:root{--bg: #f7f5ef;--surface: #ffffff;--ink: #1f2a44;--ink-soft: #5b6b85;--accent: #2f6f5e;--accent-ink: #ffffff;--socra: #eef2f7;--me: #2f6f5e;--me-ink: #ffffff;--line: #e7e2d6;--danger: #b3402f;--radius: 14px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased}button{font:inherit;cursor:pointer}.center-screen{min-height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:24px max(24px,env(safe-area-inset-left)) calc(24px + env(safe-area-inset-bottom));gap:14px}.brand{display:flex;align-items:center;gap:12px}.brand__mark{width:44px;height:44px}.brand h1{font-size:2.2rem;margin:0;letter-spacing:-.02em}.tagline{max-width:26rem;color:var(--ink-soft);line-height:1.5;font-size:1.05rem}.fineprint{color:var(--ink-soft);font-size:.85rem}.app{display:flex;flex-direction:column;height:100%}.topbar{display:flex;align-items:center;justify-content:space-between;padding:calc(10px + env(safe-area-inset-top)) 16px 10px;background:var(--surface);border-bottom:1px solid var(--line)}.topbar__home{display:flex;align-items:center;gap:8px;background:none;border:none;color:var(--ink);font-weight:700;font-size:1.1rem}.topbar__mark{width:26px;height:26px}.content{flex:1;overflow:hidden;display:flex;flex-direction:column}.btn{border:none;border-radius:var(--radius);padding:12px 18px;font-weight:600;min-height:44px}.btn--primary{background:var(--accent);color:var(--accent-ink)}.btn--primary:disabled{opacity:.5}.btn--ghost{background:var(--surface);color:var(--ink);border:1px solid var(--line)}.btn--link{background:none;color:var(--accent);padding:6px 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12px;border-radius:8px;font-size:.95rem;color:var(--ink)}.user-menu__item:hover{background:var(--socra)}.home{flex:1;overflow-y:auto;padding:20px 16px calc(24px + env(safe-area-inset-bottom));max-width:720px;width:100%;margin:0 auto}.home__heading{font-size:1.5rem;margin:8px 0 4px}.home__sub{color:var(--ink-soft);margin:0 0 16px}.home__input{width:100%;border:1px solid var(--line);border-radius:var(--radius);padding:14px;font:inherit;resize:vertical;background:var(--surface)}.home__actions{display:flex;gap:10px;margin-top:12px}.home__actions .btn--primary{margin-left:auto}.home__preview{margin-top:16px}.home__preview img{max-width:100%;border-radius:var(--radius);border:1px solid var(--line)}.home__preview-remove{display:block;margin-top:6px;background:none;border:none;color:var(--danger);font-size:.9rem}.pages{margin-top:16px}.pages__hint{color:var(--ink-soft);font-size:.85rem;margin:0 0 8px}.pages__grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(96px,1fr));gap:10px}.page-thumb{position:relative}.page-thumb__pick{display:block;width:100%;padding:0;background:none;border:none;border-radius:10px;overflow:hidden;position:relative}.page-thumb__pick img{width:100%;aspect-ratio:3 / 4;object-fit:cover;display:block;border:2px solid var(--line);border-radius:10px}.page-thumb.is-task .page-thumb__pick img{border-color:var(--accent)}.page-thumb__badge{position:absolute;left:6px;bottom:6px;background:#0000008c;color:#fff;font-size:.7rem;font-weight:700;padding:2px 8px;border-radius:999px}.page-thumb.is-task .page-thumb__badge{background:var(--accent);color:var(--accent-ink)}.page-thumb__remove{position:absolute;top:-6px;right:-6px;width:24px;height:24px;border-radius:50%;background:var(--ink);color:#fff;border:2px solid var(--surface);font-size:.9rem;line-height:1;display:flex;align-items:center;justify-content:center}.chat__pages{display:flex;gap:8px;overflow-x:auto;padding-bottom:4px;-webkit-overflow-scrolling:touch}.chat__page{position:relative;padding:0;background:none;border:none;flex:0 0 auto;border-radius:8px}.chat__page img{height:84px;width:auto;display:block;border-radius:8px;border:2px solid var(--line)}.chat__page.is-task img{border-color:var(--accent)}.chat__page-badge{position:absolute;left:4px;bottom:4px;background:#0000008c;color:#fff;font-size:.62rem;font-weight:700;padding:1px 6px;border-radius:999px}.chat__page.is-task .chat__page-badge{background:var(--accent);color:var(--accent-ink)}.recent{margin-top:28px}.recent__title{font-size:1rem;color:var(--ink-soft);margin-bottom:8px}.recent__list{list-style:none;margin:0;padding:0;display:grid;gap:8px}.recent__item{width:100%;text-align:left;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:12px 14px;display:flex;flex-direction:column;gap:2px}.recent__topic{font-weight:600}.recent__meta{color:var(--ink-soft);font-size:.85rem}.chat{flex:1;display:flex;flex-direction:column;min-height:0}.chat__loading{padding:24px;color:var(--ink-soft)}.chat__header{display:flex;align-items:center;gap:14px;padding:10px 16px;border-bottom:1px solid var(--line);background:var(--surface)}.chat__topic{font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.chat__thread{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:12px;max-width:720px;width:100%;margin:0 auto;-webkit-overflow-scrolling:touch}.bubble{max-width:85%;padding:10px 14px;border-radius:16px;line-height:1.45}.bubble p{margin:0;white-space:pre-wrap}.bubble--socra{align-self:flex-start;background:var(--socra);color:var(--ink);border-bottom-left-radius:4px}.bubble--me{align-self:flex-end;background:var(--me);color:var(--me-ink);border-bottom-right-radius:4px}.bubble--thinking{opacity:.7;font-style:italic}.bubble__who{display:block;font-size:.72rem;font-weight:700;color:var(--accent);margin-bottom:2px}.chat__compose{display:flex;gap:8px;align-items:flex-end;padding:10px 16px calc(10px + env(safe-area-inset-bottom));border-top:1px solid var(--line);background:var(--surface);max-width:720px;width:100%;margin:0 auto}.chat__input{flex:1;border:1px solid var(--line);border-radius:var(--radius);padding:10px 12px;font:inherit;resize:none;background:var(--bg)}.error{color:var(--danger);font-size:.9rem}.topbar__left{display:flex;align-items:center;gap:6px}.topbar__right{display:flex;align-items:center;gap:12px}.topbar__right .btn--link{font-size:.9rem}.topbar__menu{background:none;border:none;font-size:1.25rem;line-height:1;padding:6px 8px;color:var(--ink);border-radius:8px}.drawer-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;z-index:40;background:#1f2a4459;display:flex;justify-content:flex-start}.drawer{width:min(280px,80vw);height:100%;background:var(--surface);border-right:1px solid var(--line);padding:calc(16px + env(safe-area-inset-top)) 12px 16px;display:flex;flex-direction:column;gap:4px;box-shadow:2px 0 16px #00000014}.drawer__label{font-size:.72rem;text-transform:uppercase;letter-spacing:.04em;color:var(--ink-soft);margin:14px 8px 4px;font-weight:700}.drawer__item{display:flex;align-items:center;gap:8px;width:100%;text-align:left;background:none;border:none;padding:12px 10px;border-radius:10px;font-size:1rem;color:var(--ink)}.drawer__item.is-active{background:var(--socra);font-weight:600}.drawer__item--disabled{color:var(--ink-soft);cursor:default}.drawer__soon{margin-left:auto;font-size:.7rem;color:var(--ink-soft);border:1px solid var(--line);border-radius:999px;padding:1px 8px}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;z-index:50;background:#1f2a4473;display:flex;align-items:center;justify-content:center;padding:20px}.modal{background:var(--surface);border-radius:var(--radius);max-width:420px;width:100%;padding:22px;max-height:85vh;overflow-y:auto;box-shadow:0 12px 40px #0003}.modal__brand{display:flex;align-items:center;gap:10px;margin-bottom:12px}.modal__mark{width:32px;height:32px}.modal__title{font-size:1.25rem;margin:0}.modal__lead{color:var(--ink);line-height:1.55;margin:0 0 14px}.help-list{margin:0 0 18px;padding-left:18px;display:grid;gap:10px}.help-list li{line-height:1.5}.modal__close{width:100%}.settings{flex:1;overflow-y:auto;padding:20px 16px calc(24px + env(safe-area-inset-bottom));max-width:720px;width:100%;margin:0 auto}.settings__heading{font-size:1.5rem;margin:8px 0 4px}.settings__section{margin-top:24px}.settings__subtitle{font-size:1rem;margin:0 0 8px}.settings__meta{color:var(--ink-soft);font-size:.9rem;line-height:1.5;margin:0 0 12px}.due{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;margin-bottom:24px}.due__title{margin:0 0 2px;font-size:1.05rem}.due__sub{margin:0 0 12px;color:var(--ink-soft);font-size:.9rem}.due__list{list-style:none;margin:0;padding:0;display:grid;gap:8px}.due__item{width:100%;text-align:left;background:var(--bg);border:1px solid var(--line);border-radius:var(--radius);padding:12px 14px;display:flex;align-items:center;justify-content:space-between;gap:10px}.due__topic{font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.due__cta{color:var(--accent);font-weight:600;white-space:nowrap}.chat__badge{display:inline-block;background:var(--socra);color:var(--accent);border-radius:999px;padding:2px 8px;font-size:.72rem;font-weight:700;margin-right:8px;vertical-align:middle}.parent{flex:1;overflow-y:auto;padding:20px 16px calc(24px + env(safe-area-inset-bottom));max-width:720px;width:100%;margin:0 auto}.parent__heading{font-size:1.5rem;margin:8px 0 4px}.parent__note{color:var(--ink-soft);margin:0 0 20px;font-size:.92rem;line-height:1.5}.parent__cards{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:14px;text-align:center;display:flex;flex-direction:column;gap:4px}.stat__num{font-size:1.6rem;font-weight:700;color:var(--accent)}.stat__label{font-size:.78rem;color:var(--ink-soft);line-height:1.2}.parent__section{margin-top:28px}.parent__subtitle{font-size:1rem;margin:0 0 8px}.parent__meta{color:var(--ink-soft);font-size:.88rem;margin:0 0 12px}.spark{display:flex;align-items:flex-end;gap:8px;height:90px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:12px}.spark__col{flex:1;display:flex;flex-direction:column;align-items:center;gap:4px;height:100%;justify-content:flex-end}.spark__bar{width:100%;min-height:3px;background:var(--accent);border-radius:4px 4px 0 0}.spark__day{font-size:.65rem;color:var(--ink-soft)}.topics{list-style:none;margin:0;padding:0;display:grid;gap:12px}.topics__item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:12px 14px}.topics__head{display:flex;justify-content:space-between;gap:10px;margin-bottom:8px}.topics__name{font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.topics__next{color:var(--ink-soft);font-size:.82rem;white-space:nowrap}.meter{height:8px;background:var(--bg);border-radius:999px;overflow:hidden;border:1px solid var(--line)}.meter__fill{height:100%;background:var(--accent);border-radius:999px}.btn--sm{padding:6px 10px;font-size:.82rem}.btn--ghost.is-active{background:var(--socra);border-color:var(--accent)}.artifact{border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:12px;padding:12px 16px;margin:6px 0;background:var(--surface)}.artifact--explainer{border-left-color:#6c8cff;background:#6c8cff0f}.artifact--summary{border-left-color:#3bb273;background:#3bb27314}.artifact__head{font-weight:700;font-size:.95rem;margin-bottom:4px}.artifact__loading{color:var(--ink-soft);font-style:italic;margin:4px 0 0}.md h3{font-size:1.02rem;margin:8px 0 4px}.md h4{font-size:.92rem;margin:8px 0 4px}.md p{margin:6px 0;line-height:1.5}.md ul{margin:6px 0;padding-left:20px}.md li{margin:3px 0;line-height:1.45}.chat__header .chat__topic{flex:1;min-width:0}.chat__header .btn--sm{margin-left:auto;flex:0 0 auto;white-space:nowrap}.seg{display:inline-flex;gap:4px;flex-wrap:wrap;background:var(--bg);border:1px solid var(--line);border-radius:999px;padding:3px}.seg__btn{border:none;background:none;color:var(--ink);padding:7px 14px;border-radius:999px;font-size:.9rem}.seg__btn.is-active{background:var(--accent);color:var(--accent-ink);font-weight:600}.seg--sm .seg__btn{padding:5px 10px;font-size:.82rem}.home__lang{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:16px}.home__lang-label{color:var(--ink-soft);font-size:.85rem}.chat__subbar{display:flex;justify-content:flex-end;padding:6px 16px;border-bottom:1px solid var(--line);background:var(--surface)}.page-thumb__pdf{width:100%;aspect-ratio:3 / 4;background:var(--socra);border:2px solid var(--line);border-radius:10px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;padding:8px}.page-thumb.is-task .page-thumb__pdf{border-color:var(--accent)}.page-thumb__pdf-icon{font-size:1.8rem;line-height:1}.page-thumb__pdf-name{font-size:.65rem;color:var(--ink-soft);text-align:center;overflow:hidden;text-overflow:ellipsis;width:100%;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}.chat__page-pdf{height:84px;width:64px;background:var(--socra);border:2px solid var(--line);border-radius:8px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;padding:6px}.chat__page.is-task .chat__page-pdf{border-color:var(--accent)}.chat__page-pdf-name{font-size:.6rem;color:var(--ink-soft);text-align:center;overflow:hidden;text-overflow:ellipsis;width:100%;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}.avatar-editor__preview{display:flex;justify-content:center;margin-bottom:16px}.avatar-editor__preview svg{border-radius:50%;background:var(--bg);border:1px solid var(--line);padding:6px}.avatar-editor__label{display:block;font-size:.85rem;color:var(--ink-soft);margin:14px 0 6px}.swatches{display:flex;gap:10px;flex-wrap:wrap}.swatch{width:32px;height:32px;border-radius:50%;border:2px solid var(--line);padding:0;box-shadow:inset 0 0 0 2px var(--surface)}.swatch.is-active{border-color:var(--ink);box-shadow:inset 0 0 0 2px var(--surface),0 0 0 2px var(--ink)}.bubble-row{display:flex;align-items:flex-end;gap:8px}.bubble-row--me{justify-content:flex-end}.bubble-row--me .bubble--me{margin:0}.recent__row{position:relative;display:flex;align-items:stretch;gap:6px}.recent__row .recent__item{flex:1}.recent__item--archived{opacity:.6}.recent__menu{position:relative;display:flex;align-items:center}.recent__menu-btn{background:none;border:1px solid var(--line);border-radius:10px;width:40px;align-self:stretch;color:var(--ink-soft);font-size:1.1rem}.recent__dropdown{position:absolute;right:0;top:calc(100% + 4px);z-index:31;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:6px;min-width:160px;box-shadow:0 10px 30px #00000024;display:flex;flex-direction:column;gap:2px}.user-menu__item--danger{color:var(--danger)}.recent__archived-toggle{background:none;border:none;color:var(--ink-soft);font-size:1rem;padding:4px 0;margin-bottom:4px}.status-banner{display:flex;align-items:center;justify-content:center;gap:12px;padding:8px 16px;font-size:.88rem;font-weight:600;text-align:center}.app>.status-banner:first-child{padding-top:calc(8px + env(safe-area-inset-top))}.status-banner~.topbar{padding-top:10px}.status-banner--offline{background:#b3402f;color:#fff}.status-banner--update{background:var(--ink);color:#fff}.status-banner--ready{background:var(--accent);color:var(--accent-ink)}.status-banner__btn{border:1px solid rgba(255,255,255,.6);background:#ffffff1f;color:inherit;border-radius:999px;padding:3px 12px;font-size:.82rem;font-weight:700;white-space:nowrap}.app.is-offline [data-offline-disable],.app.is-offline .chat__compose .btn--primary,.app.is-offline .chat__input{opacity:.55;pointer-events:none}.deck{flex:1;display:flex;flex-direction:column;min-height:0;overflow-y:auto;padding-bottom:calc(24px + env(safe-area-inset-bottom))}.deck__status{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;text-align:center;padding:24px}.deck__status-big{font-size:1.2rem;font-weight:700;margin:0}.deck__status-sub{color:var(--ink-soft);margin:0;max-width:30rem;line-height:1.5}.deck__done-actions{display:flex;flex-direction:column;gap:10px;margin-top:10px;width:min(280px,100%)}.deck__progress{display:flex;align-items:center;gap:12px;max-width:560px;width:100%;margin:16px auto 0;padding:0 16px;color:var(--ink-soft);font-size:.88rem;font-weight:600}.deck__meter{flex:1}.flashcard{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;text-align:center;width:min(560px,calc(100% - 32px));min-height:260px;margin:14px auto 0;padding:24px 20px;background:var(--surface);border:1px solid var(--line);border-radius:18px;box-shadow:0 6px 24px #1f2a4414;font-size:1.1rem;line-height:1.5;color:var(--ink)}.flashcard.is-flipped{background:var(--socra);border-color:var(--accent)}.flashcard__side-label{font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-soft)}.flashcard.is-flipped .flashcard__side-label{color:var(--accent)}.flashcard__body{max-width:100%;overflow-wrap:break-word}.flashcard__tap{font-size:.8rem;color:var(--ink-soft)}.deck__hint{max-width:560px;width:100%;margin:12px auto 0;padding:0 16px;color:var(--ink-soft);text-align:center;font-size:.92rem;line-height:1.5}.deck__hint-btn{display:block;margin:8px auto 0}.deck__answers{display:flex;gap:12px;justify-content:center;width:min(560px,calc(100% - 32px));margin:16px auto 0}.deck__answers .btn{flex:1}.deck__missed{border-color:var(--danger);color:var(--danger)}.quiz-join{max-width:720px;width:100%;margin:0 auto;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px}.quiz-join__label{display:block;font-weight:600;font-size:.95rem;margin-bottom:8px}.quiz-join__row{display:flex;gap:8px}.quiz-join__input{flex:1;border:1px solid var(--line);border-radius:var(--radius);padding:12px 14px;font:inherit;font-size:1.2rem;letter-spacing:.28em;text-transform:uppercase;text-align:center;background:var(--bg)}.quiz-divider{display:flex;align-items:center;gap:12px;max-width:720px;width:100%;margin:18px auto;color:var(--ink-soft);font-size:.85rem}.quiz-divider:before,.quiz-divider:after{content:"";flex:1;height:1px;background:var(--line)}.quiz-intro{max-width:560px;width:100%;margin:14px auto 0;padding:0 16px;text-align:center;color:var(--accent);font-weight:600;line-height:1.5}.quiz-card{width:min(560px,calc(100% - 32px));margin:14px auto 0}.quiz-card__prompt{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:20px;font-size:1.1rem;line-height:1.5;box-shadow:0 6px 24px #1f2a4414}.quiz-card__options{display:grid;gap:10px;margin-top:14px}.quiz-option{display:flex;align-items:center;gap:12px;text-align:left;background:var(--surface);border:2px solid var(--line);border-radius:12px;padding:12px 14px;font-size:1rem;line-height:1.4;color:var(--ink);min-height:52px}.quiz-option.is-selected{border-color:var(--accent);background:var(--socra)}.quiz-option__letter{flex:0 0 auto;width:28px;height:28px;border-radius:50%;background:var(--bg);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.85rem;color:var(--ink-soft)}.quiz-option.is-selected .quiz-option__letter{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}.quiz-nav{display:flex;gap:12px;justify-content:space-between;width:min(560px,calc(100% - 32px));margin:18px auto 0}.quiz-nav .btn{flex:1}.quiz-result{flex:1;overflow-y:auto;width:min(620px,100%);margin:0 auto;padding:20px 16px;text-align:center}.quiz-review{list-style:none;margin:18px 0 0;padding:0;display:grid;gap:16px;text-align:left}.quiz-review__item{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:14px 16px}.quiz-review__q{font-weight:600;margin-bottom:10px}.quiz-review__opt{display:flex;align-items:flex-start;gap:8px;padding:7px 10px;border-radius:8px;font-size:.95rem;line-height:1.4}.quiz-review__opt.is-correct{background:#3bb27324;font-weight:600}.quiz-review__opt.is-wrong{background:#b3402f1f}.quiz-review__mark{flex:0 0 auto}.quiz-review__why{margin:10px 0 0;color:var(--ink-soft);font-size:.9rem;line-height:1.5}.leaderboard{margin-top:24px;text-align:left}.leaderboard__title{font-size:1.05rem;margin:0 0 10px}.leaderboard__list{list-style:none;margin:0;padding:0;display:grid;gap:6px}.leaderboard__row{display:flex;align-items:center;gap:12px;background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:10px 14px}.leaderboard__row.is-me{border-color:var(--accent);background:var(--socra)}.leaderboard__rank{flex:0 0 auto;width:26px;height:26px;border-radius:50%;background:var(--bg);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.82rem;color:var(--ink-soft)}.leaderboard__row:nth-child(1) .leaderboard__rank{background:#f6c744;color:#5a4300;border-color:#e6b52f}.leaderboard__name{flex:1;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.leaderboard__score{flex:0 0 auto;font-weight:700;color:var(--accent)}