/* ITBD Academy — one design system for every student-facing page. */
:root{
  --bg:#F6F7F5;--surface:#FFFFFF;--soft:#F1F4F2;--ink:#0E1B14;--ink-2:#3D4C44;--mute:#5E6E65;--line:#E2E7E3;--line-2:#CBD3CE;
  --acc:#0A5C34;--acc-ink:#FFFFFF;--acc-soft:#E6F2EA;--gold:#E8B23A;--gold-soft:#FBF1D6;
  --red:#B42318;--red-soft:#FDF3F1;--blue:#2645C4;--blue-soft:#E8EDFC;--orange:#B23C0A;--orange-soft:#FCECE3;--violet:#6D4ED8;
  --stage:#0B1220;--stage-2:#141D2E;
  --r-s:10px;--r-m:14px;--r-l:20px;
  --sh-s:0 1px 2px rgba(14,27,20,.06),0 4px 12px rgba(14,27,20,.05);
  --sh-m:0 2px 6px rgba(14,27,20,.06),0 18px 44px rgba(14,27,20,.10);
  --font:"Anek Bangla","Noto Sans Bengali",system-ui,sans-serif;
  --top:60px;--side:380px;
  color-scheme:light;
}
[data-theme="dark"]{
  --bg:#0A0F0C;--surface:#121A15;--soft:#16201A;--ink:#E8F0EA;--ink-2:#C3D0C7;--mute:#93A49A;--line:#24302A;--line-2:#34433A;
  --acc:#2FB36B;--acc-ink:#04150B;--acc-soft:#123222;--gold-soft:#2A2208;--red:#FF7A6E;--red-soft:#2A1513;--blue:#7D96FF;--blue-soft:#141C3A;
  --orange:#FF9A5C;--orange-soft:#2E1A0F;--sh-s:0 1px 2px rgba(0,0,0,.4);--sh-m:0 2px 8px rgba(0,0,0,.5),0 22px 48px rgba(0,0,0,.45);
  color-scheme:dark;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body.acad{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);font-stretch:87.5%;font-size:16.5px;line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
/* zero-specificity base rules, so every component's own colour wins */
:where(.acad) a{color:inherit}
:where(.acad) img{max-width:100%;height:auto}
:where(.acad) h1,:where(.acad) h2,:where(.acad) h3{line-height:1.25;margin:0;letter-spacing:-.005em}
.acad [hidden]{display:none!important}
.ic{width:1.15em;height:1.15em;flex:none;vertical-align:-.18em}
.ac-dim{color:var(--mute)} .ac-small{font-size:14px}
.ac-grow{flex:1}
.ac-wrap{max-width:1200px;margin:0 auto;padding-left:20px;padding-right:20px}
.ac-link{background:none;border:0;padding:0;color:var(--acc);font:inherit;font-weight:700;cursor:pointer;text-decoration:none}
.ac-link:hover{text-decoration:underline}
:focus-visible{outline:3px solid color-mix(in srgb,var(--acc) 55%,transparent);outline-offset:2px}

/* ───── buttons, chips ───── */
.ac-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:0 18px;border-radius:12px;border:1px solid transparent;
  font:inherit;font-weight:700;font-size:15.5px;line-height:1.2;text-decoration:none;cursor:pointer;white-space:nowrap;transition:background .15s,border-color .15s,transform .1s}
.ac-btn:active{transform:translateY(1px)}
.ac-btn[disabled],.ac-btn[aria-disabled="true"]{opacity:.55;cursor:not-allowed}
.ac-btn-main{background:var(--acc);color:var(--acc-ink)}
.ac-btn-main:hover{background:color-mix(in srgb,var(--acc) 88%,#000)}
.ac-btn-dark{background:var(--ink);color:var(--bg)}
.ac-btn-ghost{background:var(--surface);border-color:var(--line-2);color:var(--ink)}
.ac-btn-ghost:hover{border-color:var(--ink)}
.ac-btn-ghost-d{background:transparent;border-color:rgba(255,255,255,.35);color:#fff}
.ac-btn-soft{background:var(--soft);color:var(--mute);font-weight:600;cursor:default;white-space:normal;text-align:left}
.ac-btn-done{background:var(--acc-soft);color:var(--acc);cursor:default}
.ac-btn-off{background:var(--soft);color:var(--mute);cursor:default}
.ac-btn-sm{min-height:38px;padding:0 14px;font-size:14.5px;border-radius:10px}
.ac-btn-lg{min-height:52px;font-size:17px;padding:0 24px}
.ac-btn-wide{width:100%}
.ac-btn-icon{width:44px;padding:0}
.ac-icon{display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;border-radius:11px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer;flex:none}
.ac-icon.on{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.ac-fmt{display:inline-flex;align-items:center;font-size:12.5px;font-weight:800;border-radius:999px;padding:4px 11px;line-height:1.3;white-space:nowrap}
.ac-fmt-recorded{background:var(--blue-soft);color:var(--blue)}
.ac-fmt-self{background:var(--acc-soft);color:var(--acc)}
.ac-fmt-live{background:var(--orange-soft);color:var(--orange)}
.ac-chip-ghost{display:inline-flex;align-items:center;gap:6px;font-size:13px;font-weight:700;border:1px solid rgba(255,255,255,.3);border-radius:999px;padding:4px 11px;color:#fff}
.ac-tag{font-style:normal;font-size:11.5px;font-weight:800;border-radius:999px;padding:2px 8px;background:var(--gold-soft);color:#7A5600;white-space:nowrap}
[data-theme="dark"] .ac-tag{color:var(--gold)}
.ac-tag-dim{background:var(--soft);color:var(--mute)}
.ac-stars{display:inline-flex;gap:1px;color:var(--gold)}
.ac-stars i{display:inline-flex}
.ac-stars .ic{width:15px;height:15px}
.ac-stars .s-full .ic{fill:currentColor}
.ac-stars .s-half .ic{fill:url(#none);fill:color-mix(in srgb,currentColor 50%,transparent)}
.ac-stars .s-none{color:var(--line-2)}
.ac-prog{display:flex;align-items:center;gap:10px}
.ac-bar{flex:1;display:block;height:8px;border-radius:99px;background:var(--line);overflow:hidden}
.ac-bar i{display:block;height:100%;border-radius:inherit;background:var(--acc);transition:width .5s}
.ac-prog b{font-size:14px;min-width:3em;text-align:right}

/* ───── top bar ───── */
.ac-top{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.ac-top-in{max-width:1200px;margin:0 auto;padding:0 20px;height:var(--top);display:flex;align-items:center;gap:20px}
.ac-brand{display:flex;align-items:center;text-decoration:none;flex:none}
.ac-brand img{height:30px;width:auto;display:block}
[data-theme="dark"] .ac-brand img{filter:brightness(0) invert(1) opacity(.9)}
.ac-nav{display:flex;gap:4px}
.ac-nav a{text-decoration:none;font-weight:600;font-size:15px;color:var(--ink-2);padding:8px 12px;border-radius:10px}
.ac-nav a:hover,.ac-nav a[aria-current]{color:var(--ink);background:var(--soft)}
.ac-avatar{width:38px;height:38px;border-radius:50%;background:var(--ink);color:var(--bg);display:grid;place-items:center;font-weight:800;text-decoration:none;flex:none}
@media(max-width:640px){.ac-top-in{gap:10px;padding:0 14px}.ac-nav a{padding:8px}.ac-brand img{height:24px}}
@media(max-width:400px){.ac-nav a:first-child{display:none}}

/* ───── course sales page ───── */
.ac-hero{color:#EEF2F8;padding:36px 0 40px}
.ac-hero-recorded{background:#101A36}
.ac-hero-self{background:#06371F}
.ac-hero-live{background:#4F1B05}
.ac-hero-in{display:flex;flex-direction:column;gap:14px}
@media(min-width:1000px){.ac-hero-in{padding-right:420px}.ac-hero{padding:48px 0 56px}}
.ac-crumbs{display:flex;gap:8px;font-size:14px;color:rgba(238,242,248,.7)}
.ac-crumbs a{color:inherit;text-decoration:none}
.ac-crumbs a:hover{color:#fff;text-decoration:underline}
.ac-hero-badges{display:flex;flex-wrap:wrap;gap:8px}
.ac-hero h1{font-size:clamp(28px,4.6vw,44px);font-weight:800}
.ac-lead{margin:0;font-size:18.5px;line-height:1.65;color:rgba(238,242,248,.82);max-width:720px}
.ac-hero-meta{display:flex;flex-wrap:wrap;gap:8px 20px;font-size:14.5px;color:rgba(238,242,248,.85)}
.ac-hero-meta span{display:inline-flex;align-items:center;gap:6px}
.ac-hero-meta a{color:#fff;font-weight:700}
.ac-rating{display:inline-flex;align-items:center;gap:6px}
.ac-rating b{color:var(--gold);font-size:16px}
.ac-hero .ac-rating a{color:#C9D6FF;text-decoration:underline}
.ac-course-grid{display:grid;gap:28px;padding-bottom:96px;grid-template-columns:minmax(0,1fr)}
@media(min-width:1000px){.ac-course-grid{grid-template-columns:minmax(0,1fr) 380px;column-gap:40px}.ac-buy{grid-column:2;grid-row:1 / span 20;margin-top:-260px}.ac-main{grid-column:1;grid-row:1;padding-top:32px}}
.ac-buy{position:relative;z-index:5}
.ac-buy-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r-l);overflow:hidden;box-shadow:var(--sh-m)}
@media(min-width:1000px){.ac-buy-card{position:sticky;top:calc(var(--top) + 20px)}}
@media(max-width:999px){.ac-buy{margin-top:-20px}}
.ac-buy-media{position:relative;aspect-ratio:16/9;background:var(--stage);overflow:hidden}
.ac-buy-media img{width:100%;height:100%;object-fit:cover;display:block}
.ac-buy-art{display:flex;align-items:flex-end;height:100%;padding:20px;color:#fff;font-size:24px;font-weight:800;line-height:1.2}
.ac-art-recorded{background:#1D3594}.ac-art-self{background:#0A5C34}.ac-art-live{background:#7A2A07}
.ac-buy-play{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;background:linear-gradient(180deg,rgba(0,0,0,0) 30%,rgba(0,0,0,.55));color:#fff;border:0;cursor:pointer;text-decoration:none;font:inherit}
.ac-buy-play span{width:64px;height:64px;border-radius:50%;background:#fff;color:#0B1220;display:grid;place-items:center;box-shadow:0 10px 30px rgba(0,0,0,.35);transition:transform .15s}
.ac-buy-play span .ic{width:26px;height:26px;fill:currentColor}
.ac-buy-play:hover span{transform:scale(1.06)}
.ac-buy-play b{font-size:15px}
.ac-buy-body{padding:20px;display:flex;flex-direction:column;gap:12px}
.ac-price{display:flex;align-items:baseline;flex-wrap:wrap;gap:10px}
.ac-price b{font-size:32px;font-weight:800;line-height:1.1}
.ac-price del{color:var(--mute);font-size:17px}
.ac-off{font-size:13px;font-weight:800;color:var(--red);background:var(--red-soft);border-radius:999px;padding:3px 9px}
.ac-mine{display:flex;flex-direction:column;gap:8px;font-weight:700}
.ac-buy-h{margin:6px 0 0;font-weight:800;font-size:15.5px}
.ac-includes{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:9px;font-size:15px;color:var(--ink-2)}
.ac-includes li{display:flex;align-items:center;gap:10px}
.ac-includes .ic{color:var(--mute)}
.ac-main{display:flex;flex-direction:column;gap:36px;min-width:0}
.ac-box{border:1px solid var(--line);background:var(--surface);border-radius:var(--r-l);padding:24px}
.ac-main h2{font-size:24px;font-weight:800;margin-bottom:14px}
.ac-learn ul{list-style:none;margin:0;padding:0;display:grid;gap:12px 28px;grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.ac-learn li{display:flex;gap:10px;font-size:15.5px;line-height:1.55}
.ac-learn .ic{color:var(--acc);margin-top:3px}
.ac-sec-h{display:flex;flex-direction:column;gap:4px;margin-bottom:14px}
.ac-sec-h h2{margin:0}
.ac-sec-h p{margin:0;display:flex;flex-wrap:wrap;gap:6px 16px;align-items:center;font-size:14.5px}
.ac-curr{border:1px solid var(--line);border-radius:var(--r-m);overflow:hidden;background:var(--surface)}
.ac-curr-s+.ac-curr-s{border-top:1px solid var(--line)}
.ac-curr-s summary{display:flex;align-items:center;gap:12px;padding:15px 18px;cursor:pointer;list-style:none;background:var(--soft)}
.ac-curr-s summary::-webkit-details-marker{display:none}
.ac-curr-t{flex:1;min-width:0;font-size:16px}
.ac-curr-m{font-size:13.5px;color:var(--mute);white-space:nowrap}
.ac-curr-s summary .ic{transition:transform .2s;color:var(--mute)}
.ac-curr-s[open] summary .ic{transform:rotate(180deg)}
.ac-curr ul{list-style:none;margin:0;padding:6px 0}
.ac-curr li{display:flex;align-items:center;gap:12px;padding:9px 18px;font-size:15px}
.ac-curr li>.ic{color:var(--mute)}
.ac-curr li>a:not(.ac-pv),.ac-curr li>span{flex:1;min-width:0}
.ac-curr li>a:not(.ac-pv){color:var(--acc);text-decoration:underline;text-underline-offset:3px}
.ac-pv{font-size:13px;font-weight:800;color:var(--acc);text-decoration:none;white-space:nowrap}
.ac-curr time{font-size:13.5px;color:var(--mute);white-space:nowrap;font-variant-numeric:tabular-nums}
.ac-dots{margin:0;padding-left:1.3em;display:flex;flex-direction:column;gap:6px;font-size:15.5px}
.ac-prose{font-size:16.5px;line-height:1.85;overflow-wrap:anywhere}
.ac-prose>*:first-child{margin-top:0}
.ac-prose h2{font-size:22px;margin:1.4em 0 .5em}
.ac-prose h3{font-size:19px;margin:1.3em 0 .45em}
.ac-prose p{margin:.75em 0}
.ac-prose ul,.ac-prose ol{padding-left:1.4em}
.ac-prose li{margin:.3em 0}
.ac-prose a{color:var(--acc)}
.ac-prose img{border-radius:12px}
.ac-prose table{border-collapse:collapse;width:100%;margin:1em 0;font-size:15px;display:block;overflow-x:auto}
.ac-prose th,.ac-prose td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
.ac-prose th{background:var(--soft)}
.ac-prose blockquote{margin:1em 0;padding:10px 16px;border-left:4px solid var(--acc);background:var(--soft);border-radius:0 12px 12px 0}
.ac-prose .src{font-size:13.5px;color:var(--mute);border:1px solid var(--line);border-radius:8px;padding:4px 10px;display:inline-block}
.ac-prose .block{background:var(--soft);border:1px solid var(--line);border-radius:14px;padding:14px 18px;margin:1.1em 0}
.ac-prose .block.mistake{background:var(--red-soft);border-color:color-mix(in srgb,var(--red) 22%,transparent)}
.ac-prose .block.note{background:var(--gold-soft);border-color:color-mix(in srgb,var(--gold) 35%,transparent)}
.ac-prose .lbl{display:block;font-weight:800;font-size:13.5px;margin-bottom:4px;color:var(--acc)}
.ac-prose .mistake .lbl{color:var(--red)}
.ac-prose .note .lbl{color:#8A6100}
[data-theme="dark"] .ac-prose .note .lbl{color:var(--gold)}
.ac-prose details{border:1px solid var(--line);border-radius:12px;margin:.9em 0;background:var(--surface)}
.ac-prose summary{cursor:pointer;font-weight:700;padding:10px 14px}
.ac-prose details>*:not(summary){margin-left:14px;margin-right:14px}
.ac-prose pre{white-space:pre-wrap;background:var(--soft);border:1px solid var(--line);border-radius:12px;padding:12px 14px;font:14px/1.7 var(--font)}
.ac-prose pre.prompt{border-left:4px solid var(--violet)}
.ac-prose input[type=checkbox]{width:18px;height:18px;accent-color:var(--acc);vertical-align:-3px;margin-right:6px}
.ac-clamp{max-height:320px;overflow:hidden;position:relative}
.ac-clamp::after{content:"";position:absolute;left:0;right:0;bottom:0;height:80px;background:linear-gradient(transparent,var(--bg))}
.ac-clamp.open{max-height:none}.ac-clamp.open::after{display:none}
.ac-teacher{display:flex;gap:18px;align-items:flex-start}
.ac-teacher img,.ac-teacher-i{width:96px;height:96px;border-radius:50%;object-fit:cover;flex:none}
.ac-teacher-i{background:var(--acc-soft);color:var(--acc);display:grid;place-items:center;font-size:36px;font-weight:800}
.ac-teacher b{display:block;font-size:20px}
.ac-teacher span{display:block;color:var(--mute);font-size:14.5px}
.ac-teacher p{margin:8px 0 0;color:var(--ink-2)}
.ac-rev-sum{display:flex;flex-wrap:wrap;gap:20px 40px;align-items:center;margin-bottom:20px}
.ac-rev-avg{display:flex;flex-direction:column;align-items:center;gap:4px}
.ac-rev-avg b{font-size:52px;line-height:1;color:var(--gold)}
.ac-rev-avg span{font-size:13.5px;color:var(--mute)}
.ac-rev-dist{list-style:none;margin:0;padding:0;flex:1;min-width:220px;display:flex;flex-direction:column;gap:6px;font-size:13.5px}
.ac-rev-dist li{display:flex;align-items:center;gap:10px}
.ac-rev-dist .ac-bar i{background:var(--gold)}
.ac-revs{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.ac-rev{border:1px solid var(--line);border-radius:var(--r-m);padding:16px;background:var(--surface)}
.ac-rev header{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.ac-rev p{margin:8px 0 0;font-size:15px;color:var(--ink-2)}
.ac-avatar-s,.ac-av{width:34px;height:34px;border-radius:50%;background:var(--soft);color:var(--ink);display:grid;place-items:center;font-weight:800;flex:none}
.ac-faq details{border-bottom:1px solid var(--line)}
.ac-faq summary{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:16px 0;font-weight:700;cursor:pointer;list-style:none}
.ac-faq summary::-webkit-details-marker{display:none}
.ac-faq details[open] summary .ic{transform:rotate(180deg)}
.ac-faq p{margin:0 0 16px;color:var(--ink-2)}
.ac-mbar{position:fixed;left:0;right:0;bottom:0;z-index:60;display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 16px calc(10px + env(safe-area-inset-bottom));
  background:var(--surface);border-top:1px solid var(--line);box-shadow:0 -10px 30px rgba(0,0,0,.08);transform:translateY(110%);transition:transform .25s}
.ac-mbar.show{transform:none}
.ac-mbar .ac-price b{font-size:22px}
@media(min-width:1000px){.ac-mbar{display:none}}
.ac-modal{border:0;padding:0;background:transparent;max-width:min(960px,94vw);width:100%}
.ac-modal::backdrop{background:rgba(5,10,8,.75)}
.ac-modal-in{position:relative;background:#000;border-radius:16px;overflow:hidden}
.ac-modal-v{aspect-ratio:16/9}
.ac-modal-v iframe{width:100%;height:100%;border:0}
.ac-modal-x{position:absolute;top:10px;right:10px;z-index:3;width:40px;height:40px;border-radius:50%;border:0;background:rgba(255,255,255,.9);color:#000;display:grid;place-items:center;cursor:pointer}

/* ───── catalogue, my courses ───── */
.ac-pagehead{padding:36px 0 20px}
.ac-pagehead h1{font-size:clamp(28px,4vw,38px);font-weight:800}
.ac-pagehead p{margin:6px 0 0;font-size:16.5px}
.ac-filter{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:24px}
.ac-filter button{min-height:40px;padding:0 16px;border-radius:999px;border:1px solid var(--line-2);background:var(--surface);color:var(--ink);font:inherit;font-weight:600;cursor:pointer}
.ac-filter button.on{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.ac-cards{display:grid;gap:22px;grid-template-columns:repeat(auto-fill,minmax(290px,1fr));padding-bottom:64px}
.ac-card{display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--line);border-radius:var(--r-l);overflow:hidden;text-decoration:none;color:var(--ink);transition:box-shadow .2s,transform .2s}
.ac-card:hover{box-shadow:var(--sh-m);transform:translateY(-2px)}
.ac-card-art{position:relative;aspect-ratio:16/9;display:flex;align-items:flex-end;padding:18px;color:#fff;overflow:hidden}
.ac-card-art img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.ac-card-art b{position:relative;font-size:22px;line-height:1.2}
.ac-card-art .ac-fmt{position:absolute;top:14px;left:14px;background:#fff}
.ac-card-b{display:flex;flex-direction:column;gap:6px;padding:18px;flex:1}
.ac-card-t{font-size:18.5px;line-height:1.35}
.ac-card-f{margin-top:auto;padding-top:10px;display:flex;align-items:baseline;gap:10px}
.ac-card-f b{font-size:20px}
.ac-card-f del{color:var(--mute);font-size:15px}
.ac-mine-t{color:var(--acc)}
.ac-empty{background:var(--surface);border:1px dashed var(--line-2);border-radius:var(--r-l);padding:40px 24px;text-align:center;display:flex;flex-direction:column;align-items:center;gap:10px;margin-bottom:64px}
.ac-empty p{margin:0;color:var(--mute)}
.ac-mine-list{display:flex;flex-direction:column;gap:14px;padding-bottom:64px}
.ac-mine-row{display:grid;grid-template-columns:200px minmax(0,1fr) auto;gap:20px;align-items:center;background:var(--surface);border:1px solid var(--line);border-radius:var(--r-l);padding:14px}
.ac-mine-art{aspect-ratio:16/9;border-radius:12px;overflow:hidden;display:flex;align-items:flex-end;padding:12px;color:#fff;text-decoration:none}
.ac-mine-art img{width:100%;height:100%;object-fit:cover}
.ac-mine-b{display:flex;flex-direction:column;gap:6px;min-width:0}
.ac-mine-b h2{font-size:19px}
.ac-mine-b h2 a{text-decoration:none}
.ac-mine-b .ac-fmt{align-self:flex-start}
.ac-mine-b p{margin:0}
@media(max-width:720px){.ac-mine-row{grid-template-columns:minmax(0,1fr)}.ac-mine-art{display:none}.ac-mine-row .ac-btn{width:100%}}

/* ───── learning player ───── */
body.ac-learn-page{background:var(--bg)}
.ac-boot-top{height:var(--top);border-bottom:1px solid var(--line);background:var(--surface)}
.ac-boot-body{display:flex}
.ac-boot-stage{flex:1;aspect-ratio:16/9;max-height:70vh;background:var(--stage)}
.ac-boot-side{width:var(--side);background:var(--surface);border-left:1px solid var(--line)}
@media(max-width:1099px){.ac-boot-side{display:none}}
.ac-l-top{position:sticky;top:0;z-index:40;height:var(--top);display:flex;align-items:center;gap:10px;padding:0 14px;background:var(--surface);border-bottom:1px solid var(--line)}
.ac-l-back{display:flex;align-items:center;gap:6px;min-width:0;text-decoration:none;font-weight:700;font-size:15.5px;padding:8px 10px;border-radius:10px}
.ac-l-back span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ac-l-back:hover{background:var(--soft)}
.ac-ring{position:relative;display:inline-grid;place-items:center;width:36px;height:36px;flex:none}
.ac-ring svg{position:absolute;inset:0;transform:rotate(-90deg)}
.ac-ring circle{fill:none;stroke-width:3.4}
.ac-ring-bg{stroke:var(--line)}
.ac-ring-fg{stroke:var(--acc);stroke-linecap:round;transition:stroke-dashoffset .6s}
.ac-ring b{font-size:10px}
.ac-l-body{display:grid;grid-template-columns:minmax(0,1fr)}
@media(min-width:1100px){.ac-l-body{grid-template-columns:minmax(0,1fr) var(--side)}.is-theater .ac-l-body{grid-template-columns:minmax(0,1fr)}.is-theater .ac-l-side{display:none}}
.ac-l-main{min-width:0}
.ac-l-side{background:var(--surface);border-left:1px solid var(--line);min-width:0}
@media(min-width:1100px){.ac-l-side{position:sticky;top:var(--top);height:calc(100vh - var(--top));overflow-y:auto}.ac-only-m{display:none!important}}
@media(max-width:1099px){
  .ac-l-side{position:fixed;z-index:70;top:0;bottom:0;left:0;width:min(92vw,400px);transform:translateX(-102%);transition:transform .25s;overflow-y:auto;border:0;box-shadow:var(--sh-m)}
  .side-open .ac-l-side{transform:none}
  .ac-only-d{display:none!important}
}
.ac-scrim{position:fixed;inset:0;z-index:65;background:rgba(0,0,0,.45)}

.ac-stage{position:relative;background:var(--stage)}
.ac-video{position:relative;aspect-ratio:16/9;max-height:calc(100vh - var(--top) - 40px);margin:0 auto;width:100%}
.is-theater .ac-video{max-height:calc(100vh - var(--top))}
.ac-video .plyr{height:100%;--plyr-color-main:var(--acc);--plyr-font-family:var(--font)}
.ac-video .plyr video{object-fit:contain}
/* small phones: play, progress, time, mute, settings, full screen — the rest live in the keyboard and settings */
@media(max-width:520px){
  .ac-video .plyr__controls [data-plyr="rewind"],.ac-video .plyr__controls [data-plyr="fast-forward"],.ac-video .plyr__controls [data-plyr="pip"],
  .ac-video .plyr__volume input[type=range],.ac-video .plyr__time--duration,.ac-video .plyr__controls [data-plyr="captions"]{display:none}
  .ac-video .plyr__controls{padding:6px 8px;gap:2px}
}
.ac-video.is-frame iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.ac-stage-skel{aspect-ratio:16/9;max-height:70vh;background:var(--stage)}
.ac-stage-frame{aspect-ratio:16/9}
.ac-stage-frame iframe{width:100%;height:100%;border:0;display:block}
.ac-wm{position:absolute;z-index:6;pointer-events:none;user-select:none;-webkit-user-select:none;color:#fff;opacity:.38;font:600 clamp(11px,1.6vw,15px)/1.2 var(--font);text-shadow:0 1px 3px rgba(0,0,0,.85);white-space:nowrap;transform:translate(-50%,-50%);transition:left 2.5s ease,top 2.5s ease}
.ac-next{position:absolute;inset:0;z-index:8;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;background:rgba(5,9,16,.88);color:#fff;text-align:center;padding:20px}
.ac-next span{font-size:14px;opacity:.75}
.ac-next b{font-size:clamp(18px,2.6vw,26px);max-width:640px}
.ac-next-ring{position:relative;width:56px;height:56px;margin:6px 0}
.ac-next-ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.ac-next-ring circle{fill:none;stroke:rgba(255,255,255,.2);stroke-width:3}
.ac-next-ring circle.fg{stroke:#fff;stroke-dasharray:107;transition:stroke-dashoffset 1s linear}
.ac-next-ring em{position:absolute;inset:0;display:grid;place-items:center;font-style:normal;font-weight:800;font-size:18px}
.ac-next-act{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
.ac-stage-gate{display:grid;place-items:center;aspect-ratio:16/9;max-height:70vh;padding:24px}
.ac-gate{max-width:440px;text-align:center;display:flex;flex-direction:column;align-items:center;gap:10px;color:#E6ECF5}
.ac-gate h2{font-size:22px}
.ac-gate p{margin:0;color:rgba(230,236,245,.75)}
.ac-gate-i{width:56px;height:56px;border-radius:50%;background:rgba(255,255,255,.08);display:grid;place-items:center}
.ac-gate-i .ic{width:26px;height:26px}
.ac-gate .ac-btn{margin-top:6px}
@media(max-width:600px){.ac-stage-gate{aspect-ratio:auto;min-height:320px}}

.ac-paper{max-width:900px;margin:0 auto;padding:28px 20px 8px}
.ac-read{display:flex;flex-direction:column;gap:20px}
.ac-goal,.ac-keep{border-radius:var(--r-m);padding:14px 18px}
.ac-goal{background:var(--blue-soft)}
.ac-keep{background:var(--acc-soft)}
.ac-goal b,.ac-keep b{font-size:13.5px}
.ac-goal p,.ac-keep p{margin:4px 0 0}

.ac-l-content{max-width:960px;margin:0 auto;padding:0 20px 80px}
.ac-l-content.ac-l-page{padding-bottom:0;max-width:900px}
.ac-l-page+.ac-paper{padding-top:24px}
.ac-l-page .ac-lh{border-bottom:0;padding-bottom:4px}
.ac-lh{display:flex;flex-wrap:wrap;gap:14px 20px;align-items:flex-end;justify-content:space-between;padding:22px 0 16px;border-bottom:1px solid var(--line)}
.ac-lh-t{min-width:0;flex:1 1 360px}
.ac-lh-k{font-size:13.5px;font-weight:700;color:var(--mute)}
.ac-lh h1{font-size:clamp(21px,3vw,28px);font-weight:800;margin-top:4px}
.ac-lh-act{display:flex;gap:8px;flex-wrap:wrap}
.ac-tabs{display:flex;gap:2px;overflow-x:auto;border-bottom:1px solid var(--line);scrollbar-width:none;margin-top:6px}
.ac-tabs::-webkit-scrollbar{display:none}
.ac-tabs button{flex:none;min-height:48px;padding:0 16px;border:0;border-bottom:3px solid transparent;background:none;color:var(--mute);font:inherit;font-weight:700;font-size:15.5px;cursor:pointer}
.ac-tabs button.on{color:var(--ink);border-bottom-color:var(--acc)}
.ac-tabp{padding:22px 0}
.ac-over{display:flex;flex-direction:column;gap:20px}
.ac-chap{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}
.ac-chap button{display:flex;gap:16px;align-items:center;width:100%;text-align:left;padding:12px 14px;border-radius:12px;border:1px solid var(--line);background:var(--surface);color:var(--ink);font:inherit;font-size:15.5px;cursor:pointer}
.ac-chap button:hover{border-color:var(--acc)}
.ac-chap time{font-weight:800;color:var(--acc);min-width:56px;font-variant-numeric:tabular-nums}
.ac-files{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.ac-files li{display:flex;align-items:center;gap:12px;padding:10px 12px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.ac-ext{width:46px;height:46px;border-radius:10px;background:var(--acc-soft);color:var(--acc);display:grid;place-items:center;font-size:11.5px;font-weight:800;flex:none}
.ac-fn{flex:1;min-width:0;display:flex;flex-direction:column;font-weight:600;overflow-wrap:anywhere}
.ac-fn small{font-weight:500;color:var(--mute);font-size:12.5px}
.ac-row{display:flex;flex-wrap:wrap;align-items:center;gap:10px}
.ac-check{display:inline-flex;align-items:center;gap:8px;font-size:14.5px;color:var(--ink-2)}
.ac-check input{width:18px;height:18px;accent-color:var(--acc)}
.acad textarea,.acad .ac-in,.ac-qa-ans input,.ac-o-search input{width:100%;border:1px solid var(--line-2);background:var(--surface);color:var(--ink);border-radius:12px;padding:11px 13px;font:inherit;font-size:16px;outline:none;resize:vertical}
.acad textarea:focus,.acad .ac-in:focus,.ac-qa-ans input:focus{border-color:var(--acc);box-shadow:0 0 0 3px color-mix(in srgb,var(--acc) 18%,transparent)}
.ac-notes,.ac-qa{display:flex;flex-direction:column;gap:18px}
.ac-note-new,.ac-qa-new{display:flex;flex-direction:column;gap:8px;padding:16px;border:1px solid var(--line);border-radius:var(--r-m);background:var(--surface)}
.ac-note-new label,.ac-qa-new label{font-weight:700;font-size:14.5px;display:flex;align-items:center;gap:8px}
.ac-time-chip{display:inline-flex;align-items:center;gap:5px;font:inherit;font-size:13px;font-weight:800;color:var(--acc);background:var(--acc-soft);border:0;border-radius:999px;padding:3px 10px;cursor:pointer;font-variant-numeric:tabular-nums}
.ac-time-chip .ic{width:13px;height:13px}
.ac-note-list,.ac-qa-list,.ac-qa-rep{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:12px}
.ac-note-list>li{padding:14px 16px;border:1px solid var(--line);border-radius:var(--r-m);background:var(--surface)}
.ac-note-list p{margin:8px 0 0;white-space:pre-wrap}
.ac-note-h{display:flex;align-items:center;gap:8px}
.ac-note-edit{display:flex;flex-direction:column;gap:8px;margin-top:8px}
.ac-mini{background:none;border:0;color:var(--mute);font:inherit;font-size:13.5px;cursor:pointer;padding:4px 6px;border-radius:8px;display:inline-flex;align-items:center}
.ac-mini:hover{color:var(--ink);background:var(--soft)}
.ac-qa-list>li{padding:16px;border:1px solid var(--line);border-radius:var(--r-m);background:var(--surface);display:flex;flex-direction:column;gap:12px}
.ac-post{display:flex;gap:12px}
.ac-post>div{min-width:0;flex:1}
.ac-post-h{display:flex;flex-wrap:wrap;align-items:center;gap:6px 10px;font-size:14px}
.ac-post p{margin:6px 0 0;white-space:pre-wrap;overflow-wrap:anywhere}
.ac-post.is-staff .ac-av{background:var(--acc);color:var(--acc-ink)}
.ac-qa-rep{padding-left:46px}
.ac-qa-ans{display:flex;gap:8px;padding-left:46px}
.ac-qa-ans input{min-height:40px;padding:8px 12px;font-size:15px}
@media(max-width:560px){.ac-qa-rep,.ac-qa-ans{padding-left:0}}
.ac-review{display:flex;flex-direction:column;gap:10px;padding:16px;border:1px solid var(--line);border-radius:var(--r-m);background:var(--surface)}
.ac-starpick{display:flex;gap:4px}
.ac-starpick button{background:none;border:0;padding:4px;color:var(--line-2);cursor:pointer}
.ac-starpick button .ic{width:30px;height:30px}
.ac-starpick button.on{color:var(--gold)}
.ac-starpick button.on .ic{fill:currentColor}

.ac-o{padding:14px 12px 40px;display:flex;flex-direction:column;gap:8px}
.ac-o-h{display:flex;align-items:center;justify-content:space-between;padding:4px 6px 4px}
.ac-o-h b{font-size:16px}
.ac-o-search{display:flex;align-items:center;gap:8px;border:1px solid var(--line-2);border-radius:12px;padding:0 12px;background:var(--bg);color:var(--mute)}
.ac-o-search input{border:0!important;box-shadow:none!important;background:transparent!important;padding:10px 0!important;font-size:15px!important}
.ac-o-s{border:1px solid var(--line);border-radius:var(--r-m);overflow:hidden;background:var(--surface)}
.ac-o-sh{display:flex;align-items:center;gap:10px;width:100%;text-align:left;padding:12px 14px;border:0;background:var(--soft);color:var(--ink);font:inherit;cursor:pointer}
.ac-o-sh>span{flex:1;min-width:0;display:flex;flex-direction:column}
.ac-o-sh b{font-size:15px;line-height:1.4}
.ac-o-sh small{color:var(--mute);font-size:12.5px}
.ac-o-sh .ic{color:var(--mute);transition:transform .2s}
.ac-o-sh .ic.up{transform:rotate(180deg)}
.ac-o ul{list-style:none;margin:0;padding:4px}
.ac-o-l{display:flex;align-items:flex-start;gap:10px;width:100%;text-align:left;padding:9px 10px;border:0;border-radius:10px;background:none;color:var(--ink);font:inherit;cursor:pointer}
.ac-o-l:hover{background:var(--soft)}
.ac-o-l.is-on{background:var(--acc-soft)}
.ac-o-st{width:24px;height:24px;border-radius:50%;border:1.5px solid var(--line-2);display:grid;place-items:center;flex:none;margin-top:2px;color:var(--mute)}
.ac-o-st .ic{width:14px;height:14px}
.is-done .ac-o-st{background:var(--acc);border-color:var(--acc);color:var(--acc-ink)}
.is-locked{opacity:.6}
.ac-dot{width:7px;height:7px;border-radius:50%;background:var(--line-2)}
.ac-eq{display:flex;align-items:flex-end;gap:2px;height:11px}
.ac-eq b{width:3px;background:var(--acc);border-radius:2px;animation:ac-eq 1s ease-in-out infinite}
.ac-eq b:nth-child(2){animation-delay:.2s}.ac-eq b:nth-child(3){animation-delay:.4s}
@keyframes ac-eq{0%,100%{height:3px}50%{height:11px}}
.ac-o-t{flex:1;min-width:0;display:flex;flex-direction:column;font-size:14.5px;line-height:1.4;font-weight:600}
.ac-o-t small{display:flex;align-items:center;gap:5px;font-weight:500;font-size:12.5px;color:var(--mute);margin-top:2px}
.ac-o-t small .ic{width:13px;height:13px}

.ac-quiz{display:flex;flex-direction:column;gap:18px}
.ac-q-hero{display:flex;gap:16px;align-items:flex-start}
.ac-q-hero h2{font-size:24px}
.ac-q-i{width:52px;height:52px;border-radius:14px;background:var(--gold-soft);color:#7A5600;display:grid;place-items:center;flex:none}
.ac-q-stats{display:grid;gap:10px;grid-template-columns:repeat(auto-fit,minmax(130px,1fr))}
.ac-q-stats span{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 14px;display:flex;flex-direction:column;font-size:13.5px;color:var(--mute)}
.ac-q-stats b{font-size:22px;color:var(--ink)}
.ac-q-best{margin:0}.ac-q-best.ok{color:var(--acc);font-weight:700}
.ac-timer{position:sticky;top:calc(var(--top) + 10px);z-index:10;align-self:flex-end;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:6px 16px;font-weight:800;box-shadow:var(--sh-s);font-variant-numeric:tabular-nums}
.ac-timer.low{color:var(--red);border-color:var(--red)}
.ac-qs{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:14px}
.ac-q fieldset{border:1px solid var(--line);background:var(--surface);border-radius:var(--r-m);padding:18px;margin:0;display:flex;flex-direction:column;gap:9px;min-width:0}
.ac-q.is-right fieldset{border-color:var(--acc)}
.ac-q.is-wrong fieldset{border-color:var(--red)}
.ac-q legend{float:left;width:100%;padding:0;margin-bottom:8px;display:flex;gap:10px;font-weight:700;font-size:16.5px;line-height:1.5}
.ac-q-n{width:28px;height:28px;border-radius:8px;background:var(--soft);display:grid;place-items:center;font-size:14px;flex:none}
.ac-opt{display:flex;align-items:flex-start;gap:10px;padding:12px 14px;border:1.5px solid var(--line);border-radius:12px;cursor:pointer;line-height:1.45}
.ac-opt input{width:18px;height:18px;margin-top:3px;accent-color:var(--acc);flex:none}
.ac-opt.on{border-color:var(--acc);background:var(--acc-soft)}
.ac-opt.is-key{border-color:var(--acc);box-shadow:inset 0 0 0 1px var(--acc)}
.ac-opt.is-key::after{content:"✓ সঠিক";margin-left:auto;font-size:12.5px;font-weight:800;color:var(--acc)}
.ac-hint{margin:0;font-size:13px;color:var(--mute)}
.ac-q-fb{background:var(--soft);border-radius:10px;padding:10px 12px;font-size:15px}
.is-right .ac-q-fb b{color:var(--acc)}.is-wrong .ac-q-fb b{color:var(--red)}
.ac-q-fb p{margin:4px 0 0;color:var(--ink-2)}
.ac-q-res{display:flex;flex-wrap:wrap;gap:20px;align-items:center;padding:20px;border-radius:var(--r-l);border:1.5px solid var(--line);background:var(--surface)}
.ac-q-res.ok{border-color:var(--acc)}.ac-q-res.bad{border-color:var(--red)}
.ac-q-res h2{font-size:21px}
.ac-q-res p{margin:4px 0 10px;color:var(--mute)}
.ac-q-score{width:110px;height:110px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--soft)}
.ac-q-score b{font-size:28px;line-height:1}
.ac-q-score small{color:var(--mute)}

.ac-toast{position:fixed;left:50%;bottom:calc(20px + env(safe-area-inset-bottom));transform:translateX(-50%);z-index:90;background:#0E1B14;color:#fff;border-radius:14px;padding:12px 18px;font-size:15px;box-shadow:var(--sh-m);max-width:calc(100vw - 32px);animation:ac-up .25s ease}
.ac-toast a{color:var(--gold);font-weight:800;margin-left:6px}
@keyframes ac-up{from{transform:translate(-50%,16px);opacity:0}}
.ac-modal-b{position:fixed;inset:0;z-index:95;background:rgba(5,10,8,.6);display:grid;place-items:center;padding:20px}
.ac-modal-c{background:var(--surface);border-radius:var(--r-l);padding:24px;max-width:460px;width:100%;display:flex;flex-direction:column;gap:14px;box-shadow:var(--sh-m)}
.ac-modal-c h2{font-size:22px}
.ac-celebrate{text-align:center;align-items:center}
.ac-celebrate p{margin:0;color:var(--mute)}
.ac-celebrate .ac-review{width:100%;text-align:left}
.ac-cel-i{width:64px;height:64px;border-radius:50%;background:var(--acc);color:var(--acc-ink);display:grid;place-items:center}
.ac-cel-i .ic{width:32px;height:32px}
.ac-keys{margin:0;display:flex;flex-direction:column;gap:8px}
.ac-keys div{display:flex;justify-content:space-between;gap:16px;border-bottom:1px solid var(--line);padding-bottom:8px}
.ac-keys dd{margin:0;color:var(--ink-2)}
kbd{font:inherit;font-size:13px;font-weight:700;background:var(--soft);border:1px solid var(--line-2);border-bottom-width:2px;border-radius:7px;padding:2px 8px}
.ac-fatal{max-width:480px;margin:80px auto;padding:24px;text-align:center;display:flex;flex-direction:column;gap:12px;align-items:center}
.ac-skel-line,.ac-o-skel{height:80px;border-radius:12px;background:linear-gradient(90deg,var(--soft),var(--line),var(--soft));background-size:200% 100%;animation:ac-sh 1.2s linear infinite}
.ac-o-skel{height:420px;margin:14px}
@keyframes ac-sh{to{background-position:-200% 0}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}