.shell{width:100%;margin-left:auto;margin-right:auto;padding-left:1rem;padding-right:1rem}@media (min-width:640px){.shell{max-width:640px}}@media (min-width:768px){.shell{max-width:768px}}@media (min-width:1024px){.shell{max-width:1024px}}@media (min-width:1280px){.shell{max-width:1280px}}@media (min-width:1536px){.shell{max-width:1536px}}.practice-shell{padding-top:32px;padding-bottom:64px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font-family:var(--ff-body);font-weight:600;border-radius:var(--r-md);cursor:pointer;transition:background .15s,border-color .15s,color .15s,box-shadow .15s;white-space:nowrap;text-decoration:none}.btn--primary{background:var(--primary);color:#fff;border:1.5px solid var(--primary)}.btn--primary:hover{background:color-mix(in srgb,var(--primary) 88%,#000);border-color:color-mix(in srgb,var(--primary) 88%,#000)}.btn--ghost{background:transparent;color:var(--ink-2);border:1.5px solid var(--line)}.btn--ghost:hover{border-color:var(--primary);color:var(--primary);background:var(--bg-tint)}.btn--outline{background:transparent;color:var(--primary);border:1.5px solid color-mix(in srgb,var(--primary) 38%,var(--line))}.btn--outline:hover{background:var(--bg-tint);border-color:var(--primary);color:var(--primary)}.practice-hero__free-cta{position:relative;overflow:visible}.practice-hero__free-tag{position:absolute;top:-8px;right:-8px;background:var(--success);color:#fff;font-family:var(--ff-mono,monospace);font-size:9px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;padding:2px 6px;border-radius:4px;line-height:1.4;box-shadow:0 0 0 2px var(--bg);pointer-events:none}.practice-hero__courses-cta{border-color:var(--accent-2);color:var(--accent-2);background:color-mix(in srgb,var(--accent) 10%,transparent)}.practice-hero__courses-cta .btn__lead-ic{width:17px;height:17px;flex-shrink:0;color:var(--accent-2);transition:transform .15s}.practice-hero__courses-cta:hover{border-color:var(--accent-2);color:var(--accent-2);background:color-mix(in srgb,var(--accent) 18%,transparent);transform:translateY(-1px)}.practice-hero__courses-cta:hover .btn__lead-ic{transform:scale(1.08)}.btn--outline-red{background:transparent;color:#DC2626;border:1.5px solid color-mix(in srgb,#dc2626 40%,var(--line))}.btn--outline-red:hover{background:color-mix(in srgb,#DC2626 9%,transparent);border-color:#DC2626;color:#DC2626}.practice-hero__cta .btn__lead-ic{width:17px;height:17px;flex-shrink:0}.btn--lg{padding:14px 28px;font-size:15px}.btn--sm{padding:9px 18px;font-size:13.5px}.practice-hero{position:relative;padding:48px 0 56px;overflow:hidden;isolation:isolate;background:var(--bg)}.practice-hero:before{inset:-10% -10% auto auto;width:70%;aspect-ratio:1;background:radial-gradient(circle,color-mix(in srgb,var(--primary) 8%,transparent) 0,transparent 65%)}.practice-hero:after,.practice-hero:before{content:"";position:absolute;pointer-events:none;z-index:-1}.practice-hero:after{inset:0;background-image:linear-gradient(to right,color-mix(in srgb,var(--ink) 3%,transparent) 1px,transparent 1px),linear-gradient(to bottom,color-mix(in srgb,var(--ink) 3%,transparent) 1px,transparent 1px);background-size:64px 64px;-webkit-mask-image:radial-gradient(ellipse at 0 100%,black 0,transparent 60%);mask-image:radial-gradient(ellipse at 0 100%,black 0,transparent 60%);opacity:.5}.practice-hero__grid{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(280px,1fr);gap:56px;align-items:center}@media (max-width:920px){.practice-hero__grid{grid-template-columns:1fr;gap:28px}}.practice-hero__free-chip{display:inline-flex;align-items:center;gap:10px;padding:6px 14px 6px 6px;border-radius:999px;background:var(--bg-elev);border:1px solid var(--line);font-family:var(--ff-body);font-size:13px;font-weight:500;color:var(--ink-2);margin-bottom:18px}.practice-hero__free-chip-tag{background:var(--success);color:#fff;font-family:var(--ff-mono);font-size:10.5px;font-weight:700;letter-spacing:.1em;padding:3px 9px;border-radius:999px}.practice-hero__title{font-family:var(--ff-display);font-weight:700;font-size:clamp(34px,5.2vw,64px);letter-spacing:-.034em;line-height:1.02;margin:0 0 18px;color:var(--ink);max-width:18ch}.practice-hero__hl{background:var(--primary-gradient);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;font-weight:700}.practice-hero__sub{font-size:clamp(15px,1.1vw,17px);color:var(--muted);max-width:56ch;line-height:1.55;margin:0}.practice-hero__cta{display:flex;gap:12px;margin-top:28px;flex-wrap:wrap}.practice-hero__upsell{display:flex;flex-direction:column;gap:12px}.hero-course{display:flex;align-items:center;gap:12px;padding:14px 16px;width:100%;background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-lg);text-decoration:none;color:var(--ink);text-align:left;transition:border-color .15s,box-shadow .15s}.hero-course:hover{border-color:var(--primary);box-shadow:0 8px 20px -8px color-mix(in srgb,var(--primary) 20%,transparent)}.hero-course--alt{border-color:color-mix(in srgb,var(--primary) 25%,var(--line))}.hero-course__thumb{width:56px;height:56px;border-radius:var(--r-md);overflow:hidden;flex-shrink:0;background:var(--bg-tint)}.hero-course__thumb img{width:100%;height:100%;object-fit:cover}.hero-course__body{flex:1;min-width:0;display:flex;flex-direction:column;gap:2px}.hero-course__popular{font-family:var(--ff-mono);font-size:10px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--accent-2);margin-bottom:1px}.hero-course__name{font-family:var(--ff-display);font-weight:700;font-size:14px;color:var(--ink)}.hero-course__meta{font-size:12px;color:var(--muted)}.hero-course__right{flex-shrink:0;text-align:right;display:flex;flex-direction:column;gap:2px}.hero-course__deal{font-size:10.5px;color:var(--muted)}.hero-course__price-row{display:flex;align-items:baseline;gap:6px;justify-content:flex-end}.hero-course__price-now{font-family:var(--ff-display);font-weight:700;font-size:16px;color:var(--ink)}.hero-course__price-was{font-size:12px;color:var(--muted);text-decoration:line-through}.hero-course__discount{font-family:var(--ff-mono);font-size:10px;font-weight:700;color:var(--success);letter-spacing:.04em}.hero-course__discount--alt{color:var(--accent-2)}.ptabs{position:sticky;top:0;z-index:40;background:var(--bg-elev);border-bottom:1px solid var(--line);box-shadow:var(--shadow-sm)}.ptabs__row{display:flex;gap:4px;padding:6px 0;overflow-x:auto;-webkit-overflow-scrolling:touch}.ptabs__btn{display:inline-flex;align-items:center;gap:10px;padding:10px 20px;border:0;background:transparent;font-family:var(--ff-body);font-size:14px;font-weight:500;color:var(--muted);border-radius:var(--r-md);cursor:pointer;transition:background .15s,color .15s;white-space:nowrap;flex-shrink:0}.ptabs__btn:hover{background:var(--bg-tint);color:var(--ink)}.ptabs__btn.is-active{background:var(--bg-tint);color:var(--primary);font-weight:600}.ptabs__letter{font-family:var(--ff-mono);font-size:11px;font-weight:700;letter-spacing:.06em;background:var(--primary-soft);color:var(--primary);width:28px;height:28px;display:grid;place-items:center;border-radius:6px;flex-shrink:0}.ptabs__btn.is-active .ptabs__letter{background:var(--primary);color:#fff}.ptabs__title{font-size:14px}.practice-body{display:flex;gap:24px;align-items:flex-start}.topic-nav{width:clamp(240px,22vw,340px);flex-shrink:0;position:sticky;top:56px;max-height:calc(100vh - 72px);overflow-y:auto;border:1px solid var(--line);border-radius:var(--r-lg);background:var(--bg-elev);-webkit-overflow-scrolling:touch}.topic-nav__title{font-family:var(--ff-mono);font-size:10.5px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);padding:14px 16px 8px}.topic-nav__list{list-style:none;margin:0;padding:0 8px 12px}.topic-nav__group{margin-bottom:2px}.topic-nav__item{width:100%;display:flex;align-items:center;gap:8px;padding:9px 10px;border-radius:var(--r-md);border:0;background:transparent;font-family:var(--ff-body);font-size:clamp(13.5px,.95vw,15px);font-weight:500;color:var(--ink-2);text-align:left;cursor:pointer;transition:background .12s,color .12s}.topic-nav__item:hover{background:var(--bg-tint);color:var(--ink)}.topic-nav__item.is-active{background:var(--bg-tint);color:var(--primary);font-weight:600}.topic-nav__num{font-family:var(--ff-mono);font-size:10px;font-weight:700;color:var(--muted-2);letter-spacing:.06em;flex-shrink:0;width:18px}.topic-nav__item.is-active .topic-nav__num{color:var(--primary)}.topic-nav__name{flex:1;min-width:0}.topic-nav__count{font-family:var(--ff-mono);font-size:10px;font-weight:600;background:var(--bg-tint);color:var(--muted);padding:2px 6px;border-radius:999px;flex-shrink:0}.topic-nav__caret{flex-shrink:0;color:var(--muted-2);transition:transform .2s}.topic-nav__group.is-open .topic-nav__caret{transform:rotate(180deg)}.topic-nav__sublist{list-style:none;margin:0;padding:2px 0 4px 14px}.topic-nav__subitem{width:100%;display:flex;align-items:center;justify-content:space-between;gap:6px;padding:7px 10px;border-radius:var(--r-sm);border:0;background:transparent;font-family:var(--ff-body);font-size:clamp(12.5px,.88vw,14px);font-weight:400;color:var(--muted);text-align:left;cursor:pointer;transition:background .12s,color .12s}.topic-nav__subitem:hover:not(:disabled){background:var(--bg-tint);color:var(--ink)}.topic-nav__subitem.is-mastered{color:var(--success)}.topic-nav__subitem.is-empty{opacity:.45;cursor:not-allowed}.topic-nav__subname{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.topic-nav__submeta{display:flex;align-items:center;gap:4px;flex-shrink:0}.topic-nav__subcheck{color:var(--success);font-size:11px}.topic-nav__subcount{font-family:var(--ff-mono);font-size:10px;font-weight:600;color:var(--muted-2)}.practice-main{flex:1;min-width:0}.subview__head{margin-bottom:20px}.subview__eyebrow{font-family:var(--ff-mono);font-size:11px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);margin-bottom:4px}.subview__title{font-family:var(--ff-display);font-weight:700;font-size:clamp(22px,3vw,32px);letter-spacing:-.022em;margin:0;color:var(--ink);line-height:1.1}.subview__grid--variant-e{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}@media (max-width:760px){.subview__grid--variant-e{grid-template-columns:1fr;gap:10px}}.subcard-ve{position:relative;display:flex;align-items:stretch;gap:0;background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-md);overflow:hidden;transition:border-color .15s,box-shadow .15s,transform .12s}.subcard-ve:hover{border-color:var(--line-3);box-shadow:0 4px 14px -6px rgba(15,23,42,.12);transform:translateY(-1px)}.subcard-ve__body{flex:1;min-width:0;display:flex;flex-direction:column;padding:16px 20px 18px}.subcard-ve__head{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:4px}.subcard-ve__ord{font-family:var(--ff-mono);font-size:10.5px;font-weight:700;letter-spacing:.12em;color:var(--muted-2)}.subcard-ve__name{margin:0 0 14px;font-family:var(--ff-display);font-weight:600;font-size:17px;letter-spacing:-.014em;line-height:1.25;color:var(--ink)}.subcard-ve__actions{display:flex;gap:8px;margin-top:auto;align-items:center;flex-wrap:wrap}.subcard-ve__primary{display:inline-flex;align-items:center;justify-content:center;gap:7px;padding:10px 18px;background:var(--primary);color:#fff;border:0;border-radius:999px;font-family:var(--ff-body);font-size:13px;font-weight:600;white-space:nowrap;cursor:pointer;transition:background .12s,transform .08s}.subcard-ve__primary svg{flex:none}.subcard-ve__primary:hover{background:color-mix(in srgb,var(--primary) 88%,#000)}.subcard-ve__primary:active{transform:scale(.98)}.subcard-ve__primary.is-disabled{background:var(--bg-tint);color:var(--muted-2);cursor:not-allowed}.subcard-ve__primary.is-disabled:hover{background:var(--bg-tint)}.subcard-ve__ghost{display:inline-flex;align-items:center;gap:6px;padding:10px 14px;background:transparent;color:var(--ink-2);border:0;font-family:var(--ff-body);font-size:13px;font-weight:600;white-space:nowrap;cursor:pointer;border-radius:999px;transition:background .12s,color .12s}.subcard-ve__ghost svg{flex:none}.subcard-ve__ghost:hover{background:var(--bg-tint);color:var(--primary)}@media (max-width:1080px){.subcard-ve__actions{gap:6px}.subcard-ve__primary{flex:1 1 100%;justify-content:center;padding:11px 14px}.subcard-ve__ghost{flex:1 1 100%;justify-content:center;padding:10px 14px;border:1px solid var(--line)}}@media (max-width:760px){.subcard-ve__body{padding:12px 14px 14px}.subcard-ve__name{font-size:15.5px}.subcard-ve__primary{font-size:13.5px}}@media (max-width:540px){.subcard-ve__ord{font-size:10px}.subcard-ve__name{font-size:15px;line-height:1.3}}.detail__head{margin-bottom:0}.detail__title{font-family:var(--ff-display);font-weight:700;font-size:clamp(20px,3vw,28px);letter-spacing:-.02em;margin:6px 0 0;color:var(--ink);line-height:1.15}.detail__tabs{display:flex;gap:0;border-bottom:2px solid var(--line);margin:16px 0 0;position:sticky;top:50px;background:var(--bg);z-index:20}.detail__tab{display:inline-flex;align-items:center;gap:6px;padding:12px 20px;font-family:var(--ff-body);font-weight:500;font-size:14px;color:var(--muted);border:0;background:transparent;cursor:pointer;border-bottom:2px solid transparent;margin-bottom:-2px;transition:color .15s;white-space:nowrap}.detail__tab:hover{color:var(--ink)}.detail__tab.is-active{color:var(--primary);border-bottom-color:var(--primary);font-weight:600}.detail__tab svg{flex-shrink:0}.detail__content{padding:20px 0 8px}.notes-placeholder{display:flex;flex-direction:column;gap:24px;width:100%}.notes-placeholder__card{text-align:center;padding:40px 24px 36px;border:2px dashed var(--line);border-radius:var(--r-lg);background:var(--bg)}.notes-placeholder__icon{display:inline-flex;align-items:center;justify-content:center;width:64px;height:64px;border-radius:16px;background:var(--bg-tint);color:var(--primary);margin:0 auto 18px}.notes-placeholder__title{font-family:var(--ff-display);font-weight:700;font-size:18px;letter-spacing:-.01em;color:var(--ink);margin:0 0 8px}.notes-placeholder__sub{font-size:14px;color:var(--muted);line-height:1.55;max-width:38ch;margin:0 auto 20px}.notes-placeholder__types{display:flex;justify-content:center;gap:16px;flex-wrap:wrap}.notes-placeholder__type{display:inline-flex;align-items:center;gap:6px;font-family:var(--ff-body);font-weight:500;font-size:12.5px;color:var(--muted);padding:6px 12px;border:1px solid var(--line);border-radius:999px;background:var(--bg-elev)}.notes-placeholder__type svg{color:var(--primary);flex-shrink:0}.notes-placeholder__cta{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:16px 20px;background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-md)}.notes-placeholder__cta-text{font-size:13.5px;color:var(--muted);margin:0}@media (max-width:720px){.notes-placeholder__card{padding:32px 18px 28px}.notes-placeholder__cta{flex-direction:column;text-align:center;gap:10px}}.quiz{background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-lg);overflow:hidden}.quiz__head{display:flex;align-items:center;gap:12px;padding:14px 20px;border-bottom:1px solid var(--line-2);flex-wrap:wrap}.quiz__back{display:inline-flex;align-items:center;gap:6px;background:none;border:0;padding:0;font-family:var(--ff-body);font-size:13px;font-weight:500;color:var(--muted);cursor:pointer;transition:color .15s}.quiz__back:hover{color:var(--primary)}.quiz__crumb{font-family:var(--ff-display);font-weight:600;font-size:13.5px;color:var(--ink);flex:1}.quiz__counter{font-family:var(--ff-mono);font-size:13px;font-weight:600;color:var(--muted);flex-shrink:0}.quiz__counter b{color:var(--ink)}.quiz__progress{height:3px;background:var(--line-2)}.quiz__progress-fill{height:100%;background:var(--primary);transition:width .35s ease}.quiz__body{padding:28px 24px}.quiz__passage{margin-bottom:20px;font-size:14.5px;line-height:1.75;color:var(--ink-2)}.quiz__passage p{margin:0 0 12px}.quiz__passage p:last-child{margin-bottom:0}.quiz__image{max-width:100%;border-radius:var(--r-md);margin-bottom:20px;display:block}.quiz__question{font-family:var(--ff-display);font-weight:700;font-size:clamp(15px,1.4vw,18px);letter-spacing:-.01em;line-height:1.35;color:var(--ink);margin:0 0 20px}.quiz__code{background:#1e1e2e;color:#cdd6f4;border-radius:var(--r-md);font-family:Fira Code,Cascadia Code,Consolas,Menlo,monospace;font-size:13.5px;line-height:1.65;padding:16px 20px;overflow-x:auto;margin:0 0 20px;white-space:pre;border:1px solid #313244}.quiz__code code{font:inherit;background:none;padding:0;color:inherit}.quiz__options{display:flex;flex-direction:column;gap:10px}.quiz__opt{display:flex;align-items:flex-start;gap:14px;padding:14px 16px;border:1.5px solid var(--line);border-radius:var(--r-md);background:var(--bg);font:inherit;cursor:pointer;text-align:left;transition:border-color .15s,background .15s}.quiz__opt:hover:not(.is-disabled){border-color:var(--primary);background:var(--bg-tint)}.quiz__opt.is-correct{border-color:#16a34a;background:#f0fdf4}.quiz__opt.is-wrong{border-color:#dc2626;background:#fef2f2}.quiz__opt.is-disabled{cursor:default;pointer-events:none}.quiz__opt-letter{font-family:var(--ff-mono);font-size:12px;font-weight:700;letter-spacing:.04em;width:28px;height:28px;display:grid;place-items:center;border-radius:6px;background:var(--bg-tint);color:var(--muted);flex-shrink:0;transition:background .15s,color .15s}.quiz__opt.is-correct .quiz__opt-letter{background:#16a34a;color:#fff}.quiz__opt.is-wrong .quiz__opt-letter{background:#dc2626;color:#fff}.quiz__opt-text{font-family:var(--ff-body);font-size:14px;color:var(--ink-2);line-height:1.5}.quiz__explanation{margin-top:20px;background:#FAFAF9;border:1px solid #e7e5e0;border-radius:var(--r-md);overflow:hidden;font-size:13.5px;color:#3D3A35;line-height:1.7}.quiz__expl-head{display:flex;align-items:center;gap:7px;padding:10px 16px;background:#F3F0EB;border-bottom:1px solid #e7e5e0}.quiz__expl-head svg{flex-shrink:0;color:#A07C3A}.quiz__expl-label{font-size:12px;font-weight:650;letter-spacing:.02em;color:#6B5828}.quiz__expl-body{padding:14px 16px}.quiz__expl-body p{margin:0 0 5px}.quiz__expl-body p:last-child{margin-bottom:0}.quiz__expl-source{font-size:11px;color:#9B9289;margin-bottom:10px}.quiz__expl-img{display:block;max-width:100%;height:auto;margin:8px 0;border-radius:4px}.quiz__foot{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:16px 24px;border-top:1px solid var(--line-2)}.quiz__score-live{font-family:var(--ff-mono);font-size:13px;font-weight:600;color:var(--muted)}.quiz__score{padding:48px 24px;text-align:center}.quiz__score-ring{position:relative;width:120px;height:120px;margin:0 auto 24px}.quiz__score-ring svg{width:100%;height:100%;transform:rotate(-90deg)}.quiz__score-ring-bg{stroke:var(--line)}.quiz__score-ring-fill{stroke:url(#quiz-grad);transition:stroke-dashoffset 1s cubic-bezier(.4,0,.2,1)}.quiz__score-pct{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;flex-direction:column}.quiz__score-num{font-family:var(--ff-display);font-weight:800;font-size:30px;letter-spacing:-.03em;color:var(--ink);line-height:1}.quiz__score-unit{font-family:var(--ff-mono);font-size:12px;font-weight:700;color:var(--muted)}.quiz__score-title{font-family:var(--ff-display);font-weight:700;font-size:20px;letter-spacing:-.012em;color:var(--ink);margin:0 0 8px}.quiz__score-sub{font-size:14px;color:var(--muted);max-width:40ch;margin:0 auto 28px}.quiz__score-actions{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}@media (max-width:720px){.quiz__body{padding:20px 16px}.quiz__foot{padding:14px 16px}.quiz__head{padding:12px 16px}}.course-pitch{margin-top:56px}.course-pitch__head{margin-bottom:28px}.course-pitch__title{font-family:var(--ff-display);font-weight:700;font-size:clamp(18px,2vw,22px);letter-spacing:-.015em;color:var(--ink);margin:0 0 8px}.course-pitch__sub{font-size:14px;color:var(--muted);margin:0;line-height:1.55}.course-pitch__cards{display:flex;flex-wrap:wrap;gap:20px}@media (max-width:560px){.course-pitch__cards{flex-direction:column}}.xi-course-card{position:relative;display:flex;flex-direction:column;background:var(--bg-elev);border:1.5px solid var(--line);border-radius:16px;overflow:hidden;max-width:340px;transition:transform .18s,box-shadow .18s,border-color .18s;box-shadow:0 2px 8px rgba(15,23,42,.06)}.xi-course-card:hover{transform:translateY(-4px);box-shadow:0 16px 40px -8px rgba(15,23,42,.18);border-color:var(--line-3)}.xi-course-card--featured{border-color:color-mix(in srgb,var(--primary) 40%,var(--line))}.xi-course-card__badge{position:absolute;top:0;right:0;z-index:3;background:#F59E0B;color:#fff;font-family:var(--ff-mono);font-size:10px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;padding:5px 12px;border-radius:0 14px 0 10px}.xi-course__thumb{position:relative;overflow:hidden;height:160px;display:flex;flex-direction:column;align-items:center;justify-content:center}.xi-course__thumb-grid{position:absolute;inset:0;background-image:linear-gradient(90deg,rgba(255,255,255,.07) 1px,transparent 0),linear-gradient(180deg,rgba(255,255,255,.07) 1px,transparent 0);background-size:28px 28px;pointer-events:none}.xi-course__thumb-glyph{position:relative;z-index:1;font-family:var(--ff-display);font-weight:900;font-size:clamp(36px,6vw,52px);letter-spacing:-.02em;color:#fff;text-shadow:0 3px 16px rgba(0,0,0,.3)}.xi-course__thumb-label{position:absolute;bottom:12px;left:14px;z-index:1;background:rgba(0,0,0,.32);backdrop-filter:blur(6px);color:#fff;font-family:var(--ff-mono);font-size:9.5px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;padding:4px 10px;border-radius:999px}.xi-course-card__body{padding:16px 18px 12px;display:flex;flex-direction:column;gap:8px;flex:1}.xi-course-card__meta{display:flex;align-items:center;gap:6px;font-family:var(--ff-mono);font-size:10.5px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}.xi-dot{width:3px;height:3px;border-radius:50%;background:var(--muted-2);display:inline-block;flex-shrink:0}.xi-course-card__name{font-family:var(--ff-display);font-weight:700;font-size:15px;letter-spacing:-.012em;color:var(--ink);margin:0;line-height:1.3}.xi-course-card__desc{font-size:13px;color:var(--muted);line-height:1.55;margin:0;flex:1;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}.xi-course-card__foot{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:12px 18px 16px;border-top:1px solid var(--line-2)}.xi-course-card__price{display:flex;align-items:baseline;gap:7px;font-family:var(--ff-display)}.xi-course-card__price b{font-size:20px;font-weight:800;color:var(--ink)}.xi-course-card__price s{font-size:12px;color:var(--muted-2);text-decoration:line-through}.xi-btn{display:inline-flex;align-items:center;justify-content:center;font-family:var(--ff-body);font-weight:700;border-radius:10px;cursor:pointer;white-space:nowrap;border:0;text-decoration:none;transition:background .12s,box-shadow .12s,transform .08s}.xi-btn--primary{background:#2563EB;color:#fff;box-shadow:0 2px 8px rgba(37,99,235,.35)}.xi-btn--primary:hover{background:#1d4ed8;box-shadow:0 4px 14px rgba(37,99,235,.45)}.xi-btn--sm{padding:11px 22px;font-size:14px}.xi-course-card:hover .xi-btn--primary{transform:translateX(2px)}.course-modal-backdrop{position:fixed;inset:0;z-index:200;background:rgba(10,14,26,.65);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;padding:24px;animation:fadeIn .18s ease}.course-modal{position:relative;width:90vw;max-width:1100px;height:88vh;background:#fff;border-radius:16px;overflow:hidden;box-shadow:0 32px 80px -16px rgba(10,14,26,.45);display:flex;flex-direction:column;animation:slideUp .2s ease}@media (max-width:640px){.course-modal-backdrop{padding:0;align-items:flex-end}.course-modal{width:100%;max-width:100%;height:94vh;border-radius:20px 20px 0 0}}.course-modal__close{position:absolute;top:14px;right:14px;z-index:10;width:36px;height:36px;background:rgba(255,255,255,.95);border:1px solid rgba(0,0,0,.12);border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:20px;color:#374151;line-height:1;box-shadow:0 2px 8px rgba(0,0,0,.1);transition:background .12s,box-shadow .12s}.course-modal__close:hover{background:#fff;color:#111;box-shadow:0 4px 12px rgba(0,0,0,.15)}.course-modal iframe{flex:1;border:0;width:100%;height:100%}.course-modal__loader{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;background:#f8fafc;color:var(--muted);font-size:14px}.hero-course,.m-back{cursor:pointer}.m-back{display:inline-flex;align-items:center;gap:6px;background:none;border:0;padding:8px 0;color:var(--muted);font-family:var(--ff-body);font-size:13px;font-weight:500;transition:color .15s}.m-back:hover{color:var(--primary)}.m-back svg{flex-shrink:0;color:currentColor}.m-topics__head{margin-bottom:20px}.m-topics__eyebrow{font-family:var(--ff-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);margin-bottom:4px}.m-topics__title{font-family:var(--ff-display);font-weight:700;font-size:24px;letter-spacing:-.02em;margin:0 0 6px;color:var(--ink)}.m-topics__desc{font-size:14px;color:var(--muted);margin:0;line-height:1.5}.m-topics__grid{display:flex;flex-direction:column;gap:8px}.m-topic-card{display:flex;align-items:center;gap:14px;padding:16px;background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-md);text-align:left;font:inherit;color:var(--ink);cursor:pointer;min-height:64px;transition:border-color .15s,box-shadow .15s}.m-topic-card:hover{border-color:var(--primary);box-shadow:0 4px 12px -6px color-mix(in srgb,var(--primary) 25%,transparent)}.m-topic-card__num{font-family:var(--ff-mono);font-size:11px;font-weight:600;letter-spacing:.06em;color:var(--primary);background:var(--primary-soft);width:36px;height:36px;display:grid;place-items:center;border-radius:8px;flex-shrink:0}.m-topic-card__body{flex:1;min-width:0;display:flex;flex-direction:column;gap:4px}.m-topic-card__name{font-family:var(--ff-display);font-weight:600;font-size:15px;letter-spacing:-.005em;color:var(--ink)}.m-topic-card__meta{font-size:12.5px;color:var(--muted)}.m-topic-card__arrow{color:var(--muted-2);flex-shrink:0;display:flex}.m-subtopics__head{margin-bottom:20px}.m-subtopics__info{margin-top:8px}.m-subtopics__eyebrow{font-family:var(--ff-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);margin-bottom:2px}.m-subtopics__title{font-family:var(--ff-display);font-weight:700;font-size:22px;letter-spacing:-.02em;margin:0 0 4px;color:var(--ink)}.m-subtopics__list{display:flex;flex-direction:column;gap:6px}.m-sub-card{display:flex;align-items:center;gap:12px;padding:14px 16px;background:var(--bg-elev);border:1px solid var(--line);border-radius:var(--r-md);text-align:left;font:inherit;color:var(--ink);cursor:pointer;min-height:56px;transition:border-color .15s}.m-sub-card:hover{border-color:var(--primary)}.m-sub-card__num{font-family:var(--ff-mono);font-size:10.5px;font-weight:600;color:var(--muted-2);flex-shrink:0;width:20px}.m-sub-card__body{flex:1;min-width:0;display:flex;flex-direction:column;gap:6px}.m-sub-card__name{font-family:var(--ff-display);font-weight:600;font-size:14px;letter-spacing:-.005em;color:var(--ink)}.m-sub-card__badges{display:flex;gap:6px;flex-wrap:wrap}.m-sub-card__badge{font-family:var(--ff-mono);font-size:10px;font-weight:600;letter-spacing:.04em;padding:2px 8px;border-radius:4px}.m-sub-card__badge--notes{background:color-mix(in srgb,var(--primary) 8%,var(--bg));color:var(--primary)}.m-sub-card__badge--mcqs{background:var(--bg-tint);color:var(--muted)}.m-sub-card__arrow{color:var(--muted-2);flex-shrink:0;display:flex}@media (max-width:920px){.practice-shell{padding-bottom:max(64px,env(safe-area-inset-bottom,64px))}.detail__tabs{top:50px}.m-topic-card{padding:14px;gap:12px}.m-topic-card__num{width:32px;height:32px;font-size:10.5px}.m-sub-card{padding:12px 14px;gap:10px}.detail__tab{padding:11px 16px;font-size:13.5px}.detail__content{padding:16px 0 8px}.detail__title{font-size:20px}}.practice-loading{display:flex;align-items:center;justify-content:center;gap:10px;min-height:200px;color:var(--muted);font-size:14px}.practice-loading__spinner{display:inline-block;width:18px;height:18px;border:2px solid var(--line-3);border-top-color:var(--primary);border-radius:50%;animation:spin .7s linear infinite;flex-shrink:0}@keyframes spin{to{transform:rotate(1turn)}}