:root{
  --navy:#0b1f3a;--blue:#1769ff;--blue-dark:#0f52cc;--teal:#0d8f8a;--coral:#f06f4f;
  --ink:#10213b;--muted:#607087;--line:#dce5f0;--ice:#f4f8fd;--paper:#fff;--green:#168759;
  --red:#d94242;--shadow:0 22px 60px rgba(11,31,58,.12);--radius:18px
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;color:var(--ink);background:#fff;font-family:Manrope,Arial,sans-serif;line-height:1.65}a{color:inherit;text-decoration:none}img{display:block;max-width:100%}button,a{font:inherit}.skip-link{position:absolute;left:-9999px}.skip-link:focus{left:16px;top:16px;z-index:999;background:#fff;padding:12px 16px;border:2px solid var(--blue)}.container{width:min(1240px,calc(100% - 48px));margin-inline:auto}.narrow{width:min(940px,calc(100% - 48px));margin-inline:auto}.centered{text-align:center}

/* Header */
.site-header{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.95);border-bottom:1px solid var(--line);backdrop-filter:blur(16px)}.nav-wrap{height:86px;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:13px}.brand-mark{width:54px;height:62px;display:grid;place-items:center;clip-path:polygon(50% 0,94% 22%,94% 75%,50% 100%,6% 75%,6% 22%);color:#fff;background:var(--navy);font:800 17px Sora,sans-serif;position:relative}.brand-mark:after{content:"";position:absolute;inset:7px;clip-path:inherit;border:2px solid #fff}.brand-name{display:flex;flex-direction:column;line-height:1.1}.brand-name strong{font:700 20px Sora,sans-serif;letter-spacing:-.5px}.brand-name small{margin-top:7px;color:var(--muted);font-size:11px;font-weight:600}.main-nav{display:flex;align-items:center;gap:38px;font-size:14px;font-weight:650}.main-nav>a:not(.nav-whatsapp){padding:33px 0 27px;border-bottom:3px solid transparent}.main-nav>a.active,.main-nav>a:not(.nav-whatsapp):hover{color:var(--blue);border-color:var(--blue)}.nav-whatsapp{border:1.5px solid var(--navy);border-radius:8px;padding:10px 15px}.nav-whatsapp:hover{color:#fff;background:var(--navy)}.menu-button{display:none;border:0;background:transparent;padding:10px}.menu-button span{display:block;width:25px;height:2px;background:var(--navy);margin:5px}

/* Shared */
.eyebrow{display:inline-block;margin:0 0 18px;color:var(--blue);text-transform:uppercase;letter-spacing:2.2px;font-size:12px;font-weight:800}.eyebrow-light{color:#9ed9d3}h1,h2,h3{font-family:Sora,Manrope,sans-serif}.button{display:inline-flex;align-items:center;justify-content:center;gap:18px;padding:15px 23px;min-height:55px;color:#fff;background:var(--blue);border:2px solid var(--blue);border-radius:7px;font-weight:750;box-shadow:0 12px 25px rgba(23,105,255,.18);transition:.2s transform,.2s background}.button:hover{transform:translateY(-2px);background:var(--blue-dark);border-color:var(--blue-dark)}.button-outline{color:var(--blue);background:transparent;box-shadow:none}.button-outline:hover{color:#fff}.button-light{background:#fff;color:var(--navy);border-color:#fff;box-shadow:none}.button-light:hover{background:#eef5ff;color:var(--navy);border-color:#eef5ff}.teal-button{background:var(--teal);border-color:var(--teal);box-shadow:0 12px 25px rgba(13,143,138,.2)}.teal-button:hover{background:#087873;border-color:#087873}.text-link{color:var(--blue);font-weight:750;border-bottom:1px solid currentColor;padding-bottom:3px}.hero-actions{display:flex;align-items:center;gap:28px}.check-list{list-style:none;padding:0;margin:24px 0}.check-list li{position:relative;padding-left:25px;margin:10px 0;font-weight:600}.check-list li:before{content:"✓";position:absolute;left:0;color:var(--green);font-weight:900}.check-list.large li{font-size:15px;margin:13px 0}.section{padding:100px 0}.section-heading{display:flex;justify-content:space-between;align-items:flex-end;gap:60px;margin-bottom:48px}.section-heading h2,.answer-copy h2,.teacher-panel h2,.copy-grid h2,.memory-banner h2,.sample-grid h2{margin:0;font-size:clamp(32px,4vw,50px);line-height:1.08;letter-spacing:-2px}.section-heading>p{max-width:460px;margin:0;color:var(--muted)}.section-heading.centered{display:block;text-align:center}.section-heading.centered p{margin:16px auto 0}

.button-small{min-height:45px;padding:10px 16px;font-size:13px}

/* Collection homepage hero */
.collection-hero{position:relative;overflow:hidden;background:linear-gradient(90deg,#fff 0 45%,#f8fbff 100%)}.hero-grid-lines{position:absolute;right:0;top:0;width:45%;height:100%;opacity:.55;background-image:linear-gradient(#dcecff 1px,transparent 1px),linear-gradient(90deg,#dcecff 1px,transparent 1px);background-size:46px 46px;mask-image:linear-gradient(90deg,transparent,#000)}.collection-grid{position:relative;z-index:2;min-height:700px;display:grid;grid-template-columns:.42fr .58fr;align-items:center;gap:20px}.collection-copy{padding:70px 0 55px}.collection-copy h1{max-width:580px;margin:0;font-size:clamp(50px,5.4vw,76px);line-height:1.04;letter-spacing:-4px}.collection-copy h1 span{color:var(--blue)}.collection-copy>p{max-width:530px;margin:24px 0 30px;color:var(--muted);font-size:18px}.whatsapp-link:before{content:"◉";margin-right:8px}.subject-tabs{display:flex;gap:0;margin-top:58px;border-top:1px solid var(--line);max-width:520px}.subject-tabs>*{padding:15px 36px 8px 0;margin-right:36px;font-size:12px;font-weight:700;color:var(--muted);border-top:2px solid transparent;margin-top:-2px}.subject-tabs a:first-child{color:var(--blue);border-color:var(--blue)}.subject-tabs a:hover{color:var(--blue)}.collection-visual{align-self:stretch;display:flex;align-items:center;justify-content:flex-end}.collection-visual img{width:112%;max-width:none;margin-right:-7%;mix-blend-mode:multiply}

.promise-bar{background:var(--navy);color:#fff}.promise-grid{display:grid;grid-template-columns:repeat(3,1fr)}.promise-grid>div{min-height:120px;display:grid;grid-template-columns:42px 1fr;grid-template-rows:auto auto;column-gap:15px;align-content:center;padding:20px 34px;border-left:1px solid rgba(255,255,255,.14)}.promise-grid>div:last-child{border-right:1px solid rgba(255,255,255,.14)}.promise-grid span{grid-row:1/3;color:#5da1ff;font-weight:800}.promise-grid strong{font:700 18px Sora}.promise-grid small{color:#9fb0c5}

.products-section{background:#fff}.collection-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.collection-card{position:relative;min-height:485px;padding:32px;border:1px solid var(--line);border-top:5px solid var(--blue);background:#fff;display:flex;flex-direction:column;transition:.2s transform,.2s box-shadow}.collection-card:hover{transform:translateY(-5px);box-shadow:var(--shadow)}.collection-card.coral-card{border-top-color:var(--coral)}.collection-card.teal-card{border-top-color:var(--teal)}.card-number{position:absolute;right:25px;top:20px;color:#dbe5f1;font:800 38px Sora}.card-subject{font-size:11px;color:var(--blue);font-weight:800;text-transform:uppercase;letter-spacing:1.5px}.coral-card .card-subject{color:var(--coral)}.teal-card .card-subject{color:var(--teal)}.collection-card h3{margin:42px 0 14px;font-size:27px;line-height:1.12}.collection-card h3 span{font-size:17px;color:var(--muted)}.collection-card p{color:var(--muted);font-size:14px}.collection-card ul{padding-left:18px;margin:18px 0;color:var(--muted);font-size:13px}.collection-card li{margin:8px 0}.collection-card>a{margin-top:auto;font-weight:800;color:var(--blue)}.coral-card>a{color:var(--coral)}.teal-card>a{color:var(--teal)}

.answer-section{background:var(--ice)}.answer-grid{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:90px}.answer-copy p{color:var(--muted);font-size:17px;margin:22px 0}.answer-sheet{position:relative;background:#fff;border:1px solid #cfd9e6;box-shadow:var(--shadow);padding:24px 26px;transform:rotate(-1deg);background-image:linear-gradient(#e8eff7 1px,transparent 1px);background-size:100% 31px}.paper-top{display:flex;justify-content:space-between;padding-bottom:16px;border-bottom:2px solid var(--navy);font-size:11px;font-weight:800}.answer-row{position:relative;margin-top:25px;padding:8px 58px 10px 0}.answer-row b{font-size:11px;text-transform:uppercase;letter-spacing:1px}.answer-row p{margin:5px 0;font-family:"Comic Sans MS",cursive;font-size:18px}.answer-row>span{position:absolute;right:5px;top:11px;font-size:33px;font-weight:900}.wrong-row b,.wrong-row>span{color:var(--red)}.wrong-row p{text-decoration:underline wavy var(--red);text-underline-offset:5px}.correct-row b,.correct-row>span{color:var(--green)}.correct-row p{text-decoration:underline var(--green) 2px;text-underline-offset:5px}.teacher-section{background:#fff}.teacher-panel{display:grid;grid-template-columns:150px 1fr auto;align-items:center;gap:45px;padding:42px;border:1px solid var(--line)}.teacher-stamp{width:125px;height:125px;clip-path:polygon(50% 0,94% 22%,94% 75%,50% 100%,6% 75%,6% 22%);background:var(--navy);color:#fff;display:flex;flex-direction:column;align-items:center;justify-content:center}.teacher-stamp span{font:800 31px Sora}.teacher-stamp small{letter-spacing:3px}.teacher-panel p{max-width:700px;color:var(--muted);margin-bottom:0}.cta-section{padding:0 0 80px}.cta-card{background:var(--navy);color:#fff;padding:52px 58px;display:flex;align-items:center;justify-content:space-between;gap:35px}.cta-card h2{margin:0;font-size:clamp(32px,4vw,50px);letter-spacing:-2px}.cta-card p{color:#aebed2;margin:12px 0 0}.bio-cta{background:#087a75}

/* Product pages */
.product-hero{position:relative;overflow:hidden;background:#fff}.product-hero:after{content:"";position:absolute;right:0;top:0;width:48%;height:100%;z-index:0;background-image:linear-gradient(#e4efff 1px,transparent 1px),linear-gradient(90deg,#e4efff 1px,transparent 1px);background-size:44px 44px;mask-image:linear-gradient(90deg,transparent,#000)}.product-hero-grid{position:relative;z-index:1;min-height:690px;display:grid;grid-template-columns:.46fr .54fr;align-items:center;gap:30px}.product-hero-copy h1{margin:0;font-size:clamp(47px,5vw,69px);line-height:1.02;letter-spacing:-3.5px}.product-hero-copy h1 span{color:var(--blue)}.bio-hero .product-hero-copy h1 span{color:var(--teal)}.product-hero-copy>p{max-width:590px;color:var(--muted);font-size:18px;margin:25px 0 28px}.product-asset{align-self:stretch;display:flex;align-items:center;justify-content:center}.product-asset img{max-height:650px;width:auto;mix-blend-mode:multiply}.price-line{display:flex;align-items:end;gap:15px;margin:0 0 25px}.price-line strong{font:800 36px Sora}.price-line span{color:var(--muted);font-size:12px;margin-bottom:7px}.creator-badge{display:flex;align-items:center;gap:12px;margin-top:34px;padding:13px 17px;border:1px solid var(--line);width:max-content;background:#fff}.mini-mark{width:42px;height:47px;display:grid;place-items:center;background:var(--navy);color:#fff;clip-path:polygon(50% 0,94% 22%,94% 75%,50% 100%,6% 75%,6% 22%);font-weight:900}.teal-mark{background:var(--teal)}.creator-badge strong,.creator-badge small{display:block}.creator-badge strong{font-size:13px}.creator-badge small{font-size:11px;color:var(--muted)}
.exam-problem,.memory-problem{background:var(--ice)}.trap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.trap-grid article{padding:30px;border:1px solid var(--line);background:#fff}.trap-grid article>span{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;background:#fff0f0;color:var(--red);font-size:22px;font-weight:900}.benefit-grid article>span{background:#e7f6f4;color:var(--teal);font-size:14px}.trap-grid h3{margin:25px 0 9px;font-size:19px}.trap-grid p{color:var(--muted);font-size:14px;margin:0}.inside-section{background:var(--navy);color:#fff}.inside-section .section-heading>p{color:#b6c4d6}.inside-section .eyebrow{color:#75a9ff}.bio-hero+.memory-problem+.inside-section .eyebrow{color:#68d1c8}.method-cards{display:grid;grid-template-columns:repeat(4,1fr);gap:15px}.three-methods{grid-template-columns:repeat(3,1fr)}.method-cards article{min-height:255px;padding:27px;border:1px solid rgba(255,255,255,.2)}.method-cards b{width:38px;height:38px;display:grid;place-items:center;background:var(--blue)}.three-methods b{background:var(--teal)}.method-cards h3{font-size:18px;margin:32px 0 9px}.method-cards p{color:#adbbce;font-size:13px;margin:0}.answer-comparison,.bio-sample{background:#fff}.comparison-grid,.sample-grid{display:grid;grid-template-columns:1fr 1fr;gap:85px;align-items:center}.large-sheet{min-height:390px;padding:35px}.large-sheet .answer-row{margin-top:35px}.copy-section{background:var(--ice)}.copy-grid{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:80px}.copy-grid>div:first-child>p,.memory-banner p,.sample-grid>div:last-child>p{color:var(--muted);font-size:17px}.copy-stack{position:relative;min-height:390px}.copy-card{position:absolute;width:280px;height:350px;padding:28px;color:#fff;box-shadow:var(--shadow);display:flex;flex-direction:column}.copy-card span{font-size:11px;letter-spacing:1px;font-weight:800}.copy-card strong{font:700 24px Sora;margin-top:auto}.teacher-copy{right:30px;background:linear-gradient(150deg,#1769ff,#0d48b6);transform:rotate(6deg)}.student-copy{left:25px;top:28px;background:linear-gradient(150deg,#153354,#0b1f3a);transform:rotate(-5deg)}.memory-edition{background:#fff}.memory-banner{display:flex;align-items:center;justify-content:space-between;gap:50px;padding:45px;border:1px solid var(--line);border-left:5px solid var(--coral)}
.memory-card{background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);padding:45px;text-align:center}.memory-label{color:var(--teal);font-size:11px;font-weight:800;letter-spacing:2px}.memory-flow{display:flex;align-items:center;justify-content:center;gap:18px;margin:40px 0}.memory-flow b{width:105px;height:105px;border-radius:50%;display:grid;place-items:center;color:#fff;background:var(--teal);font-family:Sora}.memory-flow b:nth-of-type(2){background:var(--navy)}.memory-flow b:nth-of-type(3){background:var(--blue)}.memory-flow i{font-style:normal;color:var(--muted);font-size:24px}.memory-card p{color:var(--muted)}.bio-users{background:var(--ice)}.audience-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.audience-grid article{padding:30px;border-top:4px solid var(--teal);background:#fff}.audience-grid h3{margin:0 0 12px}.audience-grid p{color:var(--muted);margin:0}

/* About and FAQ */
.page-hero{padding:95px 0;background:linear-gradient(90deg,#fff,var(--ice))}.page-hero-grid{display:grid;grid-template-columns:1.25fr .75fr;align-items:center;gap:70px}.page-hero h1{margin:0;font-size:clamp(45px,5vw,67px);line-height:1.04;letter-spacing:-3px}.page-hero h1 span{color:var(--blue)}.page-hero p{color:var(--muted);font-size:18px;max-width:720px}.about-badge{text-align:center}.teacher-avatar{width:190px;height:220px;margin:auto;background:linear-gradient(150deg,#dbeaff,#c5e8e4);display:grid;place-items:center;position:relative;overflow:hidden}.teacher-avatar:before{content:"";position:absolute;width:105px;height:105px;border-radius:50%;top:30px;background:var(--navy)}.teacher-avatar span{z-index:2;color:#fff;font:800 28px Sora}.teacher-avatar:after{content:"";position:absolute;width:155px;height:90px;border-radius:80px 80px 0 0;bottom:-5px;background:var(--blue)}.about-badge strong,.about-badge small{display:block}.about-badge strong{margin-top:15px;font:800 22px Sora}.about-badge small{color:var(--muted)}.story-grid{display:grid;grid-template-columns:1fr 1fr;gap:85px}.story-grid h2,.next-copy h2{margin:0;font-size:clamp(32px,4vw,48px);line-height:1.1;letter-spacing:-2px}.story-grid p,.next-copy p{color:var(--muted);font-size:16px;margin-top:0}.value-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}.value-grid article{padding:30px;border:1px solid var(--line);border-top:4px solid var(--blue);background:#fff}.value-grid article>span{color:var(--blue);font-weight:800}.value-grid h3{margin:30px 0 10px}.value-grid p{color:var(--muted);font-size:14px}.next-grid{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:70px}.subject-pills{display:flex;flex-wrap:wrap;gap:10px}.subject-pills span{padding:12px 18px;border:1px solid #abd9d5;color:var(--teal);font-weight:700}.subject-pills .future{border-color:var(--line);color:var(--muted)}.faq-hero{text-align:center}.faq-hero p{margin-inline:auto}.faq-section{padding-top:70px}.faq-layout{display:grid;grid-template-columns:260px 1fr;gap:80px}.faq-layout aside{position:sticky;top:115px;align-self:start}.faq-layout aside h2{font-size:26px;margin:0}.faq-layout aside p{color:var(--muted)}.accordion details{border-bottom:1px solid var(--line)}.accordion summary{cursor:pointer;display:flex;justify-content:space-between;gap:20px;list-style:none;padding:23px 0;font:700 17px Sora}.accordion summary::-webkit-details-marker{display:none}.accordion summary span{font-size:25px;color:var(--blue)}.accordion details[open] summary span{transform:rotate(45deg)}.accordion details p{color:var(--muted);padding:0 45px 24px 0;margin:0}

/* Footer */
.site-footer{padding:62px 0 25px;background:#08172b;color:#d6e0ed}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.3fr;gap:45px}.brand-footer{color:#fff}.brand-footer .brand-mark{background:#fff;color:var(--navy)}.brand-footer .brand-mark:after{border-color:var(--navy)}.footer-grid p{color:#8497b1;font-size:12px}.footer-grid h3{color:#fff;font-size:12px;text-transform:uppercase;letter-spacing:1px;margin:0 0 14px}.footer-grid>div>a:not(.brand){display:block;color:#a7b7ca;font-size:13px;margin:8px 0}.footer-grid>div>a:hover{color:#fff}.footer-bottom{border-top:1px solid #20334c;margin-top:40px;padding-top:20px;display:flex;justify-content:space-between;color:#7388a3;font-size:11px}.whatsapp-float{position:fixed;right:22px;bottom:22px;z-index:90;display:flex;align-items:center;gap:9px;background:#1fab68;color:#fff;padding:9px 15px 9px 9px;border-radius:999px;box-shadow:0 12px 30px rgba(0,0,0,.2);font-size:12px}.whatsapp-float span{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:#fff;color:#169057;font-weight:800}

@media(max-width:1020px){.main-nav{position:absolute;top:86px;left:0;right:0;display:none;flex-direction:column;align-items:stretch;gap:0;background:#fff;padding:15px 24px 25px;border-bottom:1px solid var(--line);box-shadow:0 18px 30px rgba(0,0,0,.08)}.main-nav.open{display:flex}.main-nav>a:not(.nav-whatsapp){padding:12px 0;border:0}.nav-whatsapp{text-align:center;margin-top:10px}.menu-button{display:block}.collection-grid,.product-hero-grid{grid-template-columns:1fr;min-height:auto}.collection-copy,.product-hero-copy{text-align:center;padding:70px 0 20px}.collection-copy h1,.collection-copy>p,.product-hero-copy>p{margin-left:auto;margin-right:auto}.hero-actions,.price-line{justify-content:center}.subject-tabs{margin-left:auto;margin-right:auto;justify-content:center}.collection-visual{justify-content:center}.collection-visual img{width:min(850px,100%);margin:0}.product-asset img{max-height:570px}.promise-grid{grid-template-columns:1fr}.promise-grid>div{border-bottom:1px solid rgba(255,255,255,.14)}.collection-cards{grid-template-columns:1fr}.collection-card{min-height:390px}.answer-grid,.comparison-grid,.sample-grid,.copy-grid,.story-grid,.next-grid{grid-template-columns:1fr;gap:50px}.teacher-panel{grid-template-columns:130px 1fr}.teacher-panel>.button{grid-column:1/-1}.method-cards{grid-template-columns:1fr 1fr}.page-hero-grid{grid-template-columns:1fr;text-align:center}.faq-layout{grid-template-columns:1fr;gap:30px}.faq-layout aside{position:static;text-align:center}.footer-grid{grid-template-columns:1.5fr 1fr 1fr}.footer-grid>div:last-child{grid-column:1/-1}}

@media(max-width:680px){.container,.narrow{width:min(100% - 28px,1240px)}.nav-wrap{height:72px}.brand-mark{width:42px;height:48px;font-size:13px}.brand-name strong{font-size:16px}.brand-name small{font-size:9px}.main-nav{top:72px}.collection-grid{display:flex;flex-direction:column}.collection-copy{padding:52px 0 0}.collection-copy h1,.product-hero-copy h1,.page-hero h1{font-size:42px;letter-spacing:-2px}.collection-copy>p,.product-hero-copy>p{font-size:16px}.hero-actions{flex-direction:column;gap:15px}.hero-actions .button{width:100%}.subject-tabs{margin-top:36px}.subject-tabs>*{padding-right:16px;margin-right:16px;font-size:10px}.collection-visual img{width:110%;max-width:none}.section{padding:70px 0}.section-heading{display:block;margin-bottom:32px}.section-heading>p{margin-top:14px}.promise-grid>div{min-height:100px}.answer-grid{gap:45px}.answer-sheet{padding:20px}.answer-row p{font-size:15px}.teacher-panel{grid-template-columns:1fr;text-align:center;padding:30px 22px}.teacher-stamp{margin:auto}.teacher-panel>.button{grid-column:auto;width:100%}.cta-card{display:block;text-align:center;padding:38px 25px}.cta-card .button{margin-top:22px}.product-hero-grid{display:flex;flex-direction:column}.product-hero-copy{padding:52px 0 0}.product-asset img{max-height:480px}.price-line{flex-direction:column;align-items:center;gap:0}.creator-badge{margin-left:auto;margin-right:auto}.trap-grid,.method-cards,.three-methods,.audience-grid,.value-grid{grid-template-columns:1fr}.copy-stack{min-height:320px}.copy-card{width:210px;height:285px;padding:20px}.teacher-copy{right:2%}.student-copy{left:2%}.memory-banner{display:block;padding:30px}.memory-banner .button{margin-top:20px}.memory-flow{gap:7px}.memory-flow b{width:75px;height:75px;font-size:11px}.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:first-child,.footer-grid>div:last-child{grid-column:1/-1}.footer-bottom{display:block}.footer-bottom span{display:block;margin:5px 0}.whatsapp-float b{display:none}.whatsapp-float{padding-right:9px}.page-hero{padding:65px 0}.story-grid{gap:20px}}

@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}

/* Proportional book covers: clean A4 shapes replace the distorted generated mock-up. */
.collection-visual{min-width:0;overflow:visible}.cover-collection{position:relative;width:min(760px,100%);height:560px;margin-left:auto;perspective:1400px}.study-cover{position:absolute;width:270px;aspect-ratio:210/297;padding:31px 25px 25px;overflow:hidden;border:1px solid #d7e0eb;border-radius:5px 14px 14px 5px;background:#fff;box-shadow:-8px 10px 0 #e1e7ee,0 28px 45px rgba(10,31,58,.17);display:flex;flex-direction:column;color:var(--navy);transform-style:preserve-3d}.study-cover:before{content:"";position:absolute;left:-16%;right:-16%;bottom:-17%;height:62%;background:var(--navy);transform:skewY(-15deg);z-index:0}.study-cover:after{content:"";position:absolute;left:14px;top:0;bottom:0;width:2px;background:#e8edf3;box-shadow:4px 0 8px rgba(11,31,58,.08)}.study-cover>*{position:relative;z-index:1}.study-cover small{font:800 10px Sora,sans-serif;letter-spacing:1.6px;text-transform:uppercase;color:var(--cover-accent)}.study-cover strong{font:800 31px Sora,sans-serif;letter-spacing:-1.6px;margin-top:55px}.study-cover strong span{color:var(--cover-accent)}.study-cover b{margin-top:10px;padding-top:10px;border-top:1px solid #cfd8e4;font:700 11px Sora,sans-serif;letter-spacing:1.1px;text-transform:uppercase}.study-cover i{margin-top:auto;color:#fff;font:700 10px Sora,sans-serif;font-style:normal;letter-spacing:1px}.answering-cover{--cover-accent:var(--blue);left:50%;top:30px;z-index:3;transform:translateX(-50%)}.memory-cover{--cover-accent:var(--coral);left:1%;top:100px;z-index:2;transform:rotateY(10deg) rotateZ(-3deg)}.biology-cover{--cover-accent:var(--teal);right:0;top:92px;z-index:1;transform:rotateY(-10deg) rotateZ(3deg)}.biology-cover:before{background:#0a343f}.card-actions{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap}.preview-chip{padding:7px 10px!important;border:1px solid currentColor!important;font-size:11px!important;text-transform:uppercase;letter-spacing:.5px}.memory-actions{display:flex;align-items:center;gap:24px;flex-wrap:wrap;justify-content:flex-end}

/* Accessible five-page book preview with a real 3D page turn. */
.flipbook-section{background:linear-gradient(180deg,#f3f7fb,#fff)}.flipbook{max-width:760px;margin:0 auto;text-align:center}.flipbook-stage{position:relative;width:min(560px,100%);aspect-ratio:869/1228;margin:0 auto;perspective:1800px;touch-action:pan-y;outline:none}.flipbook-stage:focus-visible{outline:3px solid #78a7ff;outline-offset:8px}.page-underlay,.page-turn,.page-face{position:absolute;inset:0}.page-underlay,.page-face{overflow:hidden;background:#fff;border:1px solid #d6dee9;border-radius:3px 10px 10px 3px;box-shadow:0 24px 55px rgba(11,31,58,.17)}.page-underlay{z-index:1;transform:translate(10px,5px)}.page-turn{z-index:2;transform-style:preserve-3d;transform-origin:left center;will-change:transform}.page-face{backface-visibility:hidden}.page-face img,.page-underlay img{display:block;width:100%;height:100%;object-fit:contain;background:#fff;user-select:none;-webkit-user-drag:none}.page-back{transform:rotateY(180deg)}.flipbook-stage[data-direction="prev"] .page-turn{transform-origin:right center}.flipbook-stage[data-direction="prev"] .page-back{transform:rotateY(-180deg)}.flipbook-stage.is-flipping[data-direction="next"] .page-turn{animation:turnPageNext .72s cubic-bezier(.55,.05,.25,1) forwards}.flipbook-stage.is-flipping[data-direction="prev"] .page-turn{animation:turnPagePrev .72s cubic-bezier(.55,.05,.25,1) forwards}@keyframes turnPageNext{to{transform:rotateY(-180deg)}}@keyframes turnPagePrev{to{transform:rotateY(180deg)}}.page-zone{position:absolute;top:0;bottom:0;width:24%;z-index:4;border:0;background:transparent;cursor:pointer}.page-zone-prev{left:0}.page-zone-next{right:0}.page-zone:focus-visible{outline:3px solid var(--blue);outline-offset:-5px}.flip-hint{position:absolute;z-index:5;left:50%;bottom:16px;transform:translateX(-50%);padding:7px 12px;border-radius:999px;background:rgba(11,31,58,.82);color:#fff;font-size:10px;font-weight:700;pointer-events:none;opacity:.88}.flipbook-controls{display:flex;align-items:center;justify-content:center;gap:18px;margin-top:25px}.flip-arrow{width:45px;height:45px;border:1px solid #cbd6e4;background:#fff;color:var(--navy);font-size:20px;cursor:pointer}.flip-arrow:hover:not(:disabled){background:var(--navy);color:#fff}.flip-arrow:disabled{opacity:.35;cursor:not-allowed}.page-dots{display:flex;gap:8px}.page-dots button{width:9px;height:9px;padding:0;border:0;border-radius:50%;background:#b8c5d5;cursor:pointer}.page-dots button.is-active{width:25px;border-radius:999px;background:var(--blue)}.page-status{min-width:82px;color:var(--muted);font-size:12px;font-weight:700}.preview-note{margin:18px 0 0;color:var(--muted);font-size:11px}

@media(max-width:1020px){.cover-collection{width:min(760px,100%);height:520px;margin:0 auto}.study-cover{width:250px}.answering-cover{top:22px}.memory-cover{left:5%;top:85px}.biology-cover{right:5%;top:82px}.memory-actions{justify-content:center}.flipbook-section .section-heading{text-align:center}.flipbook-section .section-heading>p{margin:16px auto 0}}
@media(max-width:680px){.collection-visual{width:100%}.cover-collection{height:335px;width:100%;margin-top:15px}.study-cover{width:42%;max-width:165px;padding:19px 15px 16px;border-radius:4px 9px 9px 4px}.study-cover strong{font-size:18px;letter-spacing:-1px;margin-top:30px}.study-cover b{font-size:7px;letter-spacing:.6px}.study-cover small,.study-cover i{font-size:6px}.answering-cover{top:5px}.memory-cover{left:1%;top:48px}.biology-cover{right:1%;top:45px}.memory-actions{display:block}.memory-actions .button{width:100%;margin:0 0 18px}.flipbook-stage{width:min(90vw,480px)}.flipbook-controls{gap:10px}.page-status{display:none}.flip-hint{bottom:10px}.page-dots{gap:6px}}
@media(prefers-reduced-motion:reduce){.flipbook-stage.is-flipping .page-turn{animation-duration:.01ms!important}}

/* Real book reader powered by the locally hosted StPageFlip engine. */
.real-flipbook-section{background:linear-gradient(180deg,#edf3f9,#f8fbff 65%,#fff)}.book-reader{max-width:1120px;margin:0 auto;padding:22px 22px 18px;border:1px solid #cbd6e3;background:#dfe7f0;box-shadow:0 30px 70px rgba(11,31,58,.15);outline:none}.book-reader:focus-visible{outline:3px solid #76a8ff;outline-offset:5px}.reader-toolbar{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:12px;padding:0 4px;color:var(--navy)}.reader-toolbar div{display:flex;align-items:baseline;gap:12px}.reader-toolbar strong{font:700 16px Sora,sans-serif}.reader-toolbar span,.reader-toolbar p{color:#66768a;font-size:11px}.reader-toolbar p{margin:0}.flipbook-canvas{width:100%;height:720px;margin:0 auto;display:flex;align-items:center;justify-content:center}.flip-page{position:relative;overflow:hidden;background:#fff;border:1px solid #c8d1dc}.flip-page img{display:block;width:100%;height:100%;object-fit:contain;background:#fff;user-select:none;-webkit-user-drag:none}.flip-page:first-child:after{content:"Click or drag the cover to open";position:absolute;left:50%;bottom:18px;transform:translateX(-50%);width:max-content;max-width:85%;padding:8px 12px;border-radius:999px;background:rgba(11,31,58,.86);color:#fff;font-size:10px;font-weight:700;pointer-events:none}.preview-end-page{display:grid!important;place-items:center;padding:38px;color:#fff;background:linear-gradient(145deg,#0b1f3a,#1769ff)}.preview-end-page>div{max-width:340px;text-align:center}.preview-end-page span{display:block;margin-bottom:16px;text-transform:uppercase;letter-spacing:1.7px;font-size:10px;font-weight:800;color:#b9d2ff}.preview-end-page strong{display:block;font:700 clamp(24px,3vw,38px)/1.12 Sora,sans-serif}.preview-end-page a{display:inline-flex;margin-top:28px;padding:13px 18px;background:#fff;color:var(--navy);font-weight:800}.reader-controls{display:flex;align-items:center;justify-content:center;gap:12px;margin-top:14px}.reader-controls>button{height:44px;min-width:44px;border:1px solid #b8c5d5;background:#fff;color:var(--navy);font-weight:800;cursor:pointer}.reader-controls>button:hover:not(:disabled){background:var(--navy);color:#fff}.reader-controls>button:disabled{opacity:.35;cursor:not-allowed}.reader-controls>[data-book-status]{min-width:245px;padding:0 12px;color:#44566d;font-size:12px;font-weight:750;text-align:center}.reader-controls .reader-fullscreen,.reader-controls .reader-read{display:inline-flex;align-items:center;justify-content:center;gap:7px;padding:0 14px;font-size:12px}.reader-controls .reader-read{background:var(--blue);border-color:var(--blue);color:#fff}.reader-thumbnails{display:flex;justify-content:center;gap:10px;overflow-x:auto;margin:17px auto 0;padding:3px 3px 8px}.reader-thumbnails button{flex:0 0 76px;margin:0;padding:5px;border:2px solid transparent;background:#f4f7fa;color:#53647a;cursor:pointer}.reader-thumbnails button.is-active{border-color:var(--blue);background:#fff;color:var(--blue)}.reader-thumbnails img{display:block;width:100%;aspect-ratio:869/1228;object-fit:cover;background:#fff}.reader-thumbnails span{display:block;margin-top:5px;font-size:9px;font-weight:800}.book-reader .preview-note{text-align:center}.book-reader:fullscreen{padding:18px;background:#dfe7f0;overflow:auto}.book-reader:fullscreen .flipbook-canvas{height:calc(100vh - 175px);max-height:none}.book-reader:fullscreen .reader-thumbnails,.book-reader:fullscreen .preview-note{display:none}.reader-fallback .flipbook-canvas{height:auto;display:flex;justify-content:flex-start;gap:14px;overflow-x:auto;padding:12px}.reader-fallback .flip-page{display:block!important;flex:0 0 min(78vw,430px);aspect-ratio:869/1228}.reader-fallback .reader-controls,.reader-fallback .reader-thumbnails{display:none}body.page-reader-open{overflow:hidden}.page-reader-modal[hidden]{display:none!important}.page-reader-modal{position:fixed;inset:0;z-index:1000;display:grid;place-items:center;padding:18px;background:rgba(4,17,34,.82);backdrop-filter:blur(8px)}.page-reader-dialog{display:flex;flex-direction:column;width:min(1120px,96vw);height:min(94vh,1020px);overflow:hidden;border:1px solid #9aaabd;background:#eef3f8;box-shadow:0 35px 100px rgba(0,0,0,.38)}.page-reader-bar,.page-reader-nav{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:11px 14px;background:#fff}.page-reader-bar{border-bottom:1px solid #c5d0dc}.page-reader-bar strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:12px}.page-reader-bar>div{display:flex;align-items:center;gap:6px}.page-reader-bar button,.page-reader-nav button{min-height:38px;padding:8px 12px;border:1px solid #b8c5d5;background:#fff;color:var(--navy);font-weight:800;cursor:pointer}.page-reader-bar button:hover:not(:disabled),.page-reader-nav button:hover:not(:disabled){background:var(--navy);color:#fff}.page-reader-bar button:disabled,.page-reader-nav button:disabled{opacity:.35;cursor:not-allowed}.page-reader-bar [data-read-zoom-label]{min-width:48px;color:#40536b;font-size:11px;font-weight:800;text-align:center}.page-reader-scroll{flex:1;overflow:auto;padding:24px;text-align:center;background:#cdd7e2;overscroll-behavior:contain;scrollbar-gutter:stable}.page-reader-scroll img{display:inline-block;max-width:none;height:auto;background:#fff;box-shadow:0 18px 55px rgba(11,31,58,.24);vertical-align:top;user-select:none}.page-reader-nav{border-top:1px solid #c5d0dc}.page-reader-nav span{color:#607086;font-size:10px;font-weight:700}

@media(max-width:760px){.real-flipbook-section .container{width:100%}.real-flipbook-section .section-heading{padding-inline:18px}.book-reader{padding:14px 8px 12px;border-left:0;border-right:0}.reader-toolbar{display:block;text-align:center}.reader-toolbar div{display:block}.reader-toolbar strong,.reader-toolbar span{display:block}.reader-toolbar span{margin-top:3px}.reader-toolbar p{margin-top:7px}.flipbook-canvas{height:535px}.reader-controls{gap:7px;flex-wrap:wrap}.reader-controls>[data-book-status]{min-width:0;flex:1;max-width:170px;font-size:10px}.reader-controls .reader-fullscreen,.reader-controls .reader-read{padding:0 10px}.reader-fullscreen span,.reader-read span{display:none}.reader-thumbnails{justify-content:flex-start}.book-reader:fullscreen .flipbook-canvas{height:calc(100vh - 120px)}.page-reader-modal{padding:0}.page-reader-dialog{width:100vw;height:100dvh}.page-reader-bar{align-items:flex-start;flex-wrap:wrap}.page-reader-bar strong{width:100%}.page-reader-bar>div{width:100%;justify-content:center}.page-reader-scroll{padding:14px}.page-reader-nav{padding:8px}.page-reader-nav span{display:none}.page-reader-nav button{flex:1}}