:root{--font-display:-apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;--font-body:-apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;--font-cjk:"Noto Serif SC", "Songti SC", "STSong", serif;--font-mono:ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;--text-2xs:.6875rem;--text-xs:.75rem;--text-sm:.8125rem;--text-md:.875rem;--text-base:1rem;--text-lg:1.125rem;--text-xl:1.25rem;--text-2xl:1.5rem;--text-3xl:clamp(1.85rem, 3.7vw, 3rem);--space-1:.25rem;--space-2:.5rem;--space-3:.75rem;--space-4:1rem;--space-5:1.25rem;--space-6:1.5rem;--space-7:1.75rem;--space-8:2rem;--space-10:2.5rem;--space-12:3rem;--space-16:4rem;--color-paper:oklch(97.5% .006 165);--color-paper-raised:oklch(99.6% .002 165);--color-paper-soft:oklch(95.5% .012 165);--color-paper-muted:oklch(91.5% .025 250);--color-ink:oklch(25% .025 255);--color-ink-soft:oklch(41% .025 255);--color-muted:oklch(55% .018 255);--color-muted-soft:oklch(67% .015 255);--color-line:oklch(88% .02 250);--color-line-strong:oklch(82% .025 250);--color-accent:oklch(73% .14 190);--color-accent-strong:oklch(43% .11 190);--color-accent-soft:oklch(93% .035 190);--color-accent-ink:oklch(24% .045 190);--color-blue:oklch(61% .17 260);--color-blue-soft:oklch(93% .035 260);--color-blue-ink:oklch(31% .07 260);--color-coral:oklch(67% .16 35);--color-coral-soft:oklch(94% .03 35);--color-error:oklch(54% .17 25);--color-success:oklch(47% .12 155);--color-focus:oklch(51% .16 260);--shadow-soft:0 1px 5px oklch(25% .025 255/.05);--shadow-card:0 10px 26px oklch(25% .025 255/.07);--shadow-popover:0 18px 40px oklch(25% .025 255/.14);--radius-sm:.5rem;--radius-md:.75rem;--radius-lg:1rem;--radius-xl:1.5rem;--radius-pill:999px;--layout-max:90rem;--content-max:65rem;--sidebar-width:14.875rem;--header-height:4.5rem;--duration-fast:.14s;--duration-panel:.22s;--ease-standard:cubic-bezier(.2, .7, .2, 1);--z-header:40;--z-backdrop:45;--z-drawer:50;--color-grid:oklch(91% .015 165/.4);--color-sidebar:oklch(98.7% .004 165)}.study-app.study-app{--content-max:60rem;--sidebar-width:15rem}.study-app.study-app .study-header{background:var(--color-paper-raised);-webkit-backdrop-filter:none;backdrop-filter:none}.study-app.study-app .study-header__inner{gap:var(--space-8);grid-template-columns:13rem minmax(0,1fr) auto}.study-app.study-app .study-brand{font-size:var(--text-lg);letter-spacing:-.04em;font-weight:720}.study-app.study-app .study-brand__name b{color:var(--color-accent-strong)}.study-app.study-app .study-brand__mark{border-radius:var(--radius-md);object-fit:cover;display:block}.study-app.study-app .study-search{background:var(--color-paper-soft);width:min(100%,32rem);height:2.75rem}.study-app.study-app .study-search-wrap{justify-self:center;width:min(100%,32rem);min-width:0;position:relative}.study-app.study-app .study-search-wrap .study-search{justify-self:stretch;width:100%}.study-app.study-app .study-search-results{z-index:var(--z-drawer);top:calc(100% + var(--space-2));padding:var(--space-2);border:1px solid var(--color-line-strong);border-radius:var(--radius-lg);background:var(--color-paper-raised);box-shadow:var(--shadow-popover);position:absolute;left:0;right:0}.study-app.study-app .study-search-results__meta{justify-content:space-between;align-items:center;gap:var(--space-3);padding:var(--space-2) var(--space-3);color:var(--color-muted);font-size:var(--text-2xs);letter-spacing:.04em;text-transform:uppercase;font-weight:750;display:flex}.study-app.study-app .study-search-result{align-items:center;gap:var(--space-3);width:100%;min-width:0;min-height:3.25rem;padding:var(--space-2) var(--space-3);border-radius:var(--radius-md);text-align:left;background:0 0;border:0;grid-template-columns:2.75rem minmax(0,1fr) minmax(0,8rem);display:grid}.study-app.study-app .study-search-result:hover{background:var(--color-paper-soft)}.study-app.study-app .study-search-result__hanzi{color:var(--color-ink);font-family:var(--font-cjk);font-size:var(--text-xl);text-align:center;font-weight:500;line-height:1}.study-app.study-app .study-search-result__body{gap:2px;min-width:0;display:grid}.study-app.study-app .study-search-result__body b{color:var(--color-accent-strong);font-size:var(--text-sm);font-weight:700}.study-app.study-app .study-search-result__body small,.study-app.study-app .study-search-result__topic{min-width:0;color:var(--color-ink-soft);font-size:var(--text-xs);text-overflow:ellipsis;white-space:nowrap;line-height:1.3;overflow:hidden}.study-app.study-app .study-search-result__topic{color:var(--color-muted);text-align:right}.study-app.study-app .study-search-results__empty{padding:var(--space-4);color:var(--color-muted);font-size:var(--text-sm);text-align:center;margin:0}.study-app.study-app .study-search input{font-size:1rem}.study-app.study-app .study-header__progress .sync-status.error{color:var(--color-muted)}.study-app.study-app .study-sidebar{background:var(--color-sidebar)}.study-app.study-app .study-sidebar__inner{padding:var(--space-6) var(--space-4)}.study-app.study-app .sidebar-heading{margin-bottom:var(--space-3);justify-content:space-between;align-items:center;display:flex}.study-app.study-app .sidebar-heading p{margin:0}.study-app.study-app .drawer-close{border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-raised);width:44px;height:44px;font-size:var(--text-2xl);display:none}.study-app.study-app .study-sidebar nav button{font-weight:550;font-size:var(--text-sm);min-height:44px}.study-app.study-app .study-sidebar nav button.is-active{background:var(--color-accent-soft);border-color:#0000;font-weight:700}.study-app.study-app .study-sidebar nav button>span:last-child{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.study-app.study-app .study-sidebar__rule{margin:var(--space-5) 0}.study-app.study-app .study-sidebar__note{margin-top:var(--space-6);background:var(--color-paper-soft);padding:var(--space-4)}.study-app.study-app .sidebar-progress{gap:var(--space-2);width:100%;display:grid}.study-app.study-app .sidebar-progress strong{color:var(--color-accent-strong);font-size:var(--text-xl)}.study-app.study-app .sidebar-progress strong span{font-size:var(--text-sm);color:var(--color-muted);font-weight:400}.study-app.study-app .sidebar-progress progress{width:100%;height:6px;accent-color:var(--color-accent-strong);border-radius:var(--radius-pill);border:0}.study-app.study-app .sidebar-progress progress::-webkit-progress-bar{background:var(--color-line);border-radius:var(--radius-pill)}.study-app.study-app .sidebar-progress progress::-webkit-progress-value{background:var(--color-accent-strong);border-radius:var(--radius-pill)}.study-app.study-app .study-main{padding:var(--space-8) var(--space-10)}.study-app.study-app .study-intro{margin-bottom:var(--space-6);padding-bottom:var(--space-6);align-items:center;gap:var(--space-4)}.study-app.study-app .study-intro h1{letter-spacing:-.04em;max-width:none;font-size:clamp(1.5rem,2.4vw,2rem);font-weight:650;line-height:1.25}.study-app.study-app .study-intro__kicker{letter-spacing:.16em;margin-bottom:var(--space-2);font-size:.625rem}.study-app.study-app .study-intro__lead{max-width:none;margin-top:var(--space-2);font-size:var(--text-sm)}.study-app.study-app .study-intro__stat{text-align:right;background:0 0;border:0;padding:0}.study-app.study-app .study-intro__stat strong{font-size:var(--text-xl);font-weight:600}.study-app.study-app .study-intro__stat span{font-size:var(--text-2xs)}.study-app.study-app .study-toolbar{margin-bottom:var(--space-5)}.study-app.study-app .study-select{width:min(100%,20rem);min-width:0}.study-app.study-app .study-select>span{display:none}.study-app.study-app .study-select select{width:100%;font-size:1rem}.study-app.study-app .study-result-count{font-size:var(--text-xs)}.study-app.study-app .study-section-heading{margin-bottom:var(--space-3)}.study-app.study-app .study-section__eyebrow{display:none}.study-app.study-app .study-section-heading h2{font-size:var(--text-md);color:var(--color-muted);font-weight:600}.study-app.study-app .study-section__counter{font-variant-numeric:tabular-nums;background:0 0;border:0}.study-app.study-app .study,.study-app.study-app .quiz{max-width:46rem}.study-app.study-app .flashcard{min-height:22rem;padding:5rem var(--space-6) var(--space-6);border-radius:var(--radius-xl);box-shadow:var(--shadow-soft);background-color:var(--color-paper-raised);background-image:linear-gradient(var(--color-grid) 1px, transparent 1px), linear-gradient(90deg, var(--color-grid) 1px, transparent 1px);background-size:32px 32px}.study-app.study-app .flashcard.is-revealed{border-color:var(--color-accent)}.study-app.study-app .hanzi{font-size:clamp(3.5rem,7vw,6rem);line-height:1.2}.study-app.study-app .pinyin{margin-top:var(--space-3);font-weight:500}.study-app.study-app .hanviet{font-family:var(--font-body)}.study-app.study-app .meaning{min-height:3.25rem;padding:var(--space-3) var(--space-4);border:1px dashed var(--color-line-strong);border-radius:var(--radius-md);background:var(--color-paper-raised);color:var(--color-accent-strong);font-size:var(--text-sm)}.study-app.study-app .meaning.shown{border-style:solid;border-color:var(--color-accent);background:var(--color-accent-soft);font-size:var(--text-lg)}.study-app.study-app .card-actions button{background:var(--color-paper-raised);width:44px;height:44px}.study-app.study-app .study-actions{margin-top:var(--space-4);grid-template-columns:48px minmax(0,17rem) 48px}.study-app.study-app .study-actions button{min-height:48px}.study-app.study-app .round{background:var(--color-paper-raised);border:1px solid var(--color-line);width:48px;height:48px}.study-app.study-app .know{font-weight:650}.study-app.study-app .quiz-card{padding:4.5rem var(--space-6) var(--space-6);box-shadow:var(--shadow-soft)}.study-app.study-app .quiz-card>strong{font-size:clamp(3.5rem,7vw,5rem)}.study-app.study-app .list-grid{gap:var(--space-3);grid-template-columns:repeat(2,minmax(0,1fr))}.study-app.study-app .list-grid article{align-content:start;align-items:start;gap:var(--space-1);min-height:0;padding:var(--space-5);text-align:left;border-radius:var(--radius-md);grid-template-columns:minmax(0,1fr) 44px;display:grid}.study-app.study-app .list-grid article>button{grid-area:1/2/3;position:static}.study-app.study-app .list-grid article>:not(button){grid-column:1}.study-app.study-app .list-grid article>strong{grid-row:1;font-size:2rem}.study-app.study-app .list-grid article>span{grid-row:2;font-weight:500}.study-app.study-app .list-grid article>em{font-family:var(--font-body)}.study-app.study-app .list-grid article>p{margin:var(--space-2) 0;font-weight:550}.study-app.study-app .study-footer{margin-top:var(--space-8);padding-top:var(--space-4);font-size:var(--text-2xs)}.study-app.study-app button:active:not(:disabled){transform:translateY(1px)}@media (width<=60rem){.study-app.study-app .study-header__inner{gap:var(--space-3);grid-template-columns:44px auto minmax(0,1fr) auto}.study-app.study-app .study-header__progress{min-width:0}.study-app.study-app .study-header__progress-track{display:none}.study-app.study-app .study-sidebar{visibility:hidden;transition:none}.study-app.study-app .study-sidebar.is-open{visibility:visible}.study-app.study-app .drawer-close{place-items:center;display:grid}.study-app.study-app .study-main{padding:var(--space-6)}.study-app.study-app .study-mobile-modes{margin-bottom:var(--space-4);background:var(--color-paper-soft)}}@media (width<=40rem){.study-app.study-app .study-header__inner{padding:var(--space-2) var(--space-4);gap:var(--space-2) var(--space-3);grid-template-columns:44px minmax(0,1fr) auto;min-height:0}.study-app.study-app .study-brand{font-size:1rem}.study-app.study-app .study-search-wrap{grid-area:search;width:100%}.study-app.study-app .study-search{width:100%;height:44px}.study-app.study-app .study-search-results{top:calc(100% + var(--space-1))}.study-app.study-app .study-search-result{gap:var(--space-2);grid-template-columns:2.5rem minmax(0,1fr)}.study-app.study-app .study-search-result__topic{display:none}.study-app.study-app .study-main{padding:var(--space-5) var(--space-4)}.study-app.study-app .study-intro{margin-bottom:var(--space-4);border:0;padding-bottom:0}.study-app.study-app .study-intro h1{max-width:none;font-size:1.5rem}.study-app.study-app .study-intro__lead{font-size:var(--text-xs);line-height:1.5}.study-app.study-app .study-intro__stat{display:none}.study-app.study-app .study-toolbar{gap:var(--space-2);margin-bottom:var(--space-3);display:flex}.study-app.study-app .study-result-count{max-width:5rem;font-size:var(--text-2xs);flex:none}.study-app.study-app .study-select{flex:1;width:0}.study-app.study-app .study-select select{padding-inline:var(--space-2)}.study-app.study-app .flashcard{min-height:19rem;padding:4.5rem var(--space-4) var(--space-4)}.study-app.study-app .flashcard__toolbar{inset:var(--space-3) var(--space-3) auto}.study-app.study-app .hanzi{font-size:clamp(3.25rem,18vw,4.5rem)}.study-app.study-app .hanviet{margin-bottom:var(--space-3)}.study-app.study-app .study-actions{grid-template-columns:48px minmax(0,1fr) 48px}.study-app.study-app .list-grid{grid-template-columns:minmax(0,1fr)}.study-app.study-app .quiz-card{padding:4.5rem var(--space-4) var(--space-4)}.study-app.study-app .answers button{min-height:48px}}:root{--ink:#23312b;--muted:#6e7a74;--paper:#fbfaf5;--cream:#f2eee2;--jade:#2e6753;--jade-dark:#1f4c3d;--red:#c54d3f;--line:#dcd9ce}html{-webkit-text-size-adjust:100%}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}button,a,input,select{-webkit-tap-highlight-color:transparent}button{touch-action:manipulation}:focus-visible{outline-offset:4px;outline:3px solid #267c66}button:disabled{cursor:default;opacity:.55}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,:before,:after{transition:none!important;animation:none!important}}*{box-sizing:border-box}html{scroll-behavior:smooth}body{background:var(--paper);color:var(--ink);margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,sans-serif}button,input,select{font:inherit}button{cursor:pointer}.topbar{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;max-width:1180px;height:76px;margin:auto;padding:0 28px;display:flex}.brand{color:var(--ink);align-items:center;gap:11px;font-family:Georgia,serif;font-size:19px;font-weight:700;text-decoration:none;display:flex}.brand>span:last-child span{color:var(--red);margin-left:2px}.brand-mark{background:var(--red);color:#fff;border-radius:10px 10px 10px 3px;place-items:center;width:38px;height:38px;font-size:22px;display:grid}nav{background:#efede5;border-radius:999px;align-items:center;gap:8px;padding:5px;display:flex}nav button{color:var(--muted);background:0 0;border:0;border-radius:999px;padding:9px 17px;font-size:14px;font-weight:700}nav button.active{color:var(--jade);background:#fff;box-shadow:0 2px 8px #203a2c14}.progress-pill{color:var(--jade);align-items:center;gap:10px;font-size:13px;font-weight:800;display:flex}.progress-pill>div{background:#dfded7;border-radius:9px;width:82px;height:7px;overflow:hidden}.progress-pill i{background:var(--jade);border-radius:inherit;height:100%;display:block}.sync-status{min-width:65px;color:var(--muted);font-size:10px;font-weight:700}.sync-status.saved{color:var(--jade)}.sync-status.error{color:var(--red)}.workspace{max-width:1120px;margin:0 auto;padding:0 28px 80px}.controls{grid-template-columns:1fr 270px;gap:13px;display:grid}.search{border:1px solid var(--line);background:#fff;border-radius:15px;align-items:center;gap:10px;height:52px;padding:0 17px;display:flex}.search span{color:var(--muted);font-size:24px}.search input{width:100%;color:var(--ink);background:0 0;border:0;outline:0}.controls select{border:1px solid var(--line);color:var(--ink);background:#fff;border-radius:15px;outline:none;padding:0 15px}.topic-strip{scrollbar-width:thin;gap:8px;margin:16px 0 55px;padding-bottom:5px;display:flex;overflow-x:auto}.topic-strip button{min-width:max-content;color:var(--muted);background:0 0;border:1px solid #0000;border-radius:12px;align-items:center;gap:8px;padding:10px 13px;font-size:13px;font-weight:700;display:flex}.topic-strip button span{font-size:18px}.topic-strip button.selected{color:var(--jade-dark);background:#e6eee9;border-color:#d4e3db}.section-heading{justify-content:space-between;align-items:flex-end;margin-bottom:18px;display:flex}.section-heading p{margin-bottom:6px}.section-heading h2{margin:0;font-family:Georgia,serif;font-size:30px;font-weight:500}.section-heading>span{color:var(--muted);font-weight:700}.study{max-width:700px;margin:auto}.flashcard{background:#fffefa;border:1px solid #dedbd0;border-radius:28px;flex-direction:column;justify-content:center;align-items:center;min-height:390px;display:flex;position:relative;overflow:hidden;box-shadow:0 18px 45px #30382f0c}.flashcard:before{content:"";pointer-events:none;border:1px solid #ece8dd;border-radius:21px;position:absolute;inset:14px}.card-actions{z-index:2;gap:8px;display:flex;position:absolute;top:27px;right:29px}.card-actions button{border:1px solid var(--line);width:38px;height:38px;color:var(--red);background:#fff;border-radius:50%;font-size:20px}.card-topic{color:var(--muted);margin:0 0 15px;font-size:13px}.hanzi{font-family:Noto Serif SC,Songti SC,STSong,serif;font-size:clamp(74px,11vw,108px);font-weight:500;line-height:1.1}.pinyin{color:var(--jade);margin:11px 0 5px;font-family:Georgia,serif;font-size:22px}.hanviet{color:var(--ink);margin:0 0 24px;font-family:Georgia,serif;font-size:17px}.hanviet span{color:var(--red);letter-spacing:.1em;text-transform:uppercase;margin-right:6px;font-family:Inter,sans-serif;font-size:10px;font-weight:900}.meaning{border-top:1px solid var(--line);color:#9b9e99;text-align:center;min-width:230px;padding-top:17px;font-size:16px}.meaning.shown{color:var(--ink);font-size:20px;font-weight:700}.reveal-hitbox{z-index:1;background:0 0;border:0;position:absolute;inset:0}.study-actions{justify-content:center;align-items:center;gap:13px;margin-top:20px;display:flex}.study-actions button{border:0}.round{width:49px;height:49px;color:var(--ink);background:#eceae2;border-radius:50%;font-size:20px}.know{background:var(--jade);color:#fff;border-radius:999px;min-width:190px;padding:14px 25px;font-weight:800}.know:disabled{cursor:wait;opacity:.55}.empty{text-align:center;color:var(--muted);background:#fff;border-radius:20px;padding:80px}.list-grid{grid-template-columns:repeat(4,1fr);gap:12px;display:grid}.list-grid article{border:1px solid var(--line);text-align:center;background:#fff;border-radius:18px;flex-direction:column;align-items:center;min-height:190px;padding:25px 20px;display:flex;position:relative}.list-grid button{width:31px;height:31px;color:var(--jade);background:#e9f0ec;border:0;border-radius:50%;position:absolute;top:12px;right:12px}.list-grid strong{font-family:Noto Serif SC,serif;font-size:36px;font-weight:500}.list-grid span{color:var(--jade);margin-top:4px}.list-grid em{color:var(--red);margin-top:5px;font-family:Georgia,serif;font-size:14px;font-style:normal}.list-grid p{margin:9px 0 13px;font-weight:700}.list-grid small{color:var(--muted);margin-top:auto}.quiz{max-width:700px;margin:auto}.quiz-card{border:1px solid var(--line);background:#fff;border-radius:28px;flex-direction:column;align-items:center;padding:45px;display:flex;position:relative}.quiz-card>strong{font-family:Noto Serif SC,serif;font-size:80px;font-weight:500}.quiz-card>p{color:var(--jade);font-size:20px}.quiz-audio{color:var(--jade);background:#e9f0ec;border:0;border-radius:999px;padding:9px 15px;position:absolute;top:22px;right:22px}.answers{grid-template-columns:1fr 1fr;gap:10px;width:100%;display:grid}.answers button{border:1px solid var(--line);min-height:58px;color:var(--ink);background:#faf9f4;border-radius:13px;padding:10px;font-weight:700}.answers button.correct{color:#1d6847;background:#e9f7ef;border-color:#7cc39f}.answers button.wrong{color:#a8332a;background:#fff0ef;border-color:#d6908a}.next-quiz{color:#fff;background:var(--jade);border:0;border-radius:999px;margin-top:18px;padding:12px 20px;font-weight:800}footer{border-top:1px solid var(--line);color:var(--muted);text-align:center;padding:28px;font-size:12px}footer a{color:var(--jade)}.offline-ready{color:var(--jade);margin-right:12px;font-weight:800;display:inline-block}@media (width<=800px){.topbar{flex-wrap:wrap;gap:12px;height:auto;padding:14px 18px}.topbar nav{order:3;justify-content:center;width:100%}.controls{grid-template-columns:1fr}.topic-strip{margin-bottom:35px}.list-grid{grid-template-columns:repeat(2,1fr)}}@media (width<=500px){.progress-pill>div{display:none}nav button{padding:8px 13px}.workspace{padding:0 16px 60px}.flashcard{min-height:370px}.list-grid,.answers{grid-template-columns:1fr}.quiz-card{padding:38px 20px 25px}}:root{--ink:#172f28;--muted:#53665e;--paper:#f4f6f5;--line:#dce5df;--jade:#19634b;--jade-dark:#114a37;--red:#ae4033}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-size:1rem}.topbar{gap:16px;max-width:1120px;height:auto;min-height:80px;padding:16px 28px}.brand{letter-spacing:-.03em;white-space:nowrap;font-family:inherit;font-size:1.125rem}nav{background:#e5ece8;border-radius:15px}nav button{border-radius:11px;min-height:44px;font-size:.875rem}.progress-pill{flex-wrap:wrap;justify-content:flex-end;gap:7px}.sync-status{font-size:.75rem}.workspace{padding-bottom:36px}.controls{grid-template-columns:minmax(0,1fr) 260px}.controls>*{min-width:0;min-height:50px}.search:focus-within{border-color:var(--jade);box-shadow:0 0 0 3px #19634b18}.search input{min-width:0;font-size:1rem}.controls select{font-size:1rem}.topic-strip{gap:8px;margin:12px 0 24px}.topic-strip button{border:1px solid var(--line);background:#fff;min-height:44px;padding:8px 12px;font-size:.875rem}.section-heading{align-items:center;gap:16px}.section-heading h2{overflow-wrap:anywhere;font-family:inherit;font-size:1.375rem;font-weight:650;line-height:1.35}.section-heading p{letter-spacing:.1em;font-size:.75rem}.section-heading>span{background:#e6eee9;border-radius:10px;flex-shrink:0;padding:8px 12px;font-size:.875rem}.study,.quiz{max-width:720px}.flashcard{background:#fff;border-radius:24px;min-height:340px;padding:78px 24px 30px;box-shadow:0 12px 35px #173e2910}.flashcard:before{display:none}.card-actions{gap:10px;top:18px;right:18px}.card-actions button{background:#f4f7f5;width:44px;height:44px}.card-topic{text-align:center;max-width:100%;margin-bottom:12px;font-size:.875rem}.hanzi{overflow-wrap:anywhere;text-align:center;max-width:100%;font-size:clamp(3rem,10vw,5.5rem);line-height:1.25}.pinyin{text-align:center;font-size:1.375rem}.hanviet{text-align:center;margin-bottom:18px;font-size:1.125rem}.hanviet span{letter-spacing:.03em;font-size:.75rem}.meaning{width:100%;min-width:0;color:var(--muted);font-size:1rem}.meaning.shown{font-size:1.25rem}.reveal-hitbox{border-radius:inherit}.reveal-hitbox:focus-visible{outline-offset:-5px}.study-actions{gap:12px}.round{border-radius:16px;flex-shrink:0;width:52px;height:52px}.know{border-radius:16px;min-height:52px}.know.known{background:var(--jade-dark)}.list-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.list-grid article{overflow-wrap:anywhere;border-radius:20px;gap:3px;padding:56px 16px 20px}.load-more{background:var(--jade);color:#fff;border:0;border-radius:14px;min-height:48px;margin:20px auto 0;padding:12px 20px;font-weight:750;display:block}.list-grid button{width:44px;height:44px;top:8px;right:8px}.list-grid strong{font-size:2rem}.list-grid small{font-size:.75rem}.list-grid em{font-size:.875rem}.quiz-card{border-radius:24px;padding:72px 28px 28px}.quiz-card>strong{text-align:center;overflow-wrap:anywhere;max-width:100%;font-size:clamp(3rem,10vw,5rem)}.quiz-audio{min-height:44px;top:16px;right:16px}.answers button{min-height:60px;font-size:1rem}.answers button:disabled{opacity:1}.answer-feedback{text-align:center;font-size:1rem!important}.next-quiz,.empty button{background:var(--jade);color:#fff;border:0;border-radius:14px;min-height:48px;padding:12px 20px}.empty{border:1px solid var(--line);padding:32px 20px}.empty h3{color:var(--ink);margin:0}.empty p{margin:12px 0 20px}footer{padding:24px;font-size:.75rem;line-height:1.8}.offline-ready{margin:0 0 4px;display:block}@media (hover:hover){button:not(:disabled):hover{filter:brightness(.95)}}@media (width<=800px){.topbar{flex-wrap:wrap;padding:14px 20px}.topbar nav{order:3;justify-content:center;width:100%}.topbar nav button{flex:1}.controls{grid-template-columns:minmax(0,1fr) 220px}.list-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (width<=600px){.topbar{padding:14px 16px}.topbar nav{z-index:20;padding:10px 16px calc(10px + env(safe-area-inset-bottom));-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);border-top:1px solid var(--line);background:#f8faf9f5;border-radius:20px 20px 0 0;gap:4px;position:fixed;bottom:0;left:0;right:0;box-shadow:0 -4px 24px #173e2910}.topbar nav button{min-height:48px;padding:10px 8px;font-size:.875rem}.topbar nav button.active{background:var(--jade);color:#fff}main{padding-bottom:calc(86px + env(safe-area-inset-bottom))}.progress-pill{gap:4px;max-width:120px;font-size:.875rem}.progress-pill>div{display:none}.sync-status{text-align:right;width:100%}.workspace{padding:0 16px 28px}.controls{grid-template-columns:minmax(0,1fr);gap:10px}.topic-strip{margin-bottom:18px}.section-heading h2{font-size:1.125rem}.flashcard{border-radius:22px;min-height:310px;padding:74px 20px 26px}.study-actions{grid-template-columns:52px minmax(0,1fr) 52px;gap:10px;display:grid}.know{min-width:0;padding:12px 8px;font-size:.9375rem}.quiz-card{padding:70px 16px 24px}.answers{grid-template-columns:1fr}}@media (width<=360px){.list-grid{grid-template-columns:1fr}.brand{gap:7px;font-size:1rem}}html,body{overflow-x:clip}.study-app{background:var(--color-paper);min-height:100svh;color:var(--color-ink);font-family:var(--font-body)}.study-app a,.study-app button,.study-app input,.study-app select{-webkit-tap-highlight-color:transparent}.study-app button,.study-app input,.study-app select{font:inherit}.study-app button{color:inherit}.study-app :focus-visible{outline:3px solid var(--color-focus);outline-offset:3px}.study-app .sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.study-header{z-index:var(--z-header);border-bottom:1px solid color-mix(in oklch, var(--color-line) 88%, transparent);background:color-mix(in oklch, var(--color-paper-raised) 92%, transparent);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);position:sticky;top:0}.study-header__inner{width:min(100%, var(--layout-max));min-height:var(--header-height);padding:0 var(--space-8);align-items:center;gap:var(--space-6);grid-template-columns:auto minmax(16rem,1fr) auto;margin:0 auto;display:grid}.study-menu-button{border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-raised);width:2.75rem;height:2.75rem;color:var(--color-ink-soft);place-items:center;font-size:1.3rem;line-height:1;display:none}.study-brand{align-items:center;gap:var(--space-3);min-width:max-content;color:var(--color-ink);font-family:var(--font-display);font-size:var(--text-lg);letter-spacing:-.035em;font-weight:760;text-decoration:none;display:inline-flex}.study-brand__mark{border-radius:var(--radius-md) var(--radius-md) var(--radius-md) .25rem;background:var(--color-accent-strong);width:2.5rem;height:2.5rem;color:var(--color-paper-raised);font-family:var(--font-cjk);box-shadow:var(--shadow-soft);place-items:center;font-size:1.35rem;font-weight:600;display:grid}.study-brand__name b{color:var(--color-coral);font-weight:800}.study-search{justify-self:center;align-items:center;gap:var(--space-3);width:min(100%,35rem);height:2.875rem;padding:0 var(--space-4);border:1px solid var(--color-line);border-radius:var(--radius-pill);background:var(--color-paper-soft);color:var(--color-muted);transition:border-color var(--duration-fast) var(--ease-standard), box-shadow var(--duration-fast) var(--ease-standard), background var(--duration-fast) var(--ease-standard);display:flex}.study-search:focus-within{border-color:var(--color-blue);background:var(--color-paper-raised);box-shadow:0 0 0 .2rem color-mix(in oklch, var(--color-blue) 16%, transparent)}.study-search__icon{color:var(--color-muted);font-size:1.45rem;line-height:1}.study-search input{width:100%;min-width:0;color:var(--color-ink);font-size:var(--text-md);background:0 0;border:0;outline:0}.study-search input::placeholder{color:var(--color-muted-soft)}.study-search kbd{padding:var(--space-1) var(--space-2);border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-paper-raised);color:var(--color-muted);font-family:var(--font-mono);font-size:var(--text-2xs);flex:none}.study-header__progress{justify-content:end;align-items:center;gap:var(--space-2) var(--space-3);min-width:8.75rem;color:var(--color-accent-strong);grid-template-columns:auto 4.5rem;display:grid}.study-header__progress-value{font-size:var(--text-md);font-weight:800}.study-header__progress-track{border-radius:var(--radius-pill);background:var(--color-paper-muted);height:.4rem;overflow:hidden}.study-header__progress-track i{border-radius:inherit;background:var(--color-accent);height:100%;display:block}.study-header__progress .sync-status{min-width:0;color:var(--color-muted);font-size:var(--text-2xs);grid-column:1/-1;justify-self:end;font-weight:650}.study-header__progress .sync-status.saved{color:var(--color-success)}.study-header__progress .sync-status.error{color:var(--color-error)}.study-shell{width:min(100%, var(--layout-max));min-height:calc(100svh - var(--header-height));grid-template-columns:var(--sidebar-width) minmax(0, 1fr);margin:0 auto;display:grid}.study-sidebar{border-right:1px solid var(--color-line);background:color-mix(in oklch, var(--color-paper-soft) 42%, var(--color-paper));min-width:0}.study-sidebar__inner{top:var(--header-height);height:calc(100svh - var(--header-height));padding:var(--space-8) var(--space-4) var(--space-10);overscroll-behavior:contain;scrollbar-width:thin;position:sticky;overflow-y:auto}.study-sidebar__label{margin:0 0 var(--space-3);color:var(--color-muted);font-size:var(--text-2xs);letter-spacing:.12em;text-transform:uppercase;font-weight:800}.study-sidebar__rule{height:1px;margin:var(--space-6) 0;background:var(--color-line)}.study-app .study-sidebar nav.study-mode-nav,.study-app .study-sidebar nav.study-topic-nav{align-items:stretch;gap:var(--space-1);background:0 0;border-radius:0;padding:0;display:grid}.study-app .study-sidebar nav button{align-items:center;gap:var(--space-3);min-width:0;min-height:2.75rem;padding:var(--space-2) var(--space-3);border-radius:var(--radius-md);color:var(--color-ink-soft);font-size:var(--text-md);text-align:left;white-space:normal;background:0 0;border:1px solid #0000;font-weight:650;display:flex}.study-app .study-sidebar nav button>span:first-child{width:1.25rem;color:var(--color-muted);text-align:center;flex:0 0 1.25rem}.study-app .study-sidebar nav button.is-active{border-color:color-mix(in oklch, var(--color-accent) 18%, var(--color-line));background:var(--color-accent-soft);color:var(--color-accent-strong)}.study-app .study-sidebar nav button.is-active>span:first-child{color:var(--color-accent-strong)}.study-topic-nav button>span:last-child{overflow-wrap:anywhere}.study-sidebar__note{margin-top:var(--space-8);padding:var(--space-3);align-items:flex-start;gap:var(--space-2);border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-raised);color:var(--color-muted);display:flex}.study-sidebar__note>span{color:var(--color-accent-strong);font-size:var(--text-lg);font-weight:800;line-height:1}.study-sidebar__note p{font-size:var(--text-xs);margin:0;line-height:1.55}.study-main{min-width:0;padding:var(--space-12) clamp(var(--space-6), 5vw, var(--space-16)) var(--space-16)}.study-intro{max-width:var(--content-max);margin:0 auto var(--space-8);padding-bottom:var(--space-8);justify-content:space-between;align-items:flex-end;gap:var(--space-8);border-bottom:1px solid var(--color-line);display:flex}.study-intro__kicker,.study-section__eyebrow{margin:0 0 var(--space-2);color:var(--color-accent-strong);font-size:var(--text-2xs);letter-spacing:.14em;text-transform:uppercase;font-weight:850}.study-intro h1{max-width:13ch;color:var(--color-ink);font-family:var(--font-display);font-size:var(--text-3xl);letter-spacing:-.055em;overflow-wrap:anywhere;margin:0;line-height:1.08}.study-intro__lead{max-width:48ch;margin:var(--space-4) 0 0;color:var(--color-muted);font-size:var(--text-md);line-height:1.65}.study-intro__stat{min-width:7.5rem;padding:var(--space-4);border-left:3px solid var(--color-coral);background:var(--color-coral-soft);flex:none}.study-intro__stat strong{color:var(--color-ink);font-family:var(--font-display);font-size:var(--text-2xl);line-height:1;display:block}.study-intro__stat span{margin-top:var(--space-2);color:var(--color-muted);font-size:var(--text-xs);display:block}.study-mobile-modes{display:none}.study-toolbar{max-width:var(--content-max);margin:0 auto var(--space-10);justify-content:space-between;align-items:flex-end;gap:var(--space-4);display:flex}.study-select{gap:var(--space-2);min-width:min(100%,20rem);display:grid}.study-select>span{color:var(--color-muted);font-size:var(--text-xs);font-weight:700}.study-select select{min-width:0;min-height:2.875rem;padding:0 var(--space-4);border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-raised);color:var(--color-ink);outline:0}.study-select select:focus{border-color:var(--color-blue);box-shadow:0 0 0 .2rem color-mix(in oklch, var(--color-blue) 14%, transparent)}.study-result-count{padding-bottom:var(--space-2);color:var(--color-muted);font-size:var(--text-sm)}.study-app .study,.study-app .word-list,.study-app .quiz{max-width:var(--content-max);margin-inline:auto}.study-app .section-heading.study-section-heading{margin-bottom:var(--space-4);align-items:flex-end;gap:var(--space-4)}.study-app .study-section-heading h2{max-width:100%;color:var(--color-ink);font-family:var(--font-display);font-size:var(--text-xl);letter-spacing:-.025em;overflow-wrap:anywhere;margin:0;font-weight:720;line-height:1.25}.study-app .study-section__counter{padding:var(--space-2) var(--space-3);border:1px solid var(--color-line);border-radius:var(--radius-pill);background:var(--color-paper-raised);color:var(--color-muted);font-size:var(--text-xs);flex:none;font-weight:750}.study-app .flashcard{min-height:25rem;padding:6rem var(--space-8) var(--space-8);border:1px solid var(--color-line);border-radius:var(--radius-xl);background:var(--color-paper-raised);box-shadow:var(--shadow-card);overflow:hidden}.study-app .flashcard:before{display:none}.flashcard__toolbar{z-index:2;top:var(--space-5);right:var(--space-5);left:var(--space-5);justify-content:space-between;align-items:center;gap:var(--space-4);min-width:0;display:flex;position:absolute}.study-app .flashcard .card-topic{overflow-wrap:anywhere;min-width:0;color:var(--color-muted);font-size:var(--text-sm);text-align:left;margin:0}.study-app .flashcard .card-actions{gap:var(--space-2);flex:none;display:flex;position:static}.study-app .flashcard .card-actions button{border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-soft);width:2.75rem;height:2.75rem;color:var(--color-accent-strong);place-items:center;font-size:1.25rem;display:grid}.study-app .flashcard .card-actions button:first-child{color:var(--color-coral)}.study-app .hanzi{z-index:0;max-width:100%;color:var(--color-ink);font-family:var(--font-cjk);overflow-wrap:anywhere;text-align:center;font-size:clamp(4.5rem,10vw,7rem);font-weight:500;line-height:1;position:relative}.study-app .pinyin{z-index:0;margin:var(--space-4) 0 var(--space-2);color:var(--color-accent-strong);font-family:var(--font-display);font-size:var(--text-xl);font-weight:650;position:relative}.study-app .hanviet{z-index:0;margin:0 0 var(--space-5);color:var(--color-ink-soft);font-size:var(--text-md);text-align:center;position:relative}.study-app .hanviet span{margin-right:var(--space-2);color:var(--color-coral);font-family:var(--font-body);font-size:var(--text-2xs);letter-spacing:.08em;font-weight:850}.study-app .meaning{z-index:0;width:min(100%,31rem);min-width:0;padding-top:var(--space-4);border-top:1px solid var(--color-line);color:var(--color-muted-soft);font-size:var(--text-base);text-align:center;line-height:1.5;position:relative}.study-app .meaning.shown{color:var(--color-ink);font-size:var(--text-lg);font-weight:720}.study-app .reveal-hitbox{border-radius:inherit}.study-app .reveal-hitbox:focus-visible{outline-offset:-.3rem}.study-app .study-actions{margin-top:var(--space-4);justify-content:center;align-items:center;gap:var(--space-3);grid-template-columns:2.75rem minmax(0,15rem) 2.75rem;display:grid}.study-app .study-actions button{border:0;min-height:2.75rem}.study-app .round{border-radius:var(--radius-md);background:var(--color-paper-muted);width:2.75rem;height:2.75rem;color:var(--color-ink-soft);font-size:var(--text-lg);padding:0}.study-app .know{min-width:0;padding:var(--space-3) var(--space-4);border-radius:var(--radius-md);background:var(--color-accent-strong);color:var(--color-paper-raised);font-size:var(--text-md);font-weight:800}.study-app .know.known{background:var(--color-blue-ink)}.study-app .empty{max-width:var(--content-max);padding:var(--space-12) var(--space-6);border:1px solid var(--color-line);border-radius:var(--radius-lg);background:var(--color-paper-raised);color:var(--color-muted);text-align:center;margin-inline:auto}.study-app .empty h3{color:var(--color-ink);margin:0}.study-app .empty p{margin:0 0 var(--space-5)}.study-app .empty button{min-height:2.75rem;padding:var(--space-3) var(--space-4);border-radius:var(--radius-md);background:var(--color-accent-strong);color:var(--color-paper-raised);border:0;font-weight:750}.study-app .list-grid{gap:var(--space-3);grid-template-columns:repeat(auto-fill,minmax(12.5rem,1fr));display:grid}.study-app .list-grid article{min-width:0;min-height:12rem;padding:var(--space-8) var(--space-4) var(--space-4);align-items:center;gap:var(--space-1);border:1px solid var(--color-line);border-radius:var(--radius-lg);background:var(--color-paper-raised);text-align:center;flex-direction:column;display:flex}.study-app .list-grid article>button{top:var(--space-2);right:var(--space-2);border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-soft);width:2.75rem;height:2.75rem;color:var(--color-accent-strong);place-items:center;display:grid;position:absolute}.study-app .list-grid article{position:relative}.study-app .list-grid strong{color:var(--color-ink);font-family:var(--font-cjk);font-size:2.5rem;font-weight:500;line-height:1.1}.study-app .list-grid span{color:var(--color-accent-strong);font-size:var(--text-md);font-weight:700}.study-app .list-grid em{color:var(--color-coral);font-size:var(--text-sm);font-style:normal}.study-app .list-grid p{margin:var(--space-2) 0 var(--space-3);color:var(--color-ink-soft);font-size:var(--text-sm);overflow-wrap:anywhere;font-weight:650;line-height:1.4}.study-app .list-grid small{color:var(--color-muted);font-size:var(--text-2xs);overflow-wrap:anywhere;margin-top:auto;line-height:1.35}.study-app .load-more{min-height:2.75rem;margin:var(--space-5) auto 0;padding:var(--space-3) var(--space-5);border:1px solid var(--color-accent-strong);border-radius:var(--radius-md);background:var(--color-accent-strong);color:var(--color-paper-raised);font-size:var(--text-md);font-weight:800;display:block}.study-app .quiz-card{padding:6rem var(--space-8) var(--space-8);border:1px solid var(--color-line);border-radius:var(--radius-xl);background:var(--color-paper-raised);box-shadow:var(--shadow-card);position:relative}.study-app .quiz-card>strong{color:var(--color-ink);font-family:var(--font-cjk);text-align:center;font-size:clamp(4.5rem,10vw,7rem);font-weight:500;line-height:1;display:block}.study-app .quiz-card>p:not(.answer-feedback){color:var(--color-accent-strong);font-family:var(--font-display);font-size:var(--text-xl);text-align:center;font-weight:650}.study-app .quiz-audio{min-height:2.75rem;top:var(--space-5);right:var(--space-5);padding:var(--space-2) var(--space-3);border:1px solid var(--color-line);border-radius:var(--radius-pill);background:var(--color-blue-soft);color:var(--color-blue-ink);font-size:var(--text-sm);font-weight:750;position:absolute}.study-app .answers{gap:var(--space-3);grid-template-columns:repeat(2,minmax(0,1fr));width:100%;display:grid}.study-app .answers button{min-width:0;min-height:3.5rem;padding:var(--space-3);border:1px solid var(--color-line);border-radius:var(--radius-md);background:var(--color-paper-soft);color:var(--color-ink);font-size:var(--text-md);overflow-wrap:anywhere;font-weight:700;line-height:1.35}.study-app .answers button.correct{border-color:var(--color-success);background:color-mix(in oklch, var(--color-success) 12%, var(--color-paper-raised));color:var(--color-success)}.study-app .answers button.wrong{border-color:var(--color-error);background:color-mix(in oklch, var(--color-error) 10%, var(--color-paper-raised));color:var(--color-error)}.study-app .answers button:disabled{opacity:1}.study-app .answer-feedback{margin:var(--space-5) 0 0;color:var(--color-ink);font-size:var(--text-md);text-align:center}.study-app .next-quiz{min-height:2.75rem;margin:var(--space-4) auto 0;padding:var(--space-3) var(--space-5);border-radius:var(--radius-md);background:var(--color-accent-strong);color:var(--color-paper-raised);border:0;font-weight:800;display:block}.study-app .study-footer{max-width:var(--content-max);margin:var(--space-16) auto 0;padding:var(--space-6) 0 0;justify-content:center;gap:var(--space-2) var(--space-4);border-top:1px solid var(--color-line);color:var(--color-muted);font-size:var(--text-xs);text-align:center;flex-wrap:wrap;line-height:1.6;display:flex}.study-app .study-footer a{color:var(--color-accent-strong);font-weight:700}.study-app .offline-ready{color:var(--color-success);margin:0;font-weight:800;display:inline}.study-app button:not(:disabled):hover{filter:none}@media (hover:hover){.study-app .study-sidebar nav button:not(:disabled):hover,.study-app .study-mobile-modes button:not(:disabled):hover{background:var(--color-paper-muted)}.study-app .flashcard .card-actions button:not(:disabled):hover,.study-app .list-grid article>button:not(:disabled):hover,.study-app .round:not(:disabled):hover{border-color:var(--color-line-strong);transform:translateY(-1px)}}@media (width<=60rem){.study-header__inner{padding-inline:var(--space-5);gap:var(--space-4);grid-template-columns:auto minmax(0,1fr) auto}.study-menu-button{display:grid}.study-shell{display:block}.study-sidebar{z-index:var(--z-drawer);border-right:1px solid var(--color-line-strong);width:min(86vw,20rem);box-shadow:var(--shadow-popover);transition:transform var(--duration-panel) var(--ease-standard);position:fixed;inset:0 auto 0 0;overflow-y:auto;transform:translate(-105%)}.study-sidebar.is-open{transform:translate(0)}.study-sidebar__inner{height:100%;padding-top:var(--space-8);position:static}.study-sidebar__backdrop{z-index:var(--z-backdrop);cursor:default;background:oklch(20% .025 255/.42);border:0;position:fixed;inset:0}.study-main{max-width:72rem;padding:var(--space-10) var(--space-6) var(--space-12);margin:0 auto}.study-mobile-modes{margin:0 auto var(--space-6);padding:var(--space-1);gap:var(--space-1);border:1px solid var(--color-line);border-radius:var(--radius-lg);background:var(--color-paper-soft);grid-template-columns:repeat(3,minmax(0,1fr));display:grid}.study-app .study-mobile-modes button{border-radius:var(--radius-md);min-height:2.75rem;color:var(--color-muted);font-size:var(--text-sm);white-space:nowrap;background:0 0;border:0;font-weight:750}.study-app .study-mobile-modes button.is-active{background:var(--color-paper-raised);color:var(--color-accent-strong);box-shadow:var(--shadow-soft)}}@media (width<=40rem){.study-header__inner{min-height:7rem;padding:var(--space-3) var(--space-4);gap:var(--space-3);grid-template-columns:auto minmax(0,1fr) auto;grid-template-areas:"menu brand progress""search search search"}.study-menu-button{grid-area:menu}.study-brand{gap:var(--space-2);min-width:0;font-size:var(--text-md);grid-area:brand}.study-brand__mark{width:2.25rem;height:2.25rem;font-size:1.2rem}.study-brand__name{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.study-search{grid-area:search;justify-self:stretch;width:100%;height:3rem}.study-search input{min-width:0;font-size:1rem}.study-search kbd{display:none}.study-header__progress{grid-area:progress;min-width:0;display:block}.study-header__progress-value{font-size:var(--text-sm)}.study-header__progress-track,.study-header__progress .sync-status{display:none}.study-main{padding:var(--space-8) var(--space-4) var(--space-10)}.study-intro{margin-bottom:var(--space-6);padding-bottom:var(--space-6);display:block}.study-intro h1{max-width:17ch;font-size:clamp(1.9rem,9vw,2.5rem)}.study-intro__lead{margin-top:var(--space-3);font-size:var(--text-sm);line-height:1.55}.study-intro__stat{width:max-content;margin-top:var(--space-5);padding:var(--space-3) var(--space-4)}.study-toolbar{margin-bottom:var(--space-8);align-items:end;gap:var(--space-3)}.study-select{flex:auto;min-width:0}.study-select select{min-height:2.75rem;padding-inline:var(--space-3);font-size:var(--text-sm)}.study-result-count{max-width:7rem;padding-bottom:var(--space-2);font-size:var(--text-2xs);text-align:right;flex:none;line-height:1.25}.study-app .section-heading.study-section-heading{align-items:center}.study-app .study-section-heading h2{font-size:var(--text-lg)}.study-app .study-section__counter{padding:var(--space-2);font-size:var(--text-2xs)}.study-app .flashcard{min-height:21rem;padding:5.75rem var(--space-4) var(--space-6);border-radius:var(--radius-lg)}.flashcard__toolbar{top:var(--space-4);right:var(--space-4);left:var(--space-4);gap:var(--space-2)}.study-app .flashcard .card-topic{max-width:calc(100% - 6.5rem);font-size:var(--text-xs)}.study-app .flashcard .card-actions button{width:2.5rem;height:2.5rem}.study-app .hanzi{font-size:clamp(4rem,22vw,5.5rem)}.study-app .pinyin{margin-top:var(--space-3);font-size:var(--text-lg)}.study-app .hanviet{margin-bottom:var(--space-4);font-size:var(--text-sm)}.study-app .meaning{padding-top:var(--space-3);font-size:var(--text-sm)}.study-app .meaning.shown{font-size:var(--text-md)}.study-app .study-actions{gap:var(--space-2);grid-template-columns:2.75rem minmax(0,1fr) 2.75rem}.study-app .know{padding-inline:var(--space-2);font-size:var(--text-sm)}.study-app .list-grid{grid-template-columns:1fr}.study-app .quiz-card{padding:5.75rem var(--space-4) var(--space-6);border-radius:var(--radius-lg)}.study-app .quiz-card>strong{font-size:clamp(4rem,22vw,5.5rem)}.study-app .answers{grid-template-columns:1fr}.study-app .study-footer{margin-top:var(--space-12)}}@media (width<=22.5rem){.study-brand__name{font-size:var(--text-sm)}.study-intro h1{font-size:1.85rem}.study-toolbar{grid-template-columns:minmax(0,1fr);align-items:start;display:grid}.study-result-count{text-align:left;max-width:none;padding:0}}@media (prefers-reduced-motion:reduce){.study-app .study-sidebar,.study-app .study-search,.study-app button{transition:none}}