/* Quick Review opening screen: a compact, colorful route into the lessons. */
.cover{max-width:1120px;margin:10px auto 0;border:1px solid #dbe4f3;border-radius:27px;background:#fff;box-shadow:0 25px 65px #1737681c}
.cover-head{position:relative;display:grid;grid-template-columns:minmax(0,1fr) minmax(350px,.88fr);align-items:center;gap:22px;min-height:405px;padding:40px clamp(28px,4vw,54px);overflow:hidden;background:radial-gradient(circle at 89% 12%,#7658e9 0,transparent 31%),radial-gradient(circle at 51% 91%,#136fb5 0,transparent 42%),linear-gradient(117deg,#10254d 1%,#1d3d82 58%,#4b2d9d 100%)}
.cover-head:before,.cover-head:after{content:"";position:absolute;border-radius:50%;pointer-events:none}
.cover-head:before{width:390px;height:390px;right:-133px;top:-235px;border:1px solid #ffffff34;box-shadow:0 0 0 42px #ffffff09,0 0 0 92px #ffffff08}
.cover-head:after{width:260px;height:260px;left:39%;bottom:-208px;background:#1dd3d33b;filter:blur(26px)}
.cover-hero-copy{position:relative;z-index:2;max-width:580px}
.cover-kicker{display:inline-flex;align-items:center;gap:8px;padding:7px 12px;border-radius:99px;background:#ffffff1f;border:1px solid #ffffff50;color:#fff;font-size:.73rem;font-weight:900;letter-spacing:.075em}
.cover-kicker span{color:#ffe07b;font-size:1.05rem;line-height:1}
.cover-head h1{margin:17px 0 13px;color:#fff;font-size:clamp(2.3rem,4.4vw,3.8rem);line-height:1.03;letter-spacing:-.035em;max-width:none}
.cover-head h1 span{color:#a8f7ec}
.cover-head p{max-width:510px;margin:0;color:#eaf3ff;font-size:clamp(.96rem,1.3vw,1.09rem);line-height:1.62}
.cover-head .begin{display:inline-flex;gap:16px;margin:26px 0 9px;padding:13px 20px 13px 23px;border:1px solid #fff4bd;background:#ffe16e;color:#172957;box-shadow:0 13px 29px #0719394d;font-size:1.02rem;transition:transform .2s ease,background .2s ease,box-shadow .2s ease}
.cover-head .begin:hover{transform:translateY(-3px);background:#ffed9c;box-shadow:0 18px 31px #07193960}
.cover-head .begin span{display:grid;place-items:center;width:29px;height:29px;border-radius:50%;background:#172e5d;color:#fff;font-size:1.15rem;line-height:1}
.cover-hero-note{display:block;color:#d9e7ff;font-size:.78rem;font-weight:700}
.cover-art{position:relative;z-index:1;height:326px;min-width:0}
.cover-art-card{position:absolute;border:1px solid #ffffffd9;border-radius:18px;background:#fff;box-shadow:0 18px 35px #081f4966;transition:transform .22s ease,box-shadow .22s ease}
.cover-art-card:hover{transform:translateY(-6px) rotate(0deg);box-shadow:0 23px 43px #081f4978}
.cover-art-label{display:block;font-size:.64rem;font-weight:900;letter-spacing:.09em}
.cover-art-fraction{top:26px;left:3%;width:57%;height:164px;padding:16px 18px;transform:rotate(-5deg);background:#f8f4ff;border-color:#d9c8ff}
.cover-art-fraction .cover-art-label{color:#6443b2}
.cover-art-math{display:flex;align-items:center;gap:10px;margin:8px 0 11px;color:#5135a7;font-size:1.5rem;font-weight:900;line-height:1}
.stacked-fraction{display:inline-flex;flex-direction:column;align-items:center;justify-content:center;line-height:.95;font-size:.95em}
.stacked-fraction span:first-child{display:block;width:100%;padding:0 8px 4px;border-bottom:2.5px solid currentColor;text-align:center}
.stacked-fraction span:last-child{display:block;padding-top:4px}
.math-equals{padding:0 3px}
.cover-art-bar{display:grid;grid-template-columns:repeat(4,1fr);gap:3px;height:23px;border-radius:7px;overflow:hidden;background:#e1d8fa}
.cover-art-bar i{background:#8059e4}
.cover-art-bar i:last-child{background:#e1d8fa}
.cover-art-graph{top:4px;right:2%;width:39%;height:182px;padding:15px 16px;transform:rotate(6deg);background:#f0f7ff;border-color:#c1dcff}
.cover-art-graph .cover-art-label{color:#16559b}
.cover-art-graph svg{display:block;width:100%;height:106px;margin:1px auto 0}
.cover-art-graph strong{display:block;text-align:center;color:#1957a1;font-size:.81rem}
.cover-art-equation{bottom:4px;left:21%;width:60%;padding:15px 20px 14px;transform:rotate(2deg);background:#ecfff5;border-color:#afe9cf}
.cover-art-equation .cover-art-label{color:#087b5a}
.cover-art-equation strong{display:block;margin:4px 0;color:#0d6854;font-size:1.3rem;letter-spacing:.01em}
.cover-art-equation>span:last-child{display:inline-block;padding:3px 10px;border-radius:9px;background:#bff3d5;color:#095b45;font-size:.91rem;font-weight:850}
.cover-art-equation>span:last-child span{color:#087a54}
.cover-art-sun{position:absolute;z-index:3;top:-7px;left:49%;display:grid;place-items:center;width:44px;height:44px;border-radius:50%;background:#ffe278;color:#7b3f9b;font-size:1.65rem;box-shadow:0 8px 20px #0719393b;animation:cover-float 4s ease-in-out infinite}
@keyframes cover-float{50%{transform:translateY(-6px) rotate(8deg)}}
.cover-body{display:block;padding:27px clamp(25px,3.5vw,43px) 30px}
.cover-body-head{text-align:center;margin-bottom:19px}
.cover-body-kicker{color:#7850ba;font-size:.7rem;font-weight:900;letter-spacing:.14em}
.cover-body-head h2{margin:3px 0 4px;color:#142b53;font-size:clamp(1.3rem,2.4vw,1.68rem);line-height:1.2}
.cover-body-head p{margin:0;color:#50647c;font-size:.88rem}
.cover-steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:0}
.cover-step{position:relative;display:flex;flex-direction:column;align-items:flex-start;min-height:155px;padding:15px 17px 16px;border-radius:15px;overflow:hidden;transition:transform .2s ease,box-shadow .2s ease}
.cover-step:hover{transform:translateY(-4px);box-shadow:0 10px 22px #24406d20}
.cover-step:nth-child(1){background:#f0eaff;border:1px solid #d6c7ff}.cover-step:nth-child(2){background:#e7f6ff;border:1px solid #bbdffd}.cover-step:nth-child(3){background:#e6f9ee;border:1px solid #bce9cf}
.step-icon{position:absolute;right:15px;top:14px;display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:#fff;font-size:1.15rem;box-shadow:0 4px 12px #17376813}
.cover-step:nth-child(1) .step-icon,.cover-step:nth-child(1) .step-number{color:#6942bb}.cover-step:nth-child(2) .step-icon,.cover-step:nth-child(2) .step-number{color:#1466ae}.cover-step:nth-child(3) .step-icon,.cover-step:nth-child(3) .step-number{color:#087f5d}
.step-number{display:block;margin:0 0 8px;font-size:.68rem;font-weight:900;letter-spacing:.085em}
.cover-step b{display:block;margin:0 0 5px;color:#1a3257;font-size:1.04rem;line-height:1.2}
.cover-step>span:last-child{color:#334d68;font-size:.82rem;line-height:1.45;max-width:250px}
.cover-promise{display:flex;align-items:center;gap:12px;margin-top:16px;padding:12px 16px;border-radius:13px;background:#fff8e4;border:1px solid #ffe2a0}
.cover-promise-star{display:grid;place-items:center;flex:none;width:30px;height:30px;border-radius:9px;background:#ffdf7a;color:#795013;font-size:1rem}
.cover-promise p{margin:0;color:#514426;font-size:.84rem;line-height:1.45}
.cover-promise strong{color:#483814}
@media(max-width:750px){.cover-head{grid-template-columns:minmax(0,1fr) 290px;gap:10px;padding:31px 27px;min-height:390px}.cover-art{height:280px}.cover-art-fraction{height:150px}.cover-art-graph{height:166px}.cover-art-graph svg{height:93px}.cover-art-equation{bottom:2px}.cover-steps{gap:8px}.cover-step{padding:14px 13px}}
@media(max-width:620px){.cover{margin-top:0;border-radius:17px}.cover-head{display:block;min-height:0;padding:26px 21px 20px}.cover-head h1{margin:12px 0 9px;font-size:clamp(2.25rem,9vw,3.2rem)}.cover-head p{font-size:.96rem;line-height:1.53}.cover-head .begin{width:100%;justify-content:space-between;margin:18px 0 8px;padding:10px 12px 10px 17px;font-size:.98rem}.cover-hero-note{text-align:center}.cover-art{height:195px;max-width:400px;margin:21px auto 0}.cover-art-fraction{top:16px;left:1%;width:54%;height:126px;padding:10px 12px}.cover-art-math{font-size:1.2rem;margin:6px 0 8px}.cover-art-bar{height:15px}.cover-art-graph{top:0;right:0;width:39%;height:128px;padding:8px 10px}.cover-art-graph svg{height:74px}.cover-art-graph strong{font-size:.66rem}.cover-art-equation{left:20%;bottom:0;width:63%;padding:9px 13px}.cover-art-equation strong{font-size:1.07rem;margin:1px 0}.cover-art-equation>span:last-child{font-size:.75rem;padding:2px 7px}.cover-art-label{font-size:.56rem}.cover-art-sun{width:30px;height:30px;font-size:1.1rem}.cover-body{padding:21px 17px 23px}.cover-body-head{margin-bottom:15px}.cover-body-head p{font-size:.83rem}.cover-steps{grid-template-columns:1fr;gap:8px}.cover-step{min-height:0;padding:12px 57px 12px 13px}.step-number{margin-bottom:3px}.cover-step b{margin-bottom:3px;font-size:.94rem}.cover-step>span:last-child{max-width:none;font-size:.8rem}.cover-promise{padding:10px 11px;margin-top:12px}.cover-promise p{font-size:.77rem}}
@media(prefers-reduced-motion:reduce){.cover-art-sun{animation:none}.cover-art-card,.cover-step,.cover-head .begin{transition:none}}
.cover-actions{display:flex;align-items:center;flex-wrap:wrap;gap:11px;margin:25px 0 9px}.cover-head .cover-actions .begin{margin:0}.browse-begin{min-height:50px;padding:10px 15px;border:1px solid #e0eaff;border-radius:10px;background:#ffffff1c;color:#fff;font-weight:800}.browse-begin:hover{background:#ffffff31}
@media(max-width:620px){.cover-actions{margin:18px 0 8px}.cover-head .cover-actions .begin{order:0;margin:0}.browse-begin{order:1;width:100%;min-height:44px}}