/*! tailwindcss v4.3.3 | MIT License | https://tailwindcss.com */
@layer properties{@supports (((-webkit-hyphens:none)) and (not (margin-trim:inline))) or ((-moz-orient:inline) and (not (color:rgb(from red r g b)))){*,:before,:after,::backdrop{--tw-border-style:solid;--tw-font-weight:initial}}}@layer theme{:root,:host{--font-sans:"Avenir Next", "Segoe UI", system-ui, sans-serif;--font-mono:ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;--spacing:.25rem;--font-weight-semibold:600;--default-font-family:var(--font-sans);--default-mono-font-family:var(--font-mono);--color-navy-950:#060c18;--color-navy-900:#0b1425;--color-gold-300:#f5d69c;--color-gold-400:#e7bd77;--color-ink-100:#f4f3ef;--color-ink-300:#b4c0d3;--color-success:#83e3b2;--color-danger:#ff9aab;--font-display:"Iowan Old Style", "Palatino Linotype", Georgia, serif;--text-caption:.75rem;--text-small:.875rem;--radius-card:1.5rem;--radius-control:.8rem;--shadow-card:0 24px 70px #00000030;--animate-enter:enter .3s ease-out both}}@layer base{*,:after,:before,::backdrop{box-sizing:border-box;border:0 solid;margin:0;padding:0}::file-selector-button{box-sizing:border-box;border:0 solid;margin:0;padding:0}html,:host{-webkit-text-size-adjust:100%;tab-size:4;line-height:1.5;font-family:var(--default-font-family,-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji");font-feature-settings:var(--default-font-feature-settings,normal);font-variation-settings:var(--default-font-variation-settings,normal);-webkit-tap-highlight-color:transparent}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;-webkit-text-decoration:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:var(--default-mono-font-family,ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace);font-feature-settings:var(--default-mono-font-feature-settings,normal);font-variation-settings:var(--default-mono-font-variation-settings,normal);font-size:1em}small{font-size:80%}sub,sup{vertical-align:baseline;font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}:-moz-focusring:where(:not(iframe)){outline:auto}progress{vertical-align:baseline}summary{display:list-item}ol,ul,menu{list-style:none}img,svg,video,canvas,audio,iframe,embed,object{vertical-align:middle;display:block}img,video{max-width:100%;height:auto}button,input,select,optgroup,textarea{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}::file-selector-button{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}:where(select:is([multiple],[size])) optgroup{font-weight:bolder}:where(select:is([multiple],[size])) optgroup option{padding-inline-start:20px}::file-selector-button{margin-inline-end:4px}::placeholder{opacity:1}@supports (not ((-webkit-appearance:-apple-pay-button))) or (contain-intrinsic-size:1px){::placeholder{color:currentColor}@supports (color:color-mix(in lab, red, red)){::placeholder{color:color-mix(in oklab, currentcolor 50%, transparent)}}}textarea{resize:vertical}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-date-and-time-value{min-height:1lh;text-align:inherit}::-webkit-datetime-edit{display:inline-flex}::-webkit-datetime-edit-fields-wrapper{padding:0}::-webkit-datetime-edit{padding-block:0}::-webkit-datetime-edit-year-field{padding-block:0}::-webkit-datetime-edit-month-field{padding-block:0}::-webkit-datetime-edit-day-field{padding-block:0}::-webkit-datetime-edit-hour-field{padding-block:0}::-webkit-datetime-edit-minute-field{padding-block:0}::-webkit-datetime-edit-second-field{padding-block:0}::-webkit-datetime-edit-millisecond-field{padding-block:0}::-webkit-datetime-edit-meridiem-field{padding-block:0}::-webkit-calendar-picker-indicator{line-height:1}:-moz-ui-invalid{box-shadow:none}button,input:where([type=button],[type=reset],[type=submit]){appearance:button}::file-selector-button{appearance:button}::-webkit-inner-spin-button{height:auto}::-webkit-outer-spin-button{height:auto}[hidden]:where(:not([hidden=until-found])){display:none!important}}@layer components{.button-gold,.button-quiet,.button-danger{justify-content:center;align-items:center;gap:calc(var(--spacing) * 3);--tw-font-weight:var(--font-weight-semibold);font-weight:var(--font-weight-semibold);display:inline-flex}}@layer utilities{.visible{visibility:visible}.sr-only{clip-path:inset(50%);white-space:nowrap;border-width:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.static{position:static}.block{display:block}.hidden{display:none}.min-w-0{min-width:0}.flex-wrap{flex-wrap:wrap}.border{border-style:var(--tw-border-style);border-width:1px}}:root{--section-space:clamp(4rem, 7vw, 7rem);--line-soft:#d3ddf020;--duration-fast:.18s;--duration-normal:.3s}.premium-site{background:radial-gradient(ellipse at 75% 8%, #18315540, transparent 30%), radial-gradient(ellipse at 4% 44%, #1a2b4930, transparent 25%), var(--color-navy-950);color:var(--color-ink-100);font-family:var(--font-sans);-webkit-font-smoothing:antialiased}.premium-site h1,.premium-site h2,.premium-site h3,.premium-site p{margin-top:0}.premium-site a{text-decoration:none}.premium-site button,.premium-site input,.premium-site select{font:inherit}.premium-site button,.premium-site a,.premium-site summary{-webkit-tap-highlight-color:transparent}.premium-site [hidden]{display:none!important}.premium-site :where(a,button,summary,input,select):focus-visible{outline:2px solid var(--color-gold-300);outline-offset:5px}.premium-site ::selection{color:#fff;background:#e7bd7740}.page-container{width:min(1232px,100% - 64px);margin-inline:auto}.section-space{padding-block:var(--section-space);scroll-margin-top:80px}.section-bottom{padding-bottom:var(--section-space)}.muted{color:var(--color-ink-300)}.premium-site .eyebrow{color:var(--color-gold-400);font-size:var(--text-caption);letter-spacing:.17em;font-weight:700;line-height:1.6;display:block}.premium-site h1,.premium-site h2{font-family:var(--font-display);letter-spacing:-.035em;font-weight:400}.premium-site em{color:var(--color-gold-300);font-weight:400}.button-gold,.button-quiet,.button-danger{border-radius:var(--radius-control);cursor:pointer;min-height:50px;font-size:var(--text-small);transition:background var(--duration-fast), border-color var(--duration-fast), transform var(--duration-fast);text-align:center;border:1px solid #0000;padding:14px 21px;line-height:1.5}.button-gold{color:#151c29;background:linear-gradient(120deg,#f8dfaf,#dfb46c);border-color:#f5d69c;box-shadow:0 8px 26px #e7bd7715}.button-gold:hover:not(:disabled){background:#ffe4b2;transform:translateY(-2px)}.button-quiet{color:#dde4ee;border-color:var(--line-soft);background:#ffffff04}.button-quiet:hover:not(:disabled){background:#e7bd770b;border-color:#e7bd7770}.button-danger{color:var(--color-danger);background:#ff9aab0a;border-color:#ff9aab50}.premium-site button:disabled{opacity:.45;cursor:not-allowed}.text-link{color:var(--color-gold-300);font-size:var(--text-small);align-items:center;gap:12px;min-height:44px;font-weight:600;display:inline-flex}.text-link:hover{color:#ffeac5}.hero-actions{flex-wrap:wrap;align-items:center;gap:12px;display:flex}.icon-button{border:1px solid var(--line-soft);min-width:44px;min-height:44px;color:var(--color-ink-100);cursor:pointer;background:#ffffff03;border-radius:50%;place-items:center;font-size:20px;display:inline-grid}.icon-button:hover{color:var(--color-gold-300);border-color:#e7bd7770}.site-header{z-index:20;border-bottom:1px solid var(--line-soft);background:#060c18d9;position:relative}.header-inner{justify-content:space-between;align-items:center;gap:20px;min-height:94px;display:flex}.site-brand{color:var(--color-ink-100);align-items:center;gap:12px;display:inline-flex}.brand-mark{width:43px;height:46px;font:28px var(--font-display);color:var(--color-gold-300);background:linear-gradient(140deg,#e7bd7712,#0000);border:1px solid #e7bd7755;border-radius:12px;place-items:center;display:grid}.site-brand strong{font-size:var(--text-small);letter-spacing:.14em;display:block}.site-brand strong span{color:var(--color-gold-300)}.site-brand small{font-size:var(--text-caption);letter-spacing:.18em;color:#8d9db4;margin-top:6px;display:block}.desktop-nav{align-items:center;gap:32px;display:flex}.desktop-nav a{font-size:var(--text-small);color:#abb9cd;align-items:center;min-height:44px;display:inline-flex}.desktop-nav a:hover,.desktop-nav a[aria-current]{color:var(--color-gold-300)}.desktop-nav .nav-progress{border:1px solid var(--line-soft);color:var(--color-gold-300);border-radius:9px;gap:17px;padding:0 18px}.mobile-menu{display:none}.home-hero{grid-template-columns:1.06fr 1fr;align-items:center;gap:42px;min-height:680px;padding-block:84px 86px;display:grid}.hero-copy{z-index:2;position:relative}.hero-kicker{color:#b9c9dc;letter-spacing:.15em;font-weight:600;font-size:var(--text-caption);align-items:center;gap:9px;margin-bottom:27px;display:flex}.status-spark{background:var(--color-gold-300);border-radius:50%;width:5px;height:5px;box-shadow:0 0 12px #f5d69c99}.home-hero h1{margin-bottom:25px;font-size:clamp(44px,5.2vw,68px);line-height:1.08}.hero-copy>p{color:var(--color-ink-300);max-width:420px;margin-bottom:30px;font-size:14px;line-height:1.9}.hero-trust{color:#92a3bb;font-size:var(--text-caption);flex-wrap:wrap;gap:22px;margin-top:22px;display:flex}.hero-art{flex-direction:column;align-items:center;gap:16px;min-width:0;display:flex}.hero-image-frame{background:#060f1e;border:1px solid #e7bd7738;border-radius:24px;width:100%;padding:6px;box-shadow:0 18px 48px #00000030}.hero-image-frame img{aspect-ratio:4/3;object-fit:contain;border-radius:18px;width:100%;height:auto;display:block}.orbit{pointer-events:none;border:1px solid #e7bd771f;border-radius:50%;width:calc(100% + 45px);height:calc(100% - 14px);position:absolute;top:-4px;left:-24px;transform:rotate(-17deg)}.orbit-two{border-color:#7a9ac11c;height:calc(100% - 20px);inset:14px -24px auto;transform:rotate(20deg)}.floating-math{z-index:3;color:#e7bd7790;font:italic 31px var(--font-display);position:absolute}.math-one{top:24px;right:4px;transform:rotate(12deg)}.math-two{font-size:48px;bottom:60px;left:-20px}.hero-art-note{max-width:100%;box-shadow:var(--shadow-card);background:#101c30ed;border:1px solid #e7bd7735;border-radius:13px;align-items:center;gap:13px;padding:16px 21px;display:flex}.note-symbol{color:var(--color-gold-300);font:30px var(--font-display)}.hero-art-note strong,.hero-art-note span:not(.note-symbol){font-size:var(--text-caption);display:block}.hero-art-note strong{color:#e9e9e5;margin-bottom:4px;font-weight:600}.hero-art-note div>span{color:#a4b1c6}.art-caption{text-align:center;color:#a4b1c6;width:100%;font-size:var(--text-caption);letter-spacing:.14em}.discovery-strip{border-block:1px solid var(--line-soft);justify-content:space-between;align-items:center;gap:24px;padding-block:21px;display:flex}.discovery-strip p{font:italic 17px var(--font-display);color:#c6cddd;margin:0}.discovery-strip p span{color:var(--color-gold-300);margin-right:9px}.discovery-strip>div{font-size:var(--text-caption);color:#8c9fb8;flex-wrap:wrap;align-items:center;gap:9px;display:flex}.discovery-strip strong{color:var(--color-gold-300);font-size:var(--text-small);font-weight:600}.discovery-strip>div>span{color:#48607f;padding-inline:8px}.section-heading{justify-content:space-between;align-items:end;gap:32px;margin-bottom:34px;display:flex}.section-heading h2{margin-block:12px 0;font-size:clamp(31px,3.2vw,43px);line-height:1.2}.section-heading>p{color:#9dadc3;line-height:1.8;font-size:var(--text-small);max-width:340px;margin:0 0 5px}.category-rail{scroll-snap-type:x mandatory;scrollbar-width:thin;scrollbar-color:#66738b #101b2c;grid-auto-columns:calc(25% - 13.5px);grid-auto-flow:column;gap:18px;margin:0;padding:3px 2px 16px;list-style:none;display:grid;overflow-x:auto}.category-rail>li{scroll-snap-align:start;min-width:0}.category-card{color:inherit;border:1px solid var(--line-soft);border-radius:var(--radius-card);height:100%;min-height:321px;transition:transform var(--duration-normal), border-color var(--duration-fast);background:radial-gradient(circle at 100% 0,#263d5729,#0000 60%),#101b2ad9;flex-direction:column;padding:22px;display:flex;position:relative;overflow:hidden}.category-card:after{content:"";pointer-events:none;border:1px solid #b2c7e21c;border-radius:50%;width:145px;height:145px;position:absolute;top:38px;right:-66px;box-shadow:0 0 0 22px #ffffff02}.category-card:hover{border-color:#e7bd7770;transform:translateY(-3px)}.category-card-top{color:#778eab;font-size:var(--text-caption);letter-spacing:.14em;justify-content:space-between;align-items:center;display:flex}.category-card-top>span:last-child{color:var(--color-gold-300);font-size:18px}.category-symbol{font:39px var(--font-display);color:#d9b980;margin-block:18px 22px;line-height:1.2}.category-algebra .category-symbol{color:#a9bbe3}.category-geometry-data .category-symbol{color:#9bcdbd}.category-advanced .category-symbol{color:#c5b4db}.category-card h3{font:500 20px / 1.3 var(--font-display);letter-spacing:-.02em;min-height:50px;margin-bottom:11px}.category-card p{color:#9eafc5;font-size:var(--text-small);margin-bottom:25px;line-height:1.8}.category-card-bottom{border-top:1px solid var(--line-soft);font-size:var(--text-caption);color:#93a8c1;justify-content:space-between;align-items:center;gap:6px;margin-top:auto;padding-top:18px;display:flex}.available-tag,.soon-badge{font-size:var(--text-caption);border-radius:6px;align-items:center;gap:6px;padding:4px 8px;line-height:1.5;display:inline-flex}.available-tag{color:#d4bc8e;background:#e7bd770a;border:1px solid #e7bd7720}.available-tag:before{content:"";background:var(--color-gold-400);border-radius:50%;flex-shrink:0;width:4px;height:4px}.soon-badge{color:#a7aec7;background:#bdc3e00a;border:1px solid #bdc3e01a}.carousel-controls{color:#788eab;font-size:var(--text-caption);justify-content:space-between;align-items:center;padding-top:12px;display:flex}.carousel-controls>div{gap:8px;display:flex}.featured-section{border-block:1px solid var(--line-soft);background:linear-gradient(120deg,#111e304a,#101a2a19)}.challenge-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px;display:grid}.challenge-card{border:1px solid var(--line-soft);border-radius:var(--radius-card);color:inherit;transition:transform var(--duration-normal), border-color var(--duration-fast);background:#101a2b;flex-direction:column;display:flex;overflow:hidden}.challenge-card:hover{border-color:#e7bd7766;transform:translateY(-4px)}.challenge-art{aspect-ratio:1.7;background:#0a1424;position:relative;overflow:hidden}.challenge-art:after{content:"";pointer-events:none;background:linear-gradient(#0000 45%,#101a2b);position:absolute;inset:0}.challenge-art img{object-fit:cover;opacity:.85;width:100%;height:100%;transition:transform .5s}.challenge-card:hover img{transform:scale(1.035)}.challenge-number{z-index:2;color:#eed8ae;font-size:var(--text-caption);background:#080e1caa;border:1px solid #d5e0f22a;border-radius:7px;padding:5px 8px;position:absolute;top:16px;left:18px}.art-arrow{z-index:2;color:#e4d1ac;position:absolute;top:16px;right:17px}.challenge-copy{flex-direction:column;flex:1;padding:20px 24px 22px;display:flex}.challenge-copy .eyebrow{font-size:var(--text-caption)}.challenge-copy h3{font:27px var(--font-display);margin-block:10px}.challenge-copy p{font-size:var(--text-small);color:#a5b6cd;margin-bottom:18px;line-height:1.8}.challenge-copy .text-link{border-top:1px solid var(--line-soft);min-height:34px;font-size:var(--text-caption);justify-content:space-between;margin-top:auto;padding-top:13px}.explorer-toolbar{border:1px solid var(--line-soft);background:#0f1a2a;border-radius:17px;grid-template-columns:1fr .8fr auto;align-items:end;gap:16px;padding:21px;display:grid}.search-field,.select-field{min-width:0}.search-field>label,.select-field>label{font-size:var(--text-caption);color:#b6c4d7;margin-bottom:8px;display:block}.search-field>div{background:#080f1c;border:1px solid #b9cbe428;border-radius:9px;align-items:center;padding-left:13px;display:flex}.search-field>div>span{color:#d1b582;font-size:26px}.search-field input,.select-field select{color:#d4deed;width:100%;min-width:0;height:47px;font-size:var(--text-small);background:#080f1c;border:1px solid #b9cbe428;border-radius:9px;padding:10px 12px}.search-field input{background:0 0;border:none}.search-field input::placeholder{color:#7c91ae;opacity:1}.availability-filter{color:#a8b8ce;min-height:47px;font-size:var(--text-caption);cursor:pointer;white-space:nowrap;align-items:center;gap:9px;display:flex}.availability-filter input{accent-color:#e7bd77;width:17px;height:17px}.explorer-count{font-size:var(--text-caption);color:#91a4be;margin:19px 2px 15px}.subject-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:14px;margin:0;padding:0;list-style:none;display:grid}.subject-card{height:100%;min-height:173px;color:inherit;border:1px solid var(--line-soft);transition:border-color var(--duration-fast), background var(--duration-fast);background:#101a2999;border-radius:13px;flex-direction:column;padding:20px;display:flex;position:relative}.subject-card:hover{background:#162238;border-color:#e7bd7766}.subject-top{justify-content:space-between;align-items:center;gap:7px;margin-bottom:19px;display:flex}.subject-symbol{color:#d3bd96;font:23px / 1 var(--font-display)}.subject-card h3{font-weight:500;font-size:var(--text-small);max-width:91%;margin-bottom:12px;line-height:1.5}.subject-category{font-size:var(--text-caption);color:#8196b1;max-width:90%;margin-top:auto}.subject-arrow{color:#d1bb94;font-size:var(--text-small);position:absolute;bottom:17px;right:17px}.empty-search{text-align:center;border:1px dashed #d2dcee30;border-radius:18px;padding:42px 24px}.empty-search h3{font:25px var(--font-display)}.empty-search p{color:#a4b6cd;font-size:var(--text-small)}.progress-overview{background:radial-gradient(at 100% 0,#94744522,#0000 60%),linear-gradient(120deg,#142237,#0c1728);border:1px solid #e7bd7738;border-radius:26px;align-items:center;gap:60px;padding:50px 64px;display:flex;position:relative;overflow:hidden}.progress-ornament{color:#e7bd7708;font:300px / 1 var(--font-display);pointer-events:none;position:absolute;bottom:-60px;right:17%}.progress-copy{flex:1;position:relative}.progress-copy h2{margin-block:12px 18px;font-size:41px;line-height:1.1}.progress-copy>p{font-size:var(--text-small);color:#a9b8cb;max-width:420px;margin-bottom:0;line-height:1.9}.progress-actions{flex-direction:column;align-items:center;gap:22px;min-width:200px;display:flex;position:relative}.progress-ring{--progress:0%;background:radial-gradient(closest-side, #111e31 93%, transparent 95%), conic-gradient(#e7bd77 var(--progress), #e7bd7725 0);border-radius:50%;flex-direction:column;justify-content:center;align-items:center;width:115px;height:115px;display:flex}.progress-ring strong{font:35px var(--font-display);color:var(--color-gold-300)}.progress-ring small{color:#7d93af;font-size:17px}.progress-ring>span{font-size:var(--text-caption);color:#a8b9cf}.learning-note{align-items:center;gap:23px;padding-block:15px 90px;display:flex}.learning-note>span{color:#e7bd7766;font:92px / .8 var(--font-display)}.learning-note>div{flex:1}.learning-note h2{margin-bottom:8px;font-size:26px}.learning-note p{color:#8fa4bf;font-size:var(--text-small);margin:0}.site-footer{border-top:1px solid var(--line-soft);background:#050a14a6}.footer-grid{grid-template-columns:1.2fr .9fr 1.2fr;gap:70px;padding-block:55px 45px;display:grid}.footer-brand{color:#e5e9ef;font:22px var(--font-display)}.footer-brand>span{color:var(--color-gold-300);margin-right:8px}.footer-grid p{color:#869ab5;font-size:var(--text-small);margin-block:17px;line-height:1.9}.footer-grid h2{font-family:var(--font-sans);font-size:var(--text-caption);letter-spacing:.07em;color:#c5d0df;margin-bottom:18px;font-weight:600}.footer-grid>nav{flex-direction:column;align-items:flex-start;gap:6px;display:flex}.footer-grid>nav>a{font-size:var(--text-caption);color:#8a9eb8;min-height:32px;padding-block:6px;line-height:1.6;display:block}.footer-grid a:hover{color:var(--color-gold-300)}.footer-note{color:#7388a4;font-size:var(--text-caption)}.author-name{color:var(--color-gold-300);font-size:16px}.footer-socials{flex-wrap:wrap;gap:18px;display:flex}.premium-site .footer-socials .socialLink{font-size:var(--text-caption);color:#9bafc8;background:0 0;border:none;border-radius:0;width:auto;min-width:44px;height:auto;min-height:44px;display:inline-flex}.premium-site .footer-socials .socialLink:after{display:none}.footer-bottom{border-top:1px solid var(--line-soft);color:#6f839f;font-size:var(--text-caption);justify-content:space-between;gap:20px;padding-block:22px;line-height:1.8;display:flex}.site-footer nav a,.site-footer .author-name{align-items:center;min-height:44px;display:inline-flex}.breadcrumbs{color:#8a9eb7;font-size:var(--text-caption);padding-top:30px}.breadcrumbs ol{flex-wrap:wrap;align-items:center;gap:9px;margin:0;padding:0;list-style:none;display:flex}.breadcrumbs li{align-items:center;gap:9px;display:flex}.breadcrumbs a{color:#90a5bf;align-items:center;min-height:32px;display:inline-flex}.breadcrumbs [aria-current]{color:#ddc69b}.breadcrumbs li>span:first-child:not([aria-current]){color:#455e7d}.page-intro{padding-block:65px 48px;position:relative}.page-intro h1{max-width:950px;margin-block:17px 24px;font-size:clamp(36px,5vw,59px);line-height:1.13}.page-intro>p{color:#a7b8cf;max-width:660px;font-size:14px;line-height:1.9}.intro-facts{font-size:var(--text-small);color:#c6b28d;flex-wrap:wrap;align-items:center;gap:20px;margin-top:24px;display:flex}.category-intro{padding-right:210px}.category-large-symbol{font:95px var(--font-display);color:#e7bd7730;position:absolute;top:55px;right:65px}.empty-state{text-align:center;border:1px solid var(--line-soft);background:#101b2a88;border-radius:24px;padding:60px 30px}.empty-symbol{font:58px var(--font-display);color:#e7bd7766;margin-bottom:22px;display:block}.empty-state h1,.empty-state h2{margin-block:15px 22px;font-size:clamp(31px,4vw,46px);line-height:1.15}.empty-state p{color:#9fb1c9;max-width:580px;font-size:var(--text-small);margin-inline:auto;line-height:1.9}.empty-state .hero-actions{justify-content:center;margin-top:28px}.topic-intro{grid-template-columns:1fr 230px;align-items:center;gap:50px;padding-block:50px 42px;display:grid}.topic-intro h1{margin-block:15px 22px;font-size:clamp(35px,5vw,55px);line-height:1.15}.topic-intro p{font-size:var(--text-small);color:#a7b8ce;max-width:640px;margin-bottom:0;line-height:1.9}.topic-intro img{object-fit:cover;border:1px solid #e7bd7738;border-radius:20px;width:100%;height:150px;display:block}.quiz-container{max-width:920px}.quiz-shell{scroll-margin-top:20px}.quiz-welcome{text-align:center;background:radial-gradient(at 50% 0,#c99e4c15,#0000 70%),#101c2c;border:1px solid #e7bd7738;border-radius:25px;padding:50px 42px 35px}.quiz-welcome h2{margin-block:19px;font-size:clamp(35px,4vw,46px);line-height:1.12}.quiz-welcome>p{color:#acbbcf;font-size:var(--text-small);max-width:500px;margin:0 auto 25px;line-height:1.9}.quiz-welcome .saved-progress-note{color:#edcc91}.quiz-chapters{border-top:1px solid var(--line-soft);grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:30px;padding-top:32px;display:grid}.chapter-button{text-align:left;border:1px solid var(--line-soft);color:#d2deed;cursor:pointer;background:#0a142499;border-radius:11px;padding:17px 14px;position:relative}.chapter-button small{font-size:var(--text-caption);letter-spacing:.1em;color:#9d8b6a;margin-bottom:8px;display:block}.chapter-button strong{font-size:var(--text-small);max-width:90%;font-weight:500;display:block}.chapter-button>span{color:var(--color-gold-300);font-size:var(--text-small);position:absolute;bottom:14px;right:12px}.quiz-question{border:1px solid var(--line-soft);background:#101b2cd9;border-radius:25px;overflow:hidden}.quiz-topline{background:#0b1525;justify-content:space-between;align-items:center;gap:20px;padding:12px 29px;display:flex}.quiz-topline>span{color:#b7c6db;font-size:var(--text-caption);letter-spacing:.1em}.quiz-progress-track{background:#263345;height:3px}.quiz-progress-track>span{height:100%;transition:width var(--duration-normal);background:linear-gradient(90deg,#ac8249,#f9ddb0);display:block}.quiz-question-inner{padding:39px}.quiz-question h2{overflow-wrap:anywhere;margin-block:14px 19px;font-size:clamp(28px,4vw,43px);line-height:1.3}.question-subtitle{color:#a7b7cc;font-size:var(--text-small);margin-bottom:28px;line-height:1.8}.premium-site .quiz-shell fieldset{border:0;min-width:0;margin:0;padding:0}.premium-site .quiz-shell .choices{gap:12px}.premium-site .quiz-shell .choice{min-height:73px;box-shadow:none;background:#091422;border:1px solid #c6d6ee24;border-radius:12px;padding:13px 18px}.premium-site .quiz-shell .choice .letter{width:35px;height:35px;font-size:var(--text-small);color:#aebdd2;border-radius:9px}.premium-site .quiz-shell .choice.selected{background:#e7bd770d;border-color:#e7bd77}.premium-site .quiz-shell .choice.selected .letter{color:#122037;background:#e7bd77;border-color:#e7bd77}.premium-site .quiz-shell .choice.correct{color:#aaf2d0;opacity:1;background:#60d9a318;border-color:#83e3b2}.premium-site .quiz-shell .choice.incorrect{color:#ffb6c4;opacity:1;background:#f7819c15;border-color:#ff9aab}.premium-site .quiz-shell .choice:disabled:not(.correct,.incorrect){opacity:.6}.answer-icon{margin-left:auto;font-size:20px}.quiz-confirm{justify-content:space-between;align-items:center;gap:16px;margin-top:25px;display:flex}.quiz-confirm>span{color:#8095b2;font-size:var(--text-caption)}.quiz-feedback{animation:var(--animate-enter);outline:none;margin-top:28px}.answer-banner{background:#6be4aa0d;border:1px solid #83e3b240;border-radius:14px;align-items:flex-start;gap:16px;padding:22px;display:flex}.is-wrong .answer-banner{background:#ff9aab08;border-color:#ff9aab40}.answer-banner>span{color:var(--color-success);font-size:24px}.is-wrong .answer-banner>span{color:var(--color-danger)}.answer-banner h3{color:var(--color-success);margin-bottom:9px;font-size:17px}.is-wrong .answer-banner h3{color:var(--color-danger)}.answer-banner p{color:#bac9dc;font-size:var(--text-small);margin:0;line-height:1.8}.quiz-difficulty{background:linear-gradient(130deg,#e7bd7709,#09132355);border:1px solid #e7bd773d;border-radius:16px;margin-top:23px;padding:25px}.difficulty-heading{justify-content:space-between;align-items:center;gap:20px;display:flex}.difficulty-heading h3{font:24px var(--font-display);margin-block:7px}.difficulty-heading p{font-size:var(--text-caption);color:#a0b2ca;margin:0}.difficulty-score{white-space:nowrap;color:#efd39c}.difficulty-score strong{font:41px var(--font-display)}.difficulty-score>span{font-size:var(--text-small);color:#9c8b71}.difficulty-meter{background:#e7bd7720;border-radius:8px;height:5px;margin-block:23px 20px;overflow:hidden}.difficulty-meter>span{background:linear-gradient(90deg,#b59051,#f5d69c);height:100%;display:block}.difficulty-label{align-items:baseline;gap:20px;display:flex}.difficulty-label strong{color:#e9c790;font-size:var(--text-small)}.difficulty-label p{font-size:var(--text-small);color:#adbed4;margin-bottom:18px;line-height:1.9}.premium-site .difficultyDetails{border-top:1px solid var(--line-soft);margin-top:12px}.difficultyDetails summary{color:#dfc99e;font-size:var(--text-small);min-height:44px;padding-top:17px}.difficulty-parts{grid-template-columns:1fr 1fr;gap:13px 24px;margin-block:18px;display:grid}.difficulty-parts>div{font-size:var(--text-caption);color:#adc0d9;justify-content:space-between;gap:8px;display:flex}.difficulty-parts dd{color:#f0d7a4;margin:0}.difficultyDetails>p{color:#8fa5c0;font-size:var(--text-caption);margin-bottom:0;line-height:1.8}.solution-title{font:27px var(--font-display);margin-block:34px 22px}.premium-site .quiz-steps .step{border:1px solid var(--line-soft);background:0 0;border-radius:13px;margin-bottom:12px;padding:20px}.premium-site .quiz-steps .step h4{color:#e5e9f1;font-size:var(--text-small);font-weight:600}.premium-site .quiz-steps .step p{font-size:var(--text-small);color:#a5b8d0;line-height:1.9}.premium-site .quiz-steps .mathrow{color:#f0d6a5;font-size:23px}.premium-site .quiz-steps .mathrow.small{font-size:21px}.quiz-final-answer{text-align:center;border-block:1px solid #e7bd772c;margin-top:25px;padding-block:25px}.final-formula{font:43px var(--font-display);color:#f5d69c;margin-block:14px;display:block}.quiz-final-answer p{font-size:var(--text-small);color:#b1c0d4;margin:0}.quiz-result-actions{flex-wrap:wrap;gap:10px;margin-top:25px;display:flex}.quiz-result-actions .button-gold{margin-left:auto}.quiz-result-actions button{font-size:var(--text-small)}.series-summary{text-align:center;animation:var(--animate-enter);background:radial-gradient(circle at 50% 0,#bb92421c,#0000 50%),#111d2f;border:1px solid #e7bd7745;border-radius:24px;outline:none;padding:40px}.summary-symbol{color:#f5d69c;margin-bottom:20px;font-size:48px;display:block}.series-summary h2{margin-block:18px;font-size:40px;line-height:1.15}.series-summary>p{color:#a7b8cf;font-size:var(--text-small);max-width:480px;margin:0 auto;line-height:1.9}.summary-stats{border-block:1px solid var(--line-soft);grid-template-columns:repeat(3,1fr);margin-block:32px;padding-block:25px;display:grid}.summary-stats strong{color:#f5d69c;font:30px var(--font-display);display:block}.summary-stats span{color:#9daec6;font-size:var(--text-caption);margin-top:9px;display:block}.summary-list{text-align:left;margin:0 0 30px;padding:0;list-style:none}.summary-list>li{border-bottom:1px solid var(--line-soft);align-items:center;gap:16px;padding-block:16px;display:flex}.summary-list>li>div{flex:1}.summary-list strong{font-size:var(--text-small);font-weight:500;display:block}.summary-list div span{color:#8fa3be;font-size:var(--text-caption);margin-top:6px;display:block}.summary-list small{font-size:var(--text-caption);color:#c5ac7c}.summary-ok{color:var(--color-success)}.summary-review{color:#dbb984}.series-summary .hero-actions{justify-content:center}.topic-outline{padding-top:58px}.topic-outline>h2{margin-bottom:23px;font-size:27px}.topic-outline>ol{grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;margin:0 0 15px;padding:0;list-style:none;display:grid}.topic-outline li{border-top:1px solid var(--line-soft);padding-top:18px}.topic-outline li>span{color:#a48f6b;font-size:var(--text-caption);text-transform:uppercase;letter-spacing:.08em}.topic-outline h3{color:#d0daea;font:19px / 1.5 var(--font-display);margin-block:10px}.topic-outline p{color:#8196b2;font-size:var(--text-small);line-height:1.9}.notice{color:#f0cf95;font-size:var(--text-small);background:#e7bd770a;border:1px solid #e7bd7755;border-radius:10px;padding:14px 17px;line-height:1.8}.dialog-overlay{z-index:80;backdrop-filter:blur(7px);animation:var(--animate-enter);background:#020711b8;position:fixed;inset:0}.dialog-content{z-index:81;width:min(550px,100% - 32px);max-height:calc(100dvh - 40px);color:var(--color-ink-100);background:#101d31;border:1px solid #e7bd7755;border-radius:22px;padding:35px;position:fixed;top:50%;left:50%;overflow-y:auto;transform:translate(-50%,-50%);box-shadow:0 30px 100px #0008}.dialog-close{border:none;position:absolute;top:12px;right:12px}.dialog-content .eyebrow{padding-right:30px}.dialog-title{font:30px / 1.15 var(--font-display);letter-spacing:-.02em;margin-block:16px}.dialog-content>.muted{font-size:var(--text-small);line-height:1.8}.progress-series-list{margin:24px 0;padding:0;list-style:none}.progress-series-list li{border-bottom:1px solid var(--line-soft);justify-content:space-between;align-items:center;gap:15px;padding-block:16px;display:flex}.progress-series-list strong{font-size:var(--text-small);display:block}.progress-series-list div>span{font-size:var(--text-caption);color:#9bb0c9;margin-top:7px;display:block}.progress-series-list .text-link{white-space:nowrap;font-size:var(--text-caption)}.reset-progress{width:100%;margin-bottom:16px}.reset-confirm{border:1px solid #e7bd7730;border-radius:12px;margin-bottom:20px;padding:15px}.reset-confirm p{color:#d8c29a;font-size:var(--text-small)}.dialog-content>.button-gold{width:100%}@keyframes enter{0%{opacity:0;translate:0 6px}to{opacity:1;translate:0}}@media (width<=1080px){.page-container{width:calc(100% - 48px)}.home-hero{gap:30px;min-height:600px;padding-block:65px}.home-hero h1{font-size:52px}.category-rail{grid-auto-columns:calc(33.3333% - 12px)}.subject-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.category-card{min-height:335px}.explorer-toolbar{grid-template-columns:1fr 1fr}.availability-filter{grid-column:1/-1;min-height:32px}.footer-grid{gap:40px}.progress-overview{gap:30px;padding:40px}.hero-actions{gap:9px}.hero-copy .button-gold,.hero-copy .button-quiet{font-size:var(--text-small);padding-inline:15px}}@media (width<=800px){.page-container{width:calc(100% - 36px)}.header-inner{min-height:78px}.desktop-nav{display:none}.mobile-menu{display:block;position:relative}.mobile-menu summary{cursor:pointer;color:#d5c098;min-height:44px;font-size:var(--text-small);align-items:center;gap:8px;padding:8px;list-style:none;display:flex}.mobile-menu summary::-webkit-details-marker{display:none}.mobile-menu nav{width:205px;box-shadow:var(--shadow-card);background:#101b2df5;border:1px solid #e7bd7740;border-radius:13px;padding:10px;position:absolute;top:56px;right:0}.mobile-menu nav a{color:#d4ddeb;min-height:47px;font-size:var(--text-small);align-items:center;padding:8px 12px;display:flex}.home-hero{gap:25px;padding-block:58px 75px}.home-hero h1{font-size:43px}.hero-kicker{font-size:var(--text-caption);letter-spacing:.1em}.hero-copy>p{font-size:var(--text-small)}.hero-copy .hero-actions{flex-direction:column;align-items:flex-start}.hero-art-note{gap:10px;padding:12px}.hero-art-note strong,.hero-art-note span:not(.note-symbol){font-size:var(--text-caption)}.hero-trust{font-size:var(--text-caption);gap:10px}.discovery-strip{flex-direction:column;align-items:flex-start;gap:15px}.section-heading{align-items:flex-start;gap:22px}.section-heading h2{font-size:34px}.section-heading>p{max-width:240px;font-size:var(--text-small)}.category-rail{grid-auto-columns:calc(50% - 9px)}.challenge-grid{gap:15px}.challenge-copy{padding:15px}.challenge-copy h3{font-size:23px}.challenge-copy p{font-size:var(--text-small)}.subject-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.progress-overview{gap:25px;padding:35px}.progress-copy h2{font-size:36px}.progress-actions{min-width:170px}.learning-note{flex-wrap:wrap;gap:15px}.learning-note h2{font-size:24px}.learning-note .button-quiet{margin-left:45px}.footer-grid{grid-template-columns:1fr 1fr;gap:38px}.footer-grid>div:last-child{grid-column:1/-1}.footer-bottom{font-size:var(--text-caption)}.category-intro{padding-right:130px}.category-large-symbol{font-size:70px;right:20px}.topic-intro{grid-template-columns:1fr 150px;gap:25px}.topic-intro img{height:120px}.topic-intro h1{font-size:38px}.quiz-question-inner{padding:28px}.quiz-result-actions .button-gold{width:100%;margin-left:0}.topic-outline>ol{grid-template-columns:1fr}}@media (width<=560px){.page-container{width:calc(100% - 32px)}.site-brand{gap:9px}.brand-mark{width:35px;height:39px;font-size:24px}.site-brand strong{font-size:var(--text-caption);letter-spacing:.11em}.site-brand small{letter-spacing:.1em;display:none}.mobile-menu summary{font-size:var(--text-caption);padding-inline:3px}.home-hero{grid-template-columns:1fr;gap:40px;padding-top:45px}.home-hero h1{margin-bottom:22px;font-size:clamp(41px,10.7vw,58px)}.hero-kicker{font-size:var(--text-caption);letter-spacing:.1em;margin-bottom:23px}.hero-copy>p{font-size:var(--text-small);max-width:370px;line-height:1.85}.hero-copy .hero-actions{flex-direction:row;align-items:center;gap:10px}.hero-copy .button-gold,.hero-copy .button-quiet{font-size:var(--text-caption);min-height:48px;padding-inline:12px}.hero-trust{font-size:var(--text-caption);gap:17px}.hero-art{width:100%}.hero-art-note{padding:14px}.hero-art-note strong,.hero-art-note span:not(.note-symbol){font-size:var(--text-caption)}.orbit{width:calc(100% + 30px);left:-16px}.floating-math{font-size:26px}.math-two{bottom:42px;left:-18px}.art-caption{font-size:var(--text-caption)}.discovery-strip p{font-size:15px}.discovery-strip>div{font-size:var(--text-caption);gap:6px}.discovery-strip>div>span{padding-inline:2px}.discovery-strip strong{font-size:var(--text-small)}.section-heading{flex-direction:column;gap:18px;margin-bottom:27px}.section-heading h2{font-size:33px}.section-heading>p{max-width:none}.category-rail{grid-auto-columns:82%;gap:14px}.category-card{min-height:307px;padding:23px}.category-card h3{min-height:0}.challenge-grid{grid-template-columns:1fr;gap:23px}.challenge-copy{padding:20px 23px}.challenge-copy h3{font-size:28px}.challenge-copy p{font-size:var(--text-small)}.challenge-art{aspect-ratio:1.85}.explorer-toolbar{grid-template-columns:1fr;gap:16px;padding:17px}.search-field input,.select-field select{font-size:var(--text-small)}.availability-filter{font-size:var(--text-small);min-height:38px}.subject-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.subject-card{min-height:186px;padding:14px}.subject-top{flex-direction:column;align-items:flex-start;gap:12px;margin-bottom:15px}.subject-top .available-tag,.subject-top .soon-badge{font-size:var(--text-caption);padding:3px 5px}.subject-card h3{font-size:var(--text-small)}.subject-category{font-size:var(--text-caption)}.subject-arrow{bottom:13px;right:11px}.progress-overview{border-radius:20px;flex-direction:column;align-items:flex-start;gap:30px;padding:30px 25px}.progress-copy h2{font-size:37px}.progress-actions{flex-direction:row;justify-content:space-between;gap:20px;width:100%;min-width:0}.progress-ring{flex-shrink:0;width:83px;height:83px}.progress-ring strong{font-size:27px}.progress-actions .button-gold{font-size:var(--text-small);padding-inline:14px}.learning-note{align-items:flex-start;padding-bottom:60px}.learning-note h2{font-size:25px}.learning-note p{font-size:var(--text-small)}.footer-grid{grid-template-columns:1fr;gap:32px;padding-block:40px}.footer-grid>div:last-child{grid-column:auto}.footer-grid>nav>a{min-height:44px;font-size:var(--text-small)}.footer-grid p{font-size:var(--text-small)}.footer-bottom{font-size:var(--text-caption);flex-direction:column;gap:9px}.breadcrumbs{font-size:var(--text-caption);padding-top:19px}.page-intro{padding-block:40px 32px}.page-intro h1{font-size:37px}.page-intro>p{font-size:var(--text-small)}.category-intro{padding-right:0}.category-large-symbol{display:none}.empty-state{padding:40px 20px}.empty-state .button-gold{font-size:var(--text-small);padding-inline:13px}.topic-intro{grid-template-columns:1fr;gap:20px;padding-block:35px}.topic-intro img{object-position:center;width:100%;height:175px}.topic-intro h1{font-size:39px}.topic-intro p{font-size:var(--text-small)}.quiz-welcome{padding:32px 20px 24px}.quiz-welcome h2{font-size:35px}.quiz-welcome>p{font-size:var(--text-small)}.quiz-chapters{grid-template-columns:1fr;margin-top:25px;padding-top:23px}.chapter-button{min-height:65px;padding:13px}.quiz-topline{padding-inline:18px}.quiz-question-inner{padding:25px 18px}.premium-site .quiz-shell .choice{gap:13px;min-height:69px;padding:11px}.premium-site .quiz-shell .choice .formula{font-size:26px}.quiz-confirm{flex-direction:column;align-items:stretch;gap:17px}.quiz-difficulty{padding:20px 16px}.difficulty-heading{gap:12px}.difficulty-heading h3{font-size:21px}.difficulty-heading p{font-size:var(--text-caption);line-height:1.7}.difficulty-score strong{font-size:36px}.difficulty-label{flex-direction:column;gap:10px}.difficulty-parts{grid-template-columns:1fr}.answer-banner{gap:12px;padding:17px 14px}.answer-banner h3{font-size:15px}.premium-site .quiz-steps .step{gap:12px;padding:15px 12px}.premium-site .quiz-steps .stepNumber{min-width:27px;height:27px;font-size:var(--text-caption)}.premium-site .quiz-steps .mathrow,.premium-site .quiz-steps .mathrow.small{overflow-wrap:anywhere;font-size:18px}.quiz-result-actions{grid-template-columns:1fr;display:grid}.series-summary{padding:30px 18px}.series-summary h2{font-size:32px}.summary-stats strong{font-size:25px}.summary-stats span{font-size:var(--text-caption)}.summary-list{margin-bottom:25px}.summary-list>li{flex-wrap:wrap;gap:10px}.summary-list strong{font-size:var(--text-small)}.summary-list small{width:100%;margin-left:26px}.dialog-content{border-radius:17px;padding:30px 22px}.dialog-title{font-size:27px}.dialog-content .eyebrow{font-size:var(--text-caption)}}@media (prefers-reduced-motion:reduce){.premium-site *,.premium-site :before,.premium-site :after,.dialog-overlay,.dialog-content{scroll-behavior:auto!important;transition:none!important;animation:none!important}}@property --tw-border-style{syntax:"*";inherits:false;initial-value:solid}@property --tw-font-weight{syntax:"*";inherits:false}
