/* PCMB Master Book (/academy/pcmb): the app shell (side menu + views), the landing view, the book's paper pages
   and their page turn, and the mock tests. The site's own header and footer stay around it. */
.pc-app {
  --pc-top: 82px; --pc-sw: 304px;
  --physics: #3b82f6; --chemistry: #ea580c; --maths: #8b5cf6; --biology: #16a34a; --start: #0ea5e9; --extras: #64748b;
  --pc-ease: cubic-bezier(.2, .7, .2, 1);
  position: relative; display: grid; grid-template-columns: var(--pc-sw) minmax(0, 1fr); gap: 18px;
  max-width: 1720px; margin: 8px auto 0; padding: 0 16px 48px;
  -webkit-user-select: none; user-select: none; -webkit-touch-callout: none;
  transition: grid-template-columns .45s var(--pc-ease);
}
.pc-app input, .pc-app textarea { -webkit-user-select: text; user-select: text; }
.pc-app.side-off { --pc-sw: 0px; gap: 0; }
.pc-app [hidden] { display: none !important; }
.s-physics { --sc: var(--physics); --sc2: #1d4ed8; --st: rgba(59, 130, 246, .12); }
.s-chemistry { --sc: var(--chemistry); --sc2: #c2410c; --st: rgba(234, 88, 12, .12); }
.s-maths { --sc: var(--maths); --sc2: #6d28d9; --st: rgba(139, 92, 246, .12); }
.s-biology { --sc: var(--biology); --sc2: #15803d; --st: rgba(22, 163, 74, .12); }
.s-start { --sc: var(--start); --sc2: #0369a1; --st: rgba(14, 165, 233, .12); }
.s-extras { --sc: var(--extras); --sc2: #334155; --st: rgba(100, 116, 139, .14); }

/* ---- side menu ------------------------------------------------------------------------------------------------ */
.pc-side {
  position: sticky; top: var(--pc-top); align-self: start; height: calc(100dvh - var(--pc-top) - 12px); overflow: hidden;
  display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: 18px;
  background: linear-gradient(180deg, rgba(13, 19, 33, .92), rgba(7, 11, 20, .9)); box-shadow: var(--shadow);
  transition: opacity .3s ease, transform .45s var(--pc-ease);
}
.pc-app.side-off .pc-side { opacity: 0; transform: translateX(-24px); pointer-events: none; }
.pc-side-top { padding: 16px 14px 10px; border-bottom: 1px solid var(--line); }
.pc-brand { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; }
.pc-brand .pc-bk { width: 34px; height: 42px; border-radius: 4px 7px 7px 4px; background: linear-gradient(135deg, #1e3a8a, #6d28d9 60%, #be185d); box-shadow: inset 4px 0 0 rgba(255, 255, 255, .25), 0 8px 20px -8px rgba(99, 102, 241, .8); position: relative; flex: none; }
.pc-brand .pc-bk::after { content: 'PCMB'; position: absolute; inset: auto 0 6px; text-align: center; font: 800 8px/1 var(--display); letter-spacing: .06em; color: #fff; }
.pc-brand b { display: block; font: 700 15px/1.15 var(--display); }
.pc-brand small { display: block; color: var(--text3); font-size: 11.5px; margin-top: 2px; }
.pc-search { position: relative; margin-top: 12px; }
.pc-search input { width: 100%; height: 36px; border-radius: 10px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .04); color: var(--text); padding: 0 12px 0 34px; font: 500 13.5px var(--body); outline: none; transition: border-color .2s, box-shadow .2s; }
.pc-search input:focus { border-color: var(--gline2); box-shadow: 0 0 0 3px rgba(var(--glow1), .15); }
.pc-search svg { position: absolute; left: 11px; top: 10px; width: 16px; height: 16px; color: var(--text3); }
.pc-nav { flex: 1; overflow: auto; padding: 8px 8px 16px; scrollbar-width: thin; scrollbar-color: rgba(255, 255, 255, .15) transparent; }
.pc-it, .pc-sh, .pc-gh, .pc-cl {
  display: flex; align-items: center; gap: 9px; width: 100%; border: 0; background: none; color: var(--text2); text-align: left;
  font: 600 13.5px/1.25 var(--body); text-decoration: none; cursor: pointer; border-radius: 10px; position: relative;
  transition: background .2s, color .2s;
}
.pc-it { padding: 9px 10px; }
.pc-it:hover, .pc-sh:hover, .pc-gh:hover, .pc-cl:hover { background: rgba(255, 255, 255, .05); color: var(--text); }
.pc-it svg, .pc-sh svg.ic { width: 17px; height: 17px; flex: none; opacity: .85; }
.pc-sec { margin-top: 6px; }
.pc-sh { padding: 10px 10px; font: 700 12.5px/1 var(--display); letter-spacing: .08em; text-transform: uppercase; color: var(--text); }
.pc-sh .pc-dot, .pc-subj-head .pc-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--sc); box-shadow: 0 0 0 4px var(--st), 0 0 14px var(--sc); flex: none; }
.pc-chev { margin-left: auto; width: 14px; height: 14px; flex: none; transition: transform .35s var(--pc-ease); opacity: .6; }
.open > button > .pc-chev { transform: rotate(90deg); opacity: 1; }
.pc-fold { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .4s var(--pc-ease); }
.open > .pc-fold { grid-template-rows: 1fr; }
.pc-fold > div { overflow: hidden; min-height: 0; }
.pc-grp { margin: 2px 0 2px 8px; border-left: 1px solid var(--line); padding-left: 6px; }
.pc-gh { padding: 8px 8px; font-weight: 600; font-size: 13px; }
.pc-gh .pc-code, .pc-group .pc-code { flex: none; min-width: 30px; height: 22px; padding: 0 6px; border-radius: 7px; display: inline-grid; place-items: center; font: 800 11px/1 var(--display); color: #fff; background: linear-gradient(135deg, var(--sc), var(--sc2)); box-shadow: 0 6px 14px -6px var(--sc); }
.pc-gh span.t { flex: 1; min-width: 0; }
.pc-gh .pc-score, .pc-cl .pc-score { font: 700 10.5px/1 var(--mono); color: var(--ok-t); background: rgba(52, 211, 153, .12); border-radius: 6px; padding: 3px 5px; }
.pc-cl { padding: 6px 8px 6px 10px; font-weight: 500; font-size: 12.8px; color: var(--text3); }
.pc-cl .lv { flex: none; font: 700 9.5px/1 var(--mono); padding: 3px 4px; border-radius: 5px; background: rgba(255, 255, 255, .06); color: var(--text2); }
.pc-cl .lv.l2 { background: var(--st); color: var(--sc); }
.pc-cl.read::after { content: '✓'; margin-left: auto; color: var(--ok-t); font-size: 11px; }
.pc-cl.tst { color: var(--sc); font-weight: 700; }
.pc-cl.tst svg { width: 14px; height: 14px; flex: none; }
.pc-it.on, .pc-gh.on, .pc-cl.on { color: var(--text); background: linear-gradient(90deg, rgba(var(--glow1), .16), rgba(var(--glow1), .02)); }
.pc-it.on::before, .pc-gh.on::before, .pc-cl.on::before { content: ''; position: absolute; left: -2px; top: 7px; bottom: 7px; width: 3px; border-radius: 3px; background: var(--sc, var(--accent)); box-shadow: 0 0 10px var(--sc, var(--accent)); animation: pcBar .35s var(--pc-ease); }
@keyframes pcBar { from { transform: scaleY(0); } }
.pc-nav .hit-none { padding: 14px 10px; color: var(--text3); font-size: 13px; }
.pc-nav mark { background: rgba(250, 204, 21, .25); color: inherit; border-radius: 3px; }
.pc-side-foot { padding: 10px 14px 12px; border-top: 1px solid var(--line); font-size: 11.5px; color: var(--text3); display: flex; justify-content: space-between; gap: 8px; }
.pc-side-foot .pc-prog { flex: 1; height: 6px; border-radius: 6px; background: rgba(255, 255, 255, .07); overflow: hidden; align-self: center; }
.pc-side-foot .pc-prog i { display: block; height: 100%; width: 0; background: var(--grad); transition: width .6s var(--pc-ease); }

/* ---- main column, top bar of every view ---------------------------------------------------------------------- */
.pc-main { min-width: 0; position: relative; grid-column: 2; }
.pc-scrim { display: none; }
.pc-view { animation: pcIn .45s var(--pc-ease); }
@keyframes pcIn { from { opacity: 0; transform: translateY(10px); } }
.pc-menu-btn { display: none; }
.pc-sidetoggle { position: absolute; left: -12px; top: 18px; z-index: 6; width: 24px; height: 24px; border-radius: 50%; border: 1px solid var(--line2); background: var(--bg2); color: var(--text2); display: grid; place-items: center; cursor: pointer; transition: transform .3s; }
.pc-sidetoggle svg { width: 12px; height: 12px; transition: transform .35s var(--pc-ease); }
.pc-app.side-off .pc-sidetoggle { left: -4px; }
.pc-app.side-off .pc-sidetoggle svg { transform: rotate(180deg); }

/* ---- the landing view ------------------------------------------------------------------------------------------ */
.pc-hero { position: relative; display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); gap: 28px; align-items: center; padding: 34px 34px 30px; border-radius: 24px; border: 1px solid var(--line); overflow: hidden;
  background: radial-gradient(900px 400px at 85% 10%, rgba(139, 92, 246, .22), transparent 60%), radial-gradient(700px 360px at 10% 100%, rgba(59, 130, 246, .2), transparent 60%), linear-gradient(180deg, rgba(13, 19, 33, .9), rgba(7, 11, 20, .9)); }
.pc-hero h1 { font: 800 clamp(30px, 3.6vw, 50px)/1.05 var(--display); margin: 12px 0 14px; letter-spacing: -.02em; }
.pc-hero h1 em { font-style: normal; background: var(--grad-text); -webkit-background-clip: text; background-clip: text; color: transparent; }
.pc-hero p.pc-lead { color: var(--text2); font-size: 16.5px; line-height: 1.6; max-width: 640px; }
.pc-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.pc-tags span { font: 700 11.5px/1 var(--mono); letter-spacing: .03em; padding: 6px 9px; border-radius: 999px; border: 1px solid var(--line2); color: var(--text2); background: rgba(255, 255, 255, .03); }
.pc-cta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.pc-btn { display: inline-flex; align-items: center; gap: 8px; height: 42px; padding: 0 18px; border-radius: 12px; border: 0; cursor: pointer; text-decoration: none; font: 700 14px/1 var(--body); color: var(--ink-on-accent); background: var(--grad); box-shadow: 0 12px 30px -14px rgba(var(--glow1), .9); transition: transform .2s, box-shadow .2s, filter .2s; }
.pc-btn:hover { transform: translateY(-2px); filter: brightness(1.08); }
.pc-btn.ghost { color: var(--text); background: rgba(255, 255, 255, .05); border: 1px solid var(--line2); box-shadow: none; }
.pc-btn.sm { height: 34px; padding: 0 13px; font-size: 13px; border-radius: 10px; }
.pc-btn small { font: 700 10.5px/1 var(--mono); opacity: .8; }
.pc-stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin-top: 26px; }
.pc-stats div { padding: 12px 12px; border-radius: 14px; background: rgba(255, 255, 255, .035); border: 1px solid var(--line); }
.pc-stats b { display: block; font: 800 24px/1 var(--display); }
.pc-stats span { display: block; color: var(--text3); font-size: 12px; margin-top: 5px; }
/* the 3D book on the landing view: a card that opens the book */
.pc-cover-wrap { display: grid; place-items: center; perspective: 1600px; padding: 10px 0; }
.pc-cover { position: relative; width: min(300px, 70vw); aspect-ratio: 210 / 297; border: 0; padding: 0; cursor: pointer; background: none; transform: rotateY(-24deg) rotateX(6deg); transform-style: preserve-3d; transition: transform .8s var(--pc-ease); animation: pcFloat 6s ease-in-out infinite; }
.pc-cover:hover, .pc-cover:focus-visible { transform: rotateY(-8deg) rotateX(2deg) scale(1.03); animation-play-state: paused; }
@keyframes pcFloat { 50% { translate: 0 -8px; } }
.pc-cover .front { position: absolute; inset: 0; border-radius: 4px 12px 12px 4px; overflow: hidden; text-align: left; color: #fff; padding: 26px 22px; display: flex; flex-direction: column;
  background: radial-gradient(120% 70% at 100% 0%, rgba(244, 114, 182, .55), transparent 55%), radial-gradient(120% 80% at 0% 100%, rgba(56, 189, 248, .5), transparent 60%), linear-gradient(160deg, #1e1b4b, #312e81 45%, #1e3a8a);
  box-shadow: inset 6px 0 0 rgba(255, 255, 255, .18), inset 9px 0 12px rgba(0, 0, 0, .35), 0 40px 80px -30px rgba(0, 0, 0, .9), 0 0 60px -20px rgba(129, 140, 248, .8); }
.pc-cover .front::before { content: ''; position: absolute; inset: 0; background: repeating-linear-gradient(135deg, rgba(255, 255, 255, .04) 0 2px, transparent 2px 12px); }
.pc-cover .pages { position: absolute; top: 6px; bottom: 6px; right: -14px; width: 16px; border-radius: 0 3px 3px 0; background: repeating-linear-gradient(90deg, #f8fafc 0 1px, #e2e8f0 1px 2px); transform: rotateY(90deg) translateZ(8px); transform-origin: left; }
.pc-cover .k { font: 700 11px/1 var(--mono); letter-spacing: .14em; opacity: .85; }
.pc-cover h2 { font: 800 34px/1 var(--display); margin: 14px 0 6px; letter-spacing: -.01em; }
.pc-cover h2 span { display: block; font-size: 15px; font-weight: 600; letter-spacing: .02em; margin-top: 8px; opacity: .9; }
.pc-cover .subs { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-top: auto; position: relative; }
.pc-cover .subs i { font: 700 11px/1 var(--body); font-style: normal; padding: 8px 8px; border-radius: 8px; background: rgba(255, 255, 255, .12); backdrop-filter: blur(4px); }
.pc-cover .open-hint { position: absolute; right: 14px; top: 16px; font: 700 10px/1 var(--mono); letter-spacing: .1em; background: rgba(255, 255, 255, .18); padding: 6px 8px; border-radius: 999px; }
.pc-cover-cap { text-align: center; color: var(--text3); font-size: 12.5px; margin-top: 14px; }

.pc-block { margin-top: 26px; }
.pc-block-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 14px; }
.pc-block-head h2 { font: 800 26px/1.1 var(--display); margin: 0; }
.pc-block-head p { color: var(--text2); margin: 6px 0 0; font-size: 14.5px; max-width: 760px; line-height: 1.55; }
.pc-continue { display: none; align-items: center; gap: 14px; padding: 14px 16px; border-radius: 16px; border: 1px solid var(--gline); background: linear-gradient(90deg, rgba(var(--glow1), .12), rgba(var(--glow2), .05)); margin-top: 18px; }
.pc-continue.on { display: flex; animation: pcIn .5s var(--pc-ease); }
.pc-continue b { font-size: 14.5px; } .pc-continue span { color: var(--text2); font-size: 13px; display: block; margin-top: 3px; }
.pc-continue .pc-btn { margin-left: auto; }
.pc-subj { margin-top: 30px; }
.pc-subj-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.pc-subj-head h2 { font: 800 24px/1 var(--display); margin: 0; }
.pc-subj-head p { margin: 0 0 0 6px; color: var(--text3); font-size: 13.5px; }
.pc-groups { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 14px; }
.pc-group { position: relative; display: flex; flex-direction: column; gap: 12px; padding: 18px 18px 16px; border-radius: 18px; border: 1px solid var(--line); overflow: hidden;
  background: linear-gradient(180deg, rgba(255, 255, 255, .045), rgba(255, 255, 255, .015)); transition: transform .35s var(--pc-ease), border-color .3s, box-shadow .35s;
  animation: pcIn .6s var(--pc-ease) both; animation-delay: calc(var(--n, 0) * 70ms); }
.pc-group::before { content: ''; position: absolute; inset: 0 0 auto; height: 3px; background: linear-gradient(90deg, var(--sc), transparent); }
.pc-group:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--sc) 55%, transparent); box-shadow: 0 24px 50px -28px var(--sc); }
.pc-group header { display: flex; align-items: center; gap: 10px; }
.pc-group h3 { font: 700 16.5px/1.25 var(--display); margin: 0; }
.pc-flowmini { display: grid; grid-template-columns: 1fr auto 1fr; gap: 8px; align-items: start; }
.pc-flowmini > div { display: flex; flex-direction: column; gap: 4px; }
.pc-flowmini span { font: 700 10px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--text3); margin-bottom: 2px; }
.pc-flowmini em { font-style: normal; font-size: 12.5px; line-height: 1.3; color: var(--text2); padding: 5px 8px; border-radius: 8px; background: rgba(255, 255, 255, .04); border: 1px solid var(--line); }
.pc-flowmini > div:last-child em { border-color: color-mix(in srgb, var(--sc) 35%, transparent); background: var(--st); color: var(--text); }
.pc-flowmini em.dim { opacity: .7; font-style: italic; }
.pc-flowmini > i { align-self: center; color: var(--sc); font-style: normal; font-size: 20px; animation: pcNudge 1.8s ease-in-out infinite; }
@keyframes pcNudge { 50% { transform: translateX(4px); } }
.pc-why { margin: 0; color: var(--text2); font-size: 13.5px; line-height: 1.55; }
.pc-group footer { display: flex; align-items: center; gap: 8px; margin-top: auto; flex-wrap: wrap; }
.pc-group footer .pc-btn { height: 34px; font-size: 13px; padding: 0 13px; border-radius: 10px; }
.pc-best { margin-left: auto; font: 700 11px/1 var(--mono); color: var(--ok-t); }
.pc-grid2 { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; }
.pc-tile { padding: 16px; border-radius: 16px; border: 1px solid var(--line); background: rgba(255, 255, 255, .03); }
.pc-tile h3 { margin: 0 0 8px; font: 700 15px/1.2 var(--display); display: flex; align-items: center; gap: 8px; }
.pc-tile p, .pc-tile li { color: var(--text2); font-size: 13.2px; line-height: 1.55; margin: 0; }
.pc-tile ul { margin: 0; padding-left: 18px; }
.pc-steps { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.pc-steps span { padding: 8px 12px; border-radius: 10px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .04); font-size: 13px; color: var(--text); animation: pcGlow 6s ease-in-out infinite; animation-delay: calc(var(--n, 0) * 1s); }
.pc-steps i { color: var(--text3); font-style: normal; }
@keyframes pcGlow { 0%, 12% { border-color: var(--gline2); box-shadow: 0 0 18px -6px rgba(var(--glow1), .9); } 25%, 100% { border-color: var(--line2); box-shadow: none; } }
.pc-honest { margin-top: 26px; padding: 14px 16px; border-radius: 14px; border: 1px dashed var(--line2); color: var(--text3); font-size: 12.8px; line-height: 1.55; }

/* ---- the reader ------------------------------------------------------------------------------------------------ */
.pc-read { position: sticky; top: var(--pc-top); height: calc(100dvh - var(--pc-top) - 12px); display: flex; flex-direction: column; border-radius: 18px; border: 1px solid var(--line); overflow: hidden;
  background: radial-gradient(1200px 500px at 50% 0%, rgba(var(--glow2), .1), transparent 60%), linear-gradient(180deg, #0b1020, #070b14); }
.pc-bar { display: flex; align-items: center; gap: 6px; padding: 8px 10px; border-bottom: 1px solid var(--line); background: rgba(6, 9, 20, .7); backdrop-filter: blur(10px); flex-wrap: wrap; position: relative; z-index: 4; }
.pc-tb { height: 34px; min-width: 34px; padding: 0 10px; border-radius: 9px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .04); color: var(--text); display: inline-flex; align-items: center; justify-content: center; gap: 6px; cursor: pointer; font: 600 12.5px/1 var(--body); transition: background .2s, border-color .2s, transform .15s; }
.pc-tb:hover { background: rgba(255, 255, 255, .09); border-color: var(--gline2); }
.pc-tb:active { transform: scale(.96); }
.pc-tb[disabled] { opacity: .35; cursor: default; }
.pc-tb svg { width: 16px; height: 16px; }
.pc-tb.on { border-color: var(--gline2); background: rgba(var(--glow1), .14); }
.pc-sep { width: 1px; height: 22px; background: var(--line2); margin: 0 4px; }
.pc-where { min-width: 0; flex: 1; display: flex; flex-direction: column; padding: 0 8px; }
.pc-where b { font: 700 13px/1.2 var(--display); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pc-where span { color: var(--text3); font: 600 11.5px/1.3 var(--mono); }
.pc-zoom { font: 700 12px/1 var(--mono); min-width: 52px; }
.pc-stage { position: relative; flex: 1; overflow: auto; overscroll-behavior: contain; scrollbar-width: thin; touch-action: pan-y pinch-zoom; }
.pc-stage.grab { cursor: grab; }
.pc-scaler { position: relative; margin: 0 auto; }
.pc-book { position: absolute; left: 0; top: 0; transform-origin: 0 0; perspective: 2800px; }
.pc-slot { position: absolute; top: 0; }
.pc-slot.r { box-shadow: inset 18px 0 24px -18px rgba(0, 0, 0, .35); }
.pc-spine { position: absolute; top: 0; width: 30px; margin-left: -15px; height: 100%; pointer-events: none; z-index: 3; background: linear-gradient(90deg, transparent, rgba(0, 0, 0, .18) 45%, rgba(255, 255, 255, .08) 55%, transparent); }
.pc-edge { position: absolute; top: 0; bottom: 0; width: 13%; z-index: 4; cursor: pointer; }
.pc-edge.l { left: 0; } .pc-edge.r { right: 0; }
.pc-edge::after { content: ''; position: absolute; top: 50%; width: 38px; height: 38px; margin-top: -19px; border-radius: 50%; background: rgba(15, 23, 42, .55) no-repeat center/18px; opacity: 0; transition: opacity .25s, transform .25s; backdrop-filter: blur(4px); }
.pc-edge.l::after { left: 10px; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.6'%3E%3Cpath d='M15 5l-7 7 7 7'/%3E%3C/svg%3E"); }
.pc-edge.r::after { right: 10px; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.6'%3E%3Cpath d='M9 5l7 7-7 7'/%3E%3C/svg%3E"); }
.pc-edge:hover::after { opacity: 1; }
.pc-edge[hidden] { display: none; }
.pc-loading { position: absolute; inset: 0; display: grid; place-items: center; color: var(--text2); font-size: 13px; z-index: 9; }
.pc-loading i { width: 34px; height: 34px; border-radius: 50%; border: 3px solid rgba(255, 255, 255, .12); border-top-color: var(--accent); animation: pcSpin .8s linear infinite; display: block; margin: 0 auto 10px; }
@keyframes pcSpin { to { transform: rotate(360deg); } }
.pc-progress { height: 3px; background: rgba(255, 255, 255, .06); }
.pc-progress i { display: block; height: 100%; width: 0; background: var(--grad); transition: width .5s var(--pc-ease); }
/* the leaf that turns: its two faces are copies of the pages it carries */
.pc-leaf { position: absolute; top: 0; transform-style: preserve-3d; z-index: 5; will-change: transform; }
.pc-leaf > .face { position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden; overflow: hidden; }
.pc-leaf > .face.back { transform: rotateY(180deg); }
.pc-leaf > .face > .pg { position: absolute; left: 0; top: 0; }
.pc-leaf .shade { position: absolute; inset: 0; pointer-events: none; opacity: 0; }
.pc-leaf .front .shade { background: linear-gradient(90deg, rgba(0, 0, 0, .28), rgba(0, 0, 0, 0) 40%, rgba(255, 255, 255, .25) 75%, rgba(0, 0, 0, .1)); }
.pc-leaf .back .shade { background: linear-gradient(270deg, rgba(0, 0, 0, .3), rgba(0, 0, 0, 0) 45%, rgba(255, 255, 255, .2) 80%); }
.pc-leaf.turning .shade { animation: pcShade var(--flip, .8s) ease-in-out forwards; }
@keyframes pcShade { 0% { opacity: 0; } 50% { opacity: 1; } 100% { opacity: 0; } }
.pc-castshadow { position: absolute; top: 0; height: 100%; pointer-events: none; z-index: 4; opacity: 0; background: linear-gradient(90deg, rgba(0, 0, 0, .35), transparent); }
.pc-castshadow.go { animation: pcCast var(--flip, .8s) ease-in-out; }
@keyframes pcCast { 40% { opacity: 1; } 100% { opacity: 0; } }
.pc-hide .pc-stage, .pc-hide .pc-test { filter: blur(18px) saturate(.4); }
.pc-hide .pc-stage::after { content: 'Paused - come back to keep reading'; position: absolute; inset: 0; display: grid; place-items: center; color: #fff; font: 700 15px var(--display); }

/* ---- paper pages ----------------------------------------------------------------------------------------------- */
.pg {
  --ink: #111827; --ink2: #374151; --mut: #6b7280; --paper: #fffefb; --rule: #e5e7eb; --tint: rgba(17, 24, 39, .045); --pk: #1f2937;
  position: relative; width: var(--pw); height: var(--ph); background: var(--paper); color: var(--ink); overflow: hidden; border-radius: 2px 4px 4px 2px;
  font: 400 14.6px/1.5 var(--body); box-shadow: 0 30px 60px -30px rgba(0, 0, 0, .7), 0 0 0 1px rgba(0, 0, 0, .04);
}
.paper-sepia .pg { --ink: #2b2116; --ink2: #4a3b29; --mut: #7a6650; --paper: #f7efdc; --rule: #e6d9bd; --tint: rgba(74, 59, 41, .06); --pk: #3b2f20; }
.paper-night .pg { --ink: #e7ebf3; --ink2: #c7cfdd; --mut: #94a0b6; --paper: #121826; --rule: #263044; --tint: rgba(255, 255, 255, .05); --pk: #e7ebf3; }
.pg::before { content: ''; position: absolute; inset: 0; pointer-events: none; z-index: 2; opacity: .055;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='220'%3E%3Ctext x='10' y='120' transform='rotate(-24 150 110)' font-family='Arial' font-weight='700' font-size='17' fill='%23000'%3Eekalix.com/academy/pcmb%3C/text%3E%3C/svg%3E"); }
.paper-night .pg::before { filter: invert(1); opacity: .07; }
.pg-head { position: absolute; left: 0; right: 0; top: 0; height: 40px; display: flex; align-items: center; gap: 10px; padding: 0 var(--px) 0 var(--px); font: 700 10.5px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--sc2); border-bottom: 1px solid var(--rule); }
.paper-night .pg-head { color: var(--sc); }
.pg-head::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 5px; background: var(--sc); }
.pg-head .r { margin-left: auto; color: var(--mut); text-transform: none; letter-spacing: 0; font-weight: 600; font-family: var(--body); font-size: 11.5px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 60%; }
.pg-foot { position: absolute; left: 0; right: 0; bottom: 0; height: 34px; display: flex; align-items: center; justify-content: space-between; padding: 0 var(--px); color: var(--mut); font: 600 10.5px/1 var(--mono); border-top: 1px solid var(--rule); }
.pg-foot b { color: #fff; background: var(--sc); border-radius: 999px; padding: 4px 9px; font-weight: 700; }
.pg-body { position: absolute; left: var(--px); right: var(--px); top: 52px; bottom: 44px; overflow: hidden; }
.pg-body.over { overflow: auto; scrollbar-width: thin; }
.pg-body > .k-b { margin: 0 0 8px; }
.pg .k-cont { font: 700 11.5px/1.2 var(--body); color: #fff; background: linear-gradient(90deg, var(--sc), var(--sc2)); padding: 6px 10px; border-radius: 6px; margin-bottom: 8px; }
.pg b { font-weight: 700; }
.pg sup, .pg sub { font-size: .72em; line-height: 0; }
.pg .k-chap { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: 8px; color: #fff; background: linear-gradient(100deg, var(--sc2), var(--sc)); box-shadow: 0 10px 22px -16px var(--sc); }
.pg .k-chap .lvl { font: 800 10.5px/1 var(--mono); padding: 5px 7px; border-radius: 6px; background: rgba(255, 255, 255, .2); border: 1px solid rgba(255, 255, 255, .35); white-space: nowrap; }
.pg .k-chap h3 { font: 800 19px/1.15 var(--display); margin: 0; flex: 1; }
.pg .k-chap .tb { font: 600 11px/1 var(--body); opacity: .9; white-space: nowrap; }
.pg .k-ex { padding: 10px 12px; border-radius: 8px; background: var(--tint); border-left: 4px solid var(--sc); color: var(--ink); font-size: 14.4px; line-height: 1.55; }
.pg .k-tag { display: inline-block; font: 800 9.5px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; padding: 4px 6px; border-radius: 5px; color: #fff; background: var(--ink2); vertical-align: 1px; margin-right: 4px; }
.pg .k-ex .k-tag { background: var(--sc2); }
.paper-night .pg .k-ex .k-tag { background: var(--sc); }
.pg .k-p { color: var(--ink2); font-size: 14.2px; line-height: 1.6; padding: 0 2px; }
.pg .k-h { font: 700 15px/1.3 var(--display); color: var(--ink); margin-top: 4px; }
.pg .k-sub { font: 800 11.5px/1 var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--sc2); padding: 7px 8px; border-radius: 6px; background: var(--st); margin-top: 6px; }
.paper-night .pg .k-sub { color: var(--sc); }
.pg .k-sub::before { content: '▸ '; }
.pg .k-row { display: grid; grid-template-columns: 128px minmax(0, 1fr); gap: 10px; padding: 5px 2px 6px; border-bottom: 1px dashed var(--rule); margin-bottom: 2px !important; }
.pg .k-row > b { color: var(--sc2); font-size: 13.2px; line-height: 1.35; }
.paper-night .pg .k-row > b { color: var(--sc); }
.pg .k-row > div { font-size: 13.8px; line-height: 1.5; color: var(--ink2); }
.pg .fx { display: inline-block; font-weight: 700; color: var(--ink); background: var(--st); border-left: 3px solid var(--sc); padding: 1px 7px; border-radius: 3px; margin: 1px 6px 3px 0; line-height: 1.55; }
.pg .mn { color: var(--mut); font-size: 13px; }
.pg .k-flow { padding: 8px 10px; border-radius: 8px; border: 1px solid var(--rule); }
.pg .k-flow > b, .pg .gplan > b { display: block; font: 700 13px/1.2 var(--display); color: var(--ink); margin-bottom: 6px; }
.pg .k-chips { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 2px; }
.pg .k-chips span { font-size: 12.5px; line-height: 1.3; padding: 4px 8px; border-radius: 6px; border: 1px solid color-mix(in srgb, var(--sc) 45%, transparent); color: var(--ink); background: var(--paper); }
.pg .k-chips i { font-style: normal; color: var(--sc); padding: 0 2px; }
.pg.on .k-chips span { animation: pcChip 5s ease-in-out infinite; animation-delay: calc(var(--n, 0) * .55s); }
@keyframes pcChip { 0%, 9% { background: var(--sc); color: #fff; box-shadow: 0 6px 14px -8px var(--sc); } 18%, 100% { background: var(--paper); color: var(--ink); box-shadow: none; } }
.pg .k-trap, .pg .k-exam, .pg .k-hook, .pg .k-note { padding: 7px 10px; border-radius: 7px; font-size: 13.6px; line-height: 1.5; }
.pg .k-trap { background: rgba(220, 38, 38, .08); border-left: 4px solid #dc2626; }
.pg .k-trap .k-tag { background: #dc2626; }
.pg .k-exam { background: rgba(217, 119, 6, .1); border-left: 4px solid #d97706; }
.pg .k-exam .k-tag { background: #d97706; }
.pg .k-hook { background: rgba(139, 92, 246, .09); border-left: 4px solid #8b5cf6; }
.pg .k-hook .k-tag { background: #7c3aed; }
.pg .k-note { background: var(--tint); color: var(--ink2); }
.pg .k-eg { padding: 10px 12px 8px; border-radius: 9px; border: 1.5px solid color-mix(in srgb, #16a34a 45%, transparent); background: rgba(22, 163, 74, .06); }
.pg .k-eg .k-tag { background: #16a34a; }
.pg .k-eg > b { font: 700 14px/1.3 var(--display); color: var(--ink); }
.pg .k-eg .q { margin: 6px 0 6px; font-size: 13.8px; color: var(--ink); font-style: italic; }
.pg .k-eg ol { margin: 0; padding-left: 20px; }
.pg .k-eg li { font-size: 13.6px; line-height: 1.5; color: var(--ink2); margin-bottom: 3px; }
.pg .k-eg li::marker { color: #16a34a; font-weight: 700; }
.pg .k-tbl > b { display: block; font: 700 13px/1.2 var(--display); margin-bottom: 6px; }
.pg table { width: 100%; border-collapse: collapse; font-size: 13px; }
.pg th { text-align: left; font: 700 11.5px/1.2 var(--mono); text-transform: uppercase; letter-spacing: .04em; color: #fff; background: var(--sc2); padding: 6px 8px; }
.pg td { padding: 5px 8px; border-bottom: 1px solid var(--rule); color: var(--ink2); vertical-align: top; }
.pg tr:nth-child(even) td { background: var(--tint); }
.pg .k-fig { margin: 4px 0 10px; text-align: center; }
.pg .k-fig svg { width: 100%; height: auto; max-height: 300px; display: block; margin: 0 auto; }
.pg .k-fig figcaption { font-size: 11.8px; color: var(--mut); font-style: italic; margin-top: 4px; }
/* figure drawing classes */
.g { overflow: visible; }
.g .ax { fill: none; stroke: var(--pk); stroke-width: 1.6; }
.g .c1 { fill: none; stroke: var(--sc); stroke-width: 2.6; stroke-linecap: round; }
.g .c2 { fill: none; stroke: #e11d48; stroke-width: 2.4; stroke-linecap: round; }
.g .c3 { fill: none; stroke: #16a34a; stroke-width: 2.2; stroke-linecap: round; }
.g .c4 { fill: none; stroke: #d97706; stroke-width: 2.2; stroke-linecap: round; }
.g .dsh { fill: none; stroke: var(--mut); stroke-width: 1.3; stroke-dasharray: 5 4; }
.g .arc { fill: none; stroke: var(--mut); stroke-width: 1.3; }
.g .fill1 { fill: var(--st); stroke: none; }
.g .fill2 { fill: rgba(225, 29, 72, .12); stroke: none; }
.g .blk { fill: var(--st); stroke: var(--sc); stroke-width: 2; }
.g .pnl { fill: var(--tint); stroke: var(--rule); stroke-width: 1.2; }
.g .wire { fill: none; stroke: var(--pk); stroke-width: 2; stroke-linejoin: round; }
.g .fl { fill: none; stroke: var(--sc); stroke-width: 1.4; opacity: .75; stroke-dasharray: 6 5; animation: pcFlow 1.6s linear infinite; }
@keyframes pcFlow { to { stroke-dashoffset: -22; } }
.g .qp { fill: #e11d48; } .g .qn { fill: #2563eb; }
.g .qt { fill: #fff; font: 800 12px var(--body); text-anchor: middle; }
.g .pt { fill: var(--pk); }
.g .ball { fill: #e11d48; stroke: #fff; stroke-width: 2; }
.g .dt { fill: #64748b; }
.g text { font-family: var(--body); }
.g .lbl { fill: var(--ink); font: 700 13px var(--body); }
.g .sm { fill: var(--ink2); font: 600 11px var(--body); }
.g .cap { fill: var(--mut); font: italic 600 10.5px var(--body); }
.g .c1t { fill: var(--sc); } .g .c2t { fill: #e11d48; } .g .c3t { fill: #16a34a; } .g .c4t { fill: #d97706; }
.g .tc { text-anchor: middle; }
.g .lane { fill: var(--st); stroke: color-mix(in srgb, var(--sc) 50%, transparent); stroke-width: 1.2; }
.g .box { fill: var(--paper); stroke: var(--sc); stroke-width: 1.6; }
.g .box2 { fill: var(--paper); stroke: #e11d48; stroke-width: 1.6; }
.g .box3 { fill: var(--paper); stroke: #16a34a; stroke-width: 1.6; }
.pg.on .g .draw { stroke-dasharray: 1200; stroke-dashoffset: 1200; animation: pcDraw 2.2s var(--pc-ease, ease) .2s forwards; }
@keyframes pcDraw { to { stroke-dashoffset: 0; } }
.pg.on .g .pulse { animation: pcPulse 2s ease-in-out infinite; transform-box: fill-box; transform-origin: center; }
@keyframes pcPulse { 50% { transform: scale(1.15); opacity: .7; } }
/* a group's opening page */
.pg .k-grp { padding: 4px 2px; }
.pg .k-grp .gcode { display: inline-block; font: 800 12px/1 var(--mono); letter-spacing: .1em; color: #fff; background: linear-gradient(100deg, var(--sc2), var(--sc)); padding: 7px 11px; border-radius: 999px; }
.pg .k-grp h2 { font: 800 30px/1.08 var(--display); margin: 12px 0 14px; color: var(--ink); letter-spacing: -.01em; }
.pg .gab { display: grid; grid-template-columns: 1fr 42px 1fr; gap: 6px; align-items: center; margin-bottom: 12px; }
.pg .ga, .pg .gb { border-radius: 10px; padding: 10px 12px; border: 1.5px solid var(--rule); align-self: stretch; }
.pg .gb { border-color: color-mix(in srgb, var(--sc) 50%, transparent); background: var(--st); }
.pg .ga > span, .pg .gb > span { display: block; font: 800 9.5px/1 var(--mono); letter-spacing: .07em; text-transform: uppercase; color: var(--mut); margin-bottom: 7px; }
.pg .gb > span { color: var(--sc2); }
.paper-night .pg .gb > span { color: var(--sc); }
.pg .ga ol, .pg .gb ol { margin: 0; padding-left: 18px; font-size: 13.4px; line-height: 1.5; color: var(--ink); }
.pg .ga small, .pg .gb small { color: var(--mut); font-size: 11px; }
.pg .gab .none { margin: 0; font-size: 12.5px; color: var(--mut); font-style: italic; }
.pg .gar svg { width: 42px; fill: none; stroke: var(--sc); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.pg.on .gar svg { animation: pcNudge 1.6s ease-in-out infinite; }
.pg .why { font-size: 14px; line-height: 1.55; color: var(--ink); background: var(--tint); border-radius: 8px; padding: 9px 11px; margin: 0 0 10px; }
.pg .story { font-size: 14.2px; line-height: 1.62; color: var(--ink2); margin: 0 0 9px; }
.pg .story.s1::first-letter { float: left; font: 800 40px/.9 var(--display); color: var(--sc); padding: 4px 6px 0 0; }
.pg .gplan { border: 1px solid var(--rule); border-radius: 10px; padding: 9px 10px; margin: 4px 0 10px; }
.pg .gchk { display: flex; gap: 14px; font: 700 12px/1 var(--mono); color: var(--mut); }
/* the cover and the narrow (phone) page */
.pg.cover { color: #fff; background: radial-gradient(120% 60% at 100% 0%, rgba(244, 114, 182, .55), transparent 55%), radial-gradient(110% 70% at 0% 100%, rgba(56, 189, 248, .5), transparent 60%), linear-gradient(160deg, #1e1b4b, #312e81 45%, #1e3a8a); }
.pg.cover .pg-head, .pg.cover .pg-foot { display: none; }
.pg.cover .pg-body { inset: 0; padding: 56px var(--px) 40px; }
.pg.cover::after { content: ''; position: absolute; inset: 0; pointer-events: none; background: repeating-linear-gradient(135deg, rgba(255, 255, 255, .035) 0 2px, transparent 2px 14px); }
.pg .k-cover { height: 100%; margin: 0; display: flex; flex-direction: column; gap: 12px; color: #fff; position: relative; z-index: 3; }
.pg .k-cover .cv-k { font: 800 12px/1 var(--mono); letter-spacing: .18em; opacity: .85; }
.pg .k-cover h1 { font: 800 76px/.95 var(--display); margin: 16px 0 2px; letter-spacing: -.02em; }
.pg .k-cover .cv-s { font: 600 19px/1.45 var(--body); margin: 0; opacity: .92; max-width: 92%; }
.pg .k-cover .cv-subs { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 18px; }
.pg .k-cover .cv-subs i { font: 700 16px/1 var(--display); font-style: normal; padding: 16px 14px; border-radius: 12px; background: rgba(255, 255, 255, .12); border-left: 5px solid var(--sc); }
.pg .k-cover .cv-n { font: 600 15px/1.4 var(--body); margin-top: auto; opacity: .95; }
.pg .k-cover .cv-n b { font: 800 22px/1 var(--display); }
.pg .k-cover .cv-l { font-size: 14px; line-height: 1.55; opacity: .85; margin: 0; }
.pg .k-cover .cv-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.pg .k-cover .cv-tags span { font: 700 11px/1 var(--mono); padding: 7px 9px; border-radius: 999px; background: rgba(255, 255, 255, .14); }
.bk-phone .pg .k-cover h1 { font-size: 46px; }
.bk-phone .pg .k-cover .cv-s { font-size: 15px; }
.bk-phone .pg { font-size: 14.2px; }
.bk-phone .pg .k-row { grid-template-columns: 1fr; gap: 2px; }
.bk-phone .pg .gab { grid-template-columns: 1fr; }
.bk-phone .pg .gar { transform: rotate(90deg); justify-self: center; height: 30px; }
.bk-phone .pg .k-grp h2 { font-size: 24px; }
.bk-phone .pg table { font-size: 12px; }
.bk-phone .pg th { font-size: 10px; letter-spacing: .02em; padding: 5px; }
.bk-phone .pg td { padding: 4px 5px; overflow-wrap: anywhere; hyphens: auto; }
.bk-phone .pg .k-chap h3 { font-size: 16.5px; }
.bk-phone .pg .k-chap .tb { display: none; }
.bk-phone .pg-head .r { display: none; }
.pc-measure { position: absolute; left: -99999px; top: 0; visibility: hidden; pointer-events: none; }

/* ---- mock tests ------------------------------------------------------------------------------------------------ */
.pc-test { min-height: calc(100dvh - var(--pc-top) - 12px); border-radius: 18px; border: 1px solid var(--line); background: linear-gradient(180deg, rgba(13, 19, 33, .9), rgba(7, 11, 20, .9)); padding: 22px; }
.pc-test h2 { font: 800 26px/1.1 var(--display); margin: 0; }
.pc-test .kick { font: 700 11px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--sc); }
.pc-test .pc-lead { color: var(--text2); line-height: 1.6; margin: 10px 0 0; max-width: 760px; }
.pc-opts { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; margin: 22px 0; }
.pc-opt { text-align: left; padding: 14px; border-radius: 14px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .03); color: var(--text); cursor: pointer; transition: border-color .2s, background .2s, transform .2s; }
.pc-opt:hover { transform: translateY(-2px); }
.pc-opt b { display: block; font: 700 14.5px/1.2 var(--display); }
.pc-opt span { display: block; color: var(--text3); font-size: 12.5px; margin-top: 5px; line-height: 1.45; }
.pc-opt.on { border-color: var(--sc); background: var(--st); box-shadow: 0 0 0 3px color-mix(in srgb, var(--sc) 25%, transparent); }
.pc-opt-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 8px; }
.pc-opt-row label { color: var(--text3); font-size: 12.5px; margin-right: 4px; font-weight: 700; }
.pc-chip { height: 32px; padding: 0 12px; border-radius: 999px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .03); color: var(--text2); cursor: pointer; font: 600 12.5px/1 var(--body); }
.pc-chip.on { border-color: var(--sc); color: var(--text); background: var(--st); }
.pc-exam { display: grid; grid-template-columns: minmax(0, 1fr) 270px; gap: 18px; }
.pc-qhead { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.pc-qhead .qn { font: 800 13px/1 var(--mono); padding: 7px 10px; border-radius: 9px; color: #fff; background: linear-gradient(100deg, var(--sc2), var(--sc)); }
.pc-qhead .meta { color: var(--text3); font: 600 12px/1.3 var(--mono); }
.pc-timer { margin-left: auto; font: 800 16px/1 var(--mono); padding: 8px 12px; border-radius: 10px; border: 1px solid var(--line2); }
.pc-timer.low { color: #fca5a5; border-color: rgba(248, 113, 113, .5); animation: pcBlink 1s steps(2) infinite; }
@keyframes pcBlink { 50% { opacity: .55; } }
.pc-q { font-size: 17px; line-height: 1.6; color: var(--text); padding: 16px 18px; border-radius: 14px; background: rgba(255, 255, 255, .035); border: 1px solid var(--line); animation: pcIn .35s var(--pc-ease); }
.pc-q sup, .pc-q sub, .pc-ans sup, .pc-ans sub, .pc-rv sup, .pc-rv sub { font-size: .72em; line-height: 0; }
.pc-ans { display: grid; gap: 9px; margin: 14px 0; }
.pc-a { display: flex; align-items: center; gap: 12px; text-align: left; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .025); color: var(--text); cursor: pointer; font: 500 15px/1.45 var(--body); transition: border-color .2s, background .2s, transform .15s; animation: pcIn .35s var(--pc-ease) both; animation-delay: calc(var(--n, 0) * 50ms); }
.pc-a:hover { border-color: var(--gline2); background: rgba(255, 255, 255, .05); }
.pc-a .k { flex: none; width: 30px; height: 30px; border-radius: 9px; display: grid; place-items: center; font: 800 13px/1 var(--mono); border: 1px solid var(--line2); color: var(--text2); }
.pc-a.on { border-color: var(--sc); background: var(--st); }
.pc-a.on .k { background: var(--sc); color: #fff; border-color: var(--sc); }
.pc-num { display: flex; gap: 10px; align-items: center; margin: 14px 0; }
.pc-num input { height: 44px; width: 200px; border-radius: 12px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .04); color: var(--text); padding: 0 14px; font: 700 16px var(--mono); }
.pc-qnav { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }
.pc-pal { border-radius: 14px; border: 1px solid var(--line); padding: 14px; background: rgba(255, 255, 255, .02); align-self: start; position: sticky; top: calc(var(--pc-top) + 10px); }
.pc-pal h4 { margin: 0 0 10px; font: 700 13px/1 var(--display); }
.pc-pal .pgrid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 6px; }
.pc-pal button { height: 34px; border-radius: 8px; border: 1px solid var(--line2); background: rgba(255, 255, 255, .03); color: var(--text2); font: 700 12px/1 var(--mono); cursor: pointer; position: relative; }
.pc-pal button.ans { background: #16a34a; border-color: #16a34a; color: #fff; }
.pc-pal button.mark { background: #7c3aed; border-color: #7c3aed; color: #fff; }
.pc-pal button.mark.ans::after { content: ''; position: absolute; right: 3px; bottom: 3px; width: 7px; height: 7px; border-radius: 50%; background: #4ade80; }
.pc-pal button.seen { background: rgba(220, 38, 38, .2); border-color: rgba(220, 38, 38, .55); color: #fecaca; }
.pc-pal button.cur { outline: 2px solid var(--accent); outline-offset: 1px; }
.pc-legend { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; margin-top: 12px; font-size: 11.5px; color: var(--text3); }
.pc-legend i { display: inline-block; width: 11px; height: 11px; border-radius: 3px; vertical-align: -1px; margin-right: 5px; }
.pc-result { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 22px; align-items: center; padding: 18px; border-radius: 18px; border: 1px solid var(--line); background: rgba(255, 255, 255, .03); margin-top: 16px; }
.pc-ring { position: relative; width: 200px; height: 200px; }
.pc-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.pc-ring circle { fill: none; stroke-width: 14; }
.pc-ring .bg { stroke: rgba(255, 255, 255, .08); }
.pc-ring .fg { stroke: url(#pcRingGrad); stroke-linecap: round; transition: stroke-dashoffset 1.4s var(--pc-ease); }
.pc-ring div { position: absolute; inset: 0; display: grid; place-content: center; text-align: center; }
.pc-ring b { font: 800 40px/1 var(--display); }
.pc-ring span { color: var(--text3); font-size: 12.5px; margin-top: 4px; }
.pc-kpis { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; }
.pc-kpis div { padding: 12px; border-radius: 12px; background: rgba(255, 255, 255, .035); border: 1px solid var(--line); }
.pc-kpis b { display: block; font: 800 22px/1 var(--display); }
.pc-kpis span { color: var(--text3); font-size: 12px; }
.pc-kpis .ok b { color: var(--ok-t); } .pc-kpis .bad b { color: var(--bad-t); }
.pc-verdict { margin: 14px 0 0; font-size: 15px; line-height: 1.55; color: var(--text); }
.pc-bars { display: grid; gap: 8px; margin-top: 16px; }
.pc-bars div { display: grid; grid-template-columns: minmax(0, 220px) 1fr 52px; gap: 10px; align-items: center; font-size: 13px; color: var(--text2); }
.pc-bars i { height: 9px; border-radius: 9px; background: rgba(255, 255, 255, .07); overflow: hidden; display: block; }
.pc-bars i b { display: block; height: 100%; width: 0; border-radius: 9px; background: linear-gradient(90deg, var(--sc), var(--sc2)); transition: width 1.2s var(--pc-ease); }
.pc-bars em { font: 700 12px/1 var(--mono); font-style: normal; text-align: right; }
.pc-rv { border-radius: 14px; border: 1px solid var(--line); padding: 14px 16px; margin-top: 12px; background: rgba(255, 255, 255, .02); }
.pc-rv.ok { border-left: 4px solid #16a34a; } .pc-rv.bad { border-left: 4px solid #dc2626; } .pc-rv.sk { border-left: 4px solid #64748b; }
.pc-rv .hd { display: flex; gap: 8px; align-items: center; color: var(--text3); font: 700 11.5px/1 var(--mono); margin-bottom: 8px; flex-wrap: wrap; }
.pc-rv .hd .res { padding: 4px 7px; border-radius: 6px; color: #fff; }
.pc-rv.ok .res { background: #16a34a; } .pc-rv.bad .res { background: #dc2626; } .pc-rv.sk .res { background: #64748b; }
.pc-rv .qq { font-size: 15px; line-height: 1.55; color: var(--text); }
.pc-rv ul { list-style: none; padding: 0; margin: 10px 0; display: grid; gap: 6px; }
.pc-rv li { padding: 8px 10px; border-radius: 9px; border: 1px solid var(--line); font-size: 14px; color: var(--text2); }
.pc-rv li.rt { border-color: rgba(22, 163, 74, .6); background: rgba(22, 163, 74, .1); color: var(--text); }
.pc-rv li.wr { border-color: rgba(220, 38, 38, .55); background: rgba(220, 38, 38, .1); }
.pc-rv .xp { font-size: 14px; line-height: 1.6; color: var(--text2); background: rgba(var(--glow1), .06); border-radius: 10px; padding: 10px 12px; }
.pc-rv .xp b:first-child { color: var(--accent-hi); }
.pc-hub { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 12px; margin-top: 18px; }

.pc-mobilebar { display: none; align-items: center; gap: 8px; margin: 0 0 10px; }
/* ---- narrow screens ---------------------------------------------------------------------------------------------- */
@media (max-width: 1100px) { .pc-hero { grid-template-columns: 1fr; } .pc-cover-wrap { order: -1; } .pc-exam { grid-template-columns: 1fr; } .pc-pal { position: static; } .pc-result { grid-template-columns: 1fr; justify-items: center; } }
@media (max-width: 900px) {
  .pc-app { --pc-top: 72px; grid-template-columns: minmax(0, 1fr); gap: 0; padding: 0 10px 40px; }
  .pc-side { position: fixed; z-index: 60; left: 8px; top: 8px; bottom: 8px; height: auto; width: min(330px, calc(100vw - 40px)); transform: translateX(-110%); opacity: 1; transition: transform .45s var(--pc-ease); }
  .pc-app.side-open .pc-side { transform: none; }
  .pc-app.side-off .pc-side { opacity: 1; transform: translateX(-110%); }
  .pc-main { grid-column: 1; }
  .pc-scrim { display: block; position: fixed; inset: 0; z-index: 59; background: rgba(0, 0, 0, .55); backdrop-filter: blur(3px); opacity: 0; pointer-events: none; transition: opacity .35s; }
  .pc-app.side-open .pc-scrim { opacity: 1; pointer-events: auto; }
  .pc-sidetoggle { display: none; }
  .pc-menu-btn { display: inline-flex; }
  .pc-hero { padding: 22px 18px; }
  .pc-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .pc-groups { grid-template-columns: 1fr; }
  .pc-bar .pc-hide-sm { display: none; }
  .pc-read { border-radius: 14px; }
  .pc-test { padding: 16px 12px; }
  .pc-kpis { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .pc-bars div { grid-template-columns: 1fr 60px 44px; }
  .pc-mobilebar { display: flex; }
  .pc-bar { gap: 5px; padding: 7px 8px; }
  .pc-where { order: -1; flex: 1 0 100%; padding: 0 2px 4px; }
  .pc-where b { white-space: normal; }
}
@media (prefers-reduced-motion: reduce) {
  .pc-app *, .pc-app *::before, .pc-app *::after { animation: none !important; transition: none !important; }
}
@media print {
  body * { visibility: hidden !important; }
  body::after { visibility: visible; content: 'The PCMB Master Book is read on ekalix.com/academy/pcmb - printing is not available.'; position: fixed; inset: 40% 10% auto; font: 700 18px sans-serif; text-align: center; color: #000; }
}