@import "https://fonts.googleapis.com/css2?family=DM+Mono&family=DM+Sans:wght@400;500;600;700&family=Fraunces:opsz,wght@9..144,600;9..144,700&display=swap";:root{color:#26323b;background:#fffaf3;font-family:DM Sans,sans-serif;line-height:1.5}*{box-sizing:border-box}body{background:radial-gradient(circle at 96% 5%,#ffe8d2 0,#0000 25rem),#fffaf3;margin:0}button,input,textarea{font:inherit}button{cursor:pointer;color:inherit;background:0 0;border:0}header{-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);z-index:5;background:#fffaf3e0;border-bottom:1px solid #ece3d9;align-items:center;gap:25px;height:74px;padding:0 max(5vw,28px);display:flex;position:sticky;top:0}.brand{white-space:nowrap;align-items:center;gap:9px;font-size:19px;display:flex}.brand span{color:#fff;background:#f57655;border-radius:10px;place-items:center;width:31px;height:31px;font-weight:700;display:grid}.data-pill{color:#68757a;align-items:center;gap:6px;margin-right:auto;font-size:12px;display:flex}.dot{background:#6aba91;border-radius:50%;width:7px;height:7px}nav{gap:5px;display:flex}nav button{color:#657177;border-radius:9px;padding:8px 11px;font-size:14px;font-weight:600}nav .nav-active,nav button:hover{color:#24323a;background:#f2e9dd}main{max-width:1160px;margin:auto;padding:64px 32px 82px}.hero{grid-template-columns:1.4fr .72fr;align-items:center;gap:70px;min-height:360px;padding:22px 5vw 66px;display:grid}.kicker,.eyebrow{letter-spacing:.1em;color:#df6047;margin:0 0 10px;font-family:DM Mono,monospace;font-size:11px;font-weight:700}.kicker{align-items:center;gap:6px;display:flex}.hero h1,.page-heading h1,.formula-hero h1{letter-spacing:-.045em;color:#26343b;margin:0 0 20px;font-family:Fraunces,serif;font-size:clamp(42px,5vw,68px);line-height:1.06}.hero h1 em{color:#e26b50;font-style:normal}.lead{color:#637074;max-width:570px;margin:0 0 27px;font-size:18px}.lead.small{font-size:16px}.primary{color:#fff;background:#e9694e;border-radius:11px;align-items:center;gap:8px;padding:12px 17px;font-weight:700;display:inline-flex;box-shadow:0 5px 14px #e9694e35}.primary:hover{background:#d85e45}.hero-card{color:#fff;background:#263c46;border-radius:19px;flex-direction:column;gap:6px;padding:26px;display:flex;box-shadow:0 20px 38px #263c4626}.hero-icon{color:#24343b;background:#f9bb66;border-radius:14px;place-items:center;width:48px;height:48px;margin-bottom:15px;display:grid}.hero-card p{letter-spacing:.1em;color:#b9cbd0;margin:0;font:11px DM Mono}.hero-card strong{margin-top:3px;font:45px Fraunces}.hero-card span{color:#d1dadd;font-size:13px}.progress{background:#e7ded455;border-radius:100px;height:8px;margin:13px 0;overflow:hidden}.progress i{border-radius:inherit;background:#f9bd67;height:100%;display:block}.hero-card button{color:#f9bd67;text-align:left;font-size:13px;font-weight:700}.section-title{justify-content:space-between;align-items:end;margin:0 0 18px;display:flex}.section-title h2,.topic h2,.detail-card h2,.notes h2,.review-selector h2,.study-guide h2{letter-spacing:-.03em;margin:0;font:700 28px Fraunces}.text-button{color:#d75b43;align-items:center;gap:3px;font-size:14px;font-weight:700;display:flex}.lesson-grid{grid-template-columns:repeat(3,1fr);gap:14px;display:grid}.lesson-card{background:#fff;border:1px solid #ece4da;border-radius:14px;align-items:flex-start;gap:13px;min-height:159px;padding:18px;display:flex;position:relative}.lesson-card.unlocked{background:#fffcf8;border-color:#b3ddc5}.lesson-order{color:#8d7868;background:#f4ece1;border-radius:9px;flex:0 0 29px;place-items:center;height:29px;font:13px DM Mono;display:grid}.unlocked .lesson-order{color:#39875c;background:#dff4e6}.lesson-card h3{margin:0 0 5px;font-size:16px}.lesson-card p:not(.eyebrow){color:#68757a;margin:0 0 5px;font-size:13px;line-height:1.42}.lesson-card small{color:#8f999d;font-size:11px}.lesson-card .text-button,.lesson-card .unlock-button{position:absolute;bottom:16px;right:15px}.unlock-button{color:#fff;background:#263c46;border-radius:8px;align-items:center;gap:5px;padding:7px 9px;font-size:12px;font-weight:700;display:flex}.page-heading{margin-bottom:35px}.page-heading h1{margin-bottom:10px;font-size:50px}.page-heading>p:not(.kicker){color:#647176;margin:0;font-size:17px}.topic-list{gap:40px;display:grid}.topic{border-top:1px solid #eadfd3;grid-template-columns:210px 1fr;gap:23px;padding-top:22px;display:grid}.formula-grid{grid-template-columns:repeat(2,1fr);gap:13px;display:grid}.formula-card{text-align:left;background:#fff;border:1px solid #e8dfd4;border-radius:13px;grid-template-columns:1fr auto 20px;align-items:center;gap:15px;width:100%;padding:18px;transition:all .18s;display:grid}.formula-card:hover:not(:disabled){border-color:#efad91;transform:translateY(-2px)}.formula-card h3{margin:0 0 5px;font-size:17px}.formula-card p:not(.eyebrow){color:#68757a;margin:0;font-size:13px}.formula-card>strong{color:#de634b;white-space:nowrap;font:600 16px DM Mono}.formula-card:disabled{cursor:not-allowed}.formula-card.dim{opacity:.55}.locked-wrap{position:relative}.lock-tag{color:#8a6c52;background:#fff6ec;border:1px solid #eddfce;border-radius:6px;align-items:center;gap:4px;padding:4px 6px;font-size:10px;font-weight:700;display:flex;position:absolute;top:9px;right:9px}.search-box{background:#fff;border:1px solid #e2d8cd;border-radius:13px;align-items:center;gap:11px;max-width:720px;height:58px;padding:0 17px;display:flex}.search-box input{background:0 0;border:0;outline:0;flex:1;font-size:16px}.search-box button{color:#8a969a}.results-count{color:#748085;margin:18px 0;font-size:13px}.empty{text-align:center;color:#788387;background:#fffdf9;border:1px dashed #d8c9b9;border-radius:16px;padding:52px 25px}.empty svg{color:#e87558}.empty h2{color:#293740;margin:10px 0 4px;font:700 25px Fraunces}.empty p{margin:0 0 20px}.progress-panel{color:#fff;background:#263c46;border-radius:18px;max-width:740px;padding:27px}.big-progress{align-items:baseline;gap:9px;display:flex}.big-progress strong{font:45px Fraunces}.big-progress span{color:#c8d5d8;font-size:14px}.progress-panel p{color:#c6d2d5;margin:0;font-size:13px}.path{max-width:740px;margin-top:34px}.path-step{border-bottom:1px solid #e9dfd4;align-items:center;gap:15px;padding:16px 0;display:flex}.path-step>span{color:#8d8175;background:#eee6dc;border-radius:50%;place-items:center;width:36px;height:36px;display:grid}.path-step>span.done{color:#328457;background:#ddf3e5}.path-step h3{margin:0;font-size:16px}.path-step p:not(.eyebrow){color:#6d787c;margin:2px 0;font-size:13px}.path-step .unlock-button{margin-left:auto}.back{color:#c35a43;margin-bottom:26px;font-size:13px;font-weight:700}.formula-hero{border-bottom:1px solid #e9dfd4;justify-content:space-between;align-items:flex-start;gap:35px;padding-bottom:30px;display:flex}.formula-hero h1{margin-bottom:7px;font-size:50px}.notation{color:#df684d;margin:0 0 17px;font:600 27px DM Mono}.formula-actions{align-items:center;gap:10px;padding-top:8px;display:flex}.favorite{color:#d16b58;border:1px solid #e3d7cb;border-radius:11px;width:43px;height:43px}.favorite.active{color:#e3624c;background:#fff0eb;border-color:#f0b3a2}.detail-grid{grid-template-columns:repeat(2,1fr);gap:14px;margin:31px 0;display:grid}.detail-card{background:#fff;border:1px solid #e9dfd4;border-radius:15px;padding:23px}.detail-card h2{margin-bottom:13px;font-size:21px}.detail-card p,.detail-card li{color:#647176;font-size:14px}.detail-card ul{margin:0;padding-left:19px}.detail-card li+li{margin-top:7px}.mistakes li::marker{color:#e0694f}.example{grid-row:span 2}.example ol{color:#647176;padding-left:20px;font-size:14px}.example li+li{margin-top:7px}.answer{color:#3c8057;background:#eff8f1;border-radius:8px;margin-top:17px;padding:10px 12px;font-size:14px;display:block}.diagram{color:#d7634d;background:#fff8ef;border-radius:10px;place-items:center;height:190px;display:grid;position:relative;overflow:hidden}.diagram span{color:#8f7768;font:11px DM Mono;position:absolute;bottom:12px;left:15px}.diagram.triangle i{filter:drop-shadow(0 0 #d7634d);border-bottom:130px solid #f8b29a;border-left:83px solid #0000;border-right:83px solid #0000;width:0;height:0}.diagram.triangle b{color:#9d4738;position:absolute;top:43px;left:50%}.diagram.triangle em{font-style:normal;position:absolute;bottom:31px}.diagram.circle i{background:#f8b29a;border:2px solid #d7634d;border-radius:50%;width:128px;height:128px}.diagram.circle:after{content:"";border-top:2px solid #d7634d;width:64px;position:absolute;transform:rotate(-30deg)}.diagram.circle b{position:absolute;transform:translate(20px,-18px)}.diagram.coordinate:before,.diagram.coordinate:after{content:"";background:#dcceb9;position:absolute}.diagram.coordinate:before{width:180px;height:1px}.diagram.coordinate:after{width:1px;height:150px}.diagram.coordinate i{background:#e16a4e;border-radius:50%;width:10px;height:10px;position:absolute}.diagram.coordinate i:first-child{transform:translate(-45px,38px)}.diagram.coordinate i:nth-child(2){transform:translate(43px,-35px)}.diagram.coordinate b,.diagram.coordinate em{font:11px DM Mono;position:absolute}.diagram.coordinate b{transform:translate(-62px,62px)}.diagram.coordinate em{transform:translate(62px,-57px)}.diagram.rectangle i{background:#f8b29a;border:2px solid #d7634d;width:180px;height:100px}.diagram.rectangle b,.diagram.rectangle em{font-style:normal;position:absolute}.diagram.rectangle b{bottom:31px}.diagram.rectangle em{right:33px}.notes{background:#eaf5ef;border:1px solid #cde6d6;border-radius:16px;grid-template-columns:.55fr 1fr;gap:35px;padding:25px;display:grid}.notes p{color:#63776c;font-size:14px}.notes textarea{resize:vertical;background:#fff;border:1px solid #cadbd0;border-radius:10px;outline-color:#69a784;width:100%;min-height:104px;padding:12px}.image-upload{color:#347852;align-items:center;gap:7px;margin:13px 0 0;font-size:13px;font-weight:700;display:inline-flex}.image-upload input{display:none}.note-image{max-width:290px;margin-top:14px;position:relative}.note-image img{border-radius:8px;max-width:100%;max-height:190px;display:block}.note-image button{color:#bd503d;background:#fff;border-radius:50%;padding:4px;position:absolute;top:6px;right:6px}.note-image span{color:#5c7465;font-size:11px}.page-heading.compact{margin-bottom:23px}.difficulty-tabs{gap:8px;margin-bottom:18px;display:flex}.difficulty-tabs button{color:#6d797d;border:1px solid #dfd5c8;border-radius:20px;padding:7px 13px;font-size:13px;font-weight:700}.difficulty-tabs .selected{color:#d45d45;background:#fff0eb;border-color:#e96d52}.question-card{background:#fff;border:1px solid #e5dbd0;border-radius:17px;max-width:735px;padding:30px}.question-meta{justify-content:space-between;align-items:center;gap:12px;display:flex}.difficulty{border-radius:5px;padding:5px 7px;font:11px DM Mono}.difficulty.easy,.difficulty-dot.easy{color:#348255;background:#dff3e5}.difficulty.medium,.difficulty-dot.medium{color:#a66f14;background:#fff0cf}.difficulty.hard,.difficulty-dot.hard{color:#bb503b;background:#ffe3dc}.question-meta button{color:#c45a43;align-items:center;gap:4px;font-size:12px;font-weight:700;display:flex}.question-card h2{margin:25px 0;font:700 26px/1.25 Fraunces}.question-card label{gap:7px;font-size:13px;font-weight:700;display:grid}.question-card input{border:1px solid #dcd2c7;border-radius:9px;outline-color:#dc6a50;padding:11px}.question-actions{gap:9px;margin-top:18px;display:flex}.secondary{border:1px solid #d8cdc2;border-radius:11px;padding:11px 14px;font-size:14px;font-weight:700}.revealed{color:#3a8058;background:#eff8f2;border-radius:9px;flex-direction:column;gap:3px;margin-top:18px;padding:13px;display:flex}.revealed span{color:#637b6b;font-size:13px}.review-selector{background:#fff;border:1px solid #e8ded3;border-radius:15px;max-width:650px;margin-bottom:25px;padding:22px}.review-selector h2{margin-bottom:13px;font-size:22px}.review-selector label{border-top:1px solid #eee5da;align-items:center;gap:10px;padding:13px 2px;font-size:14px;font-weight:600;display:flex}.review-selector input{accent-color:#e26c51;width:16px;height:16px}.review-selector svg{color:#4e9b6e;margin-left:auto}.study-guide{background:#fff;border:1px solid #dcd2c7;border-radius:17px;padding:27px}.guide-head{justify-content:space-between;align-items:start;margin-bottom:18px;display:flex}.guide-head h2{font-size:25px}.guide-head>span{color:#a56f20;background:#fff1d8;border-radius:8px;align-items:center;gap:5px;padding:7px 9px;font-size:12px;font-weight:700;display:flex}.guide-formulas{grid-template-columns:repeat(2,1fr);gap:12px;display:grid}.guide-formulas article{border:1px solid #eee3d8;border-radius:10px;padding:15px}.guide-formulas h3{margin:0 0 5px;font-size:16px}.guide-formulas strong{color:#d45d46;font:600 14px DM Mono}.guide-formulas p:not(.eyebrow){color:#687479;margin:7px 0 0;font-size:13px}.guide-formulas blockquote{color:#527262;border-left:2px solid #83b99a;margin:10px 0 0;padding-left:8px;font-size:12px}.guide-practice{margin:28px 0 10px!important;font-size:23px!important}.review-questions{gap:8px;display:grid}.review-questions button{text-align:left;border:1px solid #e9e0d5;border-radius:9px;align-items:center;gap:8px;padding:11px;font-size:13px;display:flex}.review-questions button svg{margin-left:auto}.difficulty-dot{border-radius:50%;width:8px;height:8px}footer{color:#7a868a;border-top:1px solid #e7ddd2;justify-content:space-between;padding:24px max(5vw,28px);font-size:12px;display:flex}footer span:first-child{color:#e26b50;font-weight:700}.toast{color:#fff;z-index:10;background:#253d46;border-radius:10px;align-items:center;gap:8px;padding:12px 15px;font-size:13px;display:flex;position:fixed;bottom:24px;left:50%;transform:translate(-50%);box-shadow:0 7px 24px #263c4640}.toast svg{color:#8bd0a7}@media (width<=780px){header{flex-wrap:wrap;gap:10px;height:auto;min-height:64px;padding:0 18px}.data-pill{display:none}nav{width:100%;padding-bottom:9px;overflow-x:auto}nav button{white-space:nowrap}main{padding:40px 18px 58px}.hero{grid-template-columns:1fr;gap:26px;padding:6px 0 45px}.hero h1{font-size:48px}.lesson-grid,.formula-grid,.guide-formulas{grid-template-columns:1fr}.topic{grid-template-columns:1fr;gap:15px}.page-heading h1,.formula-hero h1{font-size:41px}.formula-hero{flex-direction:column}.formula-actions{padding-top:0}.detail-grid{grid-template-columns:1fr}.example{grid-row:auto}.notes{grid-template-columns:1fr;gap:12px}.question-meta{flex-direction:column;align-items:flex-start}.guide-head{flex-direction:column;gap:13px}.path-step{align-items:flex-start}.path-step .unlock-button{margin-top:5px}footer{padding:20px 18px}.data-pill{margin-left:auto}}
