@font-face{font-family:Ultane;src:url(/assets/ultane-meta-jHzTRuRb.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}:root{--course-ui-font: var(--font-display);--course-display-font: var(--font-display);--course-meta-font: "Ultane", system-ui, sans-serif;--course-ui-type: var(--weight-medium) 16px/20px var(--course-ui-font);--course-brand-type: var(--weight-medium) 24px/32px var(--course-display-font);--course-gap: var(--space-3xl);--course-card-radius: var(--ui-radius-xl);--course-edge: 10px;--course-header-clearance: 110px;--episode-size: min(640px, calc(100vw - 48px) , max(320px, calc(100svh - 220px) ));--episode-title-size: 32px;--episode-title-long-size: 26px}body:has(.course-home){background:var(--course-bg)}.course-home{color-scheme:light;background:var(--course-bg);color:var(--course-ink);font:var(--course-ui-type);height:100svh;min-height:calc(var(--episode-size) + 2 * var(--course-header-clearance));display:grid;grid-template-rows:1fr auto 1fr;overflow:clip}.course-header{position:relative;align-self:start;min-height:105px}.course-utility{font:var(--course-ui-type);text-transform:uppercase;color:var(--course-ink);background:none;border:0;padding:0;opacity:1;cursor:default;transition:color .16s}.course-utility:hover{background:none;color:var(--course-intro-ink);text-decoration:underline;text-underline-offset:4px}.course-account{position:absolute;top:var(--course-edge);left:var(--course-edge)}.course-support{position:absolute;top:var(--course-edge);right:var(--course-edge)}.course-brandline{max-width:896px;width:calc(100% - 240px);display:flex;justify-content:space-between;margin:var(--course-edge) auto 0;font:var(--course-brand-type)}.course-brandmark{position:absolute;top:var(--course-edge);left:calc(50% - 75px);width:151px;height:94.2366px}.course-logo{display:block;position:absolute;left:21px;top:0}.course-avatar{position:absolute;left:-39px;top:0;width:110px;height:137.5px;object-fit:cover;-webkit-mask-image:url("data:image/svg+xml,%3csvg%20preserveAspectRatio='none'%20overflow='visible'%20style='display:%20block;'%20width='32'%20height='32'%20viewBox='0%200%2032%2032'%20fill='none'%20xmlns='http://www.w3.org/2000/svg'%3e%3ccircle%20id='Ellipse%201'%20cx='16'%20cy='16'%20r='16'%20fill='%23D9D9D9'/%3e%3c/svg%3e");mask-image:url("data:image/svg+xml,%3csvg%20preserveAspectRatio='none'%20overflow='visible'%20style='display:%20block;'%20width='32'%20height='32'%20viewBox='0%200%2032%2032'%20fill='none'%20xmlns='http://www.w3.org/2000/svg'%3e%3ccircle%20id='Ellipse%201'%20cx='16'%20cy='16'%20r='16'%20fill='%23D9D9D9'/%3e%3c/svg%3e");-webkit-mask-size:32px 32px;mask-size:32px 32px;-webkit-mask-position:39px 5px;mask-position:39px 5px;-webkit-mask-repeat:no-repeat;mask-repeat:no-repeat}.course-main{min-width:0}.course-footer{align-self:end;text-align:center;padding-bottom:var(--course-edge)}.course-carousel{position:relative;overflow:visible;cursor:grab;-webkit-user-select:none;user-select:none;touch-action:pan-y pinch-zoom;outline:none}.course-carousel-track{position:relative;display:flex;align-items:center;gap:var(--course-gap);width:max-content;padding:0 calc((100vw - var(--episode-size)) / 2)}.course-carousel.is-dragging,.course-carousel.is-dragging *{cursor:grabbing}.episode-slide{position:relative;container-type:inline-size;flex:0 0 var(--episode-size);width:var(--episode-size);height:var(--episode-size);border-radius:var(--course-card-radius);background:var(--course-card);color:var(--course-bg);overflow:hidden;display:block;text-decoration:none;transition:background .18s}.episode-slide[href]{cursor:pointer}.episode-slide[aria-disabled=true]{cursor:grab}.episode-slide[href]:focus-visible,.course-carousel:focus-visible .episode-slide[data-active]{outline:2px solid var(--course-bg);outline-offset:-6px}.course-carousel:focus-visible .episode-intro[data-active]{outline-color:var(--course-intro-ink)}.episode-stamp{position:absolute;top:8px;width:48px;height:48px;display:grid;place-items:center}.episode-stamp-left{left:9px}.episode-stamp-right{right:8px}.episode-stamp img{position:absolute;inset:0;display:block}.episode-stamp>span{font:400 24px/32px var(--course-meta-font);opacity:.2;text-transform:uppercase}.episode-stamp-double>span{font-size:16px}.episode-cover{position:absolute;left:15.9375%;top:23.4375%;width:68.125%;height:38.28125%;object-fit:cover;pointer-events:none;transition:transform .16s var(--v2-ease)}.episode-title{position:absolute;left:50%;bottom:12.1875%;transform:translate(-50%);width:65.78125%;margin:0;text-align:center;text-transform:uppercase;font:700 var(--episode-title-size)/1 var(--course-display-font);text-wrap:balance}.episode-title-long{font-size:var(--episode-title-long-size)}.episode-open{position:absolute;bottom:3.75%;left:0;width:100%;text-align:center;font:var(--weight-medium) 16px/24px var(--course-display-font)}@supports not (font-size: round(1cqw,1px)){@container (min-width: 400px){.episode-title{--episode-title-size: 48px;--episode-title-long-size: 38px}}@container (min-width: 560px){.episode-title{--episode-title-size: 64px;--episode-title-long-size: 51px}.episode-open{font-size:20px;line-height:30px}}}@supports (font-size: round(1cqw,1px)){:root{--episode-title-size: round(10cqw, 1px);--episode-title-long-size: round(8cqw, 1px)}.episode-open{font-size:round(clamp(16px,3.125cqw,20px),1px);line-height:round(1.5em,1px)}}.episode-slide[href]:hover .episode-open{text-decoration:underline;text-underline-offset:4px}.episode-intro{background:var(--course-bg);color:var(--course-intro-ink);box-shadow:inset 0 0 0 2px var(--course-intro-line)}.episode-intro .episode-title{top:40%;bottom:auto}.intro-cover-label{position:absolute;top:16px;width:100%;text-align:center;font:400 24px/32px var(--course-meta-font);text-transform:uppercase}@media(max-width:700px){:root{--course-gap: var(--space-md);--course-card-radius: var(--ui-radius-lg);--course-header-clearance: 170px;--episode-size: min(640px, calc(100vw - 64px) , max(300px, calc(100svh - 340px) ))}.course-brandline{width:calc(100% - 48px);margin-top:118px;font:var(--weight-medium) 20px/28px var(--course-display-font)}}@media(prefers-reduced-motion:reduce){.episode-slide,.episode-cover{transition:none}}@media(hover:hover)and (pointer:fine){.episode-slide:hover{background:color-mix(in srgb,var(--course-card),white 7%)}.episode-slide:hover .episode-cover{transform:scale(1.025)}.episode-intro:hover{background:color-mix(in srgb,var(--course-bg),white 15%)}}.course-utility:disabled{opacity:1}.course-utility-bar{position:fixed;z-index:60;inset:0 0 auto;height:var(--ui-header-height);display:flex;align-items:center;justify-content:space-between;padding-inline:10px;color:var(--course-ink);font:var(--course-ui-type, var(--ui-type-control));pointer-events:none}.course-utility-bar>button,.course-utility-center{pointer-events:auto}.course-utility-center{position:absolute;left:50%;transform:translate(-50%)}.course-load-status{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:var(--space-sm);padding:var(--space-sm) var(--space-md);font:var(--ui-type-body)}.course-main,.course-brandline,.course-brandmark,.course-footer{transition:transform var(--v2-exit-duration) var(--v2-ease)}.course-main{transform-origin:50% 50%}.course-home.is-covered .course-main{transform:translateY(var(--v2-background-shift)) scale(.9)}.course-home.is-covered :is(.course-main,.course-brandline,.course-brandmark,.course-footer){transition-duration:var(--v2-duration)}.course-home.is-covered .course-brandline,.course-home.is-covered .course-brandmark{transform:translateY(-150px)}.course-home.is-covered .course-footer{transform:translateY(44px)}.course-home .course-utility{transition:transform var(--v2-exit-duration) var(--v2-ease),color var(--motion-hover)}.course-home.is-covered .course-utility{transform:translateY(-150px);transition-duration:var(--v2-duration)}@media(prefers-reduced-motion:reduce){.course-main,.course-brandline,.course-brandmark,.course-footer,.course-home.is-covered :is(.course-main,.course-brandline,.course-brandmark,.course-footer){transition-duration:1ms}.course-home .course-utility{transition:none}}.app-recovery{min-height:100dvh;display:grid;place-items:center;padding:var(--space-lg);background:var(--ui-surface);color:var(--ui-ink);text-align:center}.app-recovery h1{margin:0 0 var(--space-md);font:var(--ui-type-heading)}.app-recovery h1:focus{outline:none}.app-recovery p{margin:0 0 var(--space-lg);font:var(--ui-type-body)}@font-face{font-family:Google Sans;src:url(/assets/google-sans-regular-BfdCbcwn.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}@font-face{font-family:Google Sans;src:url(/assets/google-sans-medium-Bltv1a_x.woff2) format("woff2");font-weight:500;font-style:normal;font-display:swap}@font-face{font-family:Google Sans;src:url(/assets/google-sans-bold-B9PUnXbI.woff2) format("woff2");font-weight:700;font-style:normal;font-display:swap}@font-face{font-family:ABC Solar;src:url(/assets/abc-solar-regular-UYixBSTB.woff2) format("woff2");font-weight:400;font-style:normal;font-display:swap}@font-face{font-family:ABC Solar;src:url(/assets/abc-solar-medium-DFbFKGdp.woff2) format("woff2");font-weight:500;font-style:normal;font-display:swap}@font-face{font-family:ABC Solar;src:url(/assets/abc-solar-bold-D1DRtqKC.woff2) format("woff2");font-weight:700;font-style:normal;font-display:swap}:root{--font: "ABC Solar", system-ui, sans-serif;--font-reading: "Google Sans", system-ui, sans-serif;--font-ui: var(--font-reading);--font-display: var(--font);--font-sticker: var(--font);--weight-regular: 400;--weight-medium: 500;--weight-bold: 700;--sticker-font-size: 20px;--sticker-line-height: 24px;--sticker-font-weight: var(--weight-bold);font-synthesis:none}:root,[data-ui-theme=light]{color-scheme:light;--ui-stage: #f7e1c9;--ui-button-paper-bg: #fff;--ui-button-paper-ink: #3e0061;--ui-button-brand-bg: #3e0061;--ui-button-brand-ink: #fff;--ui-surface: #fff;--ui-ink: #111;--ui-muted: #666;--ui-sticker-gap-line: #929292;--ui-sticker-gap-stroke: 2px;--ui-control: #ebebeb;--ui-control-hover: #dfdfdf;--ui-line: #eee;--ui-action: #111;--ui-on-action: #fff;--ui-focus: #3e0061;--ui-paper: #f8f2e8;--ui-notice-surface: #f8f2e8;--ui-notice-ink: #d28e07;--ui-notice-text: #8a5b00;--ui-progress-ink: var(--ui-button-brand-bg);--ui-progress-track: #e7e0ec;--ui-crossed-ink: #808080;--ui-crossed-line: #000;--video-surface: #000;--video-ink: #fff;--video-control-hover: rgb(255 255 255 / .16);--video-menu: #202023;--video-menu-hover: #333338;--video-range-track: rgb(255 255 255 / .24);--video-controls-fade: linear-gradient(transparent, rgb(0 0 0 / .76));--video-start-surface: rgb(255 255 255 / .95);--video-start-ink: #111;--ui-success: #376446;--answer-success: #00ae4c;--ui-success-line: #799784;--ui-success-fill: #e2ecdd;--ui-error: #ad433e;--ui-sheet-shadow: 0 -12px 48px -16px rgb(24 28 36 / .045), 0 -1px 4px -1px rgb(24 28 36 / .035);--phrase-shadow: 0 2px 1px #0000000d;--sticker-dock-shadow: 0 1px 2px #342b1710, 0 8px 24px -8px #342b1720, 0 24px 64px -24px #342b1724;--lesson-action-shadow: 0 1px 3px #1c092014;--ui-card-shadow-1-x: 0px;--ui-card-shadow-1-y: 1px;--ui-card-shadow-1-blur: 3px;--ui-card-shadow-1-spread: 0px;--ui-card-shadow-1-color: #20152a06;--ui-card-shadow-2-x: 0px;--ui-card-shadow-2-y: 0px;--ui-card-shadow-2-blur: 30px;--ui-card-shadow-2-spread: 0px;--ui-card-shadow-2-color: #20152a05;--ui-card-shadow-3-x: 0px;--ui-card-shadow-3-y: 18px;--ui-card-shadow-3-blur: 50px;--ui-card-shadow-3-spread: -26px;--ui-card-shadow-3-color: #20152a28;--ui-card-shadow: var(--ui-card-shadow-1-x) var(--ui-card-shadow-1-y) var(--ui-card-shadow-1-blur) var(--ui-card-shadow-1-spread) var(--ui-card-shadow-1-color), var(--ui-card-shadow-2-x) var(--ui-card-shadow-2-y) var(--ui-card-shadow-2-blur) var(--ui-card-shadow-2-spread) var(--ui-card-shadow-2-color), var(--ui-card-shadow-3-x) var(--ui-card-shadow-3-y) var(--ui-card-shadow-3-blur) var(--ui-card-shadow-3-spread) var(--ui-card-shadow-3-color);--sticker-shadow: 0 1px 1px rgb(23 18 31 / .08), 0 2px 2px rgb(23 18 31 / .04)}[data-ui-theme=dark]{color-scheme:dark;--ui-stage: #111114;--ui-button-paper-bg: #f0efeb;--ui-button-paper-ink: #3e0061;--ui-button-brand-bg: #baa5d7;--ui-button-brand-ink: #171719;--ui-surface: #1b1b1d;--ui-ink: #f5f5f3;--ui-muted: #aaa;--ui-sticker-gap-line: #888;--ui-control: #333336;--ui-control-hover: #424246;--ui-line: #38383b;--ui-action: #f0efeb;--ui-on-action: #171719;--ui-focus: #c4afe8;--ui-paper: #343029;--ui-notice-surface: #343029;--ui-notice-ink: #edbd67;--ui-notice-text: var(--ui-notice-ink);--ui-progress-ink: var(--ui-button-brand-bg);--ui-progress-track: var(--ui-control);--ui-crossed-ink: #aaa;--ui-crossed-line: #fff;--ui-success: #b4d9bd;--ui-success-line: #789880;--ui-success-fill: #293c2c;--ui-error: #eea295;--ui-sheet-shadow: 0 -12px 48px -16px rgb(0 0 0 / .24), 0 -1px 4px -1px rgb(0 0 0 / .16);--ui-card-shadow-1-x: 0px;--ui-card-shadow-1-y: 0px;--ui-card-shadow-1-blur: 2px;--ui-card-shadow-1-spread: 0px;--ui-card-shadow-1-color: rgb(255 255 255 / .04);--ui-card-shadow-2-x: 0px;--ui-card-shadow-2-y: 0px;--ui-card-shadow-2-blur: 32px;--ui-card-shadow-2-spread: 0px;--ui-card-shadow-2-color: rgb(0 0 0 / .14);--ui-card-shadow-3-x: 0px;--ui-card-shadow-3-y: 2px;--ui-card-shadow-3-blur: 6px;--ui-card-shadow-3-spread: -2px;--ui-card-shadow-3-color: rgb(0 0 0 / .12);--ui-card-shadow: var(--ui-card-shadow-1-x) var(--ui-card-shadow-1-y) var(--ui-card-shadow-1-blur) var(--ui-card-shadow-1-spread) var(--ui-card-shadow-1-color), var(--ui-card-shadow-2-x) var(--ui-card-shadow-2-y) var(--ui-card-shadow-2-blur) var(--ui-card-shadow-2-spread) var(--ui-card-shadow-2-color), var(--ui-card-shadow-3-x) var(--ui-card-shadow-3-y) var(--ui-card-shadow-3-blur) var(--ui-card-shadow-3-spread) var(--ui-card-shadow-3-color);--sticker-dock-shadow: 0 1px 2px rgb(0 0 0 / .18), 0 8px 24px -8px rgb(0 0 0 / .28), 0 24px 64px -24px rgb(0 0 0 / .32);--lesson-action-shadow: 0 1px 3px rgb(0 0 0 / .24)}:root{--space-xs: 4px;--space-sm: 8px;--space-md: 16px;--space-lg: 24px;--space-xl: 32px;--space-2xl: 48px;--space-3xl: 64px;--space-4xl: 96px;--ui-radius-sm: 8px;--ui-radius-md: 16px;--ui-radius-lg: 24px;--ui-radius-xl: 32px;--ui-radius-round: 999px;--ui-header-height: 36px;--sheet-peek: calc(var(--space-sm) + var(--space-xs));--sheet-scale-step: .04;--ui-control-sm: 40px;--ui-control-md: 48px;--ui-control-lg: 56px;--ui-control-xl: 64px;--ui-border: 1px;--ui-focus-width: 2px;--ui-reading-size: calc(18px + var(--ui-font-step));--ui-reading-line: calc(24px + var(--ui-line-step));--ui-heading-size: calc(22px + var(--ui-font-step));--ui-heading-line: calc(28px + var(--ui-line-step));--ui-card-padding: calc(16px + var(--ui-line-step));--ui-card-radius: calc(14px + var(--ui-font-step));--ui-card-gap: calc(20px + var(--ui-line-step));--ui-reading-width: 640px;--ui-touch-target: 48px;--ui-navigation-size: 48px;--ui-sheet-title-clearance: 36px;--ui-sheet-title-gutter: calc(var(--space-sm) + var(--ui-navigation-size) + var(--ui-sheet-title-clearance));--ui-answer-height: 36px;--ui-type-system: var(--weight-medium) 14px/18px var(--font-ui);--ui-type-body: var(--weight-regular) 16px/24px var(--font-ui);--ui-type-reading: var(--weight-medium) var(--ui-reading-size)/var(--ui-reading-line) var(--font-ui);--ui-type-answer: var(--weight-bold) var(--ui-reading-size)/var(--ui-reading-line) var(--font-display);--ui-type-heading: var(--weight-regular) var(--ui-heading-size)/var(--ui-heading-line) var(--font-display);--ui-type-action: var(--weight-medium) var(--ui-reading-size)/24px var(--font-display);--ui-type-caption: var(--ui-type-system);--ui-type-copy: var(--ui-type-reading);--ui-type-title: var(--ui-type-heading);--ui-type-control: var(--ui-type-system);--ui-type-brand: var(--course-brand-type);--type-body: var(--ui-type-body);--type-caption: var(--ui-type-system);--type-heading: var(--ui-type-heading);--motion-press: .1s;--motion-hover: .16s;--motion-enter: .5s;--motion-exit: .25s;--motion-ease: cubic-bezier(.32,.72,0,1);--course-bg: #f7e1c9;--course-ink: #262626;--course-card: #3e0061;--course-intro-ink: #712105;--course-intro-line: #71210533;--v2-sheet: var(--ui-surface);--v2-ink: var(--ui-ink);--v2-paper: var(--ui-paper);--v2-radius: var(--ui-radius-md);--v2-gutter: 0px;--v2-sheet-top: calc(var(--ui-header-height) + env(safe-area-inset-top, 0px));--v2-duration: var(--motion-enter);--v2-exit-duration: var(--motion-exit);--v2-ease: var(--motion-ease);--v2-background-shift: var(--ui-control-sm);--completion-surface: #376446;--completion-ink: #fff;--story-background: #030200;--story-on-video: #fff;--story-shade: linear-gradient(transparent,rgba(0,0,0,.3) 35%,rgba(0,0,0,.9));--story-progress: #ffffff80;--story-radius: var(--ui-radius-lg);--phrase-label: #818080;--phrase-border: #ffffff1a;--sticker-paper: #fff178;--postit-top: #f7e66b;--postit-base: #fff178;--postit-correct: #b9dc93;--postit-mid: #fff27c;--postit-bottom: #ffeb68;--postit-edge: #dac044;--postit-ink: #30270f;--sticker-match-line: var(--ui-success-line);--sticker-match-ink: var(--ui-success);--sticker-match-fill: var(--ui-success-fill);--sticker-text: var(--ui-ink);--sticker-on-color: #fff;--sticker-border: rgba(255,255,255,.22);--sticker-focus: #3d3550;--sticker-target-focus: #b6a17e}@media(max-width:620px){:root{--ui-navigation-size: 36px;--ui-sheet-title-clearance: 16px}}:root{--ui-font-step: 0px;--ui-line-step: 0px;--ui-content-gutter: 16px;--lesson-display-size: 56px}@media(min-width:486px){:root{--ui-font-step: 1px;--ui-line-step: 2px;--ui-content-gutter: 20px}}@media(min-width:581px){:root{--ui-font-step: 2px;--ui-line-step: 4px;--ui-content-gutter: 24px}}@media(min-width:900px){:root{--lesson-display-size: 80px}}@media(min-width:1024px){:root{--ui-content-gutter: 28px}}@media(min-width:1280px){:root{--lesson-display-size: 112px}}@media(min-width:1440px){:root{--ui-content-gutter: 32px}}@media(min-width:1600px){:root{--lesson-display-size: 128px}}@supports (width: round(1vw,1px)){:root{--ui-font-step: round(clamp(0px, (100vw - 390px) * 2 / 191, 2px), 1px);--ui-line-step: round(clamp(0px, (100vw - 390px) * 4 / 191, 4px), 1px);--ui-content-gutter: round(16px + clamp(0px, (100vw - 390px) * 8 / 191, 8px) + clamp(0px, (100vw - 581px) * 8 / 859, 8px), 1px);--lesson-display-size: round(clamp(56px, 8vw, 128px), 1px)}}.ui-button{position:relative;display:inline-flex;align-items:center;justify-content:center;gap:var(--space-sm);min-height:var(--button-size);padding:5px 10px;border:0;border-radius:var(--ui-radius-round);font:var(--ui-type-action);text-align:center;text-decoration:none;cursor:pointer;touch-action:manipulation;user-select:none;-webkit-user-select:none;-webkit-tap-highlight-color:transparent;background:var(--button-bg);color:var(--button-ink);box-shadow:var(--lesson-action-shadow);transition:transform var(--motion-press) var(--motion-ease),background-color var(--motion-hover)}.ui-button--sm{--button-size: var(--ui-control-sm)}.ui-button--md{--button-size: var(--ui-control-md)}.ui-button--lg{--button-size: var(--ui-control-lg)}.ui-button--xl{--button-size: var(--ui-control-xl)}.ui-button--brand{--button-bg: var(--ui-button-brand-bg);--button-ink: var(--ui-button-brand-ink)}.ui-button--paper{--button-bg: var(--ui-button-paper-bg);--button-ink: var(--ui-button-paper-ink)}.ui-button:not(:disabled):not([aria-disabled=true]):active{transform:scale(.97)}.ui-button:disabled,.ui-button[aria-disabled=true]{opacity:.4;cursor:default}:is(.ui-button,.ui-icon-button,.ui-text-control):focus-visible{outline:var(--ui-focus-width) solid var(--ui-focus);outline-offset:var(--space-xs)}.ui-icon-button{position:relative;display:inline-flex;align-items:center;justify-content:center;width:var(--button-size);height:var(--button-size);min-width:var(--button-size);padding:0;border:0;border-radius:var(--ui-radius-round);background:transparent;color:var(--ui-ink);font:var(--ui-type-control);cursor:pointer;touch-action:manipulation}.ui-text-control{border:0;background:transparent;color:inherit;padding:0;font:inherit;cursor:pointer;text-underline-offset:4px}@media(hover:hover)and (pointer:fine){.ui-button:not(:disabled):not([aria-disabled=true]):hover{background:color-mix(in srgb,var(--button-bg),var(--button-ink) 8%)}.ui-text-control:hover{text-decoration:underline}}.ui-back img{display:block;flex:none}html:has(.unit-sheet){overflow:hidden}.ui-sheet{position:fixed;top:calc(var(--v2-sheet-top) + var(--sheet-peek) * var(--sheet-level, 0));left:0;right:0;bottom:0;overflow:hidden;background:var(--sheet-surface, var(--ui-surface));color:var(--ui-ink);border-radius:var(--ui-radius-xl) var(--ui-radius-xl) 0 0;transform:translateY(calc(100dvh + var(--space-xl)));opacity:1;transition:transform var(--motion-exit) var(--motion-ease);font:var(--ui-type-copy)}.ui-sheet[data-position=front]{transform:translateY(0);transition-duration:var(--motion-enter)}.ui-sheet[data-position=behind]{transform:translateY(calc(var(--sheet-peek) * var(--sheet-retreat, 0))) scale(calc(1 - var(--sheet-scale-step) * var(--sheet-distance,1)));transform-origin:50% 0;transition-duration:var(--motion-enter)}.ui-sheet-scroll{width:100%;height:100%;overflow-y:auto;overflow-x:hidden;overscroll-behavior:contain}.ui-sheet-back{position:absolute;top:var(--space-sm);left:var(--space-sm);z-index:3}.ui-sheet-close{position:absolute;top:var(--space-sm);right:var(--space-sm);z-index:3}.ui-sheet :is(h1,h2):focus{outline:none}.ui-sheet-footer{position:absolute;bottom:var(--space-lg);left:50%;transform:translate(-50%);z-index:6}.lesson-save-notice{max-width:560px;margin:var(--space-md) auto;padding:var(--space-md);font:var(--ui-type-caption)}@media(hover:hover)and (pointer:fine){.ui-back:hover{background:transparent;filter:brightness(.94)}}@media(prefers-reduced-motion:reduce){.ui-sheet[data-position],.ui-button{transition-duration:1ms}}[data-ui-theme=dark] .ui-back:not([data-tone=brand]) img{filter:invert(1)}[data-ui-theme=light] .ui-back img{filter:none}.lesson-stack-paper{position:fixed;z-index:19;top:calc(var(--v2-sheet-top) + var(--sheet-peek) * var(--paper-source-level));left:0;right:0;bottom:0;background:var(--paper-base, var(--ui-surface));border-radius:var(--ui-radius-xl) var(--ui-radius-xl) 0 0;pointer-events:none;transform-origin:50% 0;transform:translateY(calc(var(--sheet-peek) * var(--paper-retreat))) scale(calc(1 - var(--sheet-scale-step) * var(--paper-distance)));opacity:1;transition:transform var(--motion-exit) var(--motion-ease)}.lesson-stack-paper[data-open=false]{transform:translateY(100dvh) scale(calc(1 - var(--sheet-scale-step) * var(--paper-distance)))}@media(prefers-reduced-motion:reduce){.lesson-stack-paper{transition-duration:1ms}}.ui-sheet[data-tone=brand]{--sheet-surface: var(--course-card)}.lesson-stack-paper[data-tone=brand]{--paper-base: var(--course-card)}.lesson-stack[data-direction=backward] .ui-sheet[data-position]{transition-duration:var(--motion-exit)}.lesson-stack{--sheet-replay-duration: .7s;--sheet-replay-stagger: 60ms}.lesson-stack[data-replay]>.ui-sheet{transition-duration:var(--sheet-replay-duration);transition-delay:calc(var(--sheet-replay-order,0) * var(--sheet-replay-stagger))}@media(prefers-reduced-motion:reduce){.lesson-stack[data-direction=backward] .ui-sheet[data-position]{transition-duration:1ms}}.ui-sheet,.lesson-stack-paper{box-shadow:var(--ui-sheet-shadow)}.ui-sheet-stack>.ui-sheet:nth-last-of-type(n+4){box-shadow:none}[data-ui-theme=dark] :is(.ui-sheet,.lesson-stack-paper){border-top:var(--ui-border) solid var(--ui-line)}.workbench-loading{padding:var(--space-xl);font:var(--ui-type-body)}@media(any-pointer:coarse){.ui-button:before,.ui-icon-button:before{content:"";position:absolute;inset:min(0px,calc((var(--button-size) - var(--ui-touch-target)) / 2))}}.ui-sheet[data-tone=cinema]{--sheet-surface: var(--video-surface);color:var(--video-ink)}.lesson-stack-paper[data-tone=cinema]{--paper-base: var(--video-surface)}.ui-back,.ui-close{--button-size: var(--ui-navigation-size)}.ui-back img,.ui-close img{width:var(--ui-navigation-size);height:var(--ui-navigation-size)}.ui-sheet :is(.v2-instruction,.ui-sheet-title){width:min(100%,calc(100vw - 2 * var(--ui-sheet-title-gutter)));margin-inline:auto;padding-inline:0}@media(max-width:620px){.ui-back:before,.ui-close:before{content:"";position:absolute;inset:calc((var(--ui-navigation-size) - var(--ui-touch-target)) / 2)}}.ui-sheet[data-tone=success]{--sheet-surface: var(--completion-surface);color:var(--completion-ink)}.lesson-stack-paper[data-tone=success]{--paper-base: var(--completion-surface)}@layer tokens,base,layout,exercises,media;@layer tokens{:root{--content-width: 720px;--control-sm: 40px;--control-md: 48px;--control-lg: 56px;--control-xl: 64px;--navigation-width: 264px;--navigation-trigger-size: var(--control-md);--avatar-size: 28px;--recorder-control-size: var(--control-md);--segment-height: var(--control-sm);--segment-gutter: 2px;--type-body: 400 16px/1.5 var(--font);--type-caption: 400 14px/1.5 var(--font);--type-heading: var(--weight-bold) 20px/1.5 var(--font);--weight-strong: var(--weight-bold);--surface-control: #f3f3f4;--surface-hover: #ebebed;--surface-selected: #e3e2e7;--selected-bg: #000;--selected-text: #fff;--ink: #36343b;--muted: #716e78;--accent: #635b70;--accent-soft: #e7e4ec;--line: #d8d6de;--surface: #fff;--page: #fff;--action-bg: #36343b;--action-text: #fff;--focus: #93849e;--backdrop: #29213526;--video-overlay: #16082112;--video-play: #f3f3f4ee;--error: #9b463b;--surface-video: #000;--surface-postscript: #edf2e9;--surface-before-watch: #f1edf7;--surface-flashcard: #fff;--flashcard-shadow: 0 2px 6px -2px rgb(43 32 60 / 6%), 0 6px 20px -8px rgb(43 32 60 / 8%);--segment-track: #fff;--segment-thumb: var(--selected-bg);--segment-text: var(--selected-text);--recording-indicator: #c54a42;--on-video: #a8a8ad;--space-1: 4px;--space-2: 8px;--space-3: 12px;--space-4: 16px;--space-5: 24px;--space-6: 32px;--space-7: 40px;--space-8: 48px;--space-9: 64px;--space-10: 96px;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 20px;--radius-xl: 28px;--radius-full: 999px;--card-shadow: 0 0 48px 2px rgb(24 28 36 / 4.5%), 0 2px 6px -2px rgb(24 28 36 / 3%)}}@layer base{*{box-sizing:border-box}html{scroll-padding-top:var(--space-7)}body{margin:0;background:var(--page);color:var(--ink);font:var(--type-body);-webkit-font-smoothing:antialiased}button,input,select,textarea{font:inherit;color:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default}button,input,textarea,select{outline:none}a{color:inherit;text-decoration:none}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible,label:has(input:focus-visible){outline:2px solid var(--focus);outline-offset:4px}h1,h2,p,figure{margin:0}h1,h2{font:var(--type-heading)}.column-label,.exercise-number,.menu-number,.sentence-list li::marker,.interaction-hint,.match-letter,.match-end,.word-bank-heading>span:last-child,.dialogue-label,.speaker-name,.question-number,.choice-marker,.writing-footer,.recorder-time,.recorder-times,.audio-time,.media-error,.video-placeholder small,.video-player figcaption,.flashcard-caption{font:var(--type-caption)}.match-option.word,strong{font-weight:var(--weight-strong)}s{color:var(--muted);text-decoration-thickness:1px}fieldset{border:0;padding:0;margin:0;min-width:0}legend{padding:0}::selection{background:var(--surface-selected)}.sr-only{position:absolute;width:1px;height:1px;margin:calc(-1 * var(--space-1));padding:0;border:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip-link{position:fixed;z-index:20;top:8px;left:8px;padding:var(--space-2) var(--space-4);background:var(--ink);color:var(--action-text);border-radius:var(--radius-sm);transform:translateY(-160%)}.skip-link:focus{transform:translateY(0)}.button{min-height:var(--control-md);border:0;border-radius:var(--radius-md);padding:var(--space-3) var(--space-4);display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);background:var(--surface-control)}.button.primary{background:var(--action-bg);color:var(--action-text)}.button.primary:hover{opacity:.88}.text-button{min-height:var(--control-sm);border:0;padding:var(--space-1) 0;background:transparent;color:var(--muted);display:inline-flex;align-items:center;gap:var(--space-1)}.text-button:hover:enabled{color:var(--ink)}.text-button:disabled{opacity:.35}.column-label{color:var(--muted)}}@layer layout{.lesson{width:min(var(--content-width),calc(100% - 2 * var(--space-6)));margin:0 auto;padding:var(--space-9) 0 var(--space-10)}.card{background:var(--surface);box-shadow:var(--card-shadow);border:0;border-radius:var(--radius-xl);padding:var(--space-7) var(--space-7);margin-bottom:var(--space-8)}.exercise{scroll-margin-top:var(--space-7)}.exercise-header{margin-bottom:var(--space-6)}.exercise-number{display:block;font-variant-numeric:tabular-nums;color:var(--muted);margin-bottom:var(--space-4)}.extra-copy{white-space:pre-line;margin-top:var(--space-5)}.lesson-postscript{background:var(--surface-postscript);border-radius:var(--radius-xl);padding:var(--space-7);margin:var(--space-10) 0 var(--space-8)}.lesson-footer{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:var(--space-4);padding:var(--space-2) var(--space-1);color:var(--muted)}.lesson-footer a{min-height:var(--control-md);display:inline-flex;align-items:center;gap:var(--space-2)}.footer-next{justify-self:end;color:var(--ink)}.footer-previous{justify-self:start}.lesson-footer a:hover{color:var(--accent)}.back-icon{display:inline-flex;transform:rotate(180deg)}.icon-button{width:var(--control-sm);height:var(--control-sm);border:0;background:var(--surface-control);border-radius:var(--radius-full);display:grid;place-items:center}.quick-lessons{position:fixed;z-index:10;left:var(--space-5);top:50%;transform:translateY(-50%)}.quick-lessons-trigger{display:grid;place-items:center;width:var(--navigation-trigger-size);height:var(--navigation-trigger-size);border:0;border-radius:var(--radius-full);background:var(--surface);box-shadow:var(--card-shadow);color:var(--muted);transition:color .16s,background .16s}.quick-lessons-trigger:hover,.quick-lessons-trigger[aria-expanded=true]{color:var(--ink);background:var(--surface-control)}.quick-lessons-panel{position:absolute;left:100%;top:50%;transform:translateY(-50%);width:var(--navigation-width);padding-left:var(--space-3)}.quick-lessons-list{display:grid;gap:var(--space-1);max-height:calc(100dvh - 2 * var(--space-5));overflow-y:auto;padding:var(--space-2);border-radius:var(--radius-lg);background:var(--surface);box-shadow:var(--card-shadow);animation:navigation-appear .18s ease-out}.quick-lessons-list a{display:flex;align-items:center;gap:var(--space-4);padding:var(--space-3) var(--space-4);border-radius:var(--radius-md)}.quick-lessons-list a:hover{background:var(--surface-hover)}.quick-lessons-list a[aria-current=page]{background:var(--selected-bg);color:var(--selected-text);font-weight:var(--weight-strong)}.quick-lessons-list a[aria-current=page] .menu-number{color:inherit}@keyframes navigation-appear{0%{opacity:0;transform:translateY(var(--space-1))}to{opacity:1;transform:translateY(0)}}.menu-number{color:var(--muted);font-variant-numeric:tabular-nums}.not-found h1{margin-bottom:var(--space-5)}}@layer exercises{.sentence-list{margin:0;padding-left:var(--space-5)}.sentence-list li{padding-left:var(--space-2);margin-bottom:var(--space-4)}.sentence-list li::marker{color:var(--muted);font-variant-numeric:tabular-nums}.sentence-list li:last-child{margin-bottom:0}.matching-board{margin-top:var(--space-5);display:grid;grid-template-columns:1fr 1fr;column-gap:var(--space-4);row-gap:var(--space-3)}.matching-board .column-label{margin-bottom:var(--space-1)}.match-option{border:0;border-radius:var(--radius-md);min-height:var(--control-xl);background:var(--surface-control);display:flex;align-items:center;gap:var(--space-2);text-align:left;padding:var(--space-4) var(--space-3);transition:background .15s}.match-option:hover{background:var(--surface-hover)}.match-option.is-active{outline:2px solid var(--focus);outline-offset:2px}.match-option.is-active,.match-option.is-paired{background:var(--selected-bg);color:var(--selected-text)}.match-option:is(.is-active,.is-paired) :is(.match-letter,.match-end){color:inherit}.match-letter{flex-shrink:0;width:22px;height:22px;display:grid;place-items:center;color:var(--muted)}.match-end{color:var(--muted);margin-left:auto}.exercise-tools{display:flex;justify-content:flex-end;margin-top:var(--space-5);min-height:22px}.gap-list li{margin-bottom:var(--space-4)}.inline-passage{white-space:pre-line;overflow-wrap:break-word}.gap-input,.gap-select,.gap-slot{display:inline-block;max-width:100%;min-width:68px;height:var(--control-sm);border:0;border-radius:var(--radius-sm);background:var(--surface-control);padding:var(--space-1) var(--space-2);margin:var(--space-1) var(--space-1);color:var(--accent);vertical-align:baseline}.gap-input{text-align:center}.gap-input::placeholder{color:var(--muted)}.gap-select{min-width:138px;padding-right:var(--space-2);max-width:265px;cursor:pointer}.gap-select:not(.has-value){color:var(--muted)}.gap-slot{min-width:0;width:var(--gap-width, 12ch);height:auto;min-height:var(--control-sm);text-align:center}.gap-slot.filled,.gap-slot.is-active,.gap-select.has-value{background:var(--selected-bg);color:var(--selected-text)}.gap-slot.filled .gap-remove{color:inherit}.gap-slot.is-active{outline:2px solid var(--focus);outline-offset:2px}.gap-remove{margin-left:var(--space-2);color:var(--muted)}.word-bank{border:0;background:transparent;padding:0 0 var(--space-4);margin-bottom:var(--space-5)}.word-bank-heading{display:flex;justify-content:space-between;align-items:center;gap:var(--space-2);margin-bottom:var(--space-4)}.word-bank-heading>span:last-child{color:var(--muted)}.word-bank-items{display:flex;flex-wrap:wrap;gap:var(--space-2)}.word-chip{min-height:var(--control-sm);padding:var(--space-2) var(--space-3);border:0;border-radius:var(--radius-md);background:var(--surface-control);color:var(--muted)}.word-chip:hover:enabled{background:var(--surface-hover)}.word-chip.selected{background:var(--selected-bg);color:var(--selected-text)}.word-chip:disabled{opacity:.32;text-decoration:line-through}.dialogue-list{list-style:none;margin:var(--space-7) 0 0;padding:0}.dialogue-list>li{margin:0 0 var(--space-9)}.dialogue-list>li:last-child{margin-bottom:0}.dialogue-label{display:block;color:var(--muted);font-variant-numeric:tabular-nums;margin-bottom:var(--space-5)}.conversation{display:flex;flex-direction:column;gap:var(--space-5)}.dialogue-turn{display:flex;flex-direction:column;gap:var(--space-2);align-items:flex-start}.speaker-signature{order:1;display:flex;align-items:center;gap:var(--space-2);padding-left:var(--space-3)}.character-avatar{flex:0 0 var(--avatar-size);width:var(--avatar-size);height:var(--avatar-size);border-radius:var(--radius-full);overflow:hidden;background:var(--surface-control);color:var(--muted)}.character-avatar img{width:100%;height:100%;object-fit:cover;display:block}.character-avatar svg{width:100%;height:100%;padding:var(--space-1)}.speaker-name{color:var(--muted)}.speech-bubble{width:fit-content;max-width:100%;border-radius:var(--radius-lg);padding:var(--space-3) var(--space-4);background:var(--surface-control);white-space:pre-line;overflow-wrap:anywhere}.speech-bubble .gap-input,.speech-bubble .gap-slot:not(.filled):not(.is-active){background:var(--surface-selected)}.dialogue-answer-line{margin:var(--space-1) var(--space-4) 0}.choice-questions{display:grid;gap:var(--space-6)}.choice-questions legend{margin-bottom:var(--space-4)}.question-number{color:var(--muted);margin-right:var(--space-2)}.choice-options{display:grid;gap:var(--space-3)}.choice-option{background:var(--surface-control);cursor:pointer;display:flex;align-items:center;gap:var(--space-3);min-height:var(--control-lg);padding:var(--space-3) var(--space-4);border:0;border-radius:var(--radius-md);position:relative;transition:background .15s}.choice-option:hover{background:var(--surface-hover)}.choice-option.selected{background:var(--selected-bg);color:var(--selected-text)}.choice-option.selected .choice-marker{color:inherit}.choice-option input,.binary-options input{position:absolute;opacity:0;width:1px;height:1px}.choice-marker{display:grid;place-items:center;width:22px;height:22px;color:var(--muted);flex-shrink:0}.opinion .choice-options{grid-template-columns:repeat(3,minmax(0,1fr))}.opinion .choice-option{padding:var(--space-3) var(--space-2);gap:var(--space-1)}.true-false-list{display:grid;gap:var(--space-5);margin-top:var(--space-6)}.true-false-row{display:flex;align-items:center;justify-content:space-between;gap:var(--space-5);border:0}.true-false-row p{flex:1}.binary-options{display:flex;background:var(--surface-control);border:0;border-radius:var(--radius-md);padding:var(--space-1);flex-shrink:0;gap:var(--space-1)}.binary-options label{min-height:var(--control-sm);display:flex;align-items:center;justify-content:center;position:relative;cursor:pointer;padding:var(--space-2) var(--space-3);border-radius:var(--radius-sm);color:var(--muted)}.binary-options label:hover{background:var(--surface-hover)}.binary-options label.selected{background:var(--selected-bg);color:var(--selected-text)}.writing-questions{display:grid;gap:var(--space-7)}.writing-label{display:block;margin-bottom:var(--space-4)}.writing-field{border:0;border-radius:var(--radius-md);overflow:hidden;background:var(--surface-control)}.writing-field textarea{width:100%;display:block;border:0;resize:vertical;background:transparent;padding:var(--space-5);min-height:175px}.writing-field textarea:focus-visible{outline-offset:-3px}.writing-field textarea::placeholder{color:var(--muted)}.writing-footer{display:flex;justify-content:flex-end;padding:var(--space-2) var(--space-5) var(--space-4);color:var(--muted)}.speaking-prompt{margin-bottom:var(--space-6)}.recorder{display:flex;align-items:center;gap:var(--space-4);border-radius:var(--radius-lg);padding:var(--space-4);background:var(--surface-control)}.recorder-primary,.recorder-reset{display:flex;align-items:center;justify-content:center;flex:0 0 var(--recorder-control-size);height:var(--recorder-control-size);border:0;padding:0;border-radius:var(--radius-full);background:transparent}.recorder-primary{gap:var(--space-4)}.recorder[data-state=idle] .recorder-primary{flex:1;justify-content:flex-start}.recorder-knob{display:grid;place-items:center;flex:0 0 var(--recorder-control-size);height:var(--recorder-control-size);background:var(--action-bg);color:var(--action-text);border-radius:var(--radius-full)}.recorder-primary:disabled{opacity:.4}.recorder-reset{background:transparent;color:var(--muted)}.recorder-reset:hover{background:var(--surface-hover);color:var(--ink)}.recorder-content{flex:1;min-width:0}.recorder-live,.recorder-times{display:flex;align-items:center;justify-content:space-between;gap:var(--space-2)}.recorder-time,.recorder-times{font-variant-numeric:tabular-nums}.recorder-times{color:var(--muted);margin-bottom:var(--space-2)}.recording-dot{width:var(--space-2);height:var(--space-2);background:var(--recording-indicator);border-radius:var(--radius-full);animation:recording-pulse 1.2s ease-in-out infinite alternate}@keyframes recording-pulse{0%{opacity:.35}to{opacity:1}}}@layer media{.audio-player{display:flex;gap:var(--space-4);align-items:center;border:0;background:var(--surface-control);border-radius:var(--radius-lg);padding:var(--space-5)}.audio-play{display:grid;place-items:center;width:var(--control-md);height:var(--control-md);flex-shrink:0;border:0;background:var(--surface-control);border-radius:var(--radius-full);color:var(--muted)}.audio-play:hover{background:var(--surface-control)}.audio-content{flex:1;min-width:0}.audio-topline{display:flex;gap:var(--space-3);justify-content:space-between;margin-bottom:var(--space-3)}.audio-time{white-space:nowrap;font-variant-numeric:tabular-nums}.audio-time>span{color:var(--muted)}.audio-seek{display:block;width:100%;margin:0;height:3px;accent-color:var(--muted);cursor:pointer}.audio-speed{border:0;border-radius:var(--radius-sm);padding:var(--space-1);background:transparent;color:var(--muted);max-width:65px}.media-error{color:var(--error)}.video-player{margin:var(--space-6) 0 0}.video-frame,.video-placeholder{position:relative;width:100%;aspect-ratio:16 / 9;background:var(--surface-video);overflow:hidden;border-radius:var(--radius-lg)}.video-placeholder{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:var(--space-1);color:var(--on-video)}.video-placeholder small{color:var(--on-video)}.video-frame video{width:100%;height:100%;display:block;object-fit:contain}.video-overlay{position:absolute;inset:0;width:100%;border:0;background:var(--video-overlay);display:grid;place-items:center}.video-play{width:var(--control-xl);height:var(--control-xl);display:grid;place-items:center;border-radius:var(--radius-full);background:var(--video-play);color:var(--muted);transition:transform .15s}.video-overlay:hover .video-play{transform:scale(1.06)}.video-error{position:absolute;inset:0;display:grid;place-items:center;color:var(--muted);background:var(--surface-control)}.video-player figcaption{display:flex;justify-content:space-between;margin-top:var(--space-4);color:var(--muted)}.video-tabs{position:relative;isolation:isolate;display:grid;grid-template-columns:repeat(var(--segment-count),minmax(0,1fr));width:max-content;max-width:100%;padding:var(--segment-gutter);margin:var(--space-6) auto 0;border-radius:var(--radius-full);background:var(--segment-track)}.video-tabs:before{content:"";position:absolute;z-index:-1;top:var(--segment-gutter);bottom:var(--segment-gutter);left:var(--segment-gutter);width:calc((100% - 2 * var(--segment-gutter)) / var(--segment-count));border-radius:var(--radius-full);background:var(--segment-thumb);transform:translate(calc(var(--segment-index) * 100%));transition:transform .36s cubic-bezier(.22,1,.36,1)}.video-tabs button{min-height:var(--segment-height);background:transparent;border:0;padding:var(--space-2) var(--space-4);border-radius:var(--radius-full);color:var(--muted);transition:color .18s}.video-tabs button[aria-selected=true]{color:var(--segment-text)}.video-tabs+.video-gallery-panel .video-player{margin-top:var(--space-5)}}@media(max-width:767px){.lesson{width:100%;padding:var(--space-9) 0 var(--space-6)}.card{background:var(--page);padding:var(--space-5) var(--space-4);margin-bottom:var(--space-5);border-radius:0;box-shadow:none}.exercise-header{margin-bottom:var(--space-5)}.opinion .choice-options{grid-template-columns:1fr}.lesson-postscript{padding:var(--space-5) var(--space-4);border-radius:0}.before-watch.card{background:var(--surface-before-watch)}.dialogue-answer-line{margin-left:0}.matching-board{column-gap:var(--space-2);row-gap:var(--space-3)}.match-option{padding:var(--space-3) var(--space-2);gap:var(--space-1);overflow-wrap:anywhere}.match-option>span{min-width:0}.true-false-row{flex-direction:column;align-items:flex-start;gap:var(--space-3)}.binary-options label{padding:var(--space-2) var(--space-4)}.audio-player{padding:var(--space-4);gap:var(--space-3);flex-wrap:wrap}.audio-content{flex-basis:calc(100% - 60px)}.audio-topline{flex-wrap:wrap;gap:var(--space-1)}.audio-speed{margin-left:auto}.word-bank-heading{flex-wrap:wrap;gap:var(--space-3)}.recorder{gap:var(--space-3)}.video-player figcaption{gap:var(--space-3)}.video-tabs button{padding-inline:var(--space-2)}.lesson-footer{padding:var(--space-4);grid-template-columns:1fr 1fr;gap:var(--space-5) var(--space-3)}.footer-controls{grid-column:1 / -1;grid-row:2}.quick-lessons{left:auto;right:var(--space-4);top:max(var(--space-3),env(safe-area-inset-top));transform:none}.quick-lessons-panel{left:auto;right:0;top:100%;transform:none;width:min(var(--navigation-width),calc(100vw - 2 * var(--space-4)));padding:var(--space-3) 0 0}.quick-lessons-list{max-height:calc(100dvh - var(--space-10) - env(safe-area-inset-top))}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important}}@layer exercises{.before-watch{overflow:hidden;background:var(--surface-before-watch);box-shadow:none}.before-watch .icon-button{background:var(--surface-flashcard)}.flashcard-stage{height:320px;margin-top:var(--space-5);position:relative;perspective:1100px;isolation:isolate}.flashcard-front,.flashcard-back{position:absolute;inset:var(--space-3) var(--space-2) var(--space-6);border-radius:var(--radius-lg);display:flex;flex-direction:column;justify-content:center;align-items:center;gap:var(--space-5);padding:var(--space-6);text-align:center;background:var(--surface-flashcard);box-shadow:var(--flashcard-shadow)}.flashcard-back{pointer-events:none}.leaving .back-one{transition:transform .34s cubic-bezier(.2,.7,.3,1)}.back-two{transform:translateY(19px) scale(.93) rotate(2deg);z-index:0}.back-one{transform:translateY(calc(10px * (1 - var(--pull)))) scale(calc(.965 + .035 * var(--pull))) rotate(calc(-1deg * (1 - var(--pull))));z-index:1}.flashcard-front{z-index:2;cursor:grab;touch-action:pan-y;-webkit-user-select:none;user-select:none;transform:translate3d(var(--card-x),var(--card-y),0) rotate(var(--card-rotation));transform-origin:50% 90%;transition:transform .6s cubic-bezier(.18,1.45,.32,1),opacity .25s}.dragging .flashcard-front{cursor:grabbing;transition:none;animation:none}.leaving .flashcard-front{pointer-events:none;opacity:0;transition:transform .34s cubic-bezier(.2,.7,.3,1),opacity .3s;animation:none}.flashcard-term,.flashcard-meaning{max-width:100%;overflow-wrap:anywhere}.flashcard-meaning{color:var(--muted)}.flashcard-meaning strong{color:var(--ink)}.flashcard-controls{display:flex;align-items:center;justify-content:center;gap:var(--space-5);margin-top:var(--space-1)}.flashcard-controls .icon-button{width:var(--control-md);height:var(--control-md)}.flashcard-caption{color:var(--muted);min-width:50px;text-align:center;font-variant-numeric:tabular-nums}}@layer layout{.wide-video{width:calc(100vw - 2 * var(--space-5));margin-left:calc(50% - 50vw + var(--space-5));margin-top:var(--space-10);margin-bottom:var(--space-10)}.wide-video .video-player{margin:0}}@media(max-width:767px){.wide-video{width:100%;margin-left:0;margin-top:var(--space-10);margin-bottom:var(--space-10)}.wide-video .video-frame,.wide-video .video-placeholder{border-radius:0}}@layer layout{.footer-controls{display:flex;align-items:center;justify-content:center;gap:var(--space-3)}.theme-toggle{width:var(--control-md);height:var(--control-md)}}@layer tokens{:root{color-scheme:light}:root[data-theme=dark]{color-scheme:dark;--ink: #eeeaf2;--muted: #bab4c2;--accent: #cbb8dc;--accent-soft: #3b3444;--line: #48414f;--surface: #202024;--page: #151518;--surface-postscript: #263128;--surface-before-watch: #292433;--surface-flashcard: #36313f;--flashcard-shadow: 0 2px 6px -2px rgb(0 0 0 / 16%), 0 6px 20px -8px rgb(0 0 0 / 24%);--segment-track: #313137;--recording-indicator: #f0796f;--surface-control: #2d2d32;--surface-hover: #38373e;--surface-selected: #484050;--selected-bg: #e8e6ec;--selected-text: #242128;--action-bg: #ebe5f1;--action-text: #242028;--focus: #bea2d4;--backdrop: #08080c99;--video-overlay: #100e171c;--video-play: #e6e0eeee;--error: #eca395;--card-shadow: 0 0 2px rgb(255 255 255 / 4%), 0 0 32px rgb(0 0 0 / 14%), 0 2px 6px -2px rgb(0 0 0 / 12%)}@media(prefers-color-scheme:dark){:root:not([data-theme=light]){color-scheme:dark;--ink: #eeeaf2;--muted: #bab4c2;--accent: #cbb8dc;--accent-soft: #3b3444;--line: #48414f;--surface: #202024;--page: #151518;--surface-postscript: #263128;--surface-before-watch: #292433;--surface-flashcard: #36313f;--flashcard-shadow: 0 2px 6px -2px rgb(0 0 0 / 16%), 0 6px 20px -8px rgb(0 0 0 / 24%);--segment-track: #313137;--recording-indicator: #f0796f;--surface-control: #2d2d32;--surface-hover: #38373e;--surface-selected: #484050;--selected-bg: #e8e6ec;--selected-text: #242128;--action-bg: #ebe5f1;--action-text: #242028;--focus: #bea2d4;--backdrop: #08080c99;--video-overlay: #100e171c;--video-play: #e6e0eeee;--error: #eca395;--card-shadow: 0 0 2px rgb(255 255 255 / 4%), 0 0 32px rgb(0 0 0 / 14%), 0 2px 6px -2px rgb(0 0 0 / 12%)}}}@layer tokens{:root{--correct-bg: #dff3e5;--correct-ink: #17623b;--incorrect-bg: #fbe6e3;--incorrect-ink: #9d302a;--confetti-0: #36b878;--confetti-1: #a087dc;--confetti-2: #f5bf52}:root[data-theme=dark]{--correct-bg: #203e2e;--correct-ink: #9fe1b5;--incorrect-bg: #482b2c;--incorrect-ink: #ffb9b2}@media(prefers-color-scheme:dark){:root:not([data-theme=light]){--correct-bg: #203e2e;--correct-ink: #9fe1b5;--incorrect-bg: #482b2c;--incorrect-ink: #ffb9b2}}}@layer exercises{.matching-board{position:relative;grid-template-columns:minmax(0,1fr) var(--space-8) minmax(0,1fr);column-gap:0}.matching-board>.column-label:first-child,.match-option.word{grid-column:1}.matching-board>.column-label:nth-child(2),.match-option.definition{grid-column:3}.match-option{position:relative;min-width:0}.match-links{position:absolute;inset:0;width:100%;height:100%;overflow:visible;pointer-events:none}.match-links path{fill:none;stroke:var(--muted);stroke-width:2}.match-links path[data-feedback=correct]{stroke:var(--correct-ink)}.match-links path[data-feedback=incorrect]{stroke:var(--incorrect-ink);stroke-dasharray:4 4}.answer-field{display:inline-flex;align-items:center;max-width:100%;vertical-align:middle}.answer-field>input,.answer-field>select,.answer-field>button{min-width:0}.answer-mark{display:inline-grid;place-items:center;flex:0 0 auto;width:var(--space-4);font:var(--type-body);font-weight:var(--weight-strong)}.answer-field .answer-mark{margin-right:var(--space-1)}.choice-option .answer-mark{margin-left:auto}.binary-options label{gap:var(--space-1)}.word-chip{touch-action:none;cursor:grab}.word-chip:active{cursor:grabbing}.word-chip:disabled{cursor:default}}[data-feedback=correct]:is(button,select,input,label){background:var(--correct-bg);color:var(--correct-ink);box-shadow:inset 0 0 0 1px var(--correct-ink)}[data-feedback=incorrect]:is(button,select,input,label){background:var(--incorrect-bg);color:var(--incorrect-ink);box-shadow:inset 0 0 0 1px var(--incorrect-ink)}[data-feedback] :is(.choice-marker,.match-letter,.match-end,.gap-remove){color:inherit}.answer-field[data-feedback=correct]{color:var(--correct-ink)}.answer-field[data-feedback=incorrect]{color:var(--incorrect-ink)}.word-drag-preview{position:fixed;z-index:40;transform:translate(-50%,-120%);pointer-events:none;padding:var(--space-2) var(--space-3);border-radius:var(--radius-md);background:var(--selected-bg);color:var(--selected-text);box-shadow:var(--card-shadow)}.answer-confetti{position:fixed;z-index:50;pointer-events:none}.answer-confetti i{position:absolute;width:var(--space-2);height:var(--space-1);border-radius:var(--radius-full);background:var(--confetti-color);animation:answer-celebrate .8s ease-out both}@keyframes answer-celebrate{0%{transform:translate(0) rotate(0);opacity:1}65%{opacity:1}to{transform:translate(var(--dx),var(--dy)) rotate(var(--rotation));opacity:0}}@media(max-width:767px){.matching-board{grid-template-columns:minmax(0,1fr) var(--space-5) minmax(0,1fr);column-gap:0}}@media(prefers-reduced-motion:reduce){.answer-confetti{display:none}}@layer exercises{.recorder-error{margin-top:var(--space-3)}}