:root {
  --bg: #f6f8fc; --card: #ffffff; --ink: #0f172a; --muted: #64748b; --line: #e2e8f0;
  --brand: #1d4ed8; --brand2: #16a34a; --bad: #dc2626; --good: #059669; --warn: #fef3c7;
  --radius: 16px; --shadow: 0 1px 2px #0f172a0d, 0 6px 24px #0f172a0f;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0b1220; --card: #111a2e; --ink: #e5e7eb; --muted: #94a3b8; --line: #1f2a44; --warn: #3b2f0b; --shadow: 0 1px 2px #0006; }
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--ink); font: 16px/1.55 Inter, "Hind Siliguri", system-ui, sans-serif; }
html[lang="bn"] body { font-family: "Hind Siliguri", Inter, system-ui, sans-serif; }
a { color: var(--brand); }
h1 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin: .4em 0 .6em; }
h2 { font-size: 1.35rem; margin: .2em 0 .5em; } h3 { margin: .3em 0; } h4 { margin: 0 0 .4em; }
.muted { color: var(--muted); } .small { font-size: .85rem; }
.row { display: flex; gap: .5rem; flex-wrap: wrap; align-items: center; } .between { justify-content: space-between; }
.grid { display: grid; gap: 1rem; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem; box-shadow: var(--shadow); margin-bottom: 1rem; }
.btn { display: inline-flex; align-items: center; gap: .35rem; border: 1px solid var(--line); background: var(--card); color: var(--ink); padding: .6rem 1rem; border-radius: 999px; font: inherit; font-weight: 600; cursor: pointer; text-decoration: none; }
.btn:hover { border-color: var(--brand); } .btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn.big { padding: .85rem 1.4rem; font-size: 1.05rem; } .btn.sm { padding: .35rem .75rem; font-size: .88rem; }
.btn.ghost { background: transparent; } .btn.locked { opacity: .5; } .btn.rec { background: var(--bad); color: #fff; }
input, select, textarea { font: inherit; color: var(--ink); background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: .55rem .7rem; width: 100%; }
label { display: block; font-size: .9rem; font-weight: 600; margin: .5rem 0; }
label > input[type=checkbox] { width: auto; }
.note { background: var(--warn); border-radius: 12px; padding: .7rem 1rem; margin: .7rem 0; font-size: .92rem; }

/* header */
.top { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 1rem; padding: .6rem 1rem; background: color-mix(in srgb, var(--card) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.logo { font-weight: 800; font-size: 1.25rem; color: var(--ink); text-decoration: none; display: flex; align-items: center; gap: .4rem; }
.logo b { color: var(--brand2); }
.logo-mark { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 9px; background: var(--brand); color: #fff; }
#nav { display: flex; gap: .2rem; flex: 1; flex-wrap: wrap; }
#nav a { padding: .4rem .7rem; border-radius: 999px; text-decoration: none; color: var(--ink); font-weight: 600; font-size: .95rem; }
#nav a.active, #nav a:hover { background: color-mix(in srgb, var(--brand) 12%, transparent); color: var(--brand); }
.top-right { display: flex; gap: .5rem; align-items: center; }
.badge { font-size: .8rem; font-weight: 700; padding: .25rem .6rem; border-radius: 999px; border: 1px solid var(--line); text-decoration: none; }
.badge.pro { background: var(--brand2); color: #fff; border-color: var(--brand2); }
.navtoggle { display: none; background: none; border: 0; font-size: 1.5rem; color: var(--ink); }
main { max-width: 1200px; margin: 0 auto; padding: 1rem; min-height: 70vh; }
@media (max-width: 860px) {
  .navtoggle { display: block; margin-left: auto; }
  #nav { display: none; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; background: var(--card); padding: .5rem; border-bottom: 1px solid var(--line); }
  body.nav-open #nav { display: flex; }
}

/* home */
.hero { display: grid; grid-template-columns: 1.3fr 1fr; gap: 2rem; align-items: center; padding: 2rem 0; }
.hero h1 { font-size: clamp(1.9rem, 4vw, 3rem); line-height: 1.15; }
.eyebrow { color: var(--brand2); font-weight: 700; margin: 0; }
.lead { font-size: 1.15rem; color: var(--muted); }
.hero-demo { display: flex; flex-direction: column; gap: .8rem; align-items: center; }
.bubble { background: var(--bg); border-radius: 14px; padding: .8rem 1rem; position: relative; }
@media (max-width: 760px) { .hero { grid-template-columns: 1fr; padding: 1rem 0; } }
.clusters { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.cluster { text-align: left; cursor: pointer; font: inherit; color: inherit; border-top: 5px solid var(--c); }
.cluster.sel { outline: 2px solid var(--c); }
.cluster p { color: var(--muted); font-size: .92rem; margin: 0; }
.cicon, .ficon { font-size: 1.8rem; }
.feats { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.feat p { color: var(--muted); margin: 0; }
.cta { text-align: center; background: linear-gradient(135deg, color-mix(in srgb, var(--brand) 10%, var(--card)), color-mix(in srgb, var(--brand2) 10%, var(--card))); }
.detail { border-top: 5px solid var(--c); }
.tabs { display: flex; gap: .4rem; flex-wrap: wrap; margin: .6rem 0; }
.tab { border: 1px solid var(--line); background: var(--bg); color: var(--ink); padding: .45rem .9rem; border-radius: 999px; cursor: pointer; font: inherit; font-weight: 600; }
.tab.active { background: var(--brand); color: #fff; border-color: var(--brand); }
.subjects { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.subj { display: flex; flex-direction: column; gap: .4rem; margin: 0; }
.sicon { font-size: 1.5rem; }

/* avatar */
.avatar { width: 100%; max-width: 300px; margin: 0 auto; aspect-ratio: 26/30; border-radius: 20px; overflow: hidden; }
.avatar.small { max-width: 220px; }
.avatar-svg, .avatar-canvas { width: 100%; height: 100%; display: block; }
.avatar-canvas { cursor: crosshair; object-fit: cover; }
.av-head { transform-origin: 130px 220px; transition: transform .1s; }

/* tutor */
.tutor { display: grid; grid-template-columns: 320px 1fr; gap: 1rem; align-items: start; }
.tutor-side { position: sticky; top: 72px; max-height: calc(100vh - 84px); overflow: auto; }
@media (max-width: 900px) { .tutor { grid-template-columns: 1fr; } .tutor-side { position: static; max-height: none; } .tutor-main { order: -1; } .avatar { max-width: 200px; } }
.captions { min-height: 3.2em; background: var(--bg); border-radius: 12px; padding: .7rem .9rem; margin: .7rem 0; font-size: .97rem; }
.ctrls { justify-content: center; }
.custom summary { cursor: pointer; font-weight: 700; margin-top: .6rem; }
.presets { display: flex; flex-wrap: wrap; gap: .3rem; margin: .5rem 0; }
.preset { border: 1px solid var(--line); background: var(--bg); color: var(--ink); border-radius: 999px; padding: .3rem .7rem; cursor: pointer; font: inherit; font-size: .88rem; }
.preset.sel { border-color: var(--brand); color: var(--brand); }
.file { cursor: pointer; color: var(--brand); }
.clone { border-top: 1px dashed var(--line); margin-top: .7rem; padding-top: .6rem; }
.board-wrap { padding: .6rem; }
.board-title { font-weight: 700; padding: .2rem .4rem .5rem; }
.wb { background: #fffef7; background-image: radial-gradient(#e5e7eb 1px, transparent 1px); background-size: 20px 20px; border-radius: 12px; border: 1px solid var(--line); aspect-ratio: 16/9; }
.wb-svg { width: 100%; height: 100%; display: block; }
.wb-text { font-family: "Comic Sans MS", "Segoe Print", "Hind Siliguri", cursive, sans-serif; font-weight: 600; }
.stepdots { display: flex; gap: 6px; justify-content: center; padding-top: .5rem; }
.stepdots span { width: 10px; height: 10px; border-radius: 50%; background: var(--line); } .stepdots .on { background: var(--brand); } .stepdots .done { background: var(--brand2); }
.ask textarea { resize: vertical; margin-bottom: .5rem; }
.ask .row { justify-content: flex-end; }
.extras-grid { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.ex ul { margin: 0; padding-left: 1.1rem; }
.spin { width: 18px; height: 18px; border: 3px solid #fff6; border-top-color: currentColor; border-radius: 50%; display: inline-block; animation: sp .8s linear infinite; vertical-align: middle; }
@keyframes sp { to { transform: rotate(360deg); } }

/* mcq */
.mcq .q { font-weight: 600; margin: .4rem 0 .6rem; }
.opts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: .45rem; }
.opt { display: flex; gap: .55rem; align-items: center; text-align: left; border: 1.5px solid var(--line); background: var(--bg); color: var(--ink); padding: .55rem .7rem; border-radius: 12px; cursor: pointer; font: inherit; }
.opt span { display: grid; place-items: center; min-width: 26px; height: 26px; border-radius: 50%; background: var(--card); border: 1px solid var(--line); font-weight: 700; font-size: .85rem; }
.opt:hover { border-color: var(--brand); }
.opt.picked { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 12%, var(--bg)); }
.opt.right { border-color: var(--good); background: color-mix(in srgb, var(--good) 15%, var(--bg)); }
.opt.bad { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, var(--bg)); }
.exp { margin-top: .5rem; padding: .6rem .8rem; border-radius: 10px; background: var(--bg); font-size: .93rem; }
.tag { font-size: .75rem; background: var(--bg); border: 1px solid var(--line); border-radius: 999px; padding: .05rem .5rem; color: var(--muted); }
hr { border: 0; border-top: 1px solid var(--line); margin: 1rem 0; }
.setup { max-width: 640px; }
.exam-bar { position: sticky; top: 64px; z-index: 5; display: flex; justify-content: space-between; align-items: center; }
.bars { display: grid; gap: .5rem; margin: .6rem 0; }
.barrow { display: grid; grid-template-columns: minmax(110px, 200px) 1fr auto; gap: .6rem; align-items: center; font-size: .92rem; }
.bar { height: 10px; background: var(--bg); border-radius: 999px; overflow: hidden; border: 1px solid var(--line); }
.bar i { display: block; height: 100%; background: linear-gradient(90deg, var(--brand), var(--brand2)); }
.stats { grid-template-columns: repeat(3, 1fr); }
.stat { text-align: center; } .stat b { font-size: 1.8rem; display: block; } .stat span { color: var(--muted); font-size: .9rem; }

/* pricing */
.plans { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.plan { position: relative; } .plan.best { border: 2px solid var(--brand); }
.price { font-size: 2.2rem; font-weight: 800; margin: .2rem 0; } .price small { font-size: 1rem; color: var(--muted); }
.plan ul { padding-left: 1.1rem; } .plan li { margin: .3rem 0; }
.ribbon { position: absolute; top: -12px; right: 16px; background: var(--brand2); color: #fff; font-size: .8rem; font-weight: 700; padding: .2rem .7rem; border-radius: 999px; }

#toast { position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 120px); background: #0f172a; color: #fff; padding: .7rem 1.1rem; border-radius: 12px; transition: transform .3s; z-index: 50; max-width: 90vw; }
#toast.show { transform: translate(-50%, 0); }
#toast:empty{display:none}

/* footer */
.foot { background: #131c3b; color: #e5e7eb; border-top: 0; padding: 2.2rem 1rem 1.6rem; margin-top: 2rem; }
.foot-inner { max-width: 1140px; margin: 0 auto; text-align: center; }
.foot-bar { height: 5px; border-radius: 999px; margin-bottom: 1.4rem; background: linear-gradient(90deg, #e23d4f 0 20%, #4f46e5 20% 40%, #16a34a 40% 60%, #3b9be0 60% 80%, #f2a62a 80% 100%); }
.foot-links { position: relative; display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: .3rem .6rem; font-weight: 700; padding: 0 3rem; }
.foot-links a { color: #fff; text-decoration: none; } .foot-links a:hover { text-decoration: underline; }
.foot-links .sep { color: #64748b; }
.foot-mail { position: absolute; right: 0; top: 50%; transform: translateY(-50%); display: grid; place-items: center; width: 34px; height: 34px; border-radius: 9px; background: #2b3557; font-size: .95rem; }
.foot-copy { margin: 1rem 0 .7rem; }
.foot-legal { color: #8390ab; font-size: .9rem; max-width: 1120px; margin: 0 auto .7rem; }
.foot-app { margin: .6rem 0; }
.foot-privacy { color: #8390ab; font-size: .92rem; max-width: 640px; margin: .6rem auto 0; }
.foot-privacy a { color: #fff; font-weight: 700; white-space: nowrap; }
@media (max-width: 600px) { .foot-links { padding: 0; } .foot-mail { position: static; transform: none; } }
.info { max-width: 820px; } .info h3 { margin-top: 1.2rem; } .big-mail { font-size: 1.3rem; font-weight: 700; }

/* banners */
.banners { position: relative; border-radius: 22px; overflow: hidden; margin: .5rem 0 1rem; aspect-ratio: 21/8; min-height: 300px; background: #0f172a; }
.banner { position: absolute; inset: 0; display: grid; grid-template-columns: 1.1fr 1fr; text-decoration: none; color: #fff; opacity: 0; transition: opacity .7s; pointer-events: none;
  background: linear-gradient(120deg, var(--bc), color-mix(in srgb, var(--bc) 55%, #0f172a)); }
.banner.on { opacity: 1; pointer-events: auto; }
.b-text { display: flex; flex-direction: column; justify-content: center; padding: 2rem 2.4rem; gap: .4rem; z-index: 1; }
.b-text h2 { font-size: clamp(1.5rem, 3.4vw, 2.6rem); line-height: 1.15; margin: 0; }
.b-text p { font-size: clamp(.95rem, 1.5vw, 1.15rem); opacity: .92; margin: .2rem 0 .8rem; max-width: 34ch; }
.b-text .btn { align-self: flex-start; background: #fff; color: var(--bc); border: 0; }
.b-img { position: relative; overflow: hidden; }
.b-img img { width: 100%; height: 100%; object-fit: cover; display: block; transform: scale(1.04); transition: transform 6s ease-out; }
.banner.on .b-img img { transform: scale(1); }
.b-img::before { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, color-mix(in srgb, var(--bc) 85%, #0f172a) 0%, transparent 35%); z-index: 1; }
.b-nav { position: absolute; top: 50%; transform: translateY(-50%); z-index: 3; width: 38px; height: 38px; border-radius: 50%; border: 0; background: #ffffffcc; color: #0f172a; font-size: 1.5rem; line-height: 1; cursor: pointer; }
.b-nav.prev { left: 10px; } .b-nav.next { right: 10px; }
.b-dots { position: absolute; bottom: 12px; left: 0; right: 0; display: flex; justify-content: center; gap: 7px; z-index: 3; }
.b-dots button { width: 9px; height: 9px; border-radius: 999px; border: 0; background: #ffffff88; padding: 0; cursor: pointer; transition: width .3s; }
.b-dots button.on { width: 26px; background: #fff; }
@media (max-width: 760px) {
  .banners { aspect-ratio: auto; height: 520px; }
  .banner { grid-template-columns: 1fr; grid-template-rows: 1fr auto; }
  .b-img { grid-row: 1; } .b-text { grid-row: 2; padding: 1.1rem 1.2rem 2.4rem; }
  .b-img::before { background: linear-gradient(0deg, color-mix(in srgb, var(--bc) 85%, #0f172a) 0%, transparent 40%); }
  .b-nav { top: 36%; }
}

.logo-mark { width: 34px; height: 34px; background: none; border-radius: 9px; }
.logo .bd .g { color: #006A4E; } .logo .bd .r { color: #F42A41; }
@media (prefers-color-scheme: dark) { .logo .bd .g { color: #22c55e; } }
@media (min-width: 761px) { .b-text { padding-left: 4.2rem; } }

.cluster { padding: 0; overflow: hidden; display: flex; flex-direction: column; }
.cluster > h3, .cluster > p, .cluster > .cicon { padding: 0 1.1rem; }
.cluster > p { padding-bottom: 1.1rem; }
.cphoto { position: relative; height: 130px; margin-bottom: .6rem; }
.cphoto img { width: 100%; height: 100%; object-fit: cover; display: block; }
.cphoto .cicon { position: absolute; left: 12px; bottom: -16px; width: 42px; height: 42px; display: grid; place-items: center; background: var(--card); border-radius: 12px; box-shadow: var(--shadow); font-size: 1.4rem; }
.cluster h3 { margin-top: .9rem; }
.lifestrip { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1rem; margin: 1rem 0; }
.life { padding: 0; overflow: hidden; margin: 0; }
.life img { width: 100%; aspect-ratio: 3/2; object-fit: cover; display: block; }
.life figcaption { padding: .9rem 1.1rem 1.1rem; } .life p { color: var(--muted); margin: .2rem 0 0; }
.banners { aspect-ratio: auto; width: 100%; height: clamp(300px, 36vw, 460px); min-height: 0; }
@media (max-width: 760px) { .banners { height: 520px; } }
html, body { overflow-x: hidden; }

.aid-cta { display: flex; gap: 1rem; align-items: center; justify-content: space-between; flex-wrap: wrap; border-left: 5px solid #006A4E; }
.aid-grid { grid-template-columns: 1.4fr 1fr; align-items: start; }
@media (max-width: 860px) { .aid-grid { grid-template-columns: 1fr; } }
.row2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: .6rem; }
.code { font-family: ui-monospace, monospace; font-size: 1.15rem; letter-spacing: .05em; background: var(--bg); padding: .1rem .4rem; border-radius: 6px; }
.adm blockquote { margin: .5rem 0; padding: .6rem .9rem; background: var(--bg); border-radius: 10px; white-space: pre-wrap; }
.adm.approved { border-left: 5px solid var(--good); } .adm.rejected { border-left: 5px solid var(--bad); opacity: .8; } .adm.pending { border-left: 5px solid #d97706; }

.mt-grid { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.mt h3 { margin: .5rem 0 .3rem; }
.mt-table { width: 100%; border-collapse: collapse; font-size: .9rem; margin: .5rem 0; }
.mt-table td, .mt-table th { padding: .35rem .4rem; border-bottom: 1px solid var(--line); text-align: left; }
.mt-table td:not(:first-child), .mt-table th:not(:first-child) { text-align: right; white-space: nowrap; }
.chip { display: inline-flex; align-items: center; gap: .3rem; border: 1px solid var(--line); border-radius: 999px; padding: .25rem .6rem; font-weight: 600; font-size: .85rem; margin: .15rem 0; }
.choose { margin: .4rem 0 .6rem; }
.sec-h { margin: 1rem 0 .3rem; padding-top: .6rem; border-top: 3px solid var(--line); }
.tip { margin-top: .45rem; padding: .45rem .7rem; border-radius: 9px; background: color-mix(in srgb, #f59e0b 14%, var(--card)); font-size: .9rem; }
.pass { color: var(--good); font-size: 1rem; margin-left: .5rem; } .fail { color: var(--bad); font-size: 1rem; margin-left: .5rem; }
.bq { padding: .8rem 0; border-bottom: 1px solid var(--line); }
.bq-opts { margin: .3rem 0 .5rem 1.2rem; padding: 0; } .bq-opts li { margin: .15rem 0; } .bq-opts li.right { color: var(--good); font-weight: 700; }
.bq-ans { background: var(--bg); padding: .6rem .8rem; border-radius: 10px; } .bq-ans p { margin: .3rem 0 0; }
a.card.subj { text-decoration: none; color: inherit; } .subj.sel { outline: 2px solid var(--brand); }
[hidden] { display: none !important; }
a.tab { text-decoration: none; display: inline-block; }
.detail, #bankList, .tabs, #ebox { scroll-margin-top: 72px; }