}

/* ---------- 18 tablet: 600 px and wider ---------- */
@media (min-width:600px){
  :root{--gut:24px;--mw:44px}
  .sec{padding:44px 0}
  .card{padding:24px 24px}
  .leaf{padding:28px 24px 28px calc(var(--mw) + 20px)}
  .binder{padding:26px 22px 30px}
  .grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .hdr-logo img{height:40px}
  .gtab{min-width:64px}
  .gtab small{display:block}
  .lrow{grid-template-columns:44px minmax(0,1fr) auto;gap:2px 14px}
  .lrow.has-thumb{grid-template-columns:44px 104px minmax(0,1fr) auto}
  .lrow-thumb{display:block;grid-row:1 / span 2;grid-column:2;width:104px;aspect-ratio:16/9;object-fit:cover;border:3px solid #fff;box-shadow:var(--sh-1);background:var(--paper-lo)}
  .lrow.has-thumb .lrow-t,.lrow.has-thumb .lrow-d{grid-column:3}
  .lrow.has-thumb .lrow-s{grid-column:4}
  .ftr-grid{grid-template-columns:minmax(0,1.2fr) minmax(0,1fr)}
  .ftr-docs{grid-template-columns:repeat(2,minmax(0,max-content))}
  .bsheet,.bsheet-70{inset:0;margin:auto;width:min(560px,calc(100% - 48px));height:fit-content;max-height:min(84vh,760px);border-radius:8px}
  .topic-examples{margin-left:0;margin-right:0;padding:0;flex-wrap:wrap}
  .topic-subj{display:flex;flex-wrap:wrap}
  .topic-subj .rchip>span{width:auto}
  .bsheet[open]{animation:dlg-in .2s ease-out both}
  .bsheet .modal-in::before{display:none}
  .modal-in{padding:22px 26px 26px}
  .hint-pop{left:auto;right:auto;bottom:auto;width:min(360px,calc(100vw - 24px))}
  .toasts{left:auto;right:24px;justify-items:end;width:min(440px,calc(100vw - 48px))}
  .ava-pick{grid-template-columns:repeat(6,minmax(0,1fr))}
  .on-margin{position:absolute;left:0;width:var(--mw);margin:0;flex-direction:column;align-items:center;justify-content:flex-start;gap:0}
  .on-margin .mark-cap{margin:0;font-size:20px}
  .mark-ok.on-margin svg{width:40px;height:24px}
  .tbl-stack thead{position:static;width:auto;height:auto;clip:auto}
  .tbl-stack tr{display:table-row;padding:0;border:0}
  .tbl-stack td{display:table-cell;padding:12px 10px;border-bottom:1px dashed var(--line-2)}
  .tbl-stack td::before{content:none}
  .tbl-stack td.num{text-align:right!important}
}

/* ---------- 19 desktop: 1024 px and wider ---------- */
@media (min-width:1024px){
  :root{--gut:40px;--mw:72px;--hdr-h:72px;--ml:max(20px,calc((100vw - var(--wrap)) / 2 + 20px))}
  body{background-image:linear-gradient(90deg,transparent calc(var(--ml) - 1px),rgba(214,64,44,.3) calc(var(--ml) - 1px),rgba(214,64,44,.3) calc(var(--ml) + 1px),transparent calc(var(--ml) + 1px)),var(--grid-bg);
    background-size:100% 100%,30px 30px,30px 30px}
  .sec{padding:64px 0}
  .grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
  .hdr.is-hidden{transform:none}
  .hdr-text{display:inline}
  .hdr-row{gap:6px}
  .hdr-logo{margin-right:20px}
  .hdr-nav{display:flex;gap:2px;margin-right:auto}
  .hdr-link{position:relative;display:inline-flex;align-items:center;min-height:48px;padding:0 14px;border-radius:8px;color:var(--ink);font:600 17px/1 var(--f-text);text-decoration:none}
  .hdr-link:hover{background:var(--marker-soft);color:var(--ink)}
  .hdr-link[aria-current="page"]::after{content:"";position:absolute;left:10px;right:10px;bottom:6px;height:8px;
    background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 10' preserveAspectRatio='none'%3E%3Cpath d='M2 7C30 3 70 4 98 3' fill='none' stroke='%23d6402c' stroke-width='2.6' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat center/100% 100%}
  .hdr-search{display:flex;align-items:center;position:relative;width:clamp(200px,20vw,280px);margin-right:6px}
  .hdr-search .input{min-height:46px;padding:8px 14px 8px 42px;border-radius:999px;font-size:16px;border-width:1.5px}
  .hdr-search .ico{position:absolute;left:14px;top:50%;width:20px;height:20px;transform:translateY(-50%);color:var(--pencil);pointer-events:none}
  .hdr-search-btn{display:none}
  .hdr-cart{width:auto;padding:0 16px 0 12px;border-radius:999px;gap:8px;display:inline-flex;font:600 17px/1 var(--f-text)}
  .hdr-cart .cnt{position:static;box-shadow:none}
  .hdr-login{margin-left:4px}
  .bnav{position:static;z-index:auto;background:transparent;border:0;box-shadow:none;padding:0}
  .bnav-in{display:flex;gap:6px;max-width:var(--wrap);padding:14px var(--gut) 0}
  .bnav a{flex-direction:row;gap:8px;min-height:46px;padding:0 16px;border-radius:999px;font-size:16px}
  .bnav a .ico{width:22px;height:22px}
  .bnav a:hover{background:var(--marker-soft)}
  .bnav a[aria-current="page"]{background:var(--sheet);box-shadow:var(--sh-1)}
  .bnav a[aria-current="page"]::before{display:none}
  body.has-bnav{padding-bottom:0}
  body.has-bnav .toasts{bottom:24px}
  .card{padding:28px 30px}
  .leaf{padding:34px 34px 34px calc(var(--mw) + 30px)}
  .binder{padding:32px 32px 36px}
  .gtabs{--tabs-in:0px;margin:0;padding:6px 0 0 12px;overflow:visible}
  .gtab{min-width:72px}
  .chips-scroll{flex-wrap:wrap;overflow:visible;margin-left:0;margin-right:0;padding-left:0;padding-right:0}
  .bleed{margin-left:0;margin-right:0;padding-left:0;padding-right:0}
  .ftr-grid{grid-template-columns:minmax(0,1.1fr) minmax(0,1.4fr) minmax(0,.8fr)}
  .ftr-docs{grid-template-columns:minmax(0,1fr)}
  .mark-ok.on-margin svg{width:64px;height:40px}
  .hint-pop.is-tilt{transform:rotate(-1deg)}
}
@media (min-width:1024px) and (pointer:fine){
  .btn-sm{min-height:44px}
  .chip,.rchip>span{min-height:44px;padding:6px 14px}
  .chip[aria-pressed="true"],.chip[aria-current="page"],.chip.is-on,.rchip>input:checked+span{padding:5px 13px}
}

/* ---------- 20 motion and print ---------- */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-delay:0s!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
  .draw path{stroke-dashoffset:0}
  .skel{animation:none}
}
@media print{
  .hdr,.bnav,.ftr,.toasts,.hints-veil,.hint-pop{display:none!important}
  body{background:#fff}
}