/* Hero Home 1.6.2: the [hero_home] page.
   A light drafting board under liquid glass: graph-paper ground, one Herucation red, ink headlines.
   Liquid glass here is a web approximation of Apple's material (there is no official web CSS):
   real backdrop blur only on the fixed nav island and the mobile menu; in-flow plates use translucent
   fills, hairlines and a pointer-following specular highlight, so scrolling stays cheap on phones.
   Everything is scoped under .hh so the theme's global styles cannot leak in. */

body.hh-page{margin:0;background:#F0F1F2;overflow-x:hidden}
/* theme leftovers printed in wp_footer (search overlay, back-to-top ring) */
body.hh-page .edu-search-popup,body.hh-page .devsblink-progress-parent{display:none!important}
.hh{
  --paper:#F0F1F2; --sheet:#ffffff; --ink:#141414; --slate:#4A5056; --muted:#5f656b;
  --rule:#dcdfe2; --rule-strong:#c2c6cb;
  --grid:#1414140b; --grid-major:#14141417;
  --red:#D2122E; --red-hi:#E0233B; --red-deep:#A50E24; --red-wash:#D2122E12;
  --ok:#0b8a5f;
  --glass-fill:linear-gradient(140deg,rgba(255,255,255,.78),rgba(255,255,255,.42));
  --glass-edge:rgba(255,255,255,.85);
  --glass-shadow:inset 0 1px 0 rgba(255,255,255,.95),inset 0 -1px 0 rgba(20,20,20,.05),0 1px 2px rgba(20,20,20,.05),0 24px 48px -28px rgba(20,20,20,.32);
  --ring:rgba(20,20,20,.07);
  --ease:cubic-bezier(.22,1,.36,1);
  --fluid:cubic-bezier(.32,.72,0,1);
  --spring:cubic-bezier(.16,1,.3,1);
  --f-display:"Bricolage Grotesque","Segoe UI",system-ui,sans-serif;
  --f-body:"Alexandria","Segoe UI",system-ui,sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,Consolas,monospace;
  --top:calc(14px + env(safe-area-inset-top,0px));
  background:var(--paper);color:var(--ink);font:400 16px/1.65 var(--f-body);-webkit-font-smoothing:antialiased;color-scheme:light;
}
body.admin-bar .hh{--top:46px}
@media (max-width:782px){body.admin-bar .hh{--top:60px}}

/* resets against theme styles */
.hh *,.hh *::before,.hh *::after{box-sizing:border-box}
.hh h1,.hh h2,.hh h3{font-family:var(--f-display);margin:0;padding:0;color:inherit;letter-spacing:-.025em;line-height:1.05;text-wrap:balance;text-transform:none}
.hh p{margin:0;padding:0;color:inherit}
.hh a{color:inherit;text-decoration:none;box-shadow:none}
.hh a:hover,.hh a:focus{color:inherit}
.hh button{margin:0;padding:0;border:0;background:none;color:inherit;font:inherit;text-transform:none;letter-spacing:inherit;line-height:inherit;min-height:0;box-shadow:none;cursor:pointer;border-radius:0}
/* :where() keeps this reset weaker than any button style, so a red button keeps its colour while pressed or focused */
.hh button:where(:hover,:focus,:active){background:none;color:inherit}
.hh img{max-width:100%;height:auto;display:block}
.hh nav ul{margin:0;padding:0}
.hh ::selection{background:var(--red);color:#fff}
.hh :focus-visible{outline:2px solid var(--red);outline-offset:3px;border-radius:10px}
.hh .num{font-variant-numeric:tabular-nums}
.hh .ic{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}
.hh-wrap{max-width:1200px;margin:0 auto;padding-inline:20px}
.hh-paper{background-color:var(--paper);background-image:
  linear-gradient(var(--grid-major) 1px,transparent 1px),linear-gradient(90deg,var(--grid-major) 1px,transparent 1px),
  linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:120px 120px,120px 120px,24px 24px,24px 24px;background-position:-1px -1px}

/* ---------- liquid glass ---------- */
.hh .hh-glass{position:relative;background:var(--glass-fill);border:1px solid var(--glass-edge);box-shadow:var(--glass-shadow);isolation:isolate}
.hh .hh-glass::after{content:"";position:absolute;inset:0;border-radius:inherit;pointer-events:none;z-index:-1;
  background:radial-gradient(240px circle at var(--mx,20%) var(--my,0%),rgba(255,255,255,.75),transparent 60%);opacity:.7}
.hh .hh-bezel{padding:6px;border-radius:30px;background:rgba(20,20,20,.03);box-shadow:inset 0 0 0 1px var(--ring)}
.hh .hh-bezel>.hh-glass{border-radius:24px}
.hh .hh-frost{background:rgba(255,255,255,.58);-webkit-backdrop-filter:blur(22px) saturate(180%);backdrop-filter:blur(22px) saturate(180%)}
@supports not ((backdrop-filter:blur(1px)) or (-webkit-backdrop-filter:blur(1px))){.hh .hh-frost{background:rgba(255,255,255,.94)}}
@media (prefers-reduced-transparency:reduce){.hh .hh-frost,.hh .hh-glass{background:#fff!important;-webkit-backdrop-filter:none!important;backdrop-filter:none!important}}

/* ---------- buttons: liquid pills with a nested icon ---------- */
.hh .hh-btn{position:relative;display:inline-flex;align-items:center;gap:12px;height:56px;padding:0 8px 0 26px;border-radius:999px;border:0;font:700 16px/1 var(--f-display);letter-spacing:-.01em;cursor:pointer;white-space:nowrap;transition:transform .5s var(--fluid),box-shadow .5s var(--fluid),background-color .3s var(--ease),color .3s var(--ease)}
.hh .hh-btn .orb{display:grid;place-items:center;width:40px;height:40px;border-radius:50%;transition:transform .5s var(--fluid),background-color .3s var(--ease)}
.hh .hh-btn:hover .orb{transform:translate(3px,-1px) scale(1.06)}
.hh .hh-btn:active{transform:scale(.98)}
.hh .hh-btn-red,.hh .hh-btn-red:hover,.hh .hh-btn-red:focus{color:#fff}
.hh .hh-btn-red{background:linear-gradient(180deg,var(--red-hi),var(--red) 55%,#bb0f28);box-shadow:inset 0 1px 0 rgba(255,255,255,.38),inset 0 -2px 6px rgba(120,6,22,.35),0 10px 24px -10px rgba(210,18,46,.6)}
.hh .hh-btn-red .orb{background:rgba(255,255,255,.2);box-shadow:inset 0 1px 0 rgba(255,255,255,.35)}
.hh .hh-btn-red:hover{box-shadow:inset 0 1px 0 rgba(255,255,255,.45),inset 0 -2px 6px rgba(120,6,22,.35),0 16px 34px -12px rgba(210,18,46,.7)}
.hh .hh-btn-glass{color:var(--ink)}
.hh .hh-btn-glass .orb{background:rgba(20,20,20,.06)}
.hh .hh-btn-glass:hover{box-shadow:inset 0 1px 0 rgba(255,255,255,.95),0 18px 36px -22px rgba(20,20,20,.4)}
.hh .hh-btn-white,.hh .hh-btn-white:hover{color:var(--ink)}
.hh .hh-btn-white{background:linear-gradient(180deg,#fff,#f3f4f5);box-shadow:inset 0 1px 0 #fff,0 12px 30px -14px rgba(60,0,10,.55)}
.hh .hh-btn-white .orb{background:var(--red);color:#fff}
.hh .hh-btn-sm{height:44px;padding:0 6px 0 18px;font-size:14px;gap:10px}
.hh .hh-btn-sm .orb{width:32px;height:32px}

/* ---------- nav island ---------- */
.hh-island{position:fixed;z-index:9990;top:var(--top);left:50%;transform:translateX(-50%);width:min(calc(100% - 24px),980px);display:flex;align-items:center;gap:8px;padding:7px 7px 7px 18px;border-radius:999px;border:1px solid rgba(255,255,255,.8);box-shadow:inset 0 1px 0 rgba(255,255,255,.9),0 1px 2px rgba(20,20,20,.05),0 18px 40px -24px rgba(20,20,20,.35);transition:transform .6s var(--fluid)}
.hh .hh-logo{display:inline-flex;align-items:center;gap:9px;color:var(--ink)}
.hh .hh-logo svg{width:24px;height:27px}
.hh .hh-wm{font-family:"Bricolage Grotesque",system-ui,sans-serif;font-size:20px;line-height:1;letter-spacing:-.02em;font-weight:500}
.hh .hh-wm b{font-weight:800}
.hh .hh-links{position:relative;display:flex;gap:2px;margin-inline:auto}
.hh .hh-links a{position:relative;z-index:1;padding:9px 16px;border-radius:999px;font:600 14px/1.2 var(--f-body);color:var(--slate);transition:color .3s var(--ease)}
.hh .hh-links a:hover,.hh .hh-links a.on{color:var(--ink)}
.hh .hh-lens{position:absolute;top:0;left:0;height:100%;width:0;border-radius:999px;background:linear-gradient(180deg,rgba(255,255,255,.95),rgba(255,255,255,.6));box-shadow:inset 0 1px 0 #fff,0 4px 14px -6px rgba(20,20,20,.3),inset 0 0 0 1px rgba(20,20,20,.05);transition:transform .55s var(--spring),width .55s var(--spring);pointer-events:none}
.hh .hh-burger{display:none;position:relative;width:44px;height:44px;margin-inline-start:auto;border-radius:50%;background:rgba(20,20,20,.06)}
.hh .hh-burger i{position:absolute;left:13px;right:13px;height:2px;border-radius:2px;background:var(--ink);transition:transform .5s var(--fluid),opacity .3s var(--ease)}
.hh .hh-burger i:nth-child(1){top:16px}.hh .hh-burger i:nth-child(2){top:21px}.hh .hh-burger i:nth-child(3){top:26px}
.hh-menu-open .hh .hh-burger i:nth-child(1){transform:translateY(5px) rotate(45deg)}
.hh-menu-open .hh .hh-burger i:nth-child(2){opacity:0;transform:scaleX(.2)}
.hh-menu-open .hh .hh-burger i:nth-child(3){transform:translateY(-5px) rotate(-45deg)}
.hh-sheet{position:fixed;inset:0;z-index:9980;display:flex;flex-direction:column;justify-content:center;gap:6px;padding:100px 28px 40px;background:rgba(240,241,242,.72);opacity:0;visibility:hidden;transition:opacity .5s var(--fluid),visibility .5s}
.hh-menu-open .hh-sheet{opacity:1;visibility:visible}
.hh .hh-sheet a{font:800 clamp(2.4rem,11vw,3.6rem)/1.1 var(--f-display);letter-spacing:-.04em;color:var(--ink);opacity:0;transform:translateY(40px);transition:opacity .6s var(--fluid),transform .7s var(--fluid);transition-delay:calc(var(--i)*70ms)}
.hh .hh-sheet a:hover{color:var(--red)}
.hh-menu-open .hh .hh-sheet a{opacity:1;transform:none}
@media (max-width:860px){.hh .hh-links,.hh .hh-island .hh-btn-sm{display:none}.hh .hh-burger{display:block}}

/* ---------- hero ---------- */
.hh-hero{position:relative;overflow:hidden}
.hh-hero-in{display:grid;grid-template-columns:minmax(0,1.12fr) minmax(0,.88fr);gap:40px;align-items:center;padding-block:calc(var(--top) + 136px) 40px}
.hh-hero h1{font-size:clamp(3rem,7.4vw,6.2rem);font-weight:800;letter-spacing:-.05em;line-height:.94}
.hh-hero h1 .w{display:inline-block;overflow:hidden;vertical-align:top;padding-bottom:.08em}
.hh-hero h1 .w>span{display:inline-block;transform:translateY(105%);animation:hh-up .9s var(--fluid) var(--d) forwards}
@keyframes hh-up{to{transform:none}}
.hh-hero h1 .mark{position:relative;color:var(--red)}
.hh-hero h1 .mark svg{position:absolute;left:-2%;bottom:-.12em;width:104%;height:.32em;overflow:visible}
.hh-hero h1 .mark path{fill:none;stroke:var(--red);stroke-width:7;stroke-linecap:round;stroke-dasharray:420;stroke-dashoffset:420;animation:hh-ink 1s var(--ease) 1.1s forwards}
@keyframes hh-ink{to{stroke-dashoffset:0}}
.hh-hero .lede{margin-top:26px;max-width:44ch;font-size:18.5px;color:var(--slate)}
.hh-hero .ctas{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px}
.hh-rise{animation:hh-rise .9s var(--fluid) var(--d,0s) backwards}
@keyframes hh-rise{from{opacity:0;transform:translateY(26px);filter:blur(6px)}to{opacity:1;transform:none;filter:none}}

.hh-draft{position:relative;width:100%;max-width:470px;justify-self:end;aspect-ratio:1/1.06;perspective:900px}
.hh-draft .plate{position:absolute;inset:4% 2% 2% 6%;border-radius:36px;transform:rotateX(var(--rx,0deg)) rotateY(var(--ry,0deg));transition:transform .8s var(--fluid)}
.hh-draft svg{position:relative;width:100%;height:100%;overflow:visible;transform:translate3d(var(--px,0),var(--py,0),0);transition:transform .8s var(--fluid)}
.hh-draft .ol{fill:none;stroke:var(--ink);stroke-width:1.4;stroke-linejoin:round;stroke-dasharray:var(--len);stroke-dashoffset:var(--len);animation:hh-draw 1.3s var(--ease) var(--dd,0s) forwards}
@keyframes hh-draw{to{stroke-dashoffset:0}}
.hh-draft .fill{opacity:0;animation:hh-fade .7s var(--ease) var(--dd,1.2s) forwards}
@keyframes hh-fade{to{opacity:1}}
.hh-draft .cap{opacity:0;transform-box:fill-box;transform-origin:50% 100%;animation:hh-cap .9s var(--spring) 1.55s forwards}
@keyframes hh-cap{from{opacity:0;transform:translateY(-60px) rotate(-24deg)}to{opacity:1;transform:none}}
.hh-draft .bob{transform-box:fill-box;transform-origin:50% 100%;animation:hh-bob 7s ease-in-out 2.6s infinite}
@keyframes hh-bob{0%,100%{transform:rotate(0)}50%{transform:rotate(-2.5deg) translateY(-2px)}}
.hh-draft .dim{stroke:var(--red);stroke-width:1.2;fill:none;stroke-dasharray:var(--len);stroke-dashoffset:var(--len);animation:hh-draw .8s var(--ease) var(--dd,2s) forwards}
.hh-draft .lbl{font:600 13px var(--f-mono);fill:var(--red);opacity:0;animation:hh-fade .5s var(--ease) var(--dd,2.4s) forwards}
.hh-draft .lbl.ink{fill:var(--slate)}
.hh-draft .pack{position:absolute;left:-6%;bottom:-3%;max-width:250px;border-radius:20px;padding:12px 16px;font:600 12px/1.5 var(--f-mono);color:var(--slate);opacity:0;animation:hh-rise .8s var(--fluid) 2.6s forwards;transform:translate3d(var(--qx,0),var(--qy,0),0)}
.hh-draft .pack b{display:block;font:800 15px var(--f-display);color:var(--ink);letter-spacing:-.01em}

.hh-ruler{padding-bottom:30px}
.hh-ruler .hh-glass{border-radius:22px;overflow:hidden;display:grid}
.hh-ruler .ticks{position:absolute;inset:0 0 auto 0;height:14px;background-image:linear-gradient(90deg,rgba(20,20,20,.55) 1.5px,transparent 1.5px),linear-gradient(90deg,rgba(20,20,20,.28) 1px,transparent 1px);background-size:100px 14px,10px 7px;background-repeat:repeat-x;background-position:-1px 0,-1px 0;transform-origin:left;transform:scaleX(0);transition:transform 1.4s var(--fluid)}
.hh-ruler.in .ticks,.hh-ruler.done .ticks{transform:none}
.hh-ruler .cell{display:flex;align-items:flex-end;gap:10px;padding:30px 20px 14px;border-inline-start:1px solid rgba(20,20,20,.07)}
.hh-ruler .cell:first-of-type{border:0}
.hh-ruler b{font:800 32px/1 var(--f-display);letter-spacing:-.03em}
.hh-ruler .cell span{font:600 12px var(--f-mono);color:var(--muted);padding-bottom:3px}
@media (max-width:900px){
  .hh-hero-in{grid-template-columns:1fr;padding-block:calc(var(--top) + 104px) 24px}
  .hh-draft{justify-self:center;max-width:360px}
  .hh-ruler .hh-glass{grid-template-columns:repeat(2,minmax(0,1fr))!important}
  .hh-ruler .cell:nth-of-type(odd){border:0}
}

/* ---------- sections ---------- */
.hh-sec{padding-block:120px 0}
.hh .head{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:16px 40px}
.hh .head h2{font-size:clamp(2.3rem,4.8vw,3.8rem);font-weight:800;letter-spacing:-.04em;max-width:15ch}
.hh .head p{max-width:40ch;color:var(--slate)}
.hh-rv.pre{opacity:0;transform:translateY(34px);filter:blur(8px)}
.hh-rv.in{transition:opacity .9s var(--fluid),transform 1s var(--fluid),filter .9s var(--fluid);transition-delay:calc(var(--i,0)*70ms)}

.hh .faculties{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-top:40px}
.hh .fac{display:inline-flex;align-items:center;gap:10px;height:46px;padding:0 20px;border-radius:999px;font:700 15px/1 var(--f-display);color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--rule-strong)}
.hh .fac[aria-selected="true"]{color:#fff;background:linear-gradient(180deg,#2a2a2a,var(--ink));box-shadow:inset 0 1px 0 rgba(255,255,255,.18),0 10px 22px -12px rgba(20,20,20,.6)}
.hh .fac small{font:600 11px var(--f-mono);opacity:.72}
.hh .fac.soon{color:var(--muted);box-shadow:inset 0 0 0 1.5px var(--rule-strong);border:1.5px dashed transparent;cursor:default}
.hh .index-wrap{margin-top:22px}
.hh .index{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:48px;padding:12px 30px}
.hh .hh-ixr{display:grid;grid-template-columns:40px minmax(0,auto) 1fr auto 22px;align-items:baseline;gap:12px;padding:19px 0!important;margin:0!important;border-bottom:1px solid rgba(20,20,20,.07);color:var(--ink)}
.hh .hh-ixr:nth-last-child(-n+2){border-bottom:0}
.hh .hh-ixr .n{font:600 13px var(--f-mono);color:var(--red)}
.hh .hh-ixr b{font:700 19px/1.3 var(--f-display);letter-spacing:-.015em;transition:color .3s var(--ease),transform .5s var(--fluid)}
.hh .hh-ixr .lead{border-bottom:2px dotted var(--rule-strong);transform:translateY(-5px)}
.hh .hh-ixr .ct{font:600 12.5px var(--f-mono);color:var(--muted);white-space:nowrap}
.hh .hh-ixr .ic{color:var(--muted);transform:translateY(4px);transition:transform .5s var(--fluid),color .3s}
.hh .hh-ixr:hover b{color:var(--red);transform:translateX(4px)}
.hh .hh-ixr:hover .ic{color:var(--red);transform:translate(6px,4px)}
@media (max-width:760px){.hh .index{grid-template-columns:1fr;padding:6px 18px}.hh .hh-ixr:nth-last-child(2){border-bottom:1px solid rgba(20,20,20,.07)}}

.hh .filters{display:flex;gap:8px;margin-top:36px;overflow-x:auto;padding:4px 2px 10px;scrollbar-width:none}
.hh .filters::-webkit-scrollbar{display:none}
.hh .chip{flex-shrink:0;height:40px;padding:0 16px;border-radius:999px;font:600 13.5px/1 var(--f-body);color:var(--slate);transition:color .3s,transform .4s var(--fluid)}
.hh .chip:hover{color:var(--ink);transform:translateY(-1px)}
.hh .chip[aria-pressed="true"]{color:#fff;background:linear-gradient(180deg,var(--red-hi),var(--red));box-shadow:inset 0 1px 0 rgba(255,255,255,.35),0 8px 18px -10px rgba(210,18,46,.6);border-color:transparent}
.hh .grid{display:grid;gap:22px;grid-template-columns:repeat(auto-fill,minmax(min(100%,270px),1fr));margin-top:22px}
.hh .card{display:block;color:var(--ink);transition:transform .7s var(--fluid)}
.hh .card:hover{transform:translateY(-6px)}
.hh .card .hh-glass{display:flex;flex-direction:column;height:100%;overflow:hidden}
.hh .card.hide{display:none}
.hh .thumb{position:relative;margin:8px 8px 0;border-radius:18px;aspect-ratio:16/10;overflow:hidden;background:var(--paper)}
.hh .thumb img{width:100%;height:100%;object-fit:cover;transition:transform 1s var(--fluid)}
.hh .card:hover .thumb img{transform:scale(1.05)}
.hh .thumb .ph{position:absolute;inset:0;display:grid;place-items:center;background-image:linear-gradient(var(--grid-major) 1px,transparent 1px),linear-gradient(90deg,var(--grid-major) 1px,transparent 1px);background-size:20px 20px}
.hh .thumb .ph b{font:800 24px/1.05 var(--f-display);letter-spacing:-.03em;text-align:center;padding:0 16px}
.hh .thumb .cat{position:absolute;left:10px;top:10px;font:600 11px/1.3 var(--f-mono);padding:4px 9px;border-radius:999px;background:rgba(255,255,255,.86);box-shadow:inset 0 1px 0 #fff,0 2px 8px -2px rgba(20,20,20,.25)}
.hh .card .body{display:grid;gap:14px;padding:16px 18px 18px;flex:1}
.hh .card h3{font-size:18px;font-weight:700;letter-spacing:-.015em;line-height:1.25}
.hh .card .meta{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:auto}
.hh .price{font:800 17px var(--f-display)}
.hh .price del{font-size:13px;font-weight:600;color:var(--muted)}
.hh .price.free{color:var(--ok)}
.hh .go{display:inline-flex;align-items:center;gap:8px;font:700 13.5px var(--f-display);color:var(--red)}
.hh .go .orb{display:grid;place-items:center;width:30px;height:30px;border-radius:50%;background:var(--red-wash);transition:transform .5s var(--fluid),background-color .3s}
.hh .go .ic{width:15px;height:15px}
.hh .card:hover .go .orb{transform:translate(3px,-1px) scale(1.08);background:var(--red);color:#fff}
.hh .more{margin-top:28px;display:flex;justify-content:center}

.hh .diagram{position:relative;margin-top:44px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:56px}
.hh .block{position:relative}
.hh .block .hh-glass{padding:26px 24px 28px;height:100%}
.hh .block .k{display:flex;align-items:center;justify-content:space-between;font:600 12px var(--f-mono);color:var(--muted)}
.hh .block .k b{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;color:#fff;font:700 14px var(--f-mono);background:linear-gradient(180deg,var(--red-hi),var(--red));box-shadow:inset 0 1px 0 rgba(255,255,255,.4),0 6px 14px -6px rgba(210,18,46,.6)}
.hh .block h3{font-size:24px;margin-top:22px}
.hh .block p{margin-top:10px;color:var(--slate);font-size:15px}
.hh .arrow{position:absolute;top:50%;right:-56px;width:56px;height:24px;transform:translateY(-50%)}
.hh .arrow path{fill:none;stroke:var(--red);stroke-width:2;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:70;stroke-dashoffset:70;transition:stroke-dashoffset .9s var(--fluid) var(--ad,.3s)}
.hh .diagram.in .arrow path{stroke-dashoffset:0}
@media (max-width:860px){.hh .diagram{grid-template-columns:1fr;gap:44px}.hh .arrow{top:auto;bottom:-40px;right:auto;left:30px;transform:rotate(90deg)}}

/* wallet band */
.hh-band{margin-top:130px;background:linear-gradient(160deg,#e3243c,#D2122E 45%,#b40f28);color:#fff;position:relative;overflow:hidden}
.hh-band::before{content:"";position:absolute;inset:0;background-image:linear-gradient(#ffffff12 1px,transparent 1px),linear-gradient(90deg,#ffffff12 1px,transparent 1px);background-size:24px 24px;pointer-events:none}
.hh-band::after{content:"";position:absolute;width:640px;height:640px;right:-160px;top:-260px;border-radius:50%;background:radial-gradient(circle,rgba(255,211,217,.35),transparent 65%);pointer-events:none}
.hh-band .band-in{position:relative;z-index:1;display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,.8fr);gap:40px;align-items:center;padding-block:90px}
.hh-band h2{font-size:clamp(2.3rem,5vw,4rem);font-weight:800;letter-spacing:-.04em;color:#fff}
.hh-band p{margin-top:18px;max-width:42ch;color:#ffe3e7;font-size:17px}
.hh-band .hh-btn{margin-top:32px}
.hh .receipt{justify-self:end;width:min(100%,340px);border-radius:26px;padding:22px 22px 18px;color:var(--ink);font:500 13px/1.6 var(--f-mono);background:linear-gradient(140deg,rgba(255,255,255,.94),rgba(255,255,255,.76));border:1px solid rgba(255,255,255,.9);box-shadow:inset 0 1px 0 #fff,0 30px 60px -28px rgba(60,0,10,.7);transform:rotate(2deg);transition:transform .9s var(--fluid)}
.hh .receipt:hover{transform:rotate(0) translateY(-4px)}
.hh .receipt h3{font:800 18px var(--f-display);letter-spacing:-.01em;margin-bottom:8px;color:var(--ink)}
.hh .receipt .rr{display:flex;justify-content:space-between;gap:10px;padding:8px 0;border-bottom:1px dashed var(--rule-strong)}
.hh .receipt .rr:last-child{border:0}
.hh .receipt .rr b{font-weight:600}
.hh .status{display:inline-flex;align-items:center;gap:7px;color:var(--muted)}
.hh .status .dot{width:8px;height:8px;border-radius:50%;background:#e0a100;animation:hh-pulse 1.2s ease-in-out infinite}
@keyframes hh-pulse{50%{transform:scale(.6);opacity:.5}}
.hh .status.done{color:var(--ok)}
.hh .status.done .dot{display:none}
.hh .status svg{display:none;width:15px;height:15px}
.hh .status.done svg{display:block}
.hh .status svg path{fill:none;stroke:currentColor;stroke-width:2.4;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:24;stroke-dashoffset:24;transition:stroke-dashoffset .6s var(--fluid) .1s}
.hh .status.done svg path{stroke-dashoffset:0}
.hh .rr.total.flash b{animation:hh-flash 1.2s var(--ease)}
@keyframes hh-flash{30%{color:var(--ok)}}
@media (max-width:860px){.hh-band .band-in{grid-template-columns:1fr}.hh .receipt{justify-self:start;transform:none}}

.hh-contact{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:20px;padding-block:64px}
.hh-contact h2{font-size:clamp(1.7rem,3vw,2.3rem);letter-spacing:-.03em}
.hh .ways{display:flex;flex-wrap:wrap;gap:12px}
.hh .way{display:inline-flex;align-items:center;gap:10px;height:50px;padding:0 20px;border-radius:999px;font:600 15px var(--f-mono);color:var(--ink)}
.hh .way.sel{user-select:all}

.hh-foot{border-top:1px solid rgba(20,20,20,.08);padding-block:28px calc(28px + env(safe-area-inset-bottom,0px))}
.hh-foot-in{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:16px;font-size:14px;color:var(--muted)}
.hh-foot nav{display:flex;flex-wrap:wrap;gap:6px 22px}
.hh-foot nav a{color:var(--slate)}
.hh-foot nav a:hover{color:var(--red)}

@media (prefers-reduced-motion:reduce){
  .hh *,.hh *::before,.hh *::after{animation-duration:.01ms!important;animation-delay:0s!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  .hh-draft .ol,.hh-draft .dim,.hh-hero h1 .mark path{stroke-dashoffset:0!important}
  .hh-hero h1 .w>span{transform:none}
}

/* ---------- catalog (/course/) ---------- */
.hh-cat{background:transparent}
.hh-cat .hc-head{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:20px 40px;padding-top:24px}
.hh-cat .hc-title h1{font-size:clamp(2.6rem,6vw,4.6rem);font-weight:800;letter-spacing:-.05em;line-height:.95}
.hh-cat .hc-title p{margin-top:12px;font:600 13px var(--f-mono);color:var(--muted)}
.hh-cat .hc-search{display:flex;align-items:center;gap:10px;width:min(100%,420px);height:56px;padding:0 18px;border-radius:999px;cursor:text}
.hh-cat .hc-search .ic{width:20px;height:20px;color:var(--muted)}
.hh-cat .hc-search input{flex:1;min-width:0;height:100%;border:0!important;background:transparent!important;box-shadow:none!important;outline:0;font:500 15px var(--f-body);color:var(--ink);padding:0!important}
.hh-cat .hc-search:focus-within{box-shadow:var(--glass-shadow),0 0 0 4px var(--red-wash)}
.hh-cat .filters{margin-top:30px}
.hh-cat .chip .num{opacity:.6;margin-inline-start:4px;font-size:12px}
.hh-cat .grid{margin-top:22px}
.hh-cat .hc-empty{margin:40px 0 0;padding:28px;border-radius:22px;text-align:center;color:var(--slate);background:rgba(255,255,255,.6);box-shadow:inset 0 0 0 1px var(--ring)}
.hh-cat .screen-reader-text{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}

/* ===================== 1.6.2: one frame system + mobile tab bar ===================== */
/* One frame everywhere: a single glass plate, 24px corners (no frame inside a frame). */
.hh{--r-panel:24px;--r-inner:16px}
.hh .hh-bezel{padding:0!important;background:none!important;box-shadow:none!important;border-radius:var(--r-panel)!important}
.hh .hh-bezel>.hh-glass,.hh .index,.hh .receipt,.hh .block .hh-glass,.hh .card .hh-glass,.hh-ruler .hh-glass{border-radius:var(--r-panel)!important}
.hh .thumb{border-radius:var(--r-inner)!important;margin:10px 10px 0!important}
.hh-draft .plate{border-radius:28px}

/* Bottom tab bar (phones + small tablets) */
.hh-tabbar{display:none}
@media (max-width:860px){
  .hh-tabbar{position:fixed;left:12px;right:12px;bottom:calc(10px + env(safe-area-inset-bottom,0px));z-index:9985;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:4px;padding:6px;border-radius:24px;border:1px solid rgba(255,255,255,.85);box-shadow:inset 0 1px 0 rgba(255,255,255,.9),0 1px 2px rgba(20,20,20,.05),0 18px 40px -20px rgba(20,20,20,.45)}
  .hh .hh-tabbar a{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;min-height:52px;border-radius:18px;font:600 11.5px/1.1 var(--f-body);color:var(--slate);transition:background-color .3s var(--ease),color .3s var(--ease),transform .4s var(--fluid)}
  .hh .hh-tabbar a .ic{width:21px;height:21px}
  .hh .hh-tabbar a:active{transform:scale(.94)}
  .hh .hh-tabbar a.on{color:var(--red-deep);background:linear-gradient(180deg,rgba(255,255,255,.95),rgba(255,255,255,.65));box-shadow:inset 0 1px 0 #fff,inset 0 0 0 1px rgba(210,18,46,.18)}
  body.hh-has-tabbar{padding-bottom:calc(84px + env(safe-area-inset-bottom,0px))!important}
  body.hh-has-tabbar .hh .hh-burger{display:none!important}
  body.hh-has-tabbar .hh-island{padding-right:18px}
}

/* Phones: hero buttons full width, calmer type */
@media (max-width:600px){
  .hh-hero .ctas{flex-direction:column;align-items:stretch}
  .hh-hero .ctas .hh-btn{justify-content:space-between;width:100%}
  .hh-hero h1{font-size:clamp(2.6rem,12vw,3.4rem)}
  .hh .head h2{font-size:clamp(2rem,9vw,2.6rem)}
  .hh-sec{padding-block:80px 0}
  .hh-band{margin-top:90px}
  .hh-band .band-in{padding-block:64px}
  .hh .ways{width:100%}
  .hh .way{flex:1 1 100%;justify-content:center}
}
/* Tablets */
@media (min-width:601px) and (max-width:1024px){
  .hh-wrap{padding-inline:28px}
  .hh .grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .hh .diagram{gap:40px}
}

/* ---------- 1.9.0 study browser: faculty → year → subject ---------- */
.hh .hh-steps{display:flex;align-items:center;gap:10px;margin-top:26px;font:600 11.5px/1 var(--f-mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.hh .hh-steps span.on{color:var(--red-deep)}
.hh .hh-steps i{width:28px;height:1px;background:var(--rule-strong)}
.hh .hh-steps + .faculties{margin-top:16px}
.hh .hh-years{display:flex;flex-wrap:wrap;gap:12px;margin-top:18px}
.hh .hh-yr{display:flex;align-items:center;gap:14px;min-width:240px;padding:12px 20px 12px 12px!important;border-radius:20px!important;text-align:left;transition:transform .5s var(--fluid),box-shadow .4s var(--ease)}
.hh .hh-yr .yn{display:grid;place-items:center;width:46px;height:46px;border-radius:14px;font:700 20px/1 var(--f-mono);color:var(--slate);background:rgba(20,20,20,.04);box-shadow:inset 0 0 0 1px var(--ring);transition:background-color .3s var(--ease),color .3s var(--ease)}
.hh .hh-yr .yt{display:flex;flex-direction:column;gap:4px}
.hh .hh-yr .yt b{font:700 17px/1.15 var(--f-display);letter-spacing:-.015em;color:var(--ink)}
.hh .hh-yr .yt small{font:600 11.5px/1 var(--f-mono);color:var(--muted)}
.hh .hh-yr:hover{transform:translateY(-2px)}
.hh .hh-yr[aria-selected="true"]{box-shadow:var(--glass-shadow),inset 0 0 0 1.5px rgba(210,18,46,.45)}
.hh .hh-yr[aria-selected="true"] .yn{color:#fff;background:linear-gradient(180deg,var(--red-hi),var(--red));box-shadow:inset 0 1px 0 rgba(255,255,255,.35),0 8px 18px -10px rgba(210,18,46,.7)}
.hh .hh-facp .index-wrap{margin-top:16px}
@media (max-width:600px){.hh .hh-yr{flex:1 1 100%;min-width:0}.hh .hh-steps{font-size:10.5px;gap:8px}.hh .hh-steps i{width:16px}}

/* ---------- 1.9.0 sign-in card in the hero (visitors only) ---------- */
.hh .hh-login{width:100%;max-width:440px;justify-self:end}
.hh .hh-login .hh-bezel{border-radius:32px}
.hh .hh-login-in{padding:30px 30px 24px;border-radius:26px!important}
.hh .hh-login .kick{display:inline-block;font:600 11px/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--red-deep)}
.hh .hh-login h2{margin-top:12px;font-size:30px;font-weight:800;letter-spacing:-.035em}
.hh .hh-login .sub{margin-top:6px;font-size:14.5px;color:var(--slate)}
.hh .hh-login-form{display:flex;flex-direction:column;gap:14px;margin-top:22px}
.hh .hh-login .fl{display:flex;flex-direction:column;gap:7px;margin:0}
.hh .hh-login .fl>span:first-child{font:600 13px/1 var(--f-body);color:#2b3035}
.hh .hh-login input[type=text],.hh .hh-login input[type=password]{width:100%;height:50px;margin:0;padding:0 16px;border:0;border-radius:14px;background:rgba(255,255,255,.9);box-shadow:inset 0 0 0 1px rgba(20,20,20,.12),0 1px 2px rgba(20,20,20,.04);font:500 15px var(--f-body);color:var(--ink);outline:0;transition:box-shadow .25s var(--ease)}
.hh .hh-login input:focus{box-shadow:inset 0 0 0 1.5px var(--red),0 0 0 4px var(--red-wash)}
.hh .hh-login .pw{position:relative;display:block}
.hh .hh-login .pw input{padding-right:50px}
.hh .hh-login .eye{position:absolute;top:50%;right:8px;display:grid;place-items:center;width:36px;height:36px;border-radius:10px;transform:translateY(-50%);color:var(--muted)}
.hh .hh-login .eye[aria-pressed="true"]{color:var(--red)}
.hh .hh-login .row{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap;font-size:13px}
.hh .hh-login .chk{display:inline-flex;align-items:center;gap:8px;margin:0;color:var(--slate);cursor:pointer}
.hh .hh-login .chk input{width:17px;height:17px;margin:0;accent-color:var(--red)}
.hh .hh-login .row a,.hh .hh-login .alt a{color:var(--red-deep);font-weight:600}
.hh .hh-login-go{justify-content:space-between;width:100%;margin-top:4px}
.hh .hh-login .hsa-wrap{margin:4px 0 0!important}
.hh .hh-login .alt{margin-top:16px;text-align:center;font-size:14px;color:var(--slate)}
@media (max-width:900px){.hh .hh-login{justify-self:stretch;max-width:520px;margin-inline:auto}}
@media (max-width:600px){.hh .hh-login-in{padding:24px 20px 20px}.hh .hh-login h2{font-size:26px}}

/* ---------- 1.9.0 courses page: year + subject rows ---------- */
.hh .chip[hidden]{display:none!important}
.hh-cat .hc-lbl{display:inline-flex;align-items:center;min-width:72px;font:600 11px/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.hh-cat .hc-years{margin-top:30px}
.hh-cat .hc-years + .filters{margin-top:12px}
.hh-cat .hc-lbl{flex-shrink:0}
@media (max-width:600px){.hh-cat .hc-lbl{min-width:58px}}
.hh-cat .hc-empty a{color:var(--red-deep);font-weight:600}

/* ===================== 2.0 formula sheet hero ===================== */
.hh-fs-hero .fs-head{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,.8fr);gap:22px 56px;align-items:end;padding-block:calc(var(--top) + 116px) 34px}
.hh-fs-hero h1{font-size:clamp(2.9rem,6.4vw,5.6rem)}
.hh-fs-hero .fs-lead .lede{margin-top:0;font-size:17.5px}
.hh-fs-hero .fs-lead .ctas{margin-top:22px}
.hh-fs-hero .fs-grid{display:grid;grid-template-columns:minmax(0,1fr) 372px;gap:28px;align-items:start;padding-bottom:46px}
.hh .fs-desk{position:relative;min-width:0}

/* index tabs on the sheet's top edge */
.hh .fs-tabs{position:relative;z-index:1;display:flex;gap:4px;margin-bottom:-1px;padding-inline:12px;overflow-x:auto;scrollbar-width:none}
.hh .fs-tabs::-webkit-scrollbar{display:none}
.hh .fs-tab{flex-shrink:0;padding:11px 13px 10px;border-radius:12px 12px 0 0;background:#e2e5e8;color:var(--slate);font:600 13px/1 var(--f-body);box-shadow:inset 0 1px 0 rgba(255,255,255,.75),inset 0 0 0 1px rgba(20,20,20,.06);transition:background-color .3s var(--ease),color .3s var(--ease),transform .45s var(--fluid)}
.hh .fs-tab:hover{color:var(--ink);transform:translateY(-2px)}
.hh .fs-tab[aria-selected="true"]{background:#fff;color:var(--ink);box-shadow:inset 0 2px 0 var(--red),0 -10px 18px -14px rgba(20,20,20,.3);transform:none}

/* the sheet: white paper, faint rules, a red margin line like an engineer's pad */
.hh .fs-sheet{position:relative;padding:20px 24px 18px;border-radius:4px 18px 18px 18px;background-color:#fff;background-image:linear-gradient(90deg,transparent 47px,rgba(210,18,46,.32) 47px,rgba(210,18,46,.32) 48px,transparent 48px),linear-gradient(rgba(20,20,20,.045) 1px,transparent 1px);background-size:100% 100%,100% 28px;background-position:0 0,0 13px;box-shadow:0 1px 0 rgba(20,20,20,.05),0 3px 6px rgba(20,20,20,.04),0 36px 64px -34px rgba(20,20,20,.4)}
.hh .fs-page.enter{animation:fs-turn .55s var(--fluid)}
@keyframes fs-turn{from{opacity:0;transform:translateY(10px);filter:blur(3px)}to{opacity:1;transform:none;filter:none}}

/* title block strip, as on a drawing sheet */
.hh .fs-block{display:grid;grid-template-columns:1.25fr 1fr 1fr 1fr;margin:0 0 10px;border:1.5px solid var(--ink);border-radius:3px;background:#fff}
.hh .fs-block>div{padding:7px 11px 8px;border-inline-start:1px solid rgba(20,20,20,.55);min-width:0}
.hh .fs-block>div:first-child{border:0}
.hh .fs-block dt{font:600 9.5px/1.2 var(--f-mono);letter-spacing:.14em;text-transform:uppercase;color:var(--muted)}
.hh .fs-block dd{margin:3px 0 0;font:700 14px/1.2 var(--f-display);letter-spacing:-.01em;color:var(--ink);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.hh .fs-block .b-name dd{color:var(--red-deep)}

/* numbered formula rows */
.hh .fs-rows{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:28px}
.hh .fs-rows li{border-bottom:1px dashed rgba(20,20,20,.12);min-width:0}
.hh .fs-f{position:relative;display:grid;grid-template-columns:36px minmax(0,1fr);grid-template-areas:"n name" "n math";row-gap:3px;padding:12px 4px 13px 0;color:var(--ink);border-radius:8px}
.hh .fs-n{grid-area:n;padding-top:2px;font:600 12px/1.2 var(--f-mono);color:var(--red)}
.hh .fs-name{grid-area:name;font:600 12.5px/1.3 var(--f-body);color:var(--muted)}
.hh .fs-math{grid-area:math;font:500 21px/1.4 "STIX Two Text",Cambria,"Times New Roman",serif;color:var(--ink);overflow-wrap:anywhere}
.hh .fs-math i{font-style:italic}
.hh .fs-math sup,.hh .fs-math sub{font-size:.64em;line-height:0}
.hh .fs-math .fr{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;margin:0 .14em;font-size:.84em;line-height:1.15}
.hh .fs-math .fr>span:first-child{padding:0 .22em .06em;border-bottom:1px solid currentColor}
.hh .fs-math .fr>span:last-child{padding:.08em .22em 0}
.hh .fs-math .ln{display:inline-block;width:48px;height:0;margin-inline-end:8px;vertical-align:middle;border-top:3px solid var(--ink)}
.hh .fs-math .ln-dash{border-top:1.5px dashed var(--ink)}
.hh .fs-math .ln-chain{height:1.5px;border:0;background:repeating-linear-gradient(90deg,var(--ink) 0 14px,transparent 14px 18px,var(--ink) 18px 21px,transparent 21px 25px)}
.hh .fs-ring{position:absolute;top:4px;left:28px;width:calc(100% - 22px);height:calc(100% - 4px);overflow:visible;pointer-events:none}
.hh .fs-ring path{fill:none;stroke:var(--red);stroke-width:2.2;stroke-linecap:round;stroke-dasharray:1 1;stroke-dashoffset:1.001;opacity:0;transition:stroke-dashoffset .75s var(--ease),opacity .2s}
.hh .fs-go{position:absolute;right:4px;bottom:5px;font:600 17px/1 Caveat,"Segoe Print",cursive;color:var(--red);opacity:0;transform:translateY(5px) rotate(-3deg);transition:opacity .3s var(--ease),transform .55s var(--fluid);pointer-events:none}
.hh .fs-f:hover .fs-ring path,.hh .fs-f:focus-visible .fs-ring path{stroke-dashoffset:0;opacity:1}
.hh .fs-f:hover .fs-go,.hh .fs-f:focus-visible .fs-go{opacity:1;transform:rotate(-3deg)}
.hh .fs-f:focus-visible{outline:2px solid var(--red);outline-offset:2px}
.hh .fs-note{margin:10px 0 0;padding-inline-start:48px;font:600 21px/1.1 Caveat,"Segoe Print",cursive;color:var(--red);transform:rotate(-1.5deg);transform-origin:left}

/* foot: the subject's real courses */
.hh .fs-foot{display:flex;flex-wrap:wrap;align-items:center;gap:8px 10px;margin-top:14px;padding-top:13px;border-top:1.5px solid var(--ink)}
.hh .fs-taught{margin-inline-end:4px;font:600 10.5px/1 var(--f-mono);letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.hh .fs-course{display:inline-flex;align-items:center;max-width:300px;height:32px;padding:0 13px;overflow:hidden;border-radius:999px;background:var(--red-wash);color:var(--red-deep);font:600 13px/32px var(--f-body);white-space:nowrap;text-overflow:ellipsis;transition:background-color .3s var(--ease)}
.hh .fs-course:hover{background:rgba(210,18,46,.14);color:var(--red-deep)}
.hh .fs-all{display:inline-flex;align-items:center;gap:6px;margin-inline-start:auto;font:700 14px/1 var(--f-display);color:var(--ink)}
.hh .fs-all .ic{width:16px;height:16px;transition:transform .45s var(--fluid)}
.hh .fs-all:hover{color:var(--red-deep)}
.hh .fs-all:hover .ic{transform:translateX(4px)}

/* aside: the sign-in card (or welcome card) stays in reach */
.hh .fs-side{position:sticky;top:calc(var(--top) + 90px);min-width:0}
.hh .fs-side .hh-login{max-width:none;justify-self:stretch}
.hh .fs-welcome .hh-login-go+.hh-login-go{margin-top:10px}
.hh .fs-welcome .sub{margin-bottom:18px}
.hh .fs-welcome .hh-btn-glass{color:var(--ink)}

@media (max-width:1100px){.hh-fs-hero .fs-grid{grid-template-columns:minmax(0,1fr) 330px}.hh .fs-rows{column-gap:20px}.hh .fs-math{font-size:19px}}
@media (max-width:900px){
  .hh-fs-hero .fs-head{grid-template-columns:1fr;padding-block:calc(var(--top) + 96px) 24px}
  .hh-fs-hero .fs-grid{grid-template-columns:1fr}
  .hh .fs-side{position:static;max-width:520px;width:100%;justify-self:center}
}
@media (max-width:640px){
  .hh .fs-tabs{padding-inline:6px}
  .hh .fs-tab{padding:10px 13px 9px;font-size:13px}
  .hh .fs-sheet{padding:14px;border-radius:4px 14px 14px 14px;background-image:linear-gradient(90deg,transparent 37px,rgba(210,18,46,.32) 37px,rgba(210,18,46,.32) 38px,transparent 38px),linear-gradient(rgba(20,20,20,.045) 1px,transparent 1px)}
  .hh .fs-block{grid-template-columns:1fr 1fr}
  .hh .fs-block>div:nth-child(3){border-inline-start:0}
  .hh .fs-block>div:nth-child(n+3){border-top:1px solid rgba(20,20,20,.55)}
  .hh .fs-rows{grid-template-columns:1fr}
  .hh .fs-f{grid-template-columns:30px minmax(0,1fr)}
  .hh .fs-math{font-size:19px}
  .hh .fs-ring{left:22px;width:calc(100% - 16px)}
  .hh .fs-note{padding-inline-start:38px}
  .hh .fs-all{margin-inline-start:0}
}
@media (prefers-reduced-motion:reduce){.hh .fs-page.enter{animation:none}.hh .fs-ring path{transition:none}}

/* ===================== 2.2 start free ===================== */
.hh .thumb .free-tag{position:absolute;right:10px;top:10px;padding:4px 10px;border-radius:999px;background:#0b8a5f;color:#fff;font:600 11.5px/1.3 var(--f-body);box-shadow:0 6px 14px -8px rgba(11,138,95,.8)}
.hh-cat .hc-free{height:44px;padding:0 18px}
.hh-cat .hc-free[aria-pressed="true"]{color:#fff;background:linear-gradient(180deg,#119a6c,#0b8a5f);box-shadow:inset 0 1px 0 rgba(255,255,255,.3),0 8px 18px -10px rgba(11,138,95,.7)}
.hh-cat .hc-free .num{opacity:.7;margin-inline-start:4px}

/* ===================== 2.6 finder + a calmer formula sheet ===================== */
/* year → subject at the top of the page; it also turns the sheet (the tab row is gone) */
.hh .fs-findwrap{padding-bottom:22px}
.hh .fs-find{display:flex;flex-wrap:wrap;align-items:flex-end;gap:12px 14px;padding:14px 14px 14px 20px;border-radius:var(--r-panel)}
.hh .ff{display:flex;flex-direction:column;gap:7px;flex:1 1 210px;min-width:0;margin:0}
.hh .ff-l{font:600 11px/1 var(--f-mono);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.hh .ff-s{-webkit-appearance:none;appearance:none;width:100%;height:48px;margin:0;padding:0 44px 0 16px;border:0;border-radius:14px;
  background:rgba(255,255,255,.92) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234A5056' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 15px center/15px;
  box-shadow:inset 0 0 0 1px rgba(20,20,20,.12);font:600 15px/1 var(--f-body);color:var(--ink);cursor:pointer;transition:box-shadow .25s var(--ease)}
.hh .ff-s:hover{box-shadow:inset 0 0 0 1px rgba(20,20,20,.28)}
.hh .ff-s:focus-visible{outline:none;box-shadow:inset 0 0 0 1.5px var(--red),0 0 0 4px var(--red-wash)}
/* our own dropdown (heroDropdown in home.js): homepage finder + sign-up form */
.hh .fs-findwrap{position:relative;z-index:5}
.hdd{position:relative;width:100%}
.hdd-native{position:absolute!important;left:0;bottom:0;width:1px!important;height:1px!important;margin:0!important;padding:0!important;border:0!important;opacity:0!important;pointer-events:none!important}
.hdd .hdd-btn,.hdd .hdd-btn:hover,.hdd .hdd-btn:focus{display:flex;align-items:center;width:100%;height:48px;margin:0;padding:0 44px 0 16px;border:0;border-radius:14px;text-align:left;text-transform:none;letter-spacing:0;
  background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%234A5056' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 15px center/15px;
  box-shadow:inset 0 0 0 1px rgba(20,20,20,.14);font:600 15px/1.2 "Alexandria","Segoe UI",system-ui,sans-serif;color:#141414;cursor:pointer;transition:box-shadow .25s}
.hdd .hdd-btn:hover{box-shadow:inset 0 0 0 1px rgba(20,20,20,.3)}
.hdd .hdd-btn:focus-visible,.hdd .hdd-btn[aria-expanded="true"]{outline:none;box-shadow:inset 0 0 0 1.5px #D2122E,0 0 0 4px rgba(210,18,46,.12)}
.hdd .hdd-btn.is-empty{color:#6b7178;font-weight:500}
.hdd .hdd-btn:disabled{cursor:not-allowed;opacity:.6}
.hdd-val{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.hdd-pop{position:absolute;left:0;right:0;top:calc(100% + 8px);z-index:60;padding:6px;border-radius:16px;background:#fff;
  box-shadow:inset 0 0 0 1px rgba(20,20,20,.08),0 1px 2px rgba(20,20,20,.06),0 24px 48px -16px rgba(20,20,20,.38);transform-origin:top center;animation:hdd-in .2s cubic-bezier(.22,1,.36,1)}
.hdd-pop[hidden]{display:none}
@keyframes hdd-in{from{opacity:0;transform:translateY(-6px) scale(.985)}to{opacity:1;transform:none}}
.hdd .hdd-search{display:block;width:100%;height:42px;margin:0 0 6px;padding:0 14px;border:0!important;border-radius:11px!important;background:#F0F1F2!important;box-shadow:none!important;font:500 14.5px/1 "Alexandria","Segoe UI",system-ui,sans-serif;color:#141414}
.hdd .hdd-search:focus{outline:none;box-shadow:inset 0 0 0 1.5px #D2122E!important}
.hdd-list{max-height:min(300px,55vh);overflow:auto;margin:0;padding:0;list-style:none;scrollbar-width:thin;overscroll-behavior:contain}
.hdd-list:focus{outline:none}
.hdd-opt{display:flex;align-items:center;gap:10px;min-height:44px;margin:0;padding:0 12px;border-radius:11px;font:600 14.5px/1.25 "Alexandria","Segoe UI",system-ui,sans-serif;color:#141414;cursor:pointer;transition:background-color .15s}
.hdd-opt[hidden]{display:none}
.hdd-opt.is-active{background:rgba(20,20,20,.055)}
.hdd-opt[aria-selected="true"]{color:#A50E24}
.hdd-ck{width:16px;height:16px;flex-shrink:0;fill:none;stroke:currentColor;stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;opacity:0}
.hdd-opt[aria-selected="true"] .hdd-ck{opacity:1}
.hdd-t{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.hdd-ct{margin-inline-start:auto;padding-inline-start:12px;font:600 12px/1 "JetBrains Mono",ui-monospace,monospace;color:#5f656b}
.hdd-none{padding:14px 12px;color:#5f656b;font:500 14px/1.4 "Alexandria",system-ui,sans-serif}
.hdd-none[hidden]{display:none}
/* finder: glass-white field like the rest of the bar */
.hh .hdd-ff .hdd-btn,.hh .hdd-ff .hdd-btn:hover,.hh .hdd-ff .hdd-btn:focus{background-color:rgba(255,255,255,.92)}
/* sign-up: same height, border and corners as the form's other fields; red when the form flags it */
.ss-signup .hdd-ss .hdd-btn,.ss-signup .hdd-ss .hdd-btn:hover,.ss-signup .hdd-ss .hdd-btn:focus{height:50px;padding-left:20px;border-radius:14px;font-size:15px}
.ss-signup .has-error .hdd-btn{box-shadow:inset 0 0 0 1px var(--ss-err,#d92d20)!important}
@media (prefers-reduced-motion:reduce){.hdd-pop{animation:none}}
.hh .ff-go{flex:0 0 auto;height:48px}
.hh .ff-go b{font-weight:800}
/* courses page: search is the finder's third field, and the panel keeps clear of the title */
.hh-cat .hc-findwrap{margin-top:28px}
.hh .ff-q{flex:1.3 1 220px}
.hh .ff-qbox{display:flex;align-items:center;gap:9px;height:48px;padding:0 14px 0 15px;border-radius:14px;background:rgba(255,255,255,.92);box-shadow:inset 0 0 0 1px rgba(20,20,20,.12);cursor:text;transition:box-shadow .25s var(--ease)}
.hh .ff-qbox:hover{box-shadow:inset 0 0 0 1px rgba(20,20,20,.28)}
.hh .ff-qbox:focus-within{box-shadow:inset 0 0 0 1.5px var(--red),0 0 0 4px var(--red-wash)}
.hh .ff-qbox .ic{width:18px;height:18px;flex:0 0 auto;color:var(--muted)}
.hh .ff-qbox input{flex:1;min-width:0;height:100%;margin:0;padding:0!important;border:0!important;background:transparent!important;box-shadow:none!important;outline:0;font:500 15px/1 var(--f-body);color:var(--ink)}
.hh .ff-qbox input::-webkit-search-cancel-button{cursor:pointer}
@media (max-width:640px){.hh .fs-find{padding:14px}.hh .ff{flex:1 1 100%}.hh .ff-go{width:100%;justify-content:space-between}.hh-cat .hc-findwrap{margin-top:20px}}

/* the sheet: one quiet header line, more air between formulas, no rules crossing the text */
.hh .fs-sheet{padding:22px 26px 20px;border-radius:var(--r-panel);background-image:none}
.hh .fs-hd{display:flex;align-items:center;gap:8px 14px;flex-wrap:wrap;margin:0 0 4px;padding-bottom:14px;border-bottom:1px solid var(--rule)}
.hh .fs-hd b{font:800 22px/1.1 var(--f-display);letter-spacing:-.025em;color:var(--ink)}
.hh .fs-hd .fs-meta{font:600 11.5px/1.2 var(--f-mono);letter-spacing:.04em;color:var(--muted)}
.hh .fs-step{display:flex;gap:6px;margin-inline-start:auto}
.hh .fs-step button{display:grid;place-items:center;width:36px;height:36px;border-radius:50%;color:var(--slate);box-shadow:inset 0 0 0 1px var(--rule-strong);transition:color .25s var(--ease),box-shadow .25s var(--ease),transform .4s var(--fluid)}
.hh .fs-step button:hover{color:var(--ink);box-shadow:inset 0 0 0 1px var(--ink)}
.hh .fs-step button:active{transform:scale(.92)}
.hh .fs-step .ic{width:16px;height:16px}
.hh .fs-rows{column-gap:40px}
.hh .fs-rows li{border-bottom-color:rgba(20,20,20,.08)}
.hh .fs-f{padding:17px 6px 17px 0;row-gap:5px}
.hh .fs-math{font-size:22px;line-height:1.45}
.hh .fs-note{margin-top:14px;padding-inline-start:36px}
.hh .fs-foot{margin-top:16px;padding-top:14px;border-top:1px solid var(--rule)}
/* the sheet decides its own columns: two only when each formula has room to stay on one line */
.hh .fs-desk{container-type:inline-size}
@container (max-width:720px){.hh .fs-rows{grid-template-columns:1fr}.hh .fs-rows li:nth-last-child(2){border-bottom:1px dashed rgba(20,20,20,.08)}}
@media (max-width:640px){.hh .fs-sheet{padding:16px 16px 14px;background-image:none}.hh .fs-hd b{font-size:20px}.hh .fs-f{padding:14px 4px 14px 0}.hh .fs-note{padding-inline-start:30px}}

/* access period on the course cards ("14-day access") */
.hh .card .hc-acc{display:flex;align-items:center;gap:6px;margin:-6px 0 0;font:600 12px/1.2 var(--f-mono);color:var(--muted)}
.hh .card .hc-acc .ic{width:14px;height:14px;color:var(--red)}

/* course counts on the subject chips read as numbers, in their own colour */
.hh-cat .chip .num{opacity:1;margin-inline-start:6px;font:700 12px/1 var(--f-mono);color:var(--red-deep)}
.hh-cat .chip[aria-pressed="true"] .num{color:rgba(255,255,255,.85)}
.hh-cat .hc-free .num{opacity:1;color:var(--ok)}
.hh-cat .hc-free[aria-pressed="true"] .num{color:rgba(255,255,255,.85)}

/* ===================== 2.5 dark-mode switch in the nav island ===================== */
.hh .hh-mode{position:relative;display:grid;place-items:center;width:42px;height:42px;flex-shrink:0;border-radius:50%;color:var(--slate);background:rgba(20,20,20,.05);box-shadow:inset 0 0 0 1px var(--ring);transition:background-color .3s var(--ease),color .3s var(--ease),transform .45s var(--fluid)}
.hh .hh-mode:hover{color:var(--ink);background:rgba(20,20,20,.09)}
.hh .hh-mode:active{transform:scale(.92)}
.hh .hh-mode .ic{position:absolute;width:19px;height:19px;transition:transform .6s var(--fluid),opacity .3s var(--ease)}
.hh .hh-mode .hh-sun{opacity:0;transform:rotate(-90deg) scale(.5)}
html[data-theme="dark"] .hh .hh-mode .hh-moon{opacity:0;transform:rotate(90deg) scale(.5)}
html[data-theme="dark"] .hh .hh-mode .hh-sun{opacity:1;transform:none}
@media (max-width:860px){.hh .hh-island .hh-mode{margin-inline-start:auto}.hh .hh-island .hh-mode ~ .hh-burger{margin-inline-start:6px}}

/* ---------- 2.13 hero: bold statement ----------
   General and brand-led, so it never changes with universities, terms or subjects.
   The logo is drafted line by line like a blueprint, then inked; it drifts on scroll and follows the pointer at two depths.
   It is never rotated (brand rule: don't rotate the logo). */
.hh-bold{min-height:min(100svh,980px);display:flex;flex-direction:column}
.hh-bold>.hh-wrap{width:100%}
.hh-bold .hb-in{position:relative;flex:1;width:100%;display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:24px;align-items:center;padding-block:calc(var(--top) + 118px) 28px}
.hh-bold .hb-copy{position:relative;z-index:1}
.hh-bold h1{font-size:clamp(3.4rem,9.2vw,8.4rem);line-height:.92;letter-spacing:-.055em}
.hh-bold h1 .w{display:block;width:fit-content;padding-bottom:.12em;margin-bottom:-.06em}
.hh-bold h1 .hb-red{color:var(--red)}
/* the slogan sits under the headline; "hero" gets the red pen stroke once the logo is inked */
.hh-bold .hb-slogan{margin-top:26px;font:800 clamp(1.55rem,2.5vw,2.3rem)/1.15 var(--f-display);letter-spacing:-.03em;color:var(--ink)}
.hh-bold .hb-hero{position:relative;display:inline-block;color:var(--red)}
.hh-bold .hb-hero svg{position:absolute;left:-3%;bottom:-.2em;width:106%;height:.36em;overflow:visible}
.hh-bold .hb-hero path{fill:none;stroke:var(--red);stroke-width:7;stroke-linecap:round;stroke-dasharray:420;stroke-dashoffset:420;animation:hh-ink .9s var(--ease) 2.9s forwards}
.hh-bold .lede{margin-top:18px;max-width:40ch;font-size:clamp(17px,1.35vw,20px);line-height:1.55;color:var(--slate)}
.hh-bold .ctas{margin-top:36px}

/* the exploded logo: a real button (tap keeps it apart); home.js moves the five parts */
.hh .hh-bold .hb-art{position:relative;justify-self:end;width:min(100%,560px);aspect-ratio:140/152;border-radius:32px;cursor:pointer;
  transform:translate3d(0,var(--sy,0px),0);-webkit-tap-highlight-color:transparent;touch-action:pan-y}
.hh-bold .hb-tilt{position:absolute;inset:0;display:block;will-change:transform}
.hh-bold .hb-art svg{position:absolute;inset:0;width:100%;height:100%;overflow:visible}
.hh-bold .hb-fa{fill:var(--mk-a,#A50E24)}
.hh-bold .hb-fb{fill:var(--mk-b,#D2122E)}
/* a part's outline shows only while it is apart (--ol is set from how far apart it is) */
.hh-bold .hb-ol{fill:none;stroke:var(--red);stroke-width:.4;stroke-linejoin:round;stroke-opacity:var(--ol,0)}
/* construction: dashed circle and axes fade in, the circle then turns slowly like a dial; they get stronger as the logo comes apart */
.hh-bold .hb-c{fill:none;stroke:var(--ink);stroke-opacity:var(--gd,.2);stroke-width:.22;stroke-dasharray:1.2 1.8;opacity:0;animation:hh-fade .8s var(--ease) .15s forwards}
.hh-bold .hb-ring{transform-box:fill-box;transform-origin:center;animation:hh-fade .8s var(--ease) .15s forwards,hb-spin 120s linear .15s infinite}
.hh-bold .hb-ax{transform-box:fill-box;transform-origin:center;animation:hh-fade .8s var(--ease) .25s forwards,hb-sy 1s var(--ease) .25s backwards}
.hh-bold .hb-ay{transform-box:fill-box;transform-origin:center;animation:hh-fade .8s var(--ease) .35s forwards,hb-sx 1s var(--ease) .35s backwards}
@keyframes hb-spin{to{transform:rotate(360deg)}}
@keyframes hb-sy{from{transform:scaleY(0)}}
@keyframes hb-sx{from{transform:scaleX(0)}}

/* the three facts sit in one glass frame, split by hairlines */
.hh-bold .hb-facts{list-style:none;margin:0 0 40px;padding:24px 0;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:0;border-radius:var(--r-panel,24px)}
.hh-bold .hb-facts li{display:flex;gap:14px;align-items:flex-start;margin:0;padding:0 28px}
.hh-bold .hb-facts li+li{border-inline-start:1px solid var(--rule)}
.hh-bold .hb-facts .ic{width:26px;height:26px;color:var(--red);stroke-width:1.7;transition:transform .5s var(--spring)}
.hh-bold .hb-facts li:hover .ic{transform:translateY(-2px) rotate(-6deg)}
.hh-bold .hb-facts b{display:block;font:700 16px/1.3 var(--f-display);letter-spacing:-.01em}
.hh-bold .hb-facts span{display:block;margin-top:4px;font-size:14.5px;line-height:1.45;color:var(--slate)}

@media (max-width:900px){
  .hh-bold{min-height:0}
  .hh-bold .hb-in{grid-template-columns:1fr;padding-block:calc(var(--top) + 100px) 20px}
  .hh .hh-bold .hb-art{order:-1;justify-self:center;width:min(64vw,300px);margin-bottom:6px}
  .hh-bold .hb-in{padding-block:calc(var(--top) + 84px) 20px}
  .hh-bold .hb-facts{grid-template-columns:1fr;padding:4px 20px;margin-bottom:28px}
  .hh-bold .hb-facts li{align-items:center;padding:14px 0}
  .hh-bold .hb-facts li+li{border-inline-start:0;border-top:1px solid var(--rule)}
}
@media (max-width:600px){
  .hh-bold .hb-facts .ic{width:22px;height:22px}
  .hh-bold .hb-facts span{display:none}
}
@media (prefers-reduced-motion:reduce){
  .hh .hh-bold .hb-art,.hh-bold .hb-tilt{transform:none!important}
  .hh-bold .hb-c,.hh-bold .hb-ring,.hh-bold .hb-ax,.hh-bold .hb-ay{animation:none!important;opacity:1}
  .hh-bold .hb-hero path{animation:none!important;stroke-dashoffset:0}
}