:root{color-scheme:dark;--bg:#0a0a0a;--surface:#191919;--raised:#252525;--text:#f5f0e8;--muted:#bebcb6;--line:#45443f;--gold:#f0c93a;--gold-text:#f0c93a;--success:#b0dfc0;--error:#ffb6aa;--ease:cubic-bezier(.23,1,.32,1)}:root[data-theme=light]{color-scheme:light;--bg:#f5f0e8;--surface:#fff;--raised:#ece6d9;--text:#181816;--muted:#56534b;--line:#c2bba9;--gold-text:#6d5200;--success:#215b34;--error:#983525}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:16px/1.55 Inter,system-ui,sans-serif}header{max-width:1120px;margin:auto;padding:24px 32px;display:flex;align-items:center;justify-content:space-between;gap:16px;border-bottom:1px solid var(--line)}a{color:var(--gold-text);text-underline-offset:4px}.wordmark{color:var(--text);display:flex;gap:14px;align-items:center;text-decoration:none;font-size:14px}.wordmark strong{display:block;font-size:19px}.wordmark svg{width:40px;height:40px;fill:none;stroke:var(--gold-text);stroke-width:1.5}.header-actions{display:flex;gap:8px}button,input,select{font:inherit}button{min-height:48px;border:1px solid var(--line);border-radius:9px;background:var(--surface);color:var(--text);padding:10px 18px;cursor:pointer;transition:background 160ms var(--ease),transform 120ms var(--ease),border-color 160ms var(--ease)}button:hover{background:var(--raised);border-color:var(--muted)}button:active{transform:scale(.98)}button:disabled{cursor:wait;opacity:.65}button.primary{background:var(--gold);border-color:var(--gold);color:#15130a;font-weight:700}button.primary:hover{background:#ffe169}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--gold-text);outline-offset:4px}main{max-width:1056px;min-height:62vh;margin:0 auto;padding:40px 0 64px}h1{font-size:clamp(32px,5vw,56px);line-height:1.1;letter-spacing:-.04em;margin:12px 0 20px;font-weight:800}h2{font-size:24px;line-height:1.3;letter-spacing:-.02em;margin:0 0 16px}h3{font-size:18px;margin:0 0 12px}.muted{color:var(--muted)}.eyebrow{font-weight:600;color:var(--gold-text);font-size:14px}.lead{max-width:600px;font-size:18px;color:var(--muted)}.hero{display:grid;grid-template-columns:1fr auto;gap:32px;align-items:center;padding:8px 0 32px}.ring{width:160px;height:160px;border-radius:50%;background:conic-gradient(var(--gold) calc(var(--value,0)*1%),var(--raised) 0);display:grid;place-items:center}.ring>div{width:136px;height:136px;background:var(--bg);border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center}.ring strong{font-size:36px;line-height:1.1}.ring span{font-size:14px;color:var(--muted)}.nav{display:flex;gap:8px;margin:0 0 32px;flex-wrap:wrap}.nav button[aria-current=page]{border-color:var(--gold-text);background:var(--raised);font-weight:700}.grid{display:grid;grid-template-columns:1.2fr 1fr;gap:24px}.card{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:28px}.feature{border-top:3px solid var(--gold);position:relative;overflow:hidden}.feature strong.stat{display:block;font-size:56px;line-height:1.1;letter-spacing:-.04em;margin:16px 0 4px}.row{display:flex;align-items:center;justify-content:space-between;gap:16px}.actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.badge{font-size:14px;font-weight:600;display:inline-block;border:1px solid var(--line);padding:5px 10px;border-radius:6px}.badge.good{color:var(--success)}.badge.review{color:var(--error)}.topic{display:block;padding:18px 0;border-bottom:1px solid var(--line)}.topic:last-child{border:0}.topic-title{display:flex;justify-content:space-between;gap:20px;font-weight:600}.bar{height:7px;border-radius:4px;background:var(--raised);margin:10px 0;overflow:hidden}.bar span{height:100%;display:block;background:var(--gold)}.topic small{font-size:14px;color:var(--muted)}details{margin-top:18px}summary{min-height:44px;cursor:pointer;font-weight:600;padding:8px 0}.question-shell{max-width:780px;margin:auto}.question-shell .card{margin-top:20px}.question-shell h2{font-size:clamp(22px,3.5vw,30px);line-height:1.4;margin-top:24px}.answers{display:grid;gap:12px;margin:28px 0}.answer{display:flex;align-items:center;gap:16px;text-align:left;min-height:64px;font-size:17px;background:var(--bg)}.answer .letter{flex:0 0 32px;border:1px solid var(--line);border-radius:7px;height:32px;display:grid;place-items:center;font-size:14px;font-weight:700}.answer.selected{border:2px solid var(--gold-text);background:var(--raised)}.answer.correct{border:2px solid var(--success)}.answer.wrong{border:2px solid var(--error)}.feedback{border-left:3px solid var(--gold);padding:16px 20px;background:var(--raised)}.feedback strong{display:block;margin-bottom:8px}.feedback a{font-size:14px}.timer{font-variant-numeric:tabular-nums;font-size:24px;font-weight:700;color:var(--gold-text)}.question-grid{display:grid;grid-template-columns:repeat(10,1fr);gap:8px;margin:20px 0}.question-grid button{padding:0;min-height:44px;border-radius:6px;font-size:14px}.question-grid button.answered{background:var(--gold);color:#15130a}.question-grid button.current{outline:2px solid var(--text);outline-offset:2px}.score{font-size:clamp(60px,10vw,88px);font-weight:800;line-height:1;letter-spacing:-.06em;margin:24px 0 12px}.score small{font-size:30px;letter-spacing:-.03em}.review-question{padding:18px 0;border-bottom:1px solid var(--line)}.review-question p{margin:8px 0}.field{display:grid;gap:8px;margin:16px 0}input,select{min-height:48px;width:100%;padding:12px;background:var(--bg);color:var(--text);border:1px solid var(--line);border-radius:8px}label{font-weight:600}.settings-user{padding:20px 0;border-bottom:1px solid var(--line)}.settings-user .row{align-items:start}.settings-user .actions{margin-top:12px}.audit{font-size:14px;overflow-wrap:anywhere;border-bottom:1px solid var(--line);padding:16px 0}.skeleton{padding:48px;color:var(--muted);background:var(--surface);border-radius:16px}.error{border-left:4px solid var(--error)}#message{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);padding:16px 24px;max-width:90vw;background:var(--text);color:var(--bg);border-radius:12px;z-index:10;box-shadow:0 8px 24px #0004}footer{max-width:1056px;margin:0 auto;padding:24px 0 40px;border-top:1px solid var(--line);font-size:14px;color:var(--muted)}.enter{animation:enter 260ms var(--ease) both}@keyframes enter{from{transform:translateY(8px);opacity:0}to{transform:translateY(0);opacity:1}}@media(max-width:1120px){main,footer{margin:0 32px}}@media(max-width:640px){header{padding:16px}.header-actions button{padding:8px 10px;font-size:14px}.wordmark{gap:8px}.wordmark svg{width:30px;height:30px}.wordmark strong{font-size:16px}main{margin:0 16px;padding-top:28px}.hero{gap:16px;align-items:start}.hero .ring{width:104px;height:104px;margin-top:12px}.ring>div{width:86px;height:86px}.ring strong{font-size:25px}.ring span{font-size:14px}.grid{grid-template-columns:1fr}.card{padding:22px}.nav{display:grid;grid-template-columns:repeat(4,1fr);gap:6px}.nav button{padding:8px 4px;font-size:14px}.question-grid{grid-template-columns:repeat(5,1fr)}.answer{font-size:16px;padding:14px 12px}.question-shell .row{gap:12px}.question-shell h2{margin-top:20px}.actions button{flex:1}.settings-user .row{display:block}footer{margin:0 16px}.lead{font-size:16px}}@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

.brand-logo{width:172px;height:auto;display:block}.logo-light{display:none}:root[data-theme=light] .logo-dark{display:none}:root[data-theme=light] .logo-light{display:block}.app-name{font-size:16px;font-weight:700;border-left:1px solid var(--line);padding-left:14px}@media(max-width:640px){.brand-logo{width:118px}.app-name{font-size:14px;padding-left:8px}.wordmark{gap:8px}}

.hero{grid-template-columns:minmax(0,1fr) auto}.hero>div{min-width:0}.grid{grid-template-columns:minmax(0,1.2fr) minmax(0,1fr)}@media(max-width:640px){.grid{grid-template-columns:minmax(0,1fr)}}@media(max-width:400px){.brand-logo{width:98px}.header-actions{gap:6px}.header-actions button{padding:8px}.app-name{font-size:13px}}

/* The learning path is a real sequence. Keep its order stable in both themes. */
:root{--review:#f1bb54}:root[data-theme=light]{--review:#784b00}
.badge.review{color:var(--review)}
h1,h2,h3{text-wrap:balance}p{text-wrap:pretty}
.skip-link{position:absolute;left:16px;top:-100px;padding:12px;background:var(--gold);color:var(--bg);z-index:20}.skip-link:focus{top:12px}
.learning-path{display:flex;gap:24px;list-style:none;padding:0;margin:0 0 32px;flex-wrap:wrap;font-weight:600}
.learning-path li{display:flex;align-items:center;gap:10px}.learning-path li span{width:30px;height:30px;border:1px solid var(--line);border-radius:50%;display:grid;place-items:center;font-size:14px}
.learn-start,.next-lesson{display:flex;align-items:center;justify-content:space-between;gap:32px;margin-bottom:24px}
.learn-start h2{margin-top:16px}.learn-start p{max-width:60ch;margin-bottom:0}.learn-start button,.next-lesson button{flex-shrink:0}
.lesson-progress{max-width:780px;margin:24px 0 32px}.next-lesson{padding:24px 0;border-bottom:1px solid var(--line)}.next-lesson h2{margin:8px 0 0}
.topic-lessons{border-bottom:1px solid var(--line);margin:0}.topic-lessons>summary{padding:20px 0;min-height:64px;font-size:18px}.topic-lessons>summary>span+span{font-size:14px;font-weight:400;margin-left:16px}
.lesson-row{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:24px 0;border-top:1px solid var(--line)}.lesson-row>div{min-width:0}.lesson-row p{max-width:65ch;margin:8px 0 12px}.lesson-row h3{margin:0}.lesson-row button{flex-shrink:0}
.lesson-breadcrumb{margin:20px 0 0}.lesson-card h1{font-size:32px;line-height:1.3;margin:0 0 24px;letter-spacing:-.02em}.lesson-body{font-size:20px;line-height:1.65;max-width:60ch}.lesson-body p:first-child{margin-top:0}.lesson-card .actions{margin-top:36px}
.question-title{font-size:28px;line-height:1.4;letter-spacing:-.02em;margin:24px 0 16px}.question-title:focus,.lesson-card h1:focus{outline:none}
.reviewed-answers{list-style:none;padding:0}.reviewed-answers .answer{border:1px solid var(--line);border-radius:9px;padding:16px 18px;cursor:default}.reviewed-answers .answer.correct{border:2px solid var(--success);background:var(--raised)}.reviewed-answers .answer.wrong{border:2px solid var(--review)}
.answer-content{min-width:0;overflow-wrap:anywhere}.answer-label{display:block;font-weight:700;font-size:14px;margin-top:6px}.correct .answer-label{color:var(--success)}.wrong .answer-label{color:var(--review)}
.feedback{border:1px solid var(--line);border-radius:12px;padding:24px;background:var(--raised)}.feedback p{max-width:65ch;margin:20px 0}.feedback .badge{margin-bottom:0}.feedback strong{margin-bottom:6px}.feedback .correct-answer-text{font-size:20px;margin-top:16px}.feedback .correct-answer-text strong{color:var(--success)}.feedback-links{display:flex;gap:12px 24px;align-items:center;flex-wrap:wrap}.feedback-links a{display:inline-flex;min-height:44px;align-items:center}.feedback-links .lesson-link{font-size:16px;font-weight:700}
.review-question{padding:28px 0}.review-question h2{font-size:24px}.review-question .answers{margin-top:20px}.review-question .feedback p{margin:16px 0}.review-question .feedback{margin-bottom:0}
main[aria-busy=true]{cursor:progress}button:disabled{cursor:not-allowed}.skeleton{background:var(--surface)}
.lesson-source{display:inline-flex;align-items:center;min-height:44px;font-size:14px}
@media(max-width:640px){.nav{grid-template-columns:repeat(3,minmax(0,1fr))}.learning-path{gap:12px;margin-bottom:24px;font-size:14px}.learning-path li{gap:6px}.learning-path li span{width:24px;height:24px}.learn-start,.next-lesson{align-items:stretch;flex-direction:column;gap:20px}.learn-start button,.next-lesson button{width:100%}.lesson-row{align-items:stretch;flex-direction:column;gap:16px}.lesson-row button{align-self:start}.topic-lessons>summary>span+span{display:block;margin:6px 0 0 20px}.lesson-card h1{font-size:27px}.lesson-body{font-size:18px}.question-title{font-size:24px}.feedback{padding:18px}.feedback .correct-answer-text{font-size:18px}.reviewed-answers .answer{padding:14px 12px}.feedback-links{align-items:stretch;flex-direction:column;gap:4px}.header-actions{flex-wrap:wrap;justify-content:flex-end}.lesson-card .actions{margin-top:24px}}