.course-page{color:var(--ruk-text-primary)}.course-editor-shell{display:flex;flex-direction:column;gap:var(--ruk-gap-lg);max-width:1100px;margin:0 auto;padding-bottom:5rem}.course-editor-toolbar{position:sticky;top:0;z-index:var(--ruk-layer-fixed);display:flex;flex-wrap:wrap;gap:var(--ruk-gap-xs);padding:var(--ruk-gap-sm);background:color-mix(in srgb,var(--ruk-canvas) 92%,transparent);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border:1px solid var(--ruk-border-soft);border-radius:var(--ruk-curve-lg);box-shadow:var(--ruk-elevation-1)}.course-editor-toolbar button{border:1px solid var(--ruk-border-soft);background:var(--ruk-surface-1);color:var(--ruk-text-primary);border-radius:var(--ruk-curve-sm);padding:.35rem .55rem;font-size:var(--ruk-size-small);cursor:pointer}.course-editor-toolbar button:hover{border-color:var(--ruk-brand-bright)}.course-editor-toolbar button.is-active{background:var(--ruk-brand-muted);border-color:var(--ruk-brand-main)}.course-editor-content .ProseMirror{min-height:420px;max-width:42rem;margin:0 auto;padding:2rem 2.25rem 2.5rem;border:1px solid var(--ruk-border-soft);border-radius:var(--ruk-curve-lg);background:var(--ruk-canvas);outline:none;font-size:1.0625rem;line-height:1.75}.course-editor-content .ProseMirror>*+*{margin-top:.85em}.course-editor-content .ProseMirror p{margin:.35em 0}.course-editor-content .ProseMirror h2,.course-editor-content .ProseMirror h3,.course-editor-content .ProseMirror h4{margin-top:1.6em;margin-bottom:.45em;line-height:1.25;color:var(--ruk-text-heading)}.course-editor-content .ProseMirror h2:first-child,.course-editor-content .ProseMirror h3:first-child,.course-editor-content .ProseMirror h4:first-child{margin-top:0}.course-editor-content .ProseMirror img.course-rich-img{display:block;max-width:100%;height:auto;margin:1.75rem auto;border-radius:var(--ruk-curve-lg);box-shadow:var(--ruk-elevation-2)}.course-editor-content .ProseMirror hr{margin:2rem 0;border:none;border-top:1px solid var(--ruk-border-soft)}.course-editor-content .ProseMirror blockquote{margin:1.5rem 0;padding:.65rem 0 .65rem 1rem;border-left:4px solid var(--ruk-brand-bright);color:var(--ruk-text-secondary);background:color-mix(in srgb,var(--ruk-brand-muted) 35%,transparent);border-radius:0 var(--ruk-curve-sm) var(--ruk-curve-sm) 0}.course-editor-content .ProseMirror ul,.course-editor-content .ProseMirror ol{margin:.75rem 0;padding-left:1.35rem}.course-editor-content .ProseMirror .course-rich-video-wrap{margin:1.75rem 0;border-radius:var(--ruk-curve-lg);overflow:hidden;box-shadow:var(--ruk-elevation-2)}.course-rich-body{font-size:1.0625rem;line-height:1.78;color:var(--ruk-text-primary);max-width:42rem;margin:0 auto}.course-rich-body>*+*{margin-top:.85em}.course-rich-body h2,.course-rich-body h3,.course-rich-body h4{color:var(--ruk-text-heading);margin:1.65em 0 .5em;line-height:1.25}.course-rich-body h2:first-child,.course-rich-body h3:first-child,.course-rich-body 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.65rem}.course-rich-body .course-rich-video-wrap{margin:1.75rem 0;border-radius:var(--ruk-curve-lg);overflow:hidden;box-shadow:var(--ruk-elevation-2)}.course-rich-body video.course-rich-video{width:100%;max-height:70vh;border-radius:var(--ruk-curve-md);background:#000}.course-rich-body .course-rich-figure{margin:1.75rem auto;max-width:100%;text-align:center}.course-rich-body .course-rich-figure .course-rich-img{margin:0 auto}.course-rich-body .course-rich-caption{margin-top:.5rem;font-size:.9375rem;line-height:1.45;color:var(--ruk-text-secondary);font-style:italic}.course-rich-body .course-rich-video-wrap--vk{position:relative;width:100%;aspect-ratio:16 / 9;background:#0f0f12;border:1px solid var(--ruk-border-soft)}.course-rich-body .course-rich-video-frame{position:absolute;inset:0;width:100%;height:100%;border:0;border-radius:var(--ruk-curve-md)}.course-rich-body .course-rich-video-placeholder{padding:2rem;text-align:center;color:var(--ruk-text-muted);font-size:.9rem}.course-editor-content .ProseMirror .course-rich-figure{margin:1.25rem auto;max-width:100%;text-align:center}.course-editor-content .ProseMirror .course-rich-caption{margin-top:.4rem;font-size:.875rem;color:var(--ruk-text-secondary);font-style:italic}.course-editor-content .ProseMirror .course-rich-video-wrap--vk{position:relative;width:100%;aspect-ratio:16 / 9;background:#0f0f12;border-radius:var(--ruk-curve-md);border:1px solid var(--ruk-border-soft);overflow:hidden}.course-editor-content .ProseMirror .course-rich-video-frame{position:absolute;inset:0;width:100%;height:100%;border:0}.course-editor-toolbar button:disabled{opacity:.45;cursor:not-allowed}.course-fab{position:fixed;right:1.5rem;bottom:1.5rem;z-index:var(--ruk-layer-float);padding:.85rem 1.25rem;border-radius:var(--ruk-curve-pill);background:var(--ruk-brand-main);color:#fff;font-weight:var(--ruk-weight-demi);text-decoration:none;box-shadow:var(--ruk-elevation-3);-webkit-tap-highlight-color:transparent;outline:none}.course-fab:hover{background:var(--ruk-brand-deep)}.course-fab:focus,.course-fab:focus-visible{outline:none;box-shadow:var(--ruk-elevation-3),0 0 0 2px var(--ruk-canvas)}[data-theme=dark] .course-fab{color:#f8fafc}.course-card__edit-btn{display:inline-flex;align-items:center;padding:.35rem .75rem;margin-left:.35rem;border-radius:var(--ruk-curve-md);border:1px solid var(--ruk-brand-main);color:var(--ruk-brand-main);text-decoration:none;background:color-mix(in srgb,var(--ruk-brand-muted) 22%,transparent)}.course-card__edit-btn:hover{background:color-mix(in srgb,var(--ruk-brand-muted) 45%,transparent)}.course-card__links{display:flex;flex-wrap:wrap;align-items:baseline;gap:.35rem 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var(--ruk-gap-md);font-size:var(--ruk-size-small);color:var(--ruk-text-muted)}.course-preview-page__excerpt{margin:0;font-size:1.0625rem;line-height:1.55;color:var(--ruk-text-secondary)}.course-preview-banner{margin-bottom:var(--ruk-gap-lg);padding:var(--ruk-gap-md) var(--ruk-gap-lg);border-radius:var(--ruk-curve-md);background:var(--ruk-caution-soft);color:var(--ruk-text-heading);font-size:var(--ruk-size-small);line-height:1.5}.course-preview-banner--readonly{background:color-mix(in srgb,var(--ruk-brand-muted) 40%,var(--ruk-canvas));border:1px solid var(--ruk-border-soft)}.course-preview-intro{margin-bottom:var(--ruk-gap-lg)}.course-preview-intro__title{margin:0 0 var(--ruk-gap-md);font-size:1.125rem;color:var(--ruk-text-heading)}.course-preview-intro__text{margin:0;line-height:1.65;color:var(--ruk-text-primary)}.course-preview-body__inner{padding-top:var(--ruk-gap-lg)}.course-preview-page__footer{display:flex;flex-wrap:wrap;gap:var(--ruk-gap-md);margin-top:var(--ruk-gap-xl)}@media(max-width:640px){.course-preview-page{padding-bottom:2rem}}.course-grid-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:var(--ruk-gap-lg)}.course-card{border:1px solid var(--ruk-border-soft);border-radius:var(--ruk-curve-lg);overflow:hidden;background:var(--ruk-canvas);display:flex;flex-direction:column}.course-card__media{aspect-ratio:16 / 9;background:var(--ruk-surface-2);overflow:hidden}.course-card__media 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var(--ruk-gap-sm)}.admin-tool-page__lead{margin:0;max-width:52ch;line-height:1.55;color:var(--ruk-text-muted);font-size:var(--ruk-size-small)}.admin-tool-card+.admin-tool-card{margin-top:var(--ruk-gap-lg)}.admin-tool-card__actions{display:flex;flex-wrap:wrap;align-items:center;gap:var(--ruk-gap-md)}.admin-tool-card__filename{font-size:var(--ruk-size-small);color:var(--ruk-text-secondary);word-break:break-all}.admin-tool-progress{margin-top:var(--ruk-gap-lg);padding:var(--ruk-gap-lg);border-radius:var(--ruk-curve-md);border:1px solid var(--ruk-border-soft);background:var(--ruk-surface-1)}.admin-tool-progress__title{margin:0 0 var(--ruk-gap-md);font-weight:var(--ruk-weight-demi);color:var(--ruk-text-heading)}.admin-tool-progress__bar{height:10px;border-radius:var(--ruk-curve-pill);overflow:hidden;background:color-mix(in srgb,var(--ruk-ink) 10%,transparent)}.admin-tool-progress__fill{height:100%;border-radius:inherit;background:var(--ruk-brand-main);transition:width .3s 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.btn{width:100%;justify-content:center}.export-done{display:flex;align-items:center;justify-content:center;gap:var(--ruk-gap-sm);padding:var(--ruk-gap-md);border-radius:var(--ruk-curve-md);background:var(--ruk-positive-soft);color:var(--ruk-positive);font-size:var(--ruk-size-small);font-weight:var(--ruk-weight-demi)}.export-loading{display:flex;align-items:center;gap:var(--ruk-gap-md);padding:var(--ruk-gap-lg);color:var(--ruk-text-muted);font-size:var(--ruk-size-small)}.export-loading__spinner{width:20px;height:20px;border:2px solid var(--ruk-surface-3);border-top-color:var(--ruk-brand-main);border-radius:50%;animation:admin-tool-spin .7s linear infinite}@keyframes admin-tool-spin{to{transform:rotate(360deg)}}@media(min-width:640px){.export-actions{flex-direction:row;flex-wrap:wrap}.export-actions .btn{width:auto;flex:1 1 auto;min-width:200px}}@media(max-width:767px){.admin-tool-page .table-responsive{margin:0 calc(-1 * var(--ruk-gap-lg));padding:0 var(--ruk-gap-lg);width:auto}}.st-homework-show{display:grid;gap:var(--ruk-gap-xl);grid-template-columns:minmax(0,1fr);align-items:start}@media(min-width:1024px){.st-homework-show{grid-template-columns:minmax(0,2fr) minmax(260px,1fr)}}.st-homework-show__main,.st-homework-show__aside{min-width:0}.st-homework-show__main>.card+.card,.st-homework-show__main>.card+.st-hw-files{margin-top:var(--ruk-gap-xl)}.st-hw-files__title{margin:0;font-size:var(--ruk-size-normal);font-weight:var(--ruk-weight-demi)}.st-hw-gallery{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--ruk-gap-base)}@media(min-width:640px){.st-hw-gallery{grid-template-columns:repeat(3,minmax(0,1fr))}}.st-hw-gallery__item{display:block;width:100%;padding:0;border:1px solid var(--ruk-surface-3);border-radius:var(--ruk-curve-md);overflow:hidden;background:var(--ruk-surface-2);cursor:zoom-in;transition:box-shadow var(--ruk-motion-quick),transform var(--ruk-motion-quick)}.st-hw-gallery__item:hover{box-shadow:var(--ruk-elevation-2);transform:translateY(-1px)}.st-hw-gallery__item img{display:block;width:100%;aspect-ratio:4 / 3;object-fit:cover;vertical-align:middle}.st-hw-video{border-radius:var(--ruk-curve-md);overflow:hidden;border:1px solid var(--ruk-surface-3);background:#000}.st-hw-video video{display:block;width:100%;max-height:280px}.st-hw-files .st-hw-video{margin-top:var(--ruk-gap-lg)}.st-hw-video+.st-hw-video{margin-top:var(--ruk-gap-base)}.st-hw-download+.st-hw-download{margin-top:var(--ruk-gap-base)}.st-hw-download{display:flex;align-items:center;gap:var(--ruk-gap-base);padding:var(--ruk-gap-base);border-radius:var(--ruk-curve-md);border:1px solid var(--ruk-surface-3);background:var(--ruk-surface-1);text-decoration:none;color:inherit;transition:border-color var(--ruk-motion-quick),background var(--ruk-motion-quick)}.st-hw-download:hover{border-color:var(--ruk-brand-main);background:var(--ruk-surface-2);text-decoration:none}.st-hw-download__icon{font-size:1.75rem;flex-shrink:0}.st-hw-download__info{flex:1;min-width:0}.st-hw-download__name{font-weight:var(--ruk-weight-demi);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.st-hw-download__size{font-size:var(--ruk-size-small);color:var(--ruk-text-muted)}.st-hw-download__action{flex-shrink:0;font-size:1.125rem}.st-hw-lightbox{position:fixed;inset:0;z-index:var(--ruk-layer-dialog);background:#000000eb;display:flex;align-items:center;justify-content:center;padding:56px 16px 24px;box-sizing:border-box;overflow:hidden;touch-action:none}.st-hw-lightbox__close{position:absolute;top:max(12px,env(safe-area-inset-top));right:max(12px,env(safe-area-inset-right));width:44px;height:44px;border:none;border-radius:var(--ruk-curve-md);background:#ffffff26;color:#fff;font-size:1.5rem;line-height:1;cursor:pointer}.st-hw-lightbox__close:hover{background:#ffffff40}.st-hw-lightbox__img{max-width:min(100%,1200px);max-height:calc(100vh - 120px);max-height:calc(100dvh - 120px);width:auto;height:auto;object-fit:contain;border-radius:var(--ruk-curve-sm);-webkit-user-select:none;user-select:none;-webkit-user-drag:none}.st-hw-lightbox__nav{position:absolute;top:50%;transform:translateY(-50%);width:48px;height:48px;border:none;border-radius:50%;background:#ffffff26;color:#fff;font-size:2rem;line-height:1;cursor:pointer;display:flex;align-items:center;justify-content:center}.st-hw-lightbox__nav:hover{background:#ffffff47}.st-hw-lightbox__nav--prev{left:max(8px,env(safe-area-inset-left))}.st-hw-lightbox__nav--next{right:max(8px,env(safe-area-inset-right))}.st-hw-lightbox__counter{position:absolute;bottom:max(16px,env(safe-area-inset-bottom));left:50%;transform:translate(-50%);color:#ffffffd9;font-size:var(--ruk-size-small);padding:6px 14px;border-radius:var(--ruk-curve-pill);background:#00000073}html.st-hw-lightbox-open,html.st-hw-lightbox-open 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6%,var(--ruk-surface-1))}.st-hw-upload__input{position:absolute;width:0;height:0;opacity:0;pointer-events:none}.st-hw-upload__label{display:inline-flex;align-items:center;gap:var(--ruk-gap-sm);cursor:pointer;font-weight:var(--ruk-weight-demi);color:var(--ruk-brand-main)}.st-hw-upload__hint{margin-top:var(--ruk-gap-sm);font-size:var(--ruk-size-small);color:var(--ruk-text-muted);line-height:1.45}.st-hw-upload__pending{margin-top:var(--ruk-gap-base);text-align:left}.st-hw-upload__pending-item{display:flex;align-items:center;justify-content:space-between;gap:var(--ruk-gap-sm);padding:var(--ruk-gap-sm) var(--ruk-gap-base);border-radius:var(--ruk-curve-sm);background:var(--ruk-surface-2);font-size:var(--ruk-size-small);margin-top:var(--ruk-gap-xs)}.st-hw-upload__pending-item>span{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.whitespace-pre-wrap{white-space:pre-wrap}.st-hw-upload__pending-remove{border:none;background:transparent;color:var(--ruk-text-muted);cursor:pointer;padding:4px 8px;border-radius:var(--ruk-curve-sm)}.st-hw-upload__pending-remove:hover{color:var(--ruk-negative);background:var(--ruk-negative-soft)}.hw-attachments__img-wrap{position:relative}.hw-attachments__img-wrap .st-hw-gallery__item{display:block;width:100%}.hw-attachments__remove--img{top:6px;right:6px}.hw-attachments__docs{display:flex;flex-direction:column;gap:var(--ruk-gap-sm);margin-top:var(--ruk-gap-base)}.hw-attachments__doc{position:relative}.hw-attachments__remove{position:absolute;top:8px;right:8px;width:28px;height:28px;border:none;border-radius:50%;background:#0000008c;color:#fff;font-size:14px;line-height:1;cursor:pointer}.hw-attachments__remove:hover{background:var(--ruk-negative)}.thw-submission-card+.thw-submission-card{margin-top:0}.thw-submission__answer{margin-bottom:var(--ruk-gap-base)}.thw-submission__files-title{margin:0 0 var(--ruk-gap-sm);font-size:var(--ruk-size-small);font-weight:var(--ruk-weight-demi);color:var(--ruk-text-tertiary);text-transform:uppercase;letter-spacing:.04em}.thw-submission__files-box{padding:var(--ruk-gap-base);border-radius:var(--ruk-curve-md);background:var(--ruk-surface-1);border:1px solid var(--ruk-surface-3)}