:root{--g-color-black: #000;--g-color-white: #fff;--g-color-grey-50: #f6f6f6;--g-color-grey-600: #636363;--g-color-grey-700: #4d4d4d;--g-color-grey-900: #0f0f0f;--g-box-shadow: 0px 6px 12px rgba(18, 20, 23, .06), 0px 15px 24px rgba(18, 20, 23, .07), 0px -4px 12px rgba(18, 20, 23, .05);--g-font-family: Helvetica, sans-serif;--g-font-size-x-small: .75rem;--g-font-size-small: .875rem;--g-font-size-base: 1rem;--g-font-size-large: 1.25rem;--g-font-size-x-large: 1.5rem;--g-font-size-2x-large: 2rem;--g-font-size-3x-large: 2.5rem;--g-font-size-4x-large: 4rem;--g-font-weight-base: 400;--g-font-weight-semi-bold: 500;--g-font-weight-bold: 600;--g-font-weight-black: 700;--g-border-radius-small: .5rem;--g-border-radius-base: 1rem;--g-border-radius-large: 1.5rem;--g-spacing-small: .5rem;--g-spacing-base: 1rem;--g-spacing-large: 1.5rem;--g-spacing-x-large: 2rem;--g-spacing-2x-large: 2.5rem;--g-spacing-3x-large: 3rem;--g-spacing-6x-large: 6rem}*{padding:0;margin:0;box-sizing:border-box}html,body{font-family:var(--g-font-family);background-color:var(--g-color-grey-50);min-height:100vh}button{-webkit-appearance:none;-moz-appearance:none;appearance:none;background-color:transparent;border:none;cursor:pointer}a{color:inherit;text-decoration:none}.text-subtle{color:var(--g-color-grey-600);font-size:var(--g-font-size-x-small);font-weight:var(--g-font-weight-base)}.text-body-1{font-size:var(--g-font-size-2x-large);font-weight:var(--g-font-weight-base)}.text-body-2{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-base)}.text-body-3{color:var(--g-color-grey-900);font-size:var(--g-font-size-small);font-weight:var(--g-font-weight-base)}.text-display-1{font-size:var(--g-font-size-4x-large);font-weight:var(--g-font-weight-black);line-height:1.2}.text-display-2{font-size:var(--g-font-size-3x-large);font-weight:var(--g-font-weight-black);line-height:1.4}.text-display-3{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-black)}.text-heading-1{font-size:var(--g-font-size-large);font-weight:var(--g-font-weight-semi-bold)}.text-heading-2{font-size:var(--g-font-size-base);font-weight:var(--g-font-weight-semi-bold)}.container{padding:0 var(--g-spacing-6x-large);margin:auto}@media (max-width: 700px){.container{padding:0 var(--g-spacing-base)}}.nav{align-items:center;display:flex;justify-content:space-between;padding-bottom:var(--g-spacing-x-large);padding-top:var(--g-spacing-x-large);width:100%}.btn{border-radius:var(--g-border-radius-small);display:inline-block;font-weight:var(--g-font-weight-bold);padding:var(--g-spacing-base)}.btn-ghost{color:var(--g-color-grey-700)}.btn-dark{background-color:var(--g-color-black);color:var(--g-color-white)}.btn-light{background:var(--g-color-white);color:var(--g-color-black);font-weight:600}.btn-big{font-size:var(--g-font-size-large);padding:var(--g-font-size-large) var(--g-font-size-x-large)}.btn-accent{background-color:#22c55e;color:var(--g-color-white)}.btn-accent:hover{background-color:#16a34a}.btn-accent:active{background-color:#15803d}.landing-header{background-color:var(--g-color-white);position:sticky;top:0;z-index:100;border-bottom:1px solid #e2e8f0;box-shadow:0 1px 3px #0000000f;transition:transform .3s ease}.landing-header--hidden{transform:translateY(-100%)}.landing-header .nav{padding-top:var(--g-spacing-base);padding-bottom:var(--g-spacing-base)}.landing-header__actions{display:flex;align-items:center;gap:var(--g-spacing-small);flex-shrink:0}.landing-hero-bg{background:url(/hero-chess.jpg) center / cover no-repeat var(--g-color-black)}.landing-hero{color:var(--g-color-white);padding:var(--g-spacing-6x-large) 0;position:relative}.landing-hero:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background:linear-gradient(to bottom,#0000008c,#0000008c 60%,#000000b3);z-index:0}.landing-hero__inner{max-width:640px;text-align:center;display:flex;flex-direction:column;align-items:center;position:relative;z-index:1}.landing-hero__title{font-size:var(--g-font-size-4x-large);font-weight:var(--g-font-weight-black);line-height:1.1;letter-spacing:-.03em;margin-bottom:var(--g-spacing-large)}.landing-hero__subtitle{font-size:var(--g-font-size-large);color:#a1a1aa;line-height:1.6;margin-bottom:var(--g-spacing-3x-large);max-width:520px}.landing-how{padding:var(--g-spacing-6x-large) var(--g-spacing-6x-large);position:relative;overflow:hidden;color:var(--g-color-white);max-width:none}.landing-how:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;background:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 800 400' preserveAspectRatio='none'%3E%3Cdefs%3E%3ClinearGradient id='g' x1='0' y1='1' x2='1' y2='0'%3E%3Cstop offset='0%25' stop-color='%2322c55e' stop-opacity='0.12'/%3E%3Cstop offset='100%25' stop-color='%2316a34a' stop-opacity='0.2'/%3E%3C/linearGradient%3E%3C/defs%3E%3Cpath d='M0 380 Q100 370 160 340 Q220 310 280 290 Q340 270 380 230 Q420 190 460 170 Q520 140 560 110 Q620 70 700 40 Q740 25 800 10 L800 400 L0 400 Z' fill='url(%23g)'/%3E%3Cpath d='M0 380 Q100 370 160 340 Q220 310 280 290 Q340 270 380 230 Q420 190 460 170 Q520 140 560 110 Q620 70 700 40 Q740 25 800 10' fill='none' stroke='%2322c55e' stroke-width='3' stroke-opacity='0.25'/%3E%3C/svg%3E") center / 100% 100% no-repeat,#000000b3;pointer-events:none;z-index:0}.landing-how>*{position:relative;z-index:1}.landing-how__title{font-size:var(--g-font-size-2x-large);font-weight:var(--g-font-weight-black);text-align:center;margin-bottom:var(--g-spacing-3x-large);max-width:900px;margin-left:auto;margin-right:auto}.landing-how__steps{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--g-spacing-x-large);max-width:900px;margin:0 auto}.landing-step{text-align:center}.landing-step__number{display:inline-flex;align-items:center;justify-content:center;width:2.5rem;height:2.5rem;border-radius:50%;background-color:var(--g-color-white);color:var(--g-color-black);font-size:var(--g-font-size-base);font-weight:var(--g-font-weight-black);margin-bottom:var(--g-spacing-base)}.landing-step__title{font-size:var(--g-font-size-large);font-weight:var(--g-font-weight-bold);margin-bottom:var(--g-spacing-small)}.landing-step__desc{color:#a1a1aa;font-size:var(--g-font-size-small);line-height:1.6}.social-proof{padding:var(--g-spacing-3x-large) 0;background-color:var(--g-color-black);color:var(--g-color-white);overflow:hidden}.social-proof__stats{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--g-spacing-x-large);text-align:center;padding-bottom:var(--g-spacing-3x-large);border-bottom:1px solid rgba(255,255,255,.1);margin-bottom:var(--g-spacing-3x-large)}.social-proof__stat-value{display:block;font-size:var(--g-font-size-3x-large);font-weight:var(--g-font-weight-black);line-height:1.1;letter-spacing:-.02em}.social-proof__stat-label{display:block;font-size:var(--g-font-size-small);color:#a1a1aa;margin-top:.25rem;text-transform:uppercase;letter-spacing:.04em}.social-proof__testimonials-wrapper{position:relative;width:100%}.social-proof__testimonials-wrapper:before,.social-proof__testimonials-wrapper:after{content:"";position:absolute;top:0;bottom:0;width:4rem;z-index:1;pointer-events:none}.social-proof__testimonials-wrapper:before{left:0;background:linear-gradient(to right,var(--g-color-black),transparent)}.social-proof__testimonials-wrapper:after{right:0;background:linear-gradient(to left,var(--g-color-black),transparent)}.social-proof__track{display:flex;animation:scroll-testimonials 60s linear infinite;width:max-content}.social-proof__track:hover{animation-play-state:paused}.testimonial-card{flex-shrink:0;width:340px;margin-right:var(--g-spacing-large);background:#ffffff0f;border:1px solid rgba(255,255,255,.1);border-radius:var(--g-border-radius-base);padding:var(--g-spacing-large);display:flex;flex-direction:column;position:relative;overflow:hidden;cursor:pointer;outline:none;transition:border-color .3s}.testimonial-card:hover,.testimonial-card:focus-visible{border-color:#22c55e66}.testimonial-card__top{margin-bottom:var(--g-spacing-base)}.testimonial-card__name{font-size:var(--g-font-size-base);font-weight:var(--g-font-weight-bold)}.testimonial-card__quote{font-size:var(--g-font-size-small);line-height:1.6;color:#d4d4d8;margin-bottom:var(--g-spacing-large);font-style:italic;flex-grow:1}.testimonial-card__ratings{display:flex;align-items:center;justify-content:space-between;padding-top:var(--g-spacing-base);border-top:1px solid rgba(255,255,255,.08)}.testimonial-card__rating-col{display:flex;flex-direction:column;align-items:center}.testimonial-card__rating-label{font-size:var(--g-font-size-x-small);color:#a1a1aa;text-transform:uppercase;letter-spacing:.03em;margin-bottom:.15rem}.testimonial-card__rating-value{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-black);line-height:1}.testimonial-card__gained-col{display:flex;flex-direction:column;align-items:center;opacity:0;transform:scale(.8);transition:opacity .3s ease,transform .3s ease}.testimonial-card:hover .testimonial-card__gained-col,.testimonial-card:focus-visible .testimonial-card__gained-col{opacity:1;transform:scale(1)}.testimonial-card__gained{font-size:var(--g-font-size-large);font-weight:var(--g-font-weight-black);color:#22c55e;white-space:nowrap;line-height:1}.testimonial-card__timeframe{font-size:var(--g-font-size-x-small);color:#a1a1aa;margin-top:.15rem}.testimonial-card__new-rating .testimonial-card__rating-value{filter:blur(8px);transition:filter .3s ease;-webkit-user-select:none;user-select:none}.testimonial-card:hover .testimonial-card__new-rating .testimonial-card__rating-value,.testimonial-card:focus-visible .testimonial-card__new-rating .testimonial-card__rating-value{filter:blur(0)}.testimonial-card__flash{position:absolute;top:0;right:0;bottom:0;left:0;background:radial-gradient(ellipse at center,rgba(34,197,94,.15) 0%,transparent 70%);opacity:0;pointer-events:none;transition:opacity .15s ease}.testimonial-card:hover .testimonial-card__flash,.testimonial-card:focus-visible .testimonial-card__flash{animation:card-flash .6s ease-out forwards}@keyframes card-flash{0%{opacity:1}to{opacity:0}}@keyframes scroll-testimonials{0%{transform:translate(0)}to{transform:translate(calc(-100% / 3))}}@media (max-width: 700px){.social-proof__stats{grid-template-columns:repeat(3,1fr);gap:var(--g-spacing-medium);text-align:center}.social-proof__stat-value{font-size:var(--g-font-size-x-large)}.social-proof__stat-label{font-size:var(--g-font-size-x-small)}.testimonial-card{width:280px}}.landing-cta{background-color:var(--g-color-grey-50);padding:var(--g-spacing-3x-large) 0;border-top:1px solid #e2e8f0}.landing-cta__inner{text-align:center;display:flex;flex-direction:column;align-items:center}.landing-cta__text{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-semi-bold);margin-bottom:var(--g-spacing-x-large);color:var(--g-color-grey-900)}.landing-footer{padding:var(--g-spacing-x-large) 0;border-top:1px solid #e2e8f0}.landing-footer__copy{display:block;margin-top:.25rem}@media (max-width: 700px){.landing-how__steps{grid-template-columns:1fr;gap:var(--g-spacing-x-large)}.landing-hero__title{font-size:var(--g-font-size-3x-large)}}.avatar{border-radius:50%;height:2.5rem;width:2.5rem;object-fit:cover}.profile-blob{align-items:center;display:grid;gap:var(--g-spacing-base);grid-template-columns:auto 1fr}.next-steps-section{margin-top:var(--g-spacing-2x-large)}.c-user-menu{list-style:none;margin-top:.25rem}.c-user-menu button,.c-user-menu a{text-decoration:underline}.app-header{background-color:var(--g-color-white);border-bottom:1px solid #e2e8f0;box-shadow:0 1px 3px #0000000f,0 2px 6px #0000000a}.app-header__title{letter-spacing:-.02em}.app-header__name{color:var(--g-color-grey-900)}.app-header__sign-out{color:var(--g-color-grey-600);font-size:var(--g-font-size-x-small);text-decoration:none;transition:color .15s}.app-header__sign-out:hover{color:var(--g-color-black);text-decoration:underline}.puzzle-page{display:flex;flex-direction:column;align-items:center;gap:var(--g-spacing-large);padding:var(--g-spacing-x-large) 0;max-width:600px;margin:0 auto}.chess-board-wrapper{width:100%}.score-display{display:flex;align-items:center;gap:var(--g-spacing-base);font-size:var(--g-font-size-large);font-weight:var(--g-font-weight-semi-bold);background:var(--g-color-white);padding:var(--g-spacing-base) var(--g-spacing-large);border-radius:var(--g-border-radius-small);box-shadow:0 1px 3px #0000000f}.score-display__item{display:flex;align-items:center;gap:var(--g-spacing-small)}.score-display__label{color:var(--g-color-grey-600);font-weight:var(--g-font-weight-base)}.score-display__value{font-weight:var(--g-font-weight-black)}.score-display__divider{color:var(--g-color-grey-600)}.move-grid{display:grid;grid-template-columns:1fr 1fr;gap:var(--g-spacing-base);width:100%}.move-btn{border-radius:var(--g-border-radius-small);background-color:var(--g-color-grey-900);color:var(--g-color-white);font-size:var(--g-font-size-large);font-weight:var(--g-font-weight-bold);padding:var(--g-spacing-large) var(--g-spacing-base);cursor:pointer;transition:background-color .2s,box-shadow .2s,transform .1s;min-height:3.5rem;box-shadow:0 2px 4px #00000026,0 4px 8px #0000001a;border:1px solid rgba(255,255,255,.05)}.move-btn:hover:not(:disabled){background-color:var(--g-color-black);box-shadow:0 4px 8px #0003,0 6px 12px #0000001f;transform:translateY(-1px)}.move-btn:active:not(:disabled){transform:translateY(0);box-shadow:0 1px 2px #00000026}.move-btn--correct{background-color:#16a34a;box-shadow:0 2px 4px #16a34a4d,0 4px 8px #16a34a26}.move-btn--wrong{background-color:#dc2626;box-shadow:0 2px 4px #dc26264d,0 4px 8px #dc262626}.move-btn--disabled{cursor:default}.spinner{width:2.5rem;height:2.5rem;border:3px solid #e2e8f0;border-top-color:var(--g-color-black);border-radius:50%;animation:spin .8s linear infinite;margin:var(--g-spacing-6x-large) auto}@keyframes spin{to{transform:rotate(360deg)}}.onboarding{display:flex;justify-content:center;align-items:center;min-height:calc(100vh - 120px);padding:var(--g-spacing-x-large) 0}.onboarding-card{background:var(--g-color-white);border-radius:var(--g-border-radius-base);box-shadow:var(--g-box-shadow);padding:var(--g-spacing-3x-large);max-width:440px;width:100%;text-align:center}.onboarding-card__icon{font-size:3rem;margin-bottom:var(--g-spacing-base);line-height:1}.onboarding-card__title{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-black);margin-bottom:var(--g-spacing-small)}.onboarding-card__subtitle{color:var(--g-color-grey-600);font-size:var(--g-font-size-small);line-height:1.5;margin-bottom:var(--g-spacing-x-large)}.onboarding-card__input{width:100%;padding:.75rem var(--g-spacing-base);font-size:var(--g-font-size-base);font-family:var(--g-font-family);border:2px solid #e2e8f0;border-radius:var(--g-border-radius-small);outline:none;transition:border-color .15s;margin-bottom:var(--g-spacing-base)}.onboarding-card__input:focus{border-color:var(--g-color-grey-900)}.onboarding-card__input:disabled{background-color:var(--g-color-grey-50);color:var(--g-color-grey-600)}.onboarding-card__error{color:#dc2626;font-size:var(--g-font-size-small);margin-bottom:var(--g-spacing-base)}.onboarding-card__submit{width:100%;padding:.75rem var(--g-spacing-base);font-size:var(--g-font-size-base)}.onboarding-card__submit:disabled{opacity:.6;cursor:not-allowed}.dashboard{background:var(--g-color-white);border-radius:var(--g-border-radius-base);box-shadow:0 1px 3px #0000000f,0 2px 6px #0000000a;padding:var(--g-spacing-x-large);margin-bottom:var(--g-spacing-large);max-width:600px;margin-left:auto;margin-right:auto}.dashboard__header{margin-bottom:var(--g-spacing-large);padding-bottom:var(--g-spacing-base);border-bottom:1px solid #e2e8f0}.dashboard__title{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-black);margin-bottom:.25rem}.dashboard__member-since{color:var(--g-color-grey-600);font-size:var(--g-font-size-small)}.dashboard__stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:var(--g-spacing-base)}.stat-item{display:flex;flex-direction:column;align-items:center;padding:var(--g-spacing-small) 0}.stat-item__value{font-size:var(--g-font-size-x-large);font-weight:var(--g-font-weight-black);line-height:1.2}.stat-item__label{color:var(--g-color-grey-600);font-size:var(--g-font-size-x-small);font-weight:var(--g-font-weight-semi-bold);text-transform:uppercase;letter-spacing:.04em;margin-top:.25rem}@media (max-width: 600px){.dashboard__stats-grid{grid-template-columns:repeat(2,1fr)}}