:root{--ink:#172b4d;--blue:#2866e8;--yellow:#ffd952;--cream:#fffdf7;--line:#e8e4da;--muted:#667085}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--cream);color:var(--ink);font-family:Kanit,sans-serif;font-weight:400}.announcement{background:#172b4d;color:#fff;text-align:center;padding:9px 16px;font-size:14px}.header{height:82px;display:flex;align-items:center;justify-content:space-between;max-width:1200px;padding:0 26px;margin:auto}.brand{color:var(--ink);text-decoration:none;font:800 25px 'Nunito Sans',sans-serif;letter-spacing:-1.5px;display:flex;align-items:center;gap:8px}.brand span span{color:var(--blue)}.brand-mark{width:32px;height:32px;background:var(--yellow);border-radius:10px;display:grid;place-items:center;font-size:23px}.header nav{display:flex;gap:30px}.header nav a{font-size:15px;color:var(--ink);text-decoration:none}.cart-button{border:0;background:var(--blue);color:#fff;border-radius:99px;padding:10px 16px;font:500 14px Kanit;cursor:pointer}.cart-button span{background:#fff;color:var(--blue);border-radius:50%;display:inline-grid;place-items:center;width:20px;height:20px;margin-left:5px}.hero{max-width:1200px;margin:auto;padding:70px 26px 95px;display:grid;grid-template-columns:1.05fr .95fr;min-height:570px;align-items:center}.eyebrow{font:800 12px 'Nunito Sans';color:var(--blue);letter-spacing:1.6px;margin:0 0 13px}.hero h1,.section h2,.why h2{font-size:62px;line-height:1.04;letter-spacing:-2px;margin:0 0 20px;font-weight:700}.hero h1 em,.why h2 em{font-style:normal;color:var(--blue)}.hero-text{font-size:18px;line-height:1.75;color:var(--muted);max-width:530px}.hero-actions{display:flex;gap:22px;align-items:center;margin:30px 0}.button{font:500 16px Kanit;border:0;text-decoration:none;cursor:pointer;border-radius:10px;padding:13px 23px;display:inline-block}.primary{background:var(--blue);color:#fff;box-shadow:0 8px 16px #2866e833}.text-button{color:var(--ink);background:transparent;padding-left:0}.text-button span{font-size:24px;vertical-align:-2px;margin-left:4px}.trust-row{display:flex;gap:25px;margin-top:38px}.trust-row div{border-right:1px solid var(--line);padding-right:22px}.trust-row div:last-child{border:0}.trust-row b{display:block;font:800 21px 'Nunito Sans'}.trust-row small{display:block;color:var(--muted);font-size:12px;max-width:100px;line-height:1.3}.hero-art{height:390px;position:relative;background:#e8f0ff;border-radius:48% 52% 45% 55% / 44% 43% 57% 56%;overflow:hidden}.sun{position:absolute;width:280px;height:280px;border-radius:50%;background:var(--yellow);right:28px;top:55px}.math-symbol{position:absolute;font:800 45px 'Nunito 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var(--line)}.section-heading{display:flex;justify-content:space-between;align-items:end;margin-bottom:34px}.section h2,.why h2{font-size:44px}.section-heading>p{color:var(--muted);line-height:1.7;margin:0 0 7px}.grade-tabs{display:flex;gap:9px;flex-wrap:wrap;margin-bottom:25px}.grade-tab{background:#fff;border:1px solid var(--line);border-radius:8px;padding:9px 18px;color:var(--ink);font:500 15px Kanit;cursor:pointer}.grade-tab.active{background:var(--ink);color:#fff;border-color:var(--ink)}.books-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:17px}.book-card{background:#fff;border:1px solid var(--line);border-radius:15px;padding:13px;transition:.2s}.book-card:hover{transform:translateY(-4px);box-shadow:0 12px 25px #172b4d12}.cover{height:225px;border-radius:10px;padding:19px;color:#fff;position:relative;overflow:hidden}.cover:after{content:"";position:absolute;width:130px;height:130px;border:2px solid #ffffff77;border-radius:50%;right:-39px;bottom:-38px}.cover .cover-no{font:800 11px 'Nunito Sans';letter-spacing:1.2px}.cover h3{font-size:23px;line-height:1.22;margin-top:35px;position:relative;z-index:1}.cover .cover-mark{position:absolute;right:17px;top:12px;font-size:38px;font-family:'Nunito Sans'}.cover.c1{background:#2c6be8}.cover.c2{background:#ff816d}.cover.c3{background:#28a88b}.cover.c4{background:#795bdb}.book-info{padding:14px 4px 2px}.book-info p{font-size:13px;color:var(--muted);margin:0 0 9px;height:38px}.book-bottom{display:flex;align-items:center;justify-content:space-between}.book-bottom b{font-size:18px}.add-button{border:0;background:#edf2ff;color:var(--blue);font:500 14px Kanit;border-radius:7px;padding:7px 11px;cursor:pointer}.bundle-callout{margin-top:23px;background:var(--yellow);padding:20px 25px;border-radius:15px;display:flex;align-items:center;gap:17px}.bundle-icon{width:53px;height:53px;border-radius:50%;background:var(--ink);color:#fff;text-align:center;font:800 24px/27px 'Nunito Sans';padding-top:7px}.bundle-icon small{font:400 11px Kanit}.bundle-callout b{font-size:19px}.bundle-callout p{margin:1px 0;color:#5a5337;font-size:14px}.bundle-price{margin-left:auto;text-align:right}.bundle-price s{display:block;font-size:13px;color:#6f684e}.bundle-price strong{font-size:23px}.dark{background:var(--ink);color:#fff}.why{background:#e8f0ff;padding:95px max(26px,calc((100vw - 1148px)/2));display:grid;grid-template-columns:.85fr 1.15fr;gap:110px;align-items:center}.why-visual{height:370px;position:relative}.circle-text{position:absolute;width:275px;height:275px;border:1px dashed #2866e899;border-radius:50%;top:35px;left:35px;color:var(--blue);font:700 14px 'Nunito Sans';letter-spacing:3px;padding:25px}.paper{width:220px;height:275px;background:#fff;position:absolute;left:85px;top:50px;box-shadow:14px 18px 0 #ffd952;transform:rotate(-8deg);padding:35px 27px}.paper:before{content:"";display:block;position:absolute;left:0;right:0;top:20px;border-top:1px solid #ddd}.paper span{font-size:14px;color:var(--blue)}.paper b{display:block;font:800 25px 'Nunito Sans';margin-top:55px}.paper i{font:900 45px 'Nunito Sans';color:#28a88b;display:block;text-align:right;margin-top:12px}.feature{display:flex;gap:21px;border-top:1px solid #bfd0f2;padding:17px 0}.feature span{font:800 15px 'Nunito Sans';color:var(--blue)}.feature b{font-size:17px}.feature p{font-size:14px;color:var(--muted);margin:3px 0;line-height:1.5}.how{text-align:center}.how h2{font-size:40px}.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:60px;text-align:left;margin-top:38px}.steps span{width:36px;height:36px;border-radius:50%;display:grid;place-items:center;background:var(--yellow);font:800 17px 'Nunito Sans';margin-bottom:12px}.steps b{font-size:18px}.steps p{color:var(--muted);font-size:14px;line-height:1.6;margin-top:4px}footer{padding:55px 26px 35px;background:var(--ink);color:#fff;text-align:center}footer .brand{color:#fff;justify-content:center}footer p{color:#b9c7df;margin:16px 0 32px}footer small{font:12px 'Nunito Sans';color:#8fa1c0}.cart{position:fixed;right:0;top:0;bottom:0;width:min(410px,100%);background:#fff;z-index:20;transform:translateX(105%);transition:.25s;padding:22px;display:flex;flex-direction:column}.cart.show{transform:none}.cart-head{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding-bottom:14px}.cart h2{margin:0;font-size:25px}.close{border:0;background:transparent;font:300 34px Kanit;color:var(--ink);cursor:pointer;line-height:1}.cart-items{flex:1;overflow:auto}.cart-item{padding:17px 0;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;gap:10px}.cart-item b{display:block}.cart-item small{color:var(--muted)}.remove{background:none;border:0;color:#d15050;font:14px Kanit;cursor:pointer}.cart-foot{border-top:1px solid var(--line);padding-top:15px}.total{display:flex;justify-content:space-between;margin-bottom:14px;font-size:17px}.checkout{width:100%}.checkout:disabled{background:#b7c0d2;box-shadow:none;cursor:not-allowed}.overlay{display:none;position:fixed;inset:0;background:#172b4d66;z-index:19}.overlay.show{display:block}.modal{position:fixed;inset:0;z-index:30;display:none;place-items:center;background:#172b4d80;padding:18px}.modal.show{display:grid}.payment-card{max-width:410px;width:100%;background:#fff;border-radius:20px;text-align:center;padding:32px;position:relative}.payment-card h2{margin:0;font-size:27px}.payment-total{font:700 25px 'Nunito Sans';color:var(--blue);margin:8px}.qr-wrap{margin:16px auto 10px;width:210px;padding:10px;background:#fff;border:1px solid var(--line);border-radius:10px}.qr-wrap img{width:185px;height:185px;display:block;margin:auto}.qr-wrap span{font:800 12px 'Nunito Sans';color:#2866e8;letter-spacing:1px}.hint{font-size:13px;color:var(--muted);line-height:1.5}.full{width:100%;margin-top:10px}.demo-note{color:#9b8254;display:block;margin-top:12px;font-size:11px;line-height:1.4}.success-icon{width:55px;height:55px;background:#d9f6e8;color:#1d9b67;border-radius:50%;display:grid;place-items:center;font:800 28px 'Nunito Sans';margin:0 auto 13px}.success p{color:var(--muted)}.download-link{display:block;border:1px solid #c5d5fa;background:#f4f7ff;color:var(--blue);text-decoration:none;border-radius:8px;padding:9px;margin:8px 0;font-size:14px}
@media(max-width:760px){.header nav{display:none}.hero{grid-template-columns:1fr;padding-top:35px}.hero h1{font-size:48px}.hero-art{height:320px;margin-top:20px}.section-heading{display:block}.section-heading>p{margin-top:10px}.books-grid{grid-template-columns:repeat(2,1fr);gap:10px}.cover{height:180px}.cover h3{font-size:18px}.bundle-callout{flex-wrap:wrap}.bundle-price{margin-left:auto}.why{grid-template-columns:1fr;gap:20px;padding-top:65px;padding-bottom:65px}.why-visual{height:310px}.why h2,.section h2{font-size:37px}.steps{grid-template-columns:1fr;gap:22px}.trust-row{gap:11px}.trust-row div{padding-right:10px}.header{height:67px}.book-stack{left:56px}.announcement{font-size:12px}}