:root{--font-sans:"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;--font-heading:"Sora", var(--font-sans);--font-mono:"JetBrains Mono", "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;--color-bg:#fff;--color-bg-subtle:#fafafa;--color-surface:#fff;--color-border:#e5e7eb;--color-border-strong:#d1d5db;--color-text:#18181b;--color-text-muted:#6b7280;--color-text-faint:#9ca3af;--color-primary:#4f46e5;--color-primary-hover:#4338ca;--color-primary-bg:#eef2ff;--color-success:#059669;--color-success-bg:#ecfdf5;--gradient-brand:linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);--radius-sm:8px;--radius-md:12px;--radius-lg:16px;--radius-xl:22px;--shadow-sm:0 1px 2px #1018280d;--shadow-md:0 4px 16px #10182814;--shadow-lg:0 16px 40px #10182824;--shadow-glow:0 8px 24px #4f46e52e;--max-width:1120px;--ease:cubic-bezier(.16, 1, .3, 1);--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*{box-sizing:border-box}html,body{margin:0;padding:0}html{scroll-behavior:smooth}body{font-family:var(--font-sans);color:var(--color-text);background:var(--color-bg);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;font-feature-settings:"cv11", "ss01";line-height:1.5}#root{flex-direction:column;min-height:100vh;display:flex}a{color:inherit;text-decoration:none}button{font-family:inherit}h1,h2,h3,h4,h5,h6{font-family:var(--font-heading);letter-spacing:-.02em;margin:0;font-weight:700}p{margin:0}ul,ol{margin:0;padding:0}img{max-width:100%;display:block}.container{width:100%;max-width:var(--max-width);margin:0 auto;padding:0 24px}.visually-hidden{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}::selection{background:var(--color-primary-bg);color:var(--color-primary)}:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px;border-radius:4px}::-webkit-scrollbar{width:10px;height:10px}::-webkit-scrollbar-track{background:0 0}::-webkit-scrollbar-thumb{background:var(--color-border-strong);border-radius:8px}@keyframes page-enter{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}.page-enter{animation:page-enter .35s var(--ease)}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.page-enter{animation:none}}.section{padding:56px 24px}.section__header{margin-bottom:28px}.section__header h2{margin-bottom:6px;font-size:26px}.section__header p{color:var(--color-text-muted);font-size:15px}.navbar{z-index:40;-webkit-backdrop-filter:saturate(180%)blur(10px);backdrop-filter:saturate(180%)blur(10px);border-bottom:1px solid var(--color-border);background:#ffffffd9;position:sticky;top:0}.reading-progress{z-index:39;background:0 0;height:3px;position:sticky;top:64px}.reading-progress__fill{height:100%;transition:width .1s linear}.navbar__inner{align-items:center;gap:16px;height:64px;padding:0 20px;display:flex}.navbar__menu-btn{border:1px solid var(--color-border);border-radius:var(--radius-sm);background:var(--color-bg-subtle);width:36px;height:36px;color:var(--color-text);cursor:pointer;flex-shrink:0;justify-content:center;align-items:center;transition:background .15s,color .15s;display:none}.navbar__menu-btn:hover{background:var(--color-primary-bg);color:var(--color-primary)}.navbar__brand{font-family:var(--font-heading);white-space:nowrap;align-items:center;gap:10px;font-size:16px;font-weight:700;transition:opacity .15s;display:flex}.navbar__brand:hover{opacity:.85}.navbar__logo{background:var(--gradient-brand);width:30px;height:30px;box-shadow:var(--shadow-glow);border-radius:9px;flex-shrink:0;justify-content:center;align-items:center;display:flex}.navbar__links{flex:1;align-items:center;display:flex}.navbar__link{color:var(--color-text-muted);white-space:nowrap;font-size:13.5px;font-weight:600}.navbar__link:hover{color:var(--color-text)}.navbar__search{width:100%;max-width:320px;margin-left:auto;position:relative}.navbar__search-icon{color:var(--color-text-faint);pointer-events:none;position:absolute;top:50%;left:13px;transform:translateY(-50%)}.navbar__search input{border:1px solid var(--color-border);background:var(--color-bg-subtle);border-radius:999px;outline:none;width:100%;padding:9px 14px 9px 36px;font-size:14px;transition:border-color .15s,background .15s,box-shadow .15s}.navbar__search input:focus{border-color:var(--color-primary);background:var(--color-surface);box-shadow:0 0 0 3px var(--color-primary-bg)}.navbar__search-results{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);width:340px;max-width:80vw;max-height:360px;box-shadow:var(--shadow-lg);padding:6px;position:absolute;top:calc(100% + 8px);right:0;overflow-y:auto}.navbar__search-empty{color:var(--color-text-muted);padding:12px;font-size:13px}.navbar__search-result{text-align:left;border-radius:var(--radius-sm);cursor:pointer;background:0 0;border:none;flex-direction:column;gap:2px;width:100%;padding:10px 12px;display:flex}.navbar__search-result:hover{background:var(--color-bg-subtle)}.navbar__search-result-title{font-size:14px;font-weight:600}.navbar__search-result-meta{color:var(--color-text-muted);text-transform:capitalize;font-size:12px}.footer{border-top:1px solid var(--color-border);margin-top:auto;padding:28px 24px}.footer__inner{color:var(--color-text-muted);flex-wrap:wrap;justify-content:space-between;align-items:flex-start;gap:16px;font-size:13px;display:flex}.footer__muted{color:var(--color-text-faint);margin-top:2px}.footer__links{flex-wrap:wrap;gap:18px;font-weight:600;display:flex}.footer__links a:hover{color:var(--color-text)}.loader{color:var(--color-text-muted);justify-content:center;align-items:center;gap:10px;padding:48px 0;font-size:14px;display:flex}.loader__spinner{border:2px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;width:16px;height:16px;animation:.7s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.error-state{color:#991b1b;border-radius:var(--radius-md);background:#fef2f2;border:1px solid #fecaca;flex-direction:column;align-items:flex-start;gap:12px;padding:24px;font-size:14px;display:flex}.btn{border-radius:var(--radius-sm);cursor:pointer;transition:transform .15s var(--ease), box-shadow .15s ease, background .15s ease, border-color .15s ease;border:1px solid #0000;justify-content:center;align-items:center;gap:6px;padding:10px 18px;font-size:14px;font-weight:600;display:inline-flex}.btn:active{transform:translateY(1px)}.btn--primary{background:var(--gradient-brand);color:#fff;box-shadow:var(--shadow-glow)}.btn--primary:hover{transform:translateY(-1px);box-shadow:0 10px 28px #4f46e547}.btn--secondary{background:var(--color-surface);border-color:var(--color-border-strong);color:var(--color-text)}.btn--secondary:hover{border-color:var(--color-text-muted);box-shadow:var(--shadow-sm);transform:translateY(-1px)}.btn--success{background:var(--color-success-bg);color:var(--color-success);border-color:#a7f3d0}.hero{isolation:isolate;position:relative;overflow:hidden}.hero__inner{flex-direction:column;align-items:flex-start;gap:18px;max-width:760px;display:flex;position:relative}.eyebrow{letter-spacing:.06em;text-transform:uppercase;color:var(--color-primary);background:var(--color-surface);box-shadow:var(--shadow-sm);border:1px solid #e0e7ff;border-radius:999px;align-items:center;gap:7px;padding:7px 14px 7px 11px;font-size:12.5px;font-weight:700;display:inline-flex}.eyebrow:before{content:"";background:var(--gradient-brand);border-radius:50%;flex-shrink:0;width:6px;height:6px}.hero h1{font-size:44px;line-height:1.12}.hero__subtitle{color:var(--color-text-muted);max-width:620px;font-size:17px}.hero--profile{background:radial-gradient(120% 140% at 82% -10%,#1e2749 0%,#0f1424 55%,#0b0e1a 100%);border-bottom:1px solid #1c2338;padding:0}.hero--profile:before,.hero--profile:after{content:"";z-index:0;filter:blur(90px);pointer-events:none;border-radius:50%;position:absolute}.hero--profile:before{background:radial-gradient(circle,#818cf859 0%,#0000 70%);width:480px;height:480px;top:-220px;right:-60px}.hero--profile:after{background:radial-gradient(circle,#34d3992e 0%,#0000 70%);width:360px;height:360px;bottom:-200px;left:-60px}.hero--profile .hero__inner{max-width:var(--max-width);grid-template-columns:minmax(0,1fr) 320px;align-items:center;gap:48px;padding:88px 24px 72px;display:grid}.hero__content{z-index:1;flex-direction:column;align-items:flex-start;gap:14px;display:flex;position:relative}.eyebrow--dark{color:#c7d2fe;-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);background:#ffffff0f;border-color:#ffffff24}.eyebrow--dark:before{background:#818cf8}.hero__hello{color:#9ca3ec;margin-top:6px;font-size:16px;font-weight:600}.hero__name{font-family:var(--font-heading);letter-spacing:-.02em;color:#fff;font-size:52px;font-weight:800;line-height:1.08}.hero__role{color:#cbd2e8;font-size:19px;font-weight:500}.hero__role-highlight{color:#6ee7b7;font-weight:700}.hero__cursor{vertical-align:-3px;background:#6ee7b7;width:2px;height:18px;margin-left:2px;animation:1s step-end infinite cursor-blink;display:inline-block}@keyframes cursor-blink{0%,49%{opacity:1}50%,to{opacity:0}}.hero__subtitle--dark{color:#a3aad0;max-width:520px;margin-top:2px}.hero__cta-row{flex-wrap:wrap;align-items:center;gap:12px;margin-top:10px;display:flex}.btn--accent{color:#063a2a;background:linear-gradient(135deg,#6ee7b7 0%,#34d399 100%);box-shadow:0 10px 26px #34d39940}.btn--accent:hover{transform:translateY(-1px);box-shadow:0 12px 32px #34d39959}.btn--outline-light{color:#fff;background:0 0;border-color:#ffffff3d}.btn--outline-light:hover{background:#ffffff0f;border-color:#ffffff80;transform:translateY(-1px)}.hero__stats--dark{border-top:1px solid #ffffff1f;margin-top:20px;padding-top:18px}.hero__stats--dark .stat__value{color:#fff}.hero__stats--dark .stat__label{color:#8b92b8}.hero__portrait{z-index:1;aspect-ratio:1;justify-self:center;width:100%;max-width:320px;position:relative}.hero__portrait-ring{border:1.5px dashed #ffffff38;border-radius:50%;animation:40s linear infinite portrait-ring-spin;position:absolute;inset:-18px}@keyframes portrait-ring-spin{to{transform:rotate(360deg)}}.hero__portrait-img{object-fit:cover;background:#1c2338;border:4px solid #ffffff14;border-radius:50%;width:100%;height:100%;position:relative;box-shadow:0 24px 60px #00000073}.hero__portrait-vignette{pointer-events:none;border-radius:50%;position:absolute;inset:0;box-shadow:inset 0 0 0 4px #ffffff14,inset 0 0 46px 14px #090c188c}.hero__portrait-dot{pointer-events:none;border-radius:50%;position:absolute}.hero__portrait-dot--1{background:#6ee7b7;width:14px;height:14px;top:6%;left:-4%;box-shadow:0 0 0 6px #6ee7b724}.hero__portrait-dot--2{background:#818cf8;width:9px;height:9px;bottom:10%;right:-2%;box-shadow:0 0 0 5px #818cf829}.hero__floating-card{border-radius:var(--radius-lg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);background:#14182beb;border:1px solid #ffffff1f;align-items:center;gap:12px;max-width:220px;padding:14px 18px;display:flex;position:absolute;bottom:-22px;left:-34px;box-shadow:0 20px 44px #0006}.hero__floating-card-value{font-family:var(--font-heading);color:#6ee7b7;flex-shrink:0;font-size:26px;font-weight:800;line-height:1}.hero__floating-card-label{color:#c3c8e6;font-size:11.5px;font-weight:600;line-height:1.4}.hero--compact .hero__inner{grid-template-columns:minmax(0,1fr) 200px;gap:40px;padding:64px 24px 52px}.hero__name--compact{margin-top:2px;font-size:36px}.hero__location{color:#8b92b8;margin-top:-6px;font-size:13.5px}.hero__portrait--compact{max-width:200px}.hero__portrait--compact .hero__portrait-ring{inset:-12px}.instructor-byline{background:var(--color-surface);border:1px solid var(--color-border);color:var(--color-text-muted);border-radius:999px;align-items:center;gap:10px;padding:8px 16px 8px 8px;font-size:13.5px;transition:border-color .15s,box-shadow .15s;display:inline-flex}.instructor-byline:hover{border-color:var(--color-border-strong);box-shadow:var(--shadow-sm)}.instructor-byline strong{color:var(--color-text)}.instructor-byline__avatar{background:var(--color-primary);color:#fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:26px;height:26px;font-size:11px;font-weight:700;display:inline-flex}.field-note-hint{color:var(--color-primary);white-space:nowrap;font-weight:600}.hero__stats{gap:32px;margin-top:8px;display:flex}.stat{flex-direction:column;display:flex}.stat__value{font-size:24px;font-weight:700}.stat__label{color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.04em;font-size:12.5px}.topic-grid{grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:18px;display:grid}.topic-card{border:1px solid var(--color-border);border-radius:var(--radius-lg);background:var(--color-surface);transition:box-shadow .2s var(--ease), transform .2s var(--ease), border-color .2s ease;flex-direction:column;gap:12px;padding:24px 22px 22px;display:flex;position:relative;overflow:hidden}.topic-card:before{content:"";background:var(--topic-color,var(--color-primary));transform-origin:0;height:3px;transition:transform .25s var(--ease);position:absolute;top:0;left:0;right:0;transform:scaleX(0)}.topic-card:hover{box-shadow:var(--shadow-md);border-color:var(--color-border-strong);transform:translateY(-3px)}.topic-card:hover:before{transform:scaleX(1)}.topic-card__top{align-items:center;gap:12px;display:flex}.topic-card__icon{background:color-mix(in srgb, var(--topic-color,var(--color-primary)) 12%, white);width:40px;height:40px;color:var(--topic-color,var(--color-primary));border-radius:11px;flex-shrink:0;justify-content:center;align-items:center;display:flex}.topic-card h3{font-size:17.5px}.topic-card__tagline{color:var(--color-text-muted);flex:1;font-size:14px}.topic-card__levels{flex-wrap:wrap;gap:6px;display:flex}.topic-card__footer{color:var(--color-text-muted);justify-content:space-between;align-items:center;margin-top:4px;font-size:13px;display:flex}.topic-card__arrow{color:var(--topic-color,var(--color-primary));transition:transform .2s var(--ease);font-weight:700;display:inline-flex}.topic-card:hover .topic-card__arrow{transform:translate(3px)}.level-pill{text-transform:capitalize;border-radius:999px;align-items:center;gap:5px;padding:3px 10px;font-size:12px;font-weight:600;display:inline-flex}.level-pill:before{content:"";background:currentColor;border-radius:50%;flex-shrink:0;width:5px;height:5px}.level-pill[data-level=basics]{color:#059669;background:#ecfdf5}.level-pill[data-level=intermediate]{color:#b45309;background:#fffbeb}.level-pill[data-level=pro]{color:#4338ca;background:#eef2ff}.level-explainer-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;display:grid}.level-explainer{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-bg-subtle);flex-direction:column;align-items:flex-start;gap:10px;padding:20px;display:flex}.level-explainer p{color:var(--color-text-muted);font-size:14px}.progress-bar{background:var(--color-bg-subtle);border-radius:999px;width:100%;height:7px;overflow:hidden;box-shadow:inset 0 1px 2px #1018280f}.progress-bar__fill{height:100%;transition:width .4s var(--ease);border-radius:999px}.back-link{color:var(--color-text-muted);margin-bottom:20px;font-size:13px;display:inline-block}.back-link:hover{color:var(--color-text)}.topic-header{align-items:center;gap:14px;margin-bottom:28px;display:flex}.topic-header__icon{background:color-mix(in srgb, var(--topic-color,var(--color-primary)) 12%, white);width:52px;height:52px;color:var(--topic-color,var(--color-primary));border-radius:14px;flex-shrink:0;justify-content:center;align-items:center;display:flex}.topic-header h1{font-size:30px}.topic-header__tagline{color:var(--color-text-muted);margin-top:4px;font-size:15px}.level-tabs{border-bottom:1px solid var(--color-border);gap:6px;margin-bottom:24px;display:flex}.level-tab{cursor:pointer;transition:color .15s ease, border-color .2s var(--ease);color:var(--color-text-muted);text-transform:capitalize;background:0 0;border:none;border-bottom:2px solid #0000;align-items:center;gap:6px;margin-right:20px;padding:10px 4px;font-size:14px;font-weight:600;display:flex}.level-tab--active{color:var(--color-text);border-bottom-color:var(--color-primary)}.level-tab__count{color:var(--color-text-faint);background:var(--color-bg-subtle);border-radius:999px;padding:1px 7px;font-size:12px}.level-panel__description{color:var(--color-text-muted);margin-bottom:16px;font-size:14px}.level-panel__progress{color:var(--color-text-muted);flex-direction:column;gap:8px;max-width:320px;margin-bottom:24px;font-size:13px;display:flex}.lesson-list{flex-direction:column;gap:10px;display:flex}.lesson-row{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);align-items:center;gap:14px;padding:16px 18px;transition:border-color .15s,box-shadow .15s;display:flex}.lesson-row:hover{border-color:var(--color-border-strong);box-shadow:var(--shadow-sm)}.lesson-row__check{border:2px solid var(--color-border-strong);color:#0000;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:22px;height:22px;font-size:12px;display:flex}.lesson-row__check--done{background:var(--color-success-bg);border-color:var(--color-success);color:var(--color-success)}.lesson-row__body{flex-direction:column;flex:1;gap:3px;min-width:0;display:flex}.lesson-row__title{font-size:15px;font-weight:600}.lesson-row__summary{color:var(--color-text-muted);text-overflow:ellipsis;white-space:nowrap;font-size:13px;overflow:hidden}.lesson-row__minutes{color:var(--color-text-faint);flex-shrink:0;font-size:12.5px}.lesson-page__breadcrumbs{color:var(--color-text-muted);flex-wrap:wrap;align-items:center;gap:8px;margin-bottom:24px;font-size:13px;display:flex}.lesson-page__breadcrumbs a:hover{color:var(--color-text)}.lesson-page__crumb-sep{color:var(--color-text-faint)}.lesson-article{min-width:0;max-width:720px}.lesson-article__position{letter-spacing:.04em;text-transform:uppercase;color:var(--color-primary);margin-bottom:10px;font-size:12.5px;font-weight:700}.lesson-article h1{font-size:32px;line-height:1.2}.lesson-article__summary{color:var(--color-text-muted);margin-top:12px;font-size:16px}.lesson-article__minutes{color:var(--color-text-faint);border-bottom:1px solid var(--color-border);margin-top:8px;padding-bottom:24px;font-size:13px}.lesson-article__body{color:var(--color-text);margin-top:24px;font-size:16px;line-height:1.75}.lesson-article__body h2{margin-top:40px;margin-bottom:12px;scroll-margin-top:90px;font-size:23px}.lesson-article__body h3{margin-top:32px;margin-bottom:10px;scroll-margin-top:90px;font-size:19px}.lesson-article__body p{margin-bottom:16px}.lesson-article__body ul,.lesson-article__body ol{margin-bottom:16px;padding-left:22px}.lesson-article__body li{margin-bottom:6px}.lesson-article__body strong{font-weight:700}.lesson-article__body code{font-family:var(--font-mono);background:var(--color-bg-subtle);border-radius:4px;padding:2px 6px;font-size:.88em}.lesson-article__body pre{color:#e2e8f0;border-radius:var(--radius-md);box-shadow:var(--shadow-sm);background:#0f172a;border:1px solid #1e293b;margin-bottom:16px;padding:18px 20px;overflow-x:auto}.lesson-article__body pre code{color:inherit;background:0 0;padding:0;font-size:13.5px}.takeaways{border-radius:var(--radius-md);background:var(--color-bg-subtle);border-left:4px solid var(--topic-color,var(--color-primary));margin-top:32px;padding:20px 22px}.takeaways h3{margin-bottom:10px;font-size:15px}.takeaways ul{padding-left:20px}.takeaways li{color:var(--color-text);margin-bottom:8px;font-size:14.5px;line-height:1.55}.lesson-article__complete{width:100%;margin-top:28px}.lesson-nav{border-top:1px solid var(--color-border);grid-template-columns:1fr 1fr;gap:12px;margin-top:32px;padding-top:24px;display:grid}.lesson-nav__btn{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);text-align:left;cursor:pointer;flex-direction:column;align-items:flex-start;gap:4px;padding:14px 16px;transition:border-color .15s;display:flex}.lesson-nav__btn:hover:not(:disabled){border-color:var(--color-border-strong)}.lesson-nav__btn:disabled{opacity:.4;cursor:not-allowed}.lesson-nav__btn--next{text-align:right;align-items:flex-end}.lesson-nav__label{color:var(--color-text-muted);font-size:12px;font-weight:600}.lesson-nav__title{font-size:14px;font-weight:600}.not-found{text-align:center;padding:96px 24px}.not-found h1{color:var(--color-text-faint);font-size:64px}.not-found p{color:var(--color-text-muted);margin:12px 0 24px}.field-note{border-radius:var(--radius-md);background:#fffbeb;border:1px solid #fde68a;margin-top:24px;padding:18px 22px}.field-note__header{align-items:center;gap:8px;margin-bottom:8px;display:flex}.field-note__icon{color:#b45309;font-size:13px}.field-note__label{letter-spacing:.02em;text-transform:uppercase;color:#b45309;font-size:12.5px;font-weight:700}.field-note p{color:#78350f;font-size:14.5px;line-height:1.6}.instructor-page{max-width:780px;margin:0 auto}.instructor-hero{align-items:center;gap:20px;margin-bottom:20px;display:flex}.instructor-avatar{background:var(--gradient-brand);width:76px;height:76px;box-shadow:var(--shadow-glow), 0 0 0 4px var(--color-primary-bg);color:#fff;font-family:var(--font-heading);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:24px;font-weight:700;display:flex}.instructor-hero h1{margin-top:4px;font-size:30px}.instructor-hero__title{color:var(--color-text-muted);margin-top:4px;font-size:15px;font-weight:600}.instructor-hero__location{color:var(--color-text-faint);margin-top:2px;font-size:13px}.instructor-summary{color:var(--color-text);margin-bottom:20px;font-size:16px;line-height:1.7}.instructor-contact{flex-wrap:wrap;gap:10px;margin-bottom:32px;display:flex}.instructor-stats{border-top:1px solid var(--color-border);border-bottom:1px solid var(--color-border);flex-wrap:wrap;gap:40px;margin-bottom:40px;padding:24px 0;display:flex}.instructor-section{margin-bottom:40px}.instructor-section h2{margin-bottom:16px;font-size:20px}.instructor-list{flex-direction:column;gap:10px;padding-left:20px;list-style:outside;display:flex}.instructor-list li{color:var(--color-text);font-size:15px;line-height:1.6}.achievement-grid{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px;display:grid}.achievement-card{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-bg-subtle);transition:border-color .2s ease, box-shadow .2s ease, transform .2s var(--ease);padding:20px}.achievement-card:hover{border-color:var(--color-border-strong);box-shadow:var(--shadow-sm);transform:translateY(-2px)}.achievement-card h3{margin-bottom:8px;font-size:15px}.achievement-card p{color:var(--color-text-muted);font-size:13.5px;line-height:1.6}.skills-grid{flex-direction:column;gap:18px;display:flex}.skills-group h4{text-transform:uppercase;letter-spacing:.03em;color:var(--color-text-muted);margin-bottom:10px;font-size:13px;font-weight:700}.skills-tags{flex-wrap:wrap;gap:8px;display:flex}.skill-tag{background:var(--color-primary-bg);color:var(--color-primary);border-radius:999px;padding:5px 12px;font-size:13px;font-weight:600;transition:background .15s,transform .15s}.skill-tag:hover{background:var(--color-primary);color:#fff;transform:translateY(-1px)}.timeline{flex-direction:column;gap:24px;display:flex;position:relative}.timeline-item{gap:16px;display:flex}.timeline-item__dot{background:var(--color-primary);border-radius:50%;flex-shrink:0;width:10px;height:10px;margin-top:6px}.timeline-item__body{border-bottom:1px solid var(--color-border);flex:1;padding-bottom:4px}.timeline-item:last-child .timeline-item__body{border-bottom:none}.timeline-item__header{flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:12px;margin-bottom:6px;display:flex}.timeline-item__header h4{font-size:15px}.timeline-item__period{color:var(--color-text-faint);white-space:nowrap;font-size:12.5px}.timeline-item__body p{color:var(--color-text-muted);padding-bottom:16px;font-size:13.5px;line-height:1.6}.app-shell{flex:1;align-items:flex-start;display:flex}.app-shell__main{flex-direction:column;flex:1;min-width:0;display:flex}.sidebar{border-right:1px solid var(--color-border);background:var(--color-bg-subtle);z-index:30;flex-direction:column;flex-shrink:0;width:272px;height:calc(100vh - 64px);display:flex;position:sticky;top:64px}.sidebar__scroll{flex:1;padding:18px 14px 12px;overflow-y:auto}.sidebar__home{border-radius:var(--radius-sm);color:var(--color-text-muted);align-items:center;gap:8px;margin-bottom:16px;padding:8px 10px;font-size:13.5px;font-weight:600;transition:background .15s,color .15s;display:flex}.sidebar__home:hover,.sidebar__home.active{background:var(--color-surface);color:var(--color-primary);box-shadow:var(--shadow-sm)}.sidebar__loading{flex-direction:column;gap:12px;padding:4px 10px;display:flex}.sidebar__skeleton{background:linear-gradient(90deg, var(--color-border) 25%, #f3f4f6 50%, var(--color-border) 75%);background-size:200% 100%;border-radius:6px;height:14px;animation:1.4s infinite skeleton-shimmer}@keyframes skeleton-shimmer{0%{background-position:200% 0}to{background-position:-200% 0}}.sidebar__group{margin-bottom:2px}.sidebar__group-header{cursor:pointer;border-radius:var(--radius-sm);width:100%;color:var(--color-text);text-align:left;background:0 0;border:none;align-items:center;gap:9px;padding:9px 10px;font-size:13.5px;font-weight:600;transition:background .15s;display:flex}.sidebar__group-header:hover{background:var(--color-surface)}.sidebar__group--active>.sidebar__group-header{color:var(--topic-color)}.sidebar__group-icon{color:var(--topic-color);flex-shrink:0;display:flex}.sidebar__group-name{text-overflow:ellipsis;white-space:nowrap;flex:1;overflow:hidden}.sidebar__chevron{color:var(--color-text-faint);transition:transform .2s var(--ease);flex-shrink:0}.sidebar__chevron--open{transform:rotate(180deg)}.sidebar__group-body{border-left:1px solid var(--color-border);margin-left:13px;padding:2px 0 10px 10px}.sidebar__level{margin:10px 0}.sidebar__level-label{text-transform:uppercase;letter-spacing:.06em;color:var(--color-text-faint);padding:0 0 5px 12px;font-size:10.5px;font-weight:700}.sidebar__lesson-list{flex-direction:column;gap:1px;display:flex}.sidebar__lesson{border-radius:var(--radius-sm);color:var(--color-text-muted);align-items:center;gap:8px;padding:6px 10px 6px 12px;font-size:13px;line-height:1.35;transition:background .15s,color .15s;display:flex}.sidebar__lesson:hover{background:var(--color-surface);color:var(--color-text)}.sidebar__lesson--active{background:color-mix(in srgb, var(--topic-color) 12%, white);color:var(--topic-color);font-weight:600}.sidebar__lesson-title{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.sidebar__lesson-dot{border:1.5px solid var(--color-border-strong);color:#fff;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:14px;height:14px;display:flex}.sidebar__lesson--active .sidebar__lesson-dot{border-color:var(--topic-color)}.sidebar__lesson-dot--done{background:var(--color-success);border-color:var(--color-success)}.sidebar__footer{border-top:1px solid var(--color-border);flex-shrink:0;padding:12px 20px}.sidebar__footer-link{color:var(--color-text-muted);font-size:13px;font-weight:600}.sidebar__footer-link:hover{color:var(--color-primary)}.sidebar__backdrop{display:none}.lesson-page__layout{grid-template-columns:minmax(0,1fr) 220px;align-items:start;gap:48px;display:grid}.lesson-page__toc-rail{max-height:calc(100vh - 100px);padding-bottom:24px;position:sticky;top:84px;overflow-y:auto}.lesson-toc__label{text-transform:uppercase;letter-spacing:.06em;color:var(--color-text-faint);margin-bottom:10px;font-size:10.5px;font-weight:700}.lesson-toc ul{flex-direction:column;gap:1px;display:flex}.lesson-toc a{color:var(--color-text-muted);border-left:2px solid var(--color-border);padding:5px 0 5px 12px;font-size:13px;line-height:1.4;transition:color .15s,border-color .15s;display:block}.lesson-toc a:hover{color:var(--color-text)}.lesson-toc__link--active{font-weight:600;color:var(--color-primary)!important;border-left-color:var(--color-primary)!important}.lesson-toc__item--sub a{padding-left:24px;font-size:12.5px}.lesson-toc--inline{border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-bg-subtle);margin:20px 0 8px;padding:14px 16px;display:none}@media (width<=1100px){.lesson-page__layout{grid-template-columns:1fr}.lesson-page__toc-rail{display:none}.lesson-toc--inline{display:block}}@media (width<=960px){.navbar__menu-btn{display:flex}.navbar__link{display:none}.sidebar{width:84vw;max-width:320px;height:calc(100vh - 64px);transition:transform .25s var(--ease);box-shadow:var(--shadow-lg);z-index:50;position:fixed;top:64px;left:0;transform:translate(-100%)}.sidebar--open{transform:translate(0)}.sidebar__backdrop{z-index:45;cursor:pointer;background:#0f0f1766;border:none;padding:0;animation:.2s backdrop-fade;display:block;position:fixed;inset:64px 0 0}@keyframes backdrop-fade{0%{opacity:0}to{opacity:1}}}@media (width<=900px){.hero--profile .hero__inner{grid-template-columns:1fr;padding:56px 24px 76px}.hero__portrait{order:-1;max-width:220px;margin:0 auto 40px}.hero__floating-card{max-width:260px;margin:24px auto 0;position:static;transform:none}.hero__content{align-items:flex-start}}@media (width<=640px){.hero h1{font-size:32px}.hero__name{font-size:38px}.hero__role{font-size:16px}.hero__cta-row{width:100%}.hero__cta-row .btn{text-align:center;flex:1}.navbar__search{max-width:160px}.lesson-nav{grid-template-columns:1fr}.lesson-nav__btn--next{text-align:left;align-items:flex-start}.navbar__links{display:none}.instructor-hero{text-align:left;flex-direction:column;align-items:flex-start}.instructor-byline{white-space:normal}}