:root{color-scheme:light;--ink:#171638;--muted:#5e6372;--orange:#fb8c00;--line:#dde2e9}*{box-sizing:border-box}body{margin:0;background:#f9fafc;color:var(--ink);font-family:'Noto Sans Bengali',system-ui,sans-serif;line-height:1.65}a{color:inherit;text-underline-offset:5px}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible{outline:3px solid #00897b;outline-offset:5px}.shell{width:min(1080px,calc(100% - 40px));margin-inline:auto}header{background:#fff;border-bottom:1px solid var(--line)}header .shell{height:80px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:12px;font-size:28px;font-weight:800;text-decoration:none}.back{font-size:14px;padding-block:12px}.intro{padding:40px 0 24px;text-align:center}.eyebrow{font-size:13px;font-weight:700;color:#5e6372;margin:0 0 10px}h1{font-size:clamp(32px,5vw,52px);line-height:1.3;letter-spacing:-.025em;margin:0 0 14px}.intro>p:last-child{font-size:16px;color:var(--muted);margin:0}h2{font-size:22px;line-height:1.5;margin:4px 0 6px}.lesson{background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden}.player{position:relative;aspect-ratio:16/9;background:#171638}.player button{position:absolute;inset:0;width:100%;height:100%;padding:0;border:0;cursor:pointer;color:white;background:#171638;font:inherit}.player img{width:100%;height:100%;object-fit:cover;opacity:.75}.play-mark{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);display:grid;place-items:center;border-radius:50%;background:var(--orange);color:var(--ink);width:76px;height:76px;font-size:28px;padding-left:4px;box-shadow:0 4px 24px #0004}.play-label{position:absolute;bottom:18px;left:50%;transform:translateX(-50%);background:#171638;padding:6px 16px;border-radius:8px;white-space:nowrap;font-weight:700}.player iframe{position:absolute;inset:0;width:100%;height:100%;border:0}.caption{padding:18px 24px;display:flex;align-items:center;justify-content:space-between;gap:20px}.caption a{font-size:14px;white-space:nowrap;padding:12px 0}.caption h2{font-size:19px}.help{font-size:13px;color:var(--muted);margin:12px 0 0}.next{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:32px 0 40px}.next p{color:var(--muted);margin:0 0 14px}.enroll{background:var(--orange);padding:15px 28px;border-radius:12px;text-decoration:none;font-weight:800;white-space:nowrap;box-shadow:0 4px 0 #c97100}.enroll:hover{background:#ff9f20}.details{font-size:14px}footer{border-top:1px solid var(--line);padding:20px 0 28px;font-weight:700;display:flex;justify-content:space-between;gap:20px}footer span{font-size:13px;font-weight:400;color:var(--muted)}.skip{position:absolute;top:-100px;background:white;padding:12px;z-index:5}.skip:focus{top:8px}@media(max-width:640px){.shell{width:calc(100% - 32px)}header .shell{height:68px}.brand{font-size:24px;gap:8px}.back{font-size:12px}.intro{padding:28px 0 22px;text-align:left}.intro>p:last-child{font-size:14px;max-width:36ch}.caption{padding:14px;display:block}.caption h2{font-size:17px}.caption a{display:inline-block;padding:6px 0}.play-mark{width:58px;height:58px;font-size:24px}.play-label{font-size:12px;bottom:8px;padding:3px 10px}.next{display:block;padding:24px 0 30px}.next h2{font-size:22px}.next p{font-size:14px}.enroll{display:block;text-align:center;margin-top:22px;min-height:52px}.help{line-height:1.8}footer{padding-bottom:max(24px,env(safe-area-inset-bottom))}}