:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--bg-primary:#f8fafc;--sidebar-bg:#fff;--card-bg:#fff;--surface-overlay:#ffffff1a;--mobile-topbar-bg:#fffffff2;--figure-select-bg:#fffffff5;--text-primary:#0f172a;--text-secondary:#64748b;--text-body:#334155;--text-ink-strong:#111;--text-ink-warm:#24160a;--text-ink-preface:#18110a;--text-on-dark:#fff;--accent-color:#f59e0b;--accent-word-family:#d95798;--hover-bg:#fef3c7;--border-color:#e2e8f0;--border-sidebar:#d6d6d6;--border-section:#e5e7eb;--divider-strong:#0f172a80;--focus-dark-subtle:#0f172a59;--tooltip-bg:#1a222df7;--tooltip-bg-soft:#1a222df5;--tooltip-shadow:0 16px 38px #0f172a38;--tooltip-shadow-soft:0 12px 30px #0f172a33;--shadow-soft:0 4px 6px #0000000d;--shadow-card:0 4px 6px -1px #0000001a;--shadow-offset:6px 6px 0 #11111114;--shadow-offset-strong:8px 8px 0 #1111111f;--input-focus-ring:0 0 0 2px #f59e0b33;--state-success-border:#22c55e;--state-success-bg:#f0fdf4;--state-success-text:#166534;--state-warning-border:#f59e0b;--state-warning-bg:#fff7e6;--state-warning-text:#b45309;--state-danger-border:#ef4444;--state-danger-bg:#fef2f2;--state-danger-text:#991b1b;--length-hint-border:#94a3b8b3;--example-note-color:#f8d98a;--primary:var(--accent-color);--secondary:var(--text-primary);--glass-border:var(--border-color);--reading-success-surface:color-mix(in srgb, var(--state-success-bg) 92%, white);--reading-danger-surface:color-mix(in srgb, var(--state-danger-bg) 92%, white)}:root[data-theme=dark]{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--bg-primary:#0f172a;--sidebar-bg:#162033;--card-bg:#172235;--surface-overlay:#ffffff14;--mobile-topbar-bg:#0f172ae6;--figure-select-bg:#0f172af0;--text-primary:#d9e2f0;--text-secondary:#94a3b8;--text-body:#c2ccda;--text-ink-strong:#e6eef8;--text-ink-warm:#f6ddb0;--text-ink-preface:#f7e7c1;--text-on-dark:#eef4fb;--accent-color:#fbbf24;--accent-word-family:#f472b6;--hover-bg:#36260a;--border-color:#334155;--border-sidebar:#253047;--border-section:#334155;--divider-strong:#e2e8f052;--focus-dark-subtle:#94a3b873;--tooltip-bg:#020617f7;--tooltip-bg-soft:#0f172af5;--tooltip-shadow:0 18px 44px #02061780;--tooltip-shadow-soft:0 14px 34px #02061775;--shadow-soft:0 12px 28px #02061747;--shadow-card:0 12px 28px #02061757;--shadow-offset:6px 6px 0 #0206175c;--shadow-offset-strong:8px 8px 0 #0206177a;--input-focus-ring:0 0 0 2px #fbbf243d;--state-success-border:#4ade80;--state-success-bg:#10271a;--state-success-text:#bbf7d0;--state-warning-border:#fbbf24;--state-warning-bg:#3a2a0d;--state-warning-text:#fde68a;--state-danger-border:#f87171;--state-danger-bg:#36161a;--state-danger-text:#fecaca;--length-hint-border:#94a3b88f;--example-note-color:#f3c969;--primary:var(--accent-color);--secondary:var(--text-primary);--glass-border:var(--border-color);--reading-success-surface:color-mix(in srgb, var(--state-success-bg) 82%, var(--card-bg));--reading-danger-surface:color-mix(in srgb, var(--state-danger-bg) 82%, var(--card-bg))}*{box-sizing:border-box}body{background-color:var(--bg-primary);color:var(--text-primary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;margin:0;font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;transition:background-color .2s,color .2s}#root{min-height:100vh;display:flex}.app-container{width:100%;display:flex}.theme-toggle{width:2.75rem;height:2.75rem;color:var(--text-primary);cursor:pointer;background:0 0;border:0;justify-content:center;align-items:center;padding:0;transition:color .2s,transform .2s,background-color .2s;display:inline-flex}.theme-toggle:hover{background:color-mix(in srgb, var(--text-primary) 8%, transparent)}.theme-toggle:active{transform:scale(.96)}.theme-toggle:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.theme-toggle-icon-shell{width:1.45rem;height:1.45rem;display:inline-flex;position:relative}.theme-toggle-icon{justify-content:center;align-items:center;transition:opacity .22s,transform .22s,color .22s;display:inline-flex;position:absolute;inset:0}.theme-toggle-svg{width:100%;height:100%;display:block}.theme-toggle-light .theme-toggle-icon-sun{opacity:1;color:#c97a00;transform:rotate(0)scale(1)}.theme-toggle-light .theme-toggle-icon-moon{opacity:0;color:var(--text-primary);transform:rotate(28deg)scale(.72)}.theme-toggle-dark .theme-toggle-icon-sun{opacity:0;color:var(--text-primary);transform:rotate(-28deg)scale(.72)}.theme-toggle-dark .theme-toggle-icon-moon{opacity:1;color:#dbe7ff;transform:rotate(0)scale(1)}.theme-toggle-compact{width:2.45rem;height:2.45rem}.theme-toggle-compact .theme-toggle-icon-shell{width:1.35rem;height:1.35rem}.sidebar{background:var(--sidebar-bg);border-right:1px solid var(--border-sidebar);flex-direction:column;width:300px;height:100vh;transition:width .24s;display:flex;position:sticky;top:0;overflow:hidden}.sidebar.sidebar-collapsed{width:92px}.sidebar-header{border-bottom:1px solid var(--border-section);padding:2rem 1.5rem}.sidebar-header-top{justify-content:space-between;align-items:flex-start;gap:.9rem;display:flex}.sidebar-header-copy{flex:1;min-width:0}.sidebar-title-row{justify-content:space-between;align-items:center;gap:.75rem;display:flex}.sidebar-title-row h2{color:var(--text-ink-warm);letter-spacing:-.5px;margin:0;font-size:1.5rem;font-weight:800}.lang-select-shell{background:var(--text-secondary);clip-path:polygon(12% 0,88% 0,100% 50%,88% 100%,12% 100%,0 50%);justify-content:center;align-items:center;padding:2px;display:inline-flex}.lang-select{appearance:none;background:var(--sidebar-bg);color:var(--text-secondary);cursor:pointer;clip-path:polygon(12% 0,88% 0,100% 50%,88% 100%,12% 100%,0 50%);border:0;border-radius:0;padding:.5rem 1rem;font-size:.8rem;font-weight:700;transition:all .2s}.lang-select-collapsed{padding:.4rem .65rem;font-size:.72rem}.lang-select-shell:hover,.lang-select-shell:focus-within{background:var(--text-primary)}.lang-select:hover,.lang-select:focus{color:var(--text-primary);outline:none}.subtitle{color:var(--text-secondary);text-transform:uppercase;letter-spacing:.08em;margin:.45rem 0 0;font-size:.875rem;font-weight:600}.sidebar-close{border:1px solid var(--border-color);background:var(--card-bg);min-width:2.4rem;min-height:2.4rem;color:var(--text-primary);font:inherit;cursor:pointer;flex:none;justify-content:center;align-items:center;font-size:1rem;font-weight:800;display:none}.sidebar-close:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.sidebar.sidebar-collapsed .sidebar-header{padding:1.35rem .75rem 1rem}.sidebar.sidebar-collapsed .sidebar-header-top,.sidebar.sidebar-collapsed .sidebar-title-row{justify-content:center}.sidebar.sidebar-collapsed .sidebar-header-copy{justify-content:center;display:flex}.sidebar.sidebar-collapsed .sidebar-title-row h2{letter-spacing:.08em;font-size:1rem}.sidebar-nav{flex-direction:column;flex:1;justify-content:flex-start;gap:1.4rem;min-height:0;padding:1.5rem 1rem 2rem;display:flex;overflow-y:auto}.sidebar-nav-list{flex:none}.sidebar.sidebar-collapsed .sidebar-nav{padding:1rem .6rem}.sidebar-nav ul{margin:0;padding:0;list-style:none}.nav-item-group{margin-bottom:.5rem}.chapter-btn{text-align:left;background:var(--sidebar-bg);border:3px solid var(--text-secondary);width:100%;color:var(--text-primary);cursor:pointer;box-shadow:var(--shadow-offset);border-radius:0;flex-direction:column;align-items:flex-start;gap:.25rem;padding:1rem 1.15rem 1.05rem;font-size:1rem;font-weight:600;transition:all .2s;display:flex}.chapter-btn:hover{background:var(--sidebar-bg);border-color:var(--text-ink-strong)}.chapter-btn.active{background:var(--sidebar-bg);border-color:var(--text-ink-strong);color:var(--text-ink-strong);box-shadow:var(--shadow-offset-strong)}.chapter-btn-label{color:var(--text-secondary);letter-spacing:-.02em;font-size:1rem;font-weight:800}.chapter-btn-title{color:var(--text-secondary);font-size:.82rem;font-weight:600;line-height:1.3}.chapter-btn-title-active{color:var(--text-ink-strong)}.sub-nav{border-left:2px solid var(--text-secondary);margin-top:.6rem!important;margin-left:1rem!important;padding-left:.85rem!important}.sub-nav li{margin-bottom:.25rem}.sub-nav-collapsed{flex-wrap:wrap;justify-content:center;gap:.35rem;display:flex;margin-top:.45rem!important}.sub-nav-collapsed li{margin:0}.sub-btn{text-align:left;width:100%;color:var(--text-secondary);cursor:pointer;background:0 0;border:0;border-radius:0;padding:.55rem .8rem;font-size:.9rem;font-weight:600;transition:all .2s}.sub-btn:hover{color:var(--text-primary);background-color:#0000}.sub-btn.active{color:var(--text-ink-strong);box-shadow:none;text-underline-offset:.16em;background:0 0;font-weight:700;text-decoration:underline;text-decoration-thickness:.08em}.sub-btn-collapsed{border:2px solid var(--text-secondary);background:var(--sidebar-bg);width:2rem;min-width:2rem;height:2rem;color:var(--text-secondary);letter-spacing:.02em;cursor:pointer;border-radius:0;justify-content:center;align-items:center;padding:0;font-size:.72rem;font-weight:800;line-height:1;transition:border-color .2s,color .2s;display:inline-flex}.sub-btn-collapsed:hover{border-color:var(--text-ink-strong);color:var(--text-primary)}.sub-btn-collapsed.active{border-color:var(--text-ink-strong);color:var(--text-ink-strong)}.chapter-btn.current .chapter-btn-label{color:var(--text-ink-strong)}.sidebar.sidebar-collapsed .chapter-btn{text-align:center;justify-content:center;align-items:center;padding:.95rem .4rem}.sidebar.sidebar-collapsed .chapter-btn-label{font-size:1.05rem}.sidebar.sidebar-collapsed .nav-item-group{margin-bottom:.85rem}.sidebar-skeleton-list{flex-direction:column;gap:.9rem;display:flex}.sidebar-skeleton-group{flex-direction:column;gap:.55rem;display:flex}.sidebar-skeleton-chapter{border-radius:0;width:100%;height:4.25rem}.sidebar-skeleton-subnav{border-left:2px solid color-mix(in srgb, var(--border-color) 82%, transparent);flex-direction:column;gap:.5rem;margin-left:1rem;padding-left:.85rem;display:flex}.sidebar-skeleton-exercise{border-radius:.5rem;width:88%;height:.9rem}.sidebar-skeleton-exercise-short{width:66%}.sidebar-skeleton-subnav-collapsed{justify-content:center;gap:.35rem;display:flex}.sidebar-skeleton-pill{border-radius:0;width:2rem;height:2rem}.sidebar-footer{border-top:1px solid var(--border-section);justify-content:flex-start;align-items:center;gap:.6rem;padding:.7rem .8rem .9rem;display:flex}.sidebar-account-trigger{flex:auto}.sidebar.sidebar-collapsed .sidebar-footer{justify-content:center}.sidebar.sidebar-collapsed .sidebar-account-trigger{flex:none}.sidebar-collapse-toggle{width:auto;min-width:2rem;min-height:2rem;color:var(--text-primary);cursor:pointer;background:0 0;border:0;justify-content:center;align-items:center;padding:.2rem;display:inline-flex}.sidebar-collapse-toggle:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.sidebar-collapse-icon{width:.75rem;height:.75rem;position:relative;transform:rotate(135deg)}.sidebar-collapse-icon:before,.sidebar-collapse-icon:after{content:"";border-bottom:2px solid;border-right:2px solid;position:absolute;inset:0}.sidebar-collapse-icon:after{transform:translate(-.32rem,-.32rem)}.sidebar-collapse-icon-expand{transform:rotate(-45deg)}.sidebar-collapse-icon-expand:after{transform:translate(.32rem,.32rem)}@media (width<=768px){.sidebar{z-index:1200;width:min(21rem,86vw);height:100dvh;box-shadow:none;border-right-width:1px;transition:transform .24s,box-shadow .24s;position:fixed;inset:0 auto 0 0;transform:translate(-100%)}.sidebar.sidebar-collapsed{width:min(21rem,86vw)}.sidebar.sidebar-open{transform:translate(0);box-shadow:22px 0 48px #0f172a38}.sidebar-header{padding:calc(1rem + env(safe-area-inset-top,0px)) 1rem 1rem}.sidebar-header-top{align-items:center}.sidebar-close{display:inline-flex}.sidebar-nav{gap:1rem;padding:1rem .85rem 1.5rem}.chapter-btn{padding:.9rem .95rem;box-shadow:4px 4px #11111114}.chapter-btn.active{box-shadow:5px 5px #1111111f}.sub-nav{margin-left:.7rem!important;padding-left:.7rem!important}.sidebar-footer{display:none}}.chapter-view{background-color:var(--bg-primary);scroll-behavior:smooth;-webkit-overflow-scrolling:touch;flex:1;height:100%;min-height:0;position:relative;overflow-y:auto}.empty-state{justify-content:center;align-items:center;display:flex}.empty-content{text-align:center;color:var(--text-secondary);background:var(--card-bg);box-shadow:var(--shadow-soft);border-radius:12px;padding:3rem}.chapter-article{max-width:800px;margin:0 auto;padding:4rem 2rem}.chapter-layout{max-width:800px;margin:0 auto}.chapter-layout-with-reading-comprehension{position:relative}.chapter-header{text-align:center;margin-bottom:3rem}.chapter-number{text-transform:uppercase;letter-spacing:1px;color:var(--text-secondary);margin-bottom:1rem;font-size:.875rem;font-weight:600;display:inline-block}.chapter-title{color:var(--text-primary);margin:0;font-size:2.5rem;font-weight:800;line-height:1.2}.chapter-title-translation{color:var(--text-secondary);margin:.65rem 0 0;font-size:1rem;font-weight:600}.chapter-content{color:var(--text-body);font-size:1.125rem;line-height:1.8}.chapter-content p{margin-bottom:1.5rem}.chapter-content p:first-of-type:first-letter{float:left;color:var(--text-primary);margin-right:.5rem;font-size:4.5rem;font-weight:700;line-height:1}.chapter-content-no-drop-cap p:first-of-type:first-letter{float:none;font-size:inherit;line-height:inherit;font-weight:inherit;color:inherit;margin-right:0}.section-break{text-align:center;color:var(--text-secondary);opacity:.5;margin:3rem 0;font-size:2rem}.chapter-audio-panel{border:1px solid var(--border-color);background:var(--card-bg);box-shadow:var(--shadow-soft);flex-direction:column;gap:.85rem;margin-bottom:2rem;padding:1rem 1.1rem;display:flex}.chapter-audio-copy{flex-direction:column;gap:.35rem;display:flex}.chapter-audio-label,.chapter-audio-note,.chapter-audio-sync-hint{margin:0}.chapter-audio-label{letter-spacing:.08em;text-transform:uppercase;color:var(--text-secondary);font-size:.78rem;font-weight:800}.chapter-audio-note{color:var(--text-body);font-size:.98rem;line-height:1.5}.chapter-audio-sync-hint{color:var(--text-secondary);font-size:.92rem;line-height:1.45}.chapter-audio-controls{align-items:center;gap:.85rem;display:flex}.chapter-audio-player{flex:1;min-width:0}.chapter-audio-sync-toggle{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;flex-shrink:0;padding:.7rem .95rem;font-weight:700;transition:border-color .2s,background-color .2s,color .2s,transform .2s}.chapter-audio-sync-toggle:hover,.chapter-audio-sync-toggle:focus-visible{border-color:var(--accent-color)}.chapter-audio-sync-toggle:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.chapter-audio-sync-toggle-active{border-color:var(--accent-color);background:color-mix(in srgb, var(--accent-color) 12%, var(--card-bg));color:var(--text-primary)}.chapter-audio-active-word{background:color-mix(in srgb, var(--accent-color) 20%, transparent);box-shadow:0 0 0 1px color-mix(in srgb, var(--accent-color) 32%, transparent);-webkit-box-decoration-break:clone;box-decoration-break:clone;border-radius:.28em}.chapter-inline-link{color:var(--accent-color);font:inherit;font-weight:700;line-height:inherit;text-underline-offset:.15em;word-break:break-word;background:0 0;border:0;padding:0;text-decoration:underline;text-decoration-thickness:.08em;display:inline}.chapter-inline-link:hover,.chapter-inline-link:focus-visible{color:var(--text-primary)}.chapter-inline-link:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px;border-radius:4px}.inline-collocation-link{font:inherit;font-weight:700;line-height:inherit;text-underline-offset:.15em;cursor:pointer;background:0 0;border:0;padding:0;text-decoration:underline;text-decoration-thickness:.08em;display:inline}.inline-exercise-link-group{display:inline-block;position:relative}.inline-collocation-link-collocation{color:var(--accent-color)}.inline-collocation-link-word-family{color:var(--accent-word-family)}.inline-collocation-link-multi{color:color-mix(in srgb, var(--accent-color) 54%, var(--accent-word-family))}.inline-glossary-term{border-bottom:1px dotted var(--accent-color);cursor:help;display:inline;position:relative}.inline-collocation-link:hover,.inline-collocation-link:focus-visible,.inline-glossary-term:hover,.inline-glossary-term:focus-visible{color:var(--text-primary)}.inline-collocation-link:focus-visible{outline-offset:3px;border-radius:4px}.inline-collocation-link-collocation:focus-visible{outline:2px solid var(--accent-color)}.inline-collocation-link-word-family:focus-visible{outline:2px solid var(--accent-word-family);outline-offset:3px;border-radius:4px}.inline-collocation-link-multi:focus-visible{outline:2px solid color-mix(in srgb, var(--accent-color) 54%, var(--accent-word-family));outline-offset:3px;border-radius:4px}.inline-glossary-term:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px;border-radius:4px}.chapter-link-choice-popover{border:2px solid var(--text-ink-strong);background:var(--bg-primary);min-width:12rem;box-shadow:var(--shadow-offset);z-index:20;border-radius:0;flex-direction:column;gap:.4rem;padding:.8rem;display:flex;position:absolute;top:calc(100% + .55rem);left:50%;transform:translate(-50%)}.chapter-link-choice-option{border:1px solid var(--border-color);color:var(--text-primary);font:inherit;text-align:left;cursor:pointer;background:0 0;border-radius:0;padding:.55rem .8rem;font-size:.92rem;font-weight:700;transition:border-color .2s,background-color .2s}.chapter-link-choice-option:focus-visible{outline-offset:3px}.chapter-link-choice-option-collocation{border-color:color-mix(in srgb, var(--accent-color) 45%, var(--border-color))}.chapter-link-choice-option-collocation:hover,.chapter-link-choice-option-collocation:focus-visible{border-color:var(--accent-color);outline:2px solid var(--accent-color)}.chapter-link-choice-option-word-family{border-color:color-mix(in srgb, var(--accent-word-family) 45%, var(--border-color))}.chapter-link-choice-option-word-family:hover,.chapter-link-choice-option-word-family:focus-visible{border-color:var(--accent-word-family);outline:2px solid var(--accent-word-family)}.inline-glossary-term:after{content:attr(data-tooltip);background:var(--tooltip-bg-soft);width:min(22rem,80vw);color:var(--text-on-dark);box-shadow:var(--tooltip-shadow-soft);opacity:0;pointer-events:none;z-index:10;border-radius:10px;padding:.75rem .9rem;font-size:.95rem;line-height:1.45;transition:opacity .18s;position:absolute;bottom:calc(100% + .75rem);left:50%;transform:translate(-50%)}.inline-glossary-term:hover:after,.inline-glossary-term:focus-visible:after{opacity:1}.reading-comprehension-shell{display:none}.reading-comprehension-toggle-row{justify-content:flex-end;display:flex}.reading-comprehension-toggle{border:2px solid var(--text-ink-strong);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;box-shadow:var(--shadow-offset);border-radius:0;padding:.8rem 1rem;font-weight:700}.reading-comprehension-toggle:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.reading-comprehension-panel{border:2px solid var(--text-ink-strong);background:var(--bg-primary);width:min(25rem,100%);box-shadow:var(--shadow-offset);border-radius:0;padding:1.1rem}.reading-comprehension-header{flex-direction:column;gap:.45rem;margin-bottom:1.1rem;display:flex}.reading-comprehension-score{color:var(--text-secondary);margin:0;font-size:.9rem;font-weight:700}.reading-comprehension-questions{flex-direction:column;gap:1rem;display:flex}.reading-comprehension-question{border:0;min-width:0;margin:0;padding:0}.reading-comprehension-prompt{color:var(--text-primary);margin-bottom:.8rem;padding:0;font-size:.98rem;font-weight:700;line-height:1.45}.reading-comprehension-options{flex-direction:column;gap:.45rem;display:flex}.reading-comprehension-option{border:1px solid var(--border-color);cursor:pointer;align-items:flex-start;gap:.65rem;padding:.65rem .7rem;transition:border-color .2s;display:flex}.reading-comprehension-option:hover{border-color:var(--text-secondary)}.reading-comprehension-option input{width:1rem;height:1rem;accent-color:color-mix(in srgb, var(--accent-color) 38%, var(--accent-word-family));flex:none;margin:0;position:relative;top:.3rem}.reading-comprehension-option-selected:not(.reading-comprehension-option-correct):not(.reading-comprehension-option-incorrect),.reading-comprehension-option-selected:not(.reading-comprehension-option-correct):not(.reading-comprehension-option-incorrect):hover{border-color:var(--text-ink-strong)}.reading-comprehension-option-copy{flex:1;align-items:flex-start;gap:.55rem;min-width:0;display:flex}.reading-comprehension-option-id{color:var(--text-secondary);flex:0 0 1rem;font-weight:800;line-height:1.45;display:block}.reading-comprehension-option-text{color:var(--text-body);line-height:1.45;display:block}.reading-comprehension-option-correct{border-color:var(--state-success-border);background:var(--reading-success-surface);color:var(--state-success-text)}.reading-comprehension-option-incorrect{border-color:var(--state-danger-border);background:var(--reading-danger-surface);color:var(--state-danger-text)}.reading-comprehension-option-correct .reading-comprehension-option-id,.reading-comprehension-option-correct .reading-comprehension-option-text{color:var(--state-success-text)}.reading-comprehension-option-incorrect .reading-comprehension-option-id,.reading-comprehension-option-incorrect .reading-comprehension-option-text{color:var(--state-danger-text)}.reading-comprehension-feedback{letter-spacing:.01em;margin:.8rem 0 0;font-size:.92rem;font-weight:800}.reading-comprehension-feedback-correct{color:var(--state-success-text)}.reading-comprehension-feedback-incorrect{color:var(--state-danger-text)}.reading-comprehension-actions{flex-wrap:wrap;gap:.65rem;margin-top:1.15rem;display:flex}.reading-comprehension-action{border:2px solid var(--text-ink-strong);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;border-radius:0;padding:.75rem .95rem;font-weight:700}.reading-comprehension-action:disabled{opacity:.45;cursor:not-allowed}.reading-comprehension-action-primary{border-color:var(--accent-color)}.reading-comprehension-action:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.chapter-content-preface{max-width:48rem;margin:0 auto}.preface-title-line{text-align:center;letter-spacing:-.03em;color:var(--text-ink-preface);text-wrap:balance;margin:0;font-size:clamp(2.3rem,5vw,4rem);font-weight:800;line-height:1.05}.preface-title-caption{text-align:center;max-width:28rem;color:var(--text-secondary);margin:.65rem auto 0;font-size:1rem;font-weight:600;line-height:1.4}.preface-kicker{text-align:center;letter-spacing:.08em;text-transform:uppercase;max-width:34rem;color:var(--text-secondary);margin:0 auto 1.25rem;font-size:1rem;font-weight:600}.preface-divider{background:linear-gradient(90deg, transparent, var(--divider-strong), transparent);width:min(12rem,44%);height:1px;margin:1.6rem auto}.chapter-pagination{grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-top:3rem;display:grid}.chapter-pagination-link{border:1px solid var(--border-color);background:var(--bg-primary);width:100%;color:var(--text-primary);font:inherit;text-align:left;cursor:pointer;box-shadow:var(--shadow-offset);border-radius:0;flex-direction:column;gap:.35rem;padding:1rem 1.1rem;display:flex}.chapter-pagination-link-next{text-align:right}.chapter-pagination-direction{letter-spacing:.08em;text-transform:uppercase;color:var(--text-secondary);font-size:.78rem;font-weight:800}.chapter-pagination-title{font-size:1rem;font-weight:700;line-height:1.4}.chapter-pagination-link:hover,.chapter-pagination-link:focus-visible{border-color:var(--text-ink-strong)}.chapter-pagination-link:focus-visible{outline:2px solid var(--text-ink-strong);outline-offset:3px}@media (width>=1081px){.app-main-shell-sidebar-collapsed .chapter-layout,.app-main-shell-sidebar-collapsed .chapter-article{max-width:940px}.app-main-shell-sidebar-collapsed .chapter-content-preface{max-width:58rem}.chapter-layout-with-reading-comprehension .reading-comprehension-shell{z-index:5;flex-direction:column;gap:1rem;margin:0;display:flex;position:absolute;top:4rem;left:calc(100% + 1.25rem)}.chapter-layout-reading-comprehension-open{grid-template-columns:minmax(0,1fr) minmax(22rem,25rem);align-items:start;gap:2rem;max-width:1260px;display:grid}.app-main-shell-sidebar-collapsed .chapter-layout-reading-comprehension-open{grid-template-columns:minmax(0,1fr) minmax(23rem,26rem);gap:2.35rem;max-width:1380px}.chapter-layout-reading-comprehension-open .chapter-article{max-width:none;margin:0}.chapter-layout-reading-comprehension-open .reading-comprehension-shell{z-index:auto;align-self:start;margin:0;position:sticky;top:2rem;left:auto}}@media (width<=768px){.chapter-article{padding:1.5rem 1rem 2.5rem}.chapter-header{text-align:left;margin-bottom:2rem}.chapter-title{font-size:clamp(1.75rem,7vw,2rem)}.chapter-content{font-size:1rem;line-height:1.75}.chapter-audio-panel{margin-bottom:1.5rem;padding:.9rem}.chapter-audio-controls{flex-direction:column;align-items:stretch}.chapter-audio-player{flex:none;width:100%;max-width:100%;display:block}.chapter-audio-sync-toggle{width:100%}.reading-comprehension-shell{flex-direction:column;gap:.85rem;margin-top:1.75rem;display:flex}.reading-comprehension-toggle-row{justify-content:stretch}.reading-comprehension-toggle{width:100%;box-shadow:var(--shadow-soft)}.reading-comprehension-panel{box-sizing:border-box;width:100%;box-shadow:var(--shadow-soft)}.chapter-content p{margin-bottom:1.15rem}.chapter-pagination{grid-template-columns:1fr;margin-top:2.25rem}.chapter-pagination-link-next{text-align:left}.chapter-content p:first-of-type:first-letter{margin-right:.35rem;font-size:3.4rem}.preface-title-line{font-size:clamp(1.9rem,10vw,2.8rem)}.preface-title-caption,.preface-kicker{font-size:.92rem}.chapter-link-choice-popover{min-width:min(14rem,100vw - 2.5rem);left:0;transform:none}}@media (width<=1080px){.chapter-layout,.chapter-layout-with-reading-comprehension{max-width:800px;display:block}}.themed-svg{vertical-align:middle;--themed-svg-soft-white:#fff;max-width:100%;display:inline-block}.themed-svg-shell{display:block;position:relative}.themed-svg svg,.themed-svg-shell img{width:100%;height:auto;display:block}:root[data-theme=dark] .themed-svg{--themed-svg-soft-white:color-mix(in srgb, var(--text-on-dark) 90%, var(--card-bg))}:root[data-theme=dark] .themed-svg svg [fill=\#ffffff],:root[data-theme=dark] .themed-svg svg [fill=\#fff],:root[data-theme=dark] .themed-svg svg [fill="rgb(255, 255, 255)"]{fill:var(--themed-svg-soft-white)!important}:root[data-theme=dark] .themed-svg svg [stroke=\#ffffff],:root[data-theme=dark] .themed-svg svg [stroke=\#fff],:root[data-theme=dark] .themed-svg svg [stroke="rgb(255, 255, 255)"]{stroke:var(--themed-svg-soft-white)!important}.article-exercise{margin-bottom:.5rem}.article-figure{margin:0}.article-mobile-list{gap:.7rem;display:none}.article-mobile-item{border:1px solid var(--border-color);background:var(--bg-primary);justify-content:space-between;align-items:center;gap:.85rem;padding:.8rem .9rem;display:flex}.article-mobile-noun{min-width:0;color:var(--text-body);font-size:1rem;font-weight:700;line-height:1.35}.article-mobile-select{flex:0 0 5rem;width:5rem;padding:.45rem .55rem;font-size:.9rem}.article-exercise-list-mode .article-figure{display:none}.article-exercise-list-mode .article-mobile-list{display:grid}.article-figure-frame{position:relative}.article-figure-image{width:100%;height:auto;display:block}.article-figure-skeleton{width:100%;display:flex}.article-figure-skeleton-frame{aspect-ratio:771/1001;border-radius:0;width:100%}.article-prompt{position:absolute;transform:translateY(calc(-100% - .62rem))}.article-prompt-label{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.article-prompt-select{--article-select-bg:var(--figure-select-bg);--article-select-text:var(--text-primary);--article-select-border:var(--border-color);--article-select-focus-border:var(--text-primary);--article-select-focus-shadow:var(--input-focus-ring);border:1px solid var(--article-select-border);background:var(--article-select-bg);width:100%;min-width:0;color:var(--article-select-text);font:inherit;padding:.22rem .35rem;font-size:clamp(.55rem,.7vw,.82rem);font-weight:700;line-height:1.2;display:block}.article-figure .article-prompt-select{--article-figure-surface:#fff;--article-select-focus-border:#111;--article-select-focus-shadow:0 0 0 2px #1111112e;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}.article-figure .article-prompt-select-empty{--article-select-bg:var(--article-figure-surface);--article-select-text:#111;--article-select-border:#111}.article-figure .article-prompt-select option{background:var(--article-figure-surface);color:#111}:root[data-theme=dark] .article-figure .article-prompt-select{--article-figure-surface:color-mix(in srgb, var(--text-on-dark) 90%, var(--card-bg))}.article-prompt-select:focus-visible{border-color:var(--article-select-focus-border);box-shadow:var(--article-select-focus-shadow);outline:none}.article-prompt-select-filled{--article-select-border:var(--text-primary)}.article-prompt-select-correct{--article-select-border:var(--state-success-border);--article-select-bg:var(--state-success-bg);--article-select-text:var(--state-success-text)}.article-prompt-select-incorrect{--article-select-border:var(--state-danger-border);--article-select-bg:var(--state-danger-bg);--article-select-text:var(--state-danger-text)}.article-figure .article-prompt-select-correct{--article-select-bg:color-mix(in srgb, var(--state-success-border) 14%, white);--article-select-text:#14532d}.article-figure .article-prompt-select-incorrect{--article-select-bg:color-mix(in srgb, var(--state-danger-border) 12%, white);--article-select-text:#991b1b}.article-exercise-controls{flex-wrap:wrap;gap:.75rem;margin-top:1.25rem;display:flex}.article-exercise-button{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;padding:.7rem 1rem;font-weight:700}.article-exercise-button:hover{border-color:var(--text-primary)}.article-exercise-button:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.article-exercise-score{color:var(--text-secondary);margin:1rem 0 0;font-size:.98rem;font-weight:700}@media (width<=768px){.article-figure{display:none}.article-mobile-list{display:grid}.article-prompt-select{padding:.15rem .25rem;font-size:clamp(.45rem,1.8vw,.72rem)}.article-exercise-controls{gap:.6rem}.article-exercise-button{padding:.65rem .85rem;font-size:.92rem}}.hover-tooltip-layer{background:var(--tooltip-bg);color:var(--text-on-dark);box-shadow:var(--tooltip-shadow);z-index:4000;pointer-events:none;border-radius:12px;flex-direction:column;gap:.45rem;max-width:min(24rem,100vw - 24px);padding:.85rem .95rem;line-height:1.45;display:flex;position:fixed}.hover-tooltip-layer strong{font-size:.95rem}.hover-tooltip-layer span{font-size:.92rem}.cloze-test-container{flex-direction:column;gap:1.5rem;margin-top:2rem;display:flex}.cloze-test-container-compact{gap:1rem;margin-top:.5rem}.cloze-bulk-controls{flex-wrap:wrap;align-items:center;gap:.9rem;margin-bottom:.35rem;display:flex}.cloze-reset-bar{justify-content:flex-end;margin-bottom:.35rem;display:flex}.cloze-bulk-reveal-button,.cloze-selection-button{border:1px solid var(--border-color);background:var(--card-bg);min-height:2.5rem;color:var(--text-primary);font:inherit;cursor:pointer;justify-content:center;align-items:center;gap:.45rem;padding:.55rem .9rem;font-weight:600;transition:border-color .2s,color .2s,background-color .2s;display:inline-flex}.cloze-bulk-reveal-button:hover,.cloze-selection-button:hover{border-color:var(--accent-color);color:var(--accent-color)}.cloze-bulk-reveal-button:focus-visible,.cloze-selection-button:focus-visible,.cloze-selection-input:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.cloze-selection-controls{flex-wrap:wrap;align-items:center;gap:.65rem;display:inline-flex}.cloze-selection-input{border:1px solid var(--border-color);background:var(--card-bg);min-width:min(18rem,60vw);min-height:2.5rem;color:var(--text-primary);font:inherit;padding:.55rem .75rem}.cloze-sentence{color:var(--text-body);box-shadow:none;background:0 0;border-radius:0;flex-wrap:wrap;align-items:center;gap:.25rem;padding:.35rem .25rem;font-size:1.125rem;line-height:2;display:flex;overflow:visible}.cloze-sentence-number{min-width:1.9rem;color:var(--text-secondary);flex:none;justify-content:flex-end;align-items:baseline;margin-right:.2rem;font-weight:700;line-height:1;display:inline-flex}.cloze-reveal-button{width:2rem;height:2rem;color:var(--text-secondary);cursor:pointer;background:0 0;border:none;flex:none;justify-content:center;align-items:center;margin-left:.3rem;padding:0;transition:color .2s,transform .2s;display:inline-flex}.cloze-reveal-button:hover{color:var(--accent-color);transform:translateY(-1px)}.cloze-reveal-button:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px;border-radius:4px}.cloze-reveal-icon{width:1.15rem;height:1.15rem}.cloze-input{border:1px solid var(--border-color);background-color:var(--bg-primary);color:var(--text-primary);font-size:inherit;text-align:center;border-radius:4px;margin:0;padding:.25rem .5rem;font-family:inherit;transition:all .2s}.cloze-input:focus{border-color:var(--accent-color);box-shadow:var(--input-focus-ring);outline:none}.cloze-input.correct{border-color:var(--state-success-border);background-color:var(--state-success-bg);color:var(--state-success-text)}.cloze-input.revealed{border-color:var(--state-warning-border);background-color:var(--state-warning-bg);color:var(--state-warning-text)}.cloze-input.incorrect{border-color:var(--state-danger-border);background-color:var(--state-danger-bg);color:var(--state-danger-text)}.cloze-input-group{white-space:nowrap;flex:none;align-items:center;gap:0;display:inline-flex}.cloze-prefix,.cloze-suffix{display:inline-block}.cloze-answer-index-marker{color:var(--text-secondary);margin-left:.08rem;font-size:.68em;font-weight:700;line-height:1;display:inline-block;transform:translateY(-.6em)}.cloze-length-hint{border:1px solid var(--length-hint-border);background:var(--bg-primary);min-width:1.5em;color:var(--text-secondary);justify-content:center;align-items:center;margin-left:.28rem;padding:.05rem .28rem;font-size:.72em;font-weight:700;line-height:1.1;display:inline-flex;transform:translateY(-.22em)}.grammar-note{color:var(--text-secondary);cursor:help;align-items:center;margin-left:.35rem;font-style:italic;display:inline-flex;position:relative}.grammar-note:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px;border-radius:4px}.grammar-tooltip{max-width:min(24rem,100vw - 24px)}.grammar-tooltip strong{font-style:normal}.grammar-tooltip span{font-size:.92rem}.grammar-example{color:var(--example-note-color)}@media (width<=768px){.cloze-test-container{gap:1.1rem}.cloze-bulk-controls{gap:.65rem}.cloze-bulk-reveal-button,.cloze-selection-button,.cloze-selection-controls{width:100%}.cloze-selection-input{flex:12rem;width:100%;min-width:0}.cloze-reset-bar{justify-content:stretch}.cloze-sentence{gap:.18rem;padding:.25rem 0;font-size:1rem;line-height:1.8}.cloze-sentence-number{min-width:1.6rem;margin-right:.12rem}.cloze-reveal-button{width:1.85rem;height:1.85rem;margin-left:.15rem}}.sentence-completion{padding-top:1.25rem}.sentence-bank-shell{margin-bottom:1.5rem}.sentence-bank-header{justify-content:space-between;align-items:baseline;gap:1rem;margin-bottom:.85rem;display:flex}.sentence-bank-header h3,.sentence-bank-header p{margin:0}.sentence-bank-header h3{text-transform:uppercase;letter-spacing:.06em;color:var(--text-primary);font-size:1rem;font-weight:800}.sentence-bank-header p{color:var(--text-secondary);font-size:.92rem}.sentence-bank{flex-wrap:wrap;gap:.75rem;display:flex}.sentence-token{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:grab;padding:.7rem .95rem;font-weight:700}.sentence-token:hover:not(:disabled){border-color:var(--text-primary)}.sentence-token:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.sentence-token-selected{border-color:var(--accent-word-family);box-shadow:0 0 0 2px #d9579824}.sentence-token-distractor{color:var(--text-primary)}.sentence-token-example{text-decoration:line-through}.sentence-token-used{cursor:default}.sentence-token-used-incorrect{cursor:grab}.sentence-token-used-incorrect,.sentence-token-used-correct{color:var(--text-secondary)}.sentence-token-used-correct{text-decoration:line-through}.sentence-list{gap:.85rem;display:grid}.sentence-card{border:1px solid var(--border-color);background:var(--bg-primary);padding:1rem 1.1rem}.sentence-card-example{border-style:dashed}.sentence-card-solved{border-color:var(--state-success-border);background:var(--state-success-bg)}.sentence-card-header{margin-bottom:.45rem}.sentence-card-number{color:var(--text-secondary);font-weight:800}.sentence-card-example-badge{border:1px solid var(--border-color);color:var(--text-secondary);text-transform:uppercase;letter-spacing:.05em;padding:.2rem .5rem;font-size:.75rem;font-weight:700}.sentence-card-text{color:var(--text-body);margin:0;font-size:1.02rem;line-height:1.8}.sentence-blank{border:1px solid var(--border-color);min-width:5.4rem;min-height:2.2rem;color:var(--text-primary);font:inherit;vertical-align:baseline;cursor:pointer;background:0 0;justify-content:center;align-items:center;margin:0 .22rem;padding:.15rem .65rem;font-weight:700;display:inline-flex}.sentence-blank-empty:before{content:" ";visibility:hidden}.sentence-blank:hover:not(:disabled){border-color:var(--text-primary)}.sentence-blank:focus-visible{outline:2px solid var(--accent-color);outline-offset:2px}.sentence-blank-correct{border-color:var(--state-success-border);background:var(--state-success-bg);color:var(--state-success-text)}.sentence-blank-incorrect{border-color:var(--state-danger-border);background:var(--state-danger-bg);color:var(--state-danger-text)}.sentence-blank-drag-over{border-color:var(--accent-word-family);box-shadow:0 0 0 2px #d9579824}.sentence-blank-example{cursor:default}.sentence-completion-controls{flex-wrap:wrap;gap:.75rem;margin-top:1.25rem;display:flex}.sentence-completion-button{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;padding:.7rem 1rem;font-weight:700}.sentence-completion-button:hover{border-color:var(--text-primary)}.sentence-completion-button:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.sentence-completion-score{color:var(--text-secondary);margin:1rem 0 0;font-size:.98rem;font-weight:700}@media (width<=768px){.sentence-bank-header{flex-direction:column;align-items:flex-start;gap:.35rem}.sentence-bank{gap:.6rem}.sentence-token{padding:.65rem .8rem;font-size:.92rem}.sentence-card{padding:.85rem .9rem}.sentence-card-text{font-size:.98rem;line-height:1.75}.sentence-blank{min-width:4.7rem;min-height:2rem;margin:.12rem .18rem;padding:.12rem .5rem}}.difficulty-badge{vertical-align:middle;flex-shrink:0;width:2rem;height:auto;display:inline-block}.difficulty-badge-trigger{cursor:help;justify-content:center;align-items:center;display:inline-flex}.difficulty-badge-trigger:focus-visible{outline:2px solid var(--focus-dark-subtle);outline-offset:3px}.difficulty-badge-tooltip{max-width:min(10rem,100vw - 24px)}.difficulty-badge-tooltip span{font-size:.88rem;font-weight:600}:root[data-theme=dark] .difficulty-badge svg>g>rect[fill=\#000000],:root[data-theme=dark] .difficulty-badge svg>g>rect[fill="rgb(0, 0, 0)"]{fill:var(--text-on-dark)!important;stroke:var(--text-on-dark)!important}:root[data-theme=dark] .difficulty-badge svg>g>rect[fill=\#ffffff],:root[data-theme=dark] .difficulty-badge svg>g>rect[fill="rgb(255, 255, 255)"]{fill:var(--card-bg)!important;stroke:var(--text-on-dark)!important}.exercise-view{background-color:var(--bg-primary);scroll-behavior:smooth;-webkit-overflow-scrolling:touch;flex:1;height:100%;min-height:0;padding:4rem 2rem;position:relative;overflow-y:auto}.exercise-article{max-width:920px;margin:0 auto}.collocation-section{background:var(--card-bg);box-shadow:var(--shadow-card);border-radius:0;padding:2rem}.exercise-support-copy{margin-bottom:1.5rem}.exercise-support-copy-outro{margin-top:1.75rem;margin-bottom:0}.exercise-support-paragraph{color:var(--text-body);margin:0;font-size:1.08rem;line-height:1.8}.cloze-exercises{padding-top:1.5rem}.cloze-exercises-compact{padding-top:.35rem}.exercise-header{justify-content:space-between;align-items:flex-start;gap:1.5rem;margin-bottom:1.25rem;padding-bottom:1.25rem;display:flex}.exercise-header-start{align-items:flex-start;gap:1rem;min-width:0;display:flex}.exercise-return-button{border:1px solid var(--border-color);background:var(--bg-primary);color:var(--text-primary);font:inherit;cursor:pointer;flex:none;align-items:center;gap:.45rem;padding:.65rem .8rem;font-weight:700;display:inline-flex}.exercise-return-button:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.exercise-return-button-icon{font-size:1rem;line-height:1}.pagination-header{justify-content:center;align-items:center;gap:1.5rem;padding:.25rem 0 0;display:flex}.exercise-header-end{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:1rem;display:flex}.exercise-header-action{border:1px solid var(--border-color);background:var(--card-bg);color:var(--text-primary);font:inherit;cursor:pointer;padding:.55rem .8rem;font-size:.9rem;font-weight:700}.exercise-header-action:hover{border-color:var(--text-primary)}.exercise-header-action:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.page-btn{border:1px solid var(--border-color);color:var(--text-primary);cursor:pointer;background:0 0;border-radius:50%;justify-content:center;align-items:center;width:36px;height:36px;font-size:1.25rem;font-weight:700;transition:all .2s;display:flex}.page-btn:not(:disabled):hover{background:var(--hover-bg);border-color:var(--accent-color);color:var(--accent-color)}.page-btn:disabled{opacity:.3;cursor:not-allowed}.page-indicator{color:var(--text-secondary);font-size:1rem;font-weight:600}.exercise-header-copy{min-width:0}.exercise-title-row{flex-wrap:wrap;align-items:center;gap:.65rem;display:inline-flex}.exercise-type{color:var(--text-primary);text-transform:uppercase;letter-spacing:1px;font-size:2rem;font-weight:800}.exercise-difficulty-badge{width:2.1rem}.exercise-type-translation{color:var(--text-secondary);margin:.45rem 0 0;font-size:.98rem;font-weight:600}.collocation-word h3{color:var(--text-primary);margin-top:0;margin-bottom:1rem;font-size:2.5rem}.definition{align-items:baseline;gap:1rem;margin-bottom:2rem;display:flex}.def-label{background:var(--text-primary);color:var(--bg-primary);text-transform:uppercase;border-radius:4px;padding:.25rem .75rem;font-size:.875rem;font-weight:600}.definition p{color:var(--text-secondary);margin:0;font-size:1.125rem;font-style:italic}.word-family-figure{background:0 0;border:0;border-radius:0;margin:0 0 2rem;padding:0}.word-family-graphic-frame{isolation:isolate;position:relative}.word-family-graphic{z-index:1;width:100%;height:auto;display:block;position:relative}.word-family-graphic-skeleton{width:100%;display:flex}.word-family-graphic-skeleton-frame{aspect-ratio:4/3;border-radius:0;width:100%}.word-family-hotspot{z-index:2;display:block;position:absolute}.word-family-hotspot-hit-area{cursor:help;display:block;position:absolute;inset:0}.word-family-hotspot:focus-visible{outline:2px solid var(--focus-dark-subtle);outline-offset:2px}.word-family-hotspot-tooltip{max-width:min(18rem,100vw - 24px)}.word-family-hotspot-tooltip strong{font-size:.95rem}.word-family-hotspot-tooltip span{font-size:.9rem;line-height:1.45}.case-marker{cursor:help;border-radius:999px;justify-content:center;align-items:center;min-width:1.5rem;min-height:1.5rem;display:inline-flex;position:relative}.case-marker:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.case-tooltip{max-width:min(16rem,100vw - 24px)}.case-tooltip strong{font-size:.92rem}.case-tooltip span{font-size:.88rem;font-weight:500}.collocation-table{margin-bottom:2rem;overflow-x:auto}.collocation-table table{border-collapse:collapse;width:100%}.collocation-table td{border-bottom:1px solid var(--border-color);color:var(--text-body);padding:1rem}.collocation-table .col1{text-align:right;width:30%}.collocation-table .col2{text-align:center;color:var(--accent-color);width:40%}.collocation-table .col3{text-align:left;width:25%}.collocation-table .col4{text-align:center;width:5%;color:var(--text-secondary);font-weight:700}.collocation-main-word-mobile{display:none}@media (width>=1081px){.app-main-shell-sidebar-collapsed .exercise-article{max-width:1080px}.app-main-shell-sidebar-collapsed .exercise-view{padding-left:2.5rem;padding-right:2.5rem}}@media (width<=768px){.exercise-view{padding:1rem 1rem 2rem}.collocation-section{padding:1rem}.exercise-header-copy{display:none}.exercise-header{justify-content:center;align-items:center;margin-bottom:.85rem;padding-bottom:.85rem}.exercise-header-start{justify-content:center;width:100%}.pagination-header{justify-content:center;gap:.85rem;padding-top:0}.exercise-header-end{justify-content:center;width:100%}.exercise-header-action-desktop-only{display:none}.exercise-type{letter-spacing:.04em;font-size:1.45rem}.exercise-return-button{padding:.6rem .75rem;font-size:.92rem}.collocation-word h3{margin-bottom:.75rem;font-size:1.9rem}.definition{flex-direction:column;gap:.55rem;margin-bottom:1.4rem}.definition p,.exercise-support-paragraph{font-size:1rem}.page-btn{width:34px;height:34px}.page-indicator{font-size:.92rem}.collocation-table{margin:0 0 1.5rem;padding:0;overflow:visible}.collocation-table table,.collocation-table tbody{display:block}.collocation-table tr{border:1px solid var(--border-color);background:var(--bg-primary);flex-wrap:wrap;align-items:center;gap:.35rem .45rem;padding:.85rem .9rem;display:flex}.collocation-table tr+tr{margin-top:.65rem}.collocation-table td{border-bottom:0;padding:0;font-size:.98rem;width:auto!important}.collocation-table td:empty{display:none}.collocation-table .col1,.collocation-table .col2,.collocation-table .col3{text-align:left}.collocation-table .col1{color:var(--text-secondary)}.collocation-main-word-desktop{display:none}.collocation-main-word-mobile{display:inline}.collocation-table .col4{border:1px solid var(--border-color);background:var(--card-bg);border-radius:999px;justify-content:center;align-items:center;margin-left:auto;padding:.15rem .4rem;display:inline-flex}.cloze-exercises{padding-top:1rem}}.app-container{background:var(--bg-primary);width:100%;height:100vh;min-height:100vh;display:flex}.app-main-shell{flex-direction:column;flex:1;min-width:0;height:100vh;display:flex}.app-main-shell-sidebar-collapsed{flex-basis:0}.app-main-content{flex:1;min-height:0}.app-main-content-sidebar-collapsed{width:100%}.app-status-card{flex-direction:column;gap:1rem;max-width:32rem;display:flex}.app-status-card h2,.app-status-card p{margin:0}.app-status-detail{color:var(--text-secondary);font-size:.92rem;line-height:1.5}.app-status-action{border:1px solid var(--border-color);background:var(--bg-primary);min-width:12rem;color:var(--text-primary);font:inherit;cursor:pointer;align-self:center;padding:.8rem 1rem;font-weight:700;transition:border-color .2s,background-color .2s,color .2s}.app-status-action:hover,.app-status-action:focus-visible{border-color:var(--accent-color)}.app-status-action:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.app-sidebar-backdrop,.mobile-topbar{display:none}.mobile-topbar-actions{align-items:center;gap:.6rem;display:inline-flex}.mobile-account-button{border-color:var(--border-color);background:var(--card-bg)}.skeleton-block{background:color-mix(in srgb, var(--border-color) 58%, var(--card-bg));border-radius:0;position:relative;overflow:hidden}.skeleton-block:after{content:"";background:linear-gradient(90deg,#0000 0%,#ffffff57 50%,#0000 100%);animation:1.95s ease-in-out infinite skeleton-shimmer;position:absolute;inset:0;transform:translate(-100%)}.app-content-skeleton-view{display:block}.app-content-skeleton-shell{grid-template-columns:minmax(0,1fr);gap:2rem;max-width:1240px;margin:0 auto;padding:4rem 2rem;display:grid}.app-content-skeleton-card{background:var(--card-bg);width:100%;max-width:860px;box-shadow:var(--shadow-card);margin:0 auto;padding:2.2rem}.app-content-skeleton-header{flex-direction:column;align-items:center;gap:.9rem;margin-bottom:2rem;display:flex}.app-content-skeleton-kicker{width:6.5rem;height:.85rem}.app-content-skeleton-title{border-radius:1rem;width:min(30rem,88%);height:2.6rem}.app-content-skeleton-title-secondary{width:min(18rem,62%);height:1rem}.app-content-skeleton-audio{border:1px solid var(--border-color);flex-direction:column;gap:.8rem;margin-bottom:1.75rem;padding:1rem 1.1rem;display:flex}.app-content-skeleton-audio-label{width:5rem;height:.8rem}.app-content-skeleton-audio-bar{border-radius:.9rem;width:100%;height:2.75rem}.app-content-skeleton-copy{flex-direction:column;gap:.9rem;display:flex}.app-content-skeleton-copy-secondary{margin-top:1.75rem}.app-content-skeleton-line{border-radius:.7rem;width:100%;height:1rem}.app-content-skeleton-line-short{width:72%}@keyframes skeleton-shimmer{to{transform:translate(100%)}}@media (width<=768px){.app-container{height:100dvh;min-height:100dvh;position:relative;overflow:hidden}.app-main-shell{height:100dvh}.app-sidebar-backdrop{opacity:0;pointer-events:none;z-index:1100;background:#0f172a6b;border:0;padding:0;transition:opacity .22s;display:block;position:fixed;inset:0}.app-sidebar-backdrop.visible{opacity:1;pointer-events:auto}.mobile-topbar{padding:calc(.85rem + env(safe-area-inset-top,0px)) calc(1rem + env(safe-area-inset-right,0px)) .85rem calc(1rem + env(safe-area-inset-left,0px));border-bottom:1px solid var(--border-section);background:var(--mobile-topbar-bg);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);align-items:center;gap:.7rem;display:flex}.mobile-menu-button{border:1px solid var(--border-color);background:var(--card-bg);min-height:2.75rem;color:var(--text-primary);font:inherit;cursor:pointer;flex:none;align-items:center;gap:.7rem;padding:.6rem .9rem;font-weight:700;display:inline-flex}.mobile-menu-button:focus-visible{outline:2px solid var(--accent-color);outline-offset:3px}.mobile-menu-icon{flex-direction:column;gap:.24rem;display:inline-flex}.mobile-menu-icon span{background:currentColor;width:1rem;height:2px;display:block}.mobile-menu-label{font-size:.94rem}.mobile-topbar-copy{flex-direction:column;flex:1;gap:.15rem;min-width:0;display:flex}.mobile-topbar-kicker,.mobile-topbar-title{margin:0}.mobile-topbar-kicker{letter-spacing:.08em;text-transform:uppercase;color:var(--text-secondary);font-size:.7rem;font-weight:800}.mobile-topbar-title{color:var(--text-primary);font-size:.95rem;font-weight:700;line-height:1.3}.mobile-topbar-actions{flex:none}.app-content-skeleton-shell{gap:1.2rem;padding:1.5rem 1rem 2.5rem}.app-content-skeleton-card{padding:1.2rem}.app-content-skeleton-header{align-items:flex-start;margin-bottom:1.4rem}.app-content-skeleton-title{width:min(18rem,100%);height:2rem}.app-content-skeleton-title-secondary{width:min(11rem,80%)}}