:root{--ink:#182230;--muted:#667085;--line:#e4e7ec;--soft:#f8fafc;--brand:var(--lt-color-cobalt-500,#2f5fe0);--brand-dark:var(--lt-color-cobalt-600,#2850c8);--blue:#2f5fe0;--green:#067647;--shadow:0 12px 32px rgba(16,24,40,.10);font-family:Inter,"Segoe UI",Roboto,Arial,sans-serif;color:var(--ink);background:#f6f7f9}
*{box-sizing:border-box}body{margin:0;min-width:320px;background:#f6f7f9}.hidden{display:none!important}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}button,input,textarea,select{font:inherit}button,a,input,textarea,select{outline-color:#84adff}button{cursor:pointer}.lesson-app{min-height:100vh}.lesson-header{height:68px;padding:0 24px;display:grid;grid-template-columns:260px 1fr auto;align-items:center;gap:20px;background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30}.lesson-brand{display:flex;align-items:center;gap:11px}.lesson-brand>div{display:flex;flex-direction:column;line-height:1.15}.lesson-brand span{font-size:12px;color:var(--muted)}.brand-mark{width:36px;height:36px;border-radius:11px;display:grid;place-items:center;color:#fff;background:linear-gradient(145deg,#f97066,#d92d20);font-weight:900;text-decoration:none;box-shadow:none}.header-center{min-width:0;display:flex;align-items:center;gap:14px}.lesson-title-field{width:min(560px,55vw)}.lesson-title-field input{width:100%;border:1px solid transparent;background:transparent;padding:9px 12px;border-radius:9px;font-size:17px;font-weight:700;text-align:center}.lesson-title-field input:hover,.lesson-title-field input:focus{border-color:var(--line);background:#fff}.header-actions{display:flex;align-items:center;justify-content:flex-end;gap:8px}.avatar-button{width:38px;height:38px;border-radius:50%;display:grid;place-items:center;background:var(--lt-color-cobalt-100,#dbe6fc);color:var(--lt-color-cobalt-700,#2142ab);font-weight:800;text-decoration:none}.primary-button,.ghost-button,.danger-button,.icon-button{border-radius:9px;border:1px solid transparent;padding:9px 14px;font-weight:700;transition:.16s ease}.primary-button{background:var(--brand);color:#fff;box-shadow:0 2px 4px rgba(16,24,40,.08)}.primary-button:hover{background:var(--brand-dark);transform:translateY(-1px)}.primary-button:disabled{opacity:.55;cursor:wait;transform:none}.primary-button.large{padding:13px 20px;font-size:15px}.primary-button.wide{width:100%;padding:12px}.ghost-button{background:#fff;color:#344054;border-color:#d0d5dd}.ghost-button:hover{background:#f9fafb}.danger-button{background:#fff;color:#b42318;border-color:#fda29b}.danger-button:hover{background:#fff3f2}.icon-button{width:34px;height:34px;padding:0;font-size:20px;background:#fff;color:#475467;border-color:#d0d5dd}.global-status{margin:0;padding:9px 24px;background:#eaf0fe;color:#2142ab;font-size:13px;text-align:center}.global-status.error{background:#fef3f2;color:#b42318}.global-status:empty{display:none}.save-state{font-size:12px;color:var(--green);padding-right:6px}.save-state[data-state="saving"]{color:#b54708}.save-state[data-state="dirty"]{color:#475467}.save-state[data-state="error"]{color:#b42318}.lesson-app[data-view="library"] .editor-only,.lesson-app[data-view="library"] .editor-view{display:none}.lesson-app[data-view="editor"] .library-view{display:none}.library-view{max-width:1180px;margin:0 auto;padding:58px 32px 80px}.library-hero{display:flex;justify-content:space-between;align-items:flex-end;gap:32px;margin-bottom:38px}.eyebrow{margin:0 0 8px;color:var(--brand);font-size:11px;font-weight:900;letter-spacing:.13em}.library-hero h1{font-size:38px;letter-spacing:-.04em;margin:0 0 10px}.library-hero p{max-width:680px;color:var(--muted);margin:0;line-height:1.55}.library-toolbar{display:flex;justify-content:space-between;gap:16px;margin-bottom:32px}.search-field{flex:1;max-width:460px;background:#fff;border:1px solid #d0d5dd;border-radius:10px;padding:0 13px;display:flex;align-items:center;gap:9px;color:#667085}.search-field input{width:100%;border:0;padding:11px 0;background:transparent;outline:0}.section-heading{display:flex;justify-content:space-between;align-items:end;margin-bottom:17px}.section-heading h2{font-size:20px;margin:0}.section-heading p{margin:4px 0 0;color:var(--muted);font-size:13px}.draft-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.draft-card{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;transition:.18s ease;min-width:0}.draft-card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:var(--lt-color-cobalt-300,#7d9cf0)}.draft-cover{height:138px;background:linear-gradient(135deg,#eaf0fe,#f5f8fc 48%,#eff8ff);padding:18px;display:flex;align-items:center;justify-content:center}.draft-cover-preview{width:74%;height:90px;border-radius:6px;background:#fff;box-shadow:0 7px 18px rgba(16,24,40,.12);padding:15px;display:flex;flex-direction:column;gap:7px}.draft-cover-preview i{height:7px;border-radius:8px;background:#e4e7ec}.draft-cover-preview i:first-child{width:60%;height:10px;background:var(--brand)}.draft-cover-preview i:last-child{width:82%}.draft-card-body{padding:17px}.draft-card h3{font-size:16px;margin:0 0 7px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.draft-meta{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:12px}.draft-card-actions{display:flex;gap:8px;margin-top:15px}.draft-card-actions button{flex:1}.empty-library{grid-column:1/-1;background:#fff;border:1px dashed #d0d5dd;border-radius:14px;text-align:center;padding:58px 24px;color:var(--muted)}.empty-library strong{display:block;color:var(--ink);font-size:18px;margin-bottom:7px}.editor-view{height:calc(100vh - 68px);display:grid;grid-template-columns:250px minmax(420px,1fr) 300px;overflow:hidden}.slide-panel,.inspector-panel{background:#fff;overflow:auto}.slide-panel{border-right:1px solid var(--line);padding:18px 14px}.panel-heading{display:flex;justify-content:space-between;align-items:center;padding:0 3px 14px}.panel-heading>div{display:flex;gap:8px;align-items:center}.panel-heading span{font-size:11px;color:var(--muted);background:#f2f4f7;border-radius:10px;padding:2px 7px}.slide-list{display:flex;flex-direction:column;gap:10px}.slide-item{display:grid;grid-template-columns:22px 1fr;gap:7px;align-items:start;border:1px solid transparent;border-radius:10px;padding:6px;background:transparent;text-align:left;color:#344054}.slide-item:hover{background:#f9fafb}.slide-item[aria-selected="true"]{border-color:var(--brand);background:#eaf0fe;box-shadow:0 0 0 2px rgba(47,95,224,.10)}.slide-number{font-size:11px;color:#98a2b3;padding-top:22px;text-align:center}.slide-thumb{aspect-ratio:16/9;background:#fff;border:1px solid #d0d5dd;border-radius:6px;padding:9px;box-shadow:0 2px 5px rgba(16,24,40,.06);overflow:hidden}.slide-thumb strong{font-size:9px;display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.slide-thumb i{display:block;height:4px;background:#eaecf0;border-radius:4px;margin-top:7px}.slide-thumb i:nth-child(3){width:72%}.slide-item[aria-selected="true"] .slide-thumb{border-color:var(--brand)}.add-slide-button{width:100%;margin-top:12px;padding:10px;border:1px dashed #d0d5dd;background:#fff;border-radius:9px;color:#475467;font-weight:700}.canvas-column{background:#eef0f3;display:flex;flex-direction:column;min-width:0}.canvas-toolbar{height:52px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 16px}.block-picker{display:flex;align-items:center;gap:5px;overflow:auto}.block-picker>span{font-size:11px;font-weight:800;color:#667085;margin-right:2px}.block-picker button{white-space:nowrap;border:0;background:#f2f4f7;color:#344054;border-radius:7px;padding:7px 9px;font-size:12px;font-weight:650}.block-picker button:hover{background:#dbe6fc;color:#2142ab}.zoom-label{font-size:12px;color:#667085}.canvas-stage{flex:1;overflow:auto;padding:42px;display:grid;place-items:start center}.slide-canvas{width:min(880px,100%);aspect-ratio:16/9;min-height:420px;background:#fff;border-radius:4px;box-shadow:0 15px 45px rgba(16,24,40,.14);padding:48px 54px;display:flex;flex-direction:column;gap:15px;overflow:auto}.slide-canvas.two-column{display:grid;grid-template-columns:1fr 1fr;align-content:start}.slide-canvas h1.slide-heading{font-size:30px;line-height:1.15;margin:0 0 6px;grid-column:1/-1}.canvas-empty{margin:auto;color:#98a2b3;text-align:center}.canvas-empty strong{display:block;color:#475467;margin-bottom:5px}.lesson-block{position:relative;border:1px solid transparent;border-radius:9px;padding:12px 14px;min-height:46px}.lesson-block:hover{border-color:#d0d5dd}.lesson-block.selected{border-color:#84adff;box-shadow:0 0 0 3px #eff4ff}.lesson-block-tools{display:none;position:absolute;right:6px;top:-13px;background:#fff;border:1px solid #d0d5dd;border-radius:7px;box-shadow:0 4px 10px rgba(16,24,40,.1);overflow:hidden}.lesson-block:hover .lesson-block-tools,.lesson-block.selected .lesson-block-tools{display:flex}.lesson-block-tools button{border:0;background:#fff;padding:4px 7px;color:#475467}.lesson-block-tools button:hover{background:#f2f4f7}.block-rich-text{white-space:pre-wrap;line-height:1.6}.block-callout{background:#eff8ff;border-left:4px solid #2e90fa;padding:13px 15px}.block-callout.warning{background:#fffaeb;border-left-color:#f79009}.block-callout.success{background:#ecfdf3;border-left-color:#12b76a}.block-callout.danger{background:#fef3f2;border-left-color:#f04438}.block-callout strong{display:block;margin-bottom:4px}.block-formula{text-align:center;font-family:"Times New Roman",serif;font-size:24px;background:#f9fafb}.block-image{display:flex;flex-direction:column;align-items:center}.block-image img{max-width:100%;max-height:250px;border-radius:7px;object-fit:contain}.block-caption{font-size:12px;color:#667085;margin-top:6px}.block-placeholder{padding:26px;border:1px dashed #d0d5dd;border-radius:8px;text-align:center;color:#98a2b3}.block-video a{display:flex;min-height:90px;align-items:center;justify-content:center;background:#101828;border-radius:8px;color:#fff;text-decoration:none}.inspector-panel{border-left:1px solid var(--line)}.inspector-tabs{height:52px;border-bottom:1px solid var(--line);display:flex}.inspector-tabs button{flex:1;border:0;background:#fff;color:#667085;font-weight:700}.inspector-tabs button.active{color:var(--brand);box-shadow:inset 0 -2px var(--brand)}.inspector-section{padding:20px}.inspector-section h2{font-size:14px;margin:0 0 18px}.inspector-section label{display:block;font-size:12px;font-weight:700;color:#475467;margin-bottom:14px}.inspector-section input,.inspector-section textarea,.inspector-section select,.lesson-dialog input,.lesson-dialog select{display:block;width:100%;margin-top:6px;border:1px solid #d0d5dd;border-radius:8px;padding:9px 10px;background:#fff;color:var(--ink)}.inspector-section textarea{min-height:120px;resize:vertical}.switch-row{display:flex;align-items:center;justify-content:space-between;font-size:12px;font-weight:650;padding:10px 0;border-bottom:1px solid #f2f4f7}.switch-row input{width:38px;height:21px;margin:0;accent-color:var(--brand)}.slide-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:20px}.slide-actions button{padding:8px;font-size:12px}.keyboard-tip{margin:12px 20px 20px;padding:12px;border-radius:8px;background:#f9fafb;color:#667085;font-size:11px;display:flex;flex-direction:column;gap:4px}.block-type{font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:#98a2b3;margin-bottom:14px}.lesson-dialog,.preview-dialog{border:0;border-radius:16px;padding:0;box-shadow:0 24px 70px rgba(16,24,40,.25);color:var(--ink)}dialog::backdrop{background:rgba(16,24,40,.58);backdrop-filter:blur(3px)}.lesson-dialog{width:min(520px,calc(100vw - 30px))}.lesson-dialog form{padding:30px;position:relative}.lesson-dialog h2{margin:0 0 7px;font-size:24px}.lesson-dialog form>p:not(.eyebrow){color:var(--muted);line-height:1.5}.lesson-dialog label{display:block;font-size:13px;font-weight:700;margin-top:20px}.dialog-close{border:0;background:transparent;font-size:27px;color:#667085;line-height:1;position:absolute;right:18px;top:16px}.dialog-actions{display:flex;justify-content:flex-end;gap:9px;margin-top:26px}.preview-dialog{width:min(1080px,calc(100vw - 30px));height:min(760px,calc(100vh - 30px));background:#eef0f3}.preview-header{height:64px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 24px}.preview-header>div{display:flex;flex-direction:column}.preview-header span{font-size:11px;color:var(--muted)}.preview-header .dialog-close{position:static}.preview-body{height:calc(100% - 116px);display:grid;grid-template-columns:50px 1fr 50px;align-items:center;gap:12px;padding:24px}.preview-canvas{margin:auto;max-height:100%;min-height:0}.preview-nav{border:0;background:#fff;width:42px;height:42px;border-radius:50%;font-size:28px;color:#475467;box-shadow:0 4px 12px rgba(16,24,40,.14)}.preview-nav:disabled{opacity:.3}.preview-footer{height:52px;padding:0 28px;display:flex;align-items:center;gap:14px;background:#fff}.preview-footer span{font-size:12px;color:#667085}.progress-track{height:5px;background:#eaecf0;border-radius:5px;flex:1;overflow:hidden}.progress-track i{height:100%;display:block;background:var(--brand);transition:width .2s}.publish-summary{background:#f9fafb;border:1px solid var(--line);border-radius:10px;padding:13px 15px;margin:18px 0;font-size:13px}.publish-summary strong{display:block;margin-bottom:3px}.assignment-section{margin-top:20px;border-top:1px solid var(--line);padding-top:4px}.success-banner{margin:16px 0;background:#ecfdf3;color:#067647;border-radius:8px;padding:11px;font-size:12px;font-weight:700}.toast-region{position:fixed;right:22px;bottom:22px;z-index:100;display:flex;flex-direction:column;gap:9px}.toast{max-width:360px;background:#101828;color:#fff;padding:12px 16px;border-radius:10px;box-shadow:var(--shadow);font-size:13px;animation:toast-in .18s ease}.toast.error{background:#b42318}@keyframes toast-in{from{opacity:0;transform:translateY(8px)}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;animation:none!important;transition:none!important}}
.slide-item{position:relative;cursor:pointer}.slide-reorder{display:none;position:absolute;right:8px;bottom:8px;background:#fff;border:1px solid #d0d5dd;border-radius:6px;overflow:hidden;box-shadow:0 2px 6px rgba(16,24,40,.1)}.slide-item:hover .slide-reorder,.slide-item:focus-within .slide-reorder,.slide-item[aria-selected="true"] .slide-reorder{display:flex}.slide-reorder button{border:0;background:#fff;color:#475467;padding:3px 6px;font-size:11px}.slide-reorder button:hover{background:#f2f4f7}.slide-reorder button:disabled{opacity:.3;cursor:default}

/* ===== YC-01/02: responsive, inspector, canvas, dialogs, focus (agentcoder1) =====
   Class contract (on dinh): .inspector-toggle, .inspector-panel.is-open, .inspector-backdrop(.is-visible), .inspector-close,
   .block-picker__group, .slide-item.is-current, .lesson-block-tools, .lesson-confirm-dialog(.is-danger),
   .lesson-confirm-dialog__title/__message/__actions, .slide-canvas--present, .lesson-block--question */
:root{--focus:#2f5fe0}
:where(button,a,input,textarea,select,summary,[tabindex]):focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:6px}
.slide-canvas:focus-visible{outline:3px solid var(--focus);outline-offset:3px}
.primary-button:focus-visible{outline-color:var(--focus);box-shadow:0 0 0 2px #fff}

/* Canvas: noi dung dai lam slide cao them thay vi khoa cuon; 16:9 chi la chieu cao toi thieu */
.slide-canvas{overflow:visible;min-width:0;overflow-wrap:anywhere}
.slide-canvas>*{min-width:0}
.canvas-stage{min-height:0}
.preview-canvas{overflow:auto;aspect-ratio:auto;width:min(880px,100%);max-height:100%;min-height:min(100%,320px)}
.preview-body{grid-template-rows:minmax(0,1fr)}
.slide-canvas--present{font-size:1.3em;line-height:1.5}
.slide-canvas--present h1.slide-heading{font-size:2.1em}

.lesson-block--question{background:#f8fafc;border:1px solid #d0d5dd}
.lesson-block--question .lesson-question{background:#fff}

/* Cong cu khoi: hover, chon hoac focus-within; du lon de cham */
.lesson-block:focus-within{border-color:#84adff}
.lesson-block:focus-within .lesson-block-tools{display:flex}
.lesson-block-tools button{min-width:36px;min-height:36px;font-size:14px}
.lesson-block-tools button:focus-visible{outline-offset:-3px}
@media(hover:none){.lesson-block-tools{top:-18px}}

/* Danh sach slide: cuon duoc, slide hien tai noi bat */
.slide-panel{overscroll-behavior:contain}
.slide-item[aria-selected="true"],.slide-item.is-current{border-color:var(--brand);background:#eaf0fe;box-shadow:0 0 0 3px rgba(47,95,224,.18)}
.slide-item[aria-selected="true"] .slide-number,.slide-item.is-current .slide-number{color:var(--brand-dark);font-weight:900}
.slide-item[aria-selected="true"]:before,.slide-item.is-current:before{content:"";position:absolute;left:-12px;top:12px;bottom:12px;width:4px;border-radius:4px;background:var(--brand)}
.slide-thumb strong{white-space:normal;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}
.slide-item:focus-visible{outline-offset:-2px}

/* Thanh them khoi: nhan chu day du, xuong dong khi hep */
.canvas-toolbar{height:auto;min-height:52px;padding:8px 16px;gap:10px;align-items:flex-start}
.block-picker{flex-wrap:wrap;overflow:visible;gap:6px;flex:1;min-width:0}
.block-picker button{min-height:36px;padding:7px 11px;font-size:13px;white-space:normal;text-align:left;line-height:1.25}
.block-picker__group{display:inline-flex;flex-wrap:wrap;align-items:center;gap:6px;padding-left:8px;border-left:1px solid var(--line)}
.block-picker__group>span{font-size:11px;font-weight:800;color:#667085}
.block-picker button[data-add-question],.block-picker button[data-question-type]{background:#eff4ff;color:#1849a9}
.zoom-label{padding-top:9px;white-space:nowrap}

/* Inspector: mo bang class, khong dua hover */
.inspector-toggle{display:none;align-items:center;gap:6px;min-height:36px;padding:7px 12px;border:1px solid #d0d5dd;border-radius:9px;background:#fff;color:#344054;font-weight:700;font-size:13px;white-space:nowrap}
.inspector-toggle[aria-expanded="true"]{background:#eaf0fe;border-color:var(--brand);color:#2142ab}
.inspector-backdrop,.inspector-close{display:none}
.inspector-panel{overscroll-behavior:contain}

@media(max-width:1050px){
 .editor-view{grid-template-columns:210px minmax(0,1fr)}
 .inspector-toggle{display:inline-flex}
 .inspector-panel{position:fixed;right:0;top:68px;bottom:0;width:min(340px,92vw);z-index:40;box-shadow:-12px 0 30px rgba(16,24,40,.18);transform:translateX(100%);visibility:hidden;transition:transform .2s ease,visibility 0s .2s}
 .inspector-panel.is-open,.inspector-panel:focus-within{transform:none;visibility:visible;transition:transform .2s ease}
 .inspector-close{display:inline-flex;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:0;background:#fff;font-size:24px;color:#475467}
 .inspector-backdrop.is-visible{display:block;position:fixed;inset:68px 0 0 0;z-index:35;background:rgba(16,24,40,.35)}
 .canvas-stage{padding:24px}
 .draft-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:720px){
 .lesson-header{height:auto;min-height:62px;padding:10px 14px;grid-template-columns:auto 1fr;gap:10px}
 .lesson-brand span{display:none}
 .header-center{grid-column:1/-1;grid-row:2}
 .lesson-title-field{width:100%}
 .header-actions{grid-column:2;grid-row:1;flex-wrap:wrap}
 .header-actions .ghost-button{padding:8px 11px;font-size:13px}
 .save-state{font-size:11px}
 .global-status{padding:7px 12px}
 .library-view{padding:34px 18px 60px}
 .library-hero{align-items:flex-start;flex-direction:column}
 .library-hero h1{font-size:31px}
 .library-toolbar{align-items:stretch}
 .draft-grid{grid-template-columns:1fr}
 .avatar-button{display:none}
 /* Soan tren dien thoai: dai slide nam ngang phia tren, trang cuon tu nhien */
 .editor-view{height:auto;min-height:calc(100vh - 115px);overflow:visible;grid-template-columns:minmax(0,1fr);grid-template-rows:auto minmax(0,1fr)}
 .slide-panel{border-right:0;border-bottom:1px solid var(--line);padding:8px 10px;overflow:visible}
 .panel-heading{padding:0 2px 6px}
 .slide-list{flex-direction:row;overflow-x:auto;overflow-y:hidden;padding:4px 2px 12px;scroll-snap-type:x proximity;-webkit-overflow-scrolling:touch}
 .slide-item{flex:0 0 118px;grid-template-columns:1fr;scroll-snap-align:start;padding:5px}
 .slide-item[aria-selected="true"]:before,.slide-item.is-current:before{left:10px;right:10px;top:auto;bottom:-7px;width:auto;height:4px}
 .slide-number{display:block;padding-top:0;text-align:left;font-size:11px;font-weight:700}
 .slide-thumb{padding:6px}
 .slide-thumb strong{font-size:9px}
 .slide-reorder{bottom:4px;right:4px}
 .slide-reorder button{min-width:30px;min-height:28px}
 .add-slide-button{display:none}
 .canvas-toolbar{padding:8px 10px}
 .block-picker>span{display:block;width:100%}
 .block-picker button{font-size:13px;min-height:40px}
 .block-picker__group{border-left:0;padding-left:0;width:100%}
 .zoom-label{display:none}
 .canvas-stage{padding:12px;overflow:visible}
 .slide-canvas{padding:22px 18px;min-height:300px;aspect-ratio:auto;width:100%}
 .slide-canvas.two-column{grid-template-columns:minmax(0,1fr)}
 .slide-canvas h1.slide-heading{font-size:22px}
 .lesson-block{padding:12px 10px}
 .inspector-panel{top:115px;width:min(360px,100vw)}
 .inspector-backdrop.is-visible{inset:115px 0 0 0}
 .inspector-toggle{position:fixed;right:12px;bottom:14px;z-index:30;min-height:48px;padding:0 16px;box-shadow:0 6px 18px rgba(16,24,40,.25);background:var(--brand);color:#fff;border-color:var(--brand-dark);border-radius:24px}
 .inspector-toggle[aria-expanded="true"]{background:#fff;color:#2142ab}
 .preview-dialog{width:100vw;height:100dvh;max-width:100vw;max-height:100dvh;border-radius:0}
 .preview-body{grid-template-columns:minmax(0,1fr);grid-template-rows:minmax(0,1fr);padding:10px;height:calc(100% - 116px)}
 .preview-canvas{grid-column:1;grid-row:1;width:100%;max-height:100%}
 .preview-nav{width:48px;height:48px;position:absolute;bottom:62px;z-index:2}
 #previewPrevious{left:12px}#previewNext{right:12px}
 .preview-header{padding:0 14px}
 .preview-footer{padding:0 14px}
 .lesson-dialog form{padding:22px 18px}
 .toast-region{left:12px;right:12px;bottom:76px}.toast{max-width:none}
}
@media(min-width:1500px){.slide-canvas{width:min(1040px,100%)}.editor-view{grid-template-columns:270px minmax(420px,1fr) 320px}}

/* Hop thoai xac nhan thay confirm() */
.lesson-confirm-dialog{width:min(440px,calc(100vw - 30px));border:0;border-radius:16px;padding:0;box-shadow:0 24px 70px rgba(16,24,40,.3);color:var(--ink);background:#fff}
.lesson-confirm-dialog>form,.lesson-confirm-dialog>div{padding:26px 26px 22px;margin:0}
.lesson-confirm-dialog__title{margin:0 0 8px;font-size:20px;line-height:1.3}
.lesson-confirm-dialog__message{margin:0;color:#475467;line-height:1.55;overflow-wrap:anywhere}
.lesson-confirm-dialog__actions{display:flex;justify-content:flex-end;flex-wrap:wrap;gap:10px;margin-top:22px}
.lesson-confirm-dialog__actions button{min-height:44px;min-width:96px}
.lesson-confirm-dialog.is-danger .lesson-confirm-dialog__title{color:#b42318}
.lesson-confirm-dialog.is-danger .lesson-confirm-dialog__actions .primary-button{background:#d92d20}
.lesson-confirm-dialog[open]{animation:toast-in .16s ease}
@media(max-width:480px){.lesson-confirm-dialog__actions{flex-direction:column-reverse}.lesson-confirm-dialog__actions button{width:100%}}

@media(pointer:coarse){.icon-button,.dialog-close{min-width:44px;min-height:44px}.inspector-tabs button{min-height:48px}.slide-actions button{min-height:44px}}
.slide-canvas{aspect-ratio:auto;min-height:495px}
.slide-canvas>*{flex-shrink:0}
.preview-canvas{min-height:min(100%,320px)}
.ghost-button,.primary-button,.danger-button{white-space:nowrap}
@media(min-width:1500px){.slide-canvas{min-height:585px}}
@media(max-width:720px){.slide-canvas{min-height:300px}}
@media(min-width:721px){.lesson-app[data-view="editor"]{display:flex;flex-direction:column;height:100vh;height:100dvh}.lesson-app[data-view="editor"] .editor-view{flex:1;height:auto;min-height:0}}

/* Banner trạng thái/khôi phục (JS dựng bằng style inline) */
#lessonBanner[hidden]{display:none!important}
#lessonBanner{position:sticky;top:68px;z-index:25;box-shadow:0 4px 14px rgba(16,24,40,.08);line-height:1.5}
#lessonBanner[data-kind="error"]{background:#fef3f2!important;color:#7a271a!important}
#lessonBanner button{min-height:40px;white-space:nowrap}
#lessonBanner button:focus-visible{outline:3px solid #155eef;outline-offset:2px}
@media(max-width:720px){#lessonBanner{top:0;margin:8px 10px!important}#lessonBanner button{flex:1 1 140px}}

/* ===== Sửa lỗi từ ảnh UI thật ===== */
/* (1) Editor câu hỏi trong inspector */
.inspector-section .lesson-question-editor__field,.lesson-question-editor .lesson-question-editor__field{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:44px;margin:0 0 10px;font-size:13px;font-weight:700;color:#475467}
.inspector-section .lesson-question-editor__field:has(>input:not([type=checkbox]):not([type=radio])),.inspector-section .lesson-question-editor__field:has(>textarea),.inspector-section .lesson-question-editor__field:has(>select){display:block}
.inspector-section .lesson-question-editor input[type=checkbox],.inspector-section .lesson-question-editor input[type=radio]{display:inline-block;width:22px;height:22px;min-height:0;margin:0;padding:0;flex:none;accent-color:var(--brand)}
.inspector-section .lesson-question-editor__type{display:none}
.inspector-section .lesson-question-editor{padding:12px;margin:0 0 12px}
.inspector-section .lesson-question-editor legend{font-size:14px;max-width:100%;white-space:normal}
.inspector-section .lesson-question-editor textarea{min-height:90px}
/* (2) công cụ khối không đè nội dung trên điện thoại */
@media(max-width:720px),(hover:none){
 .lesson-block-tools{position:static;display:none;width:max-content;margin:0 0 8px auto}
 .lesson-block.selected .lesson-block-tools,.lesson-block:focus-within .lesson-block-tools{display:flex}
 .lesson-block-tools button{min-width:44px;min-height:44px}
}
@media(max-width:720px){
 /* (3) picker một hàng cuộn ngang */
 .block-picker{flex-wrap:nowrap;overflow-x:auto;overflow-y:hidden;align-items:center;padding-bottom:4px;-webkit-overflow-scrolling:touch;scroll-snap-type:x proximity}
 .block-picker>span{display:block;width:auto;flex:none}
 .block-picker button{flex:none;white-space:nowrap;scroll-snap-align:start}
 .block-picker__group{flex:none;flex-wrap:nowrap;width:auto;border-left:1px solid var(--line);padding-left:8px;margin-left:2px}
 .canvas-toolbar{min-width:0}
 /* (4) bảng thuộc tính chừa chỗ cho nền mờ; toast nằm dưới bảng */
 .inspector-panel{width:min(320px,86vw)}
 .toast-region{z-index:30}
}
/* (6) Báo cáo */
.report-dialog{padding:0;max-width:96vw}
.report-dialog #reportBody{padding:56px 26px 26px}
.report-dialog .dialog-close{top:8px;right:8px;min-width:44px;min-height:44px;z-index:2}
.report-dialog h2{margin:0 0 6px;padding-right:48px;font-size:22px}
.report-dialog h3{font-size:16px;margin:22px 0 8px}
.report-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--line);border-radius:10px;-webkit-overflow-scrolling:touch}
.report-table{border-collapse:collapse;width:100%;min-width:520px;font-size:13px}
.report-table th,.report-table td{padding:8px 10px;text-align:left;border-bottom:1px solid #eaecf0;vertical-align:top}
.report-table th{background:#f9fafb;white-space:nowrap;font-weight:800;position:sticky;top:0}
.report-table th:first-child,.report-table td:first-child{min-width:140px;position:sticky;left:0;background:#fff}
.report-table th:first-child{background:#f9fafb}
.report-table td:not(:first-child){white-space:nowrap}
@media(max-width:720px){.report-dialog{width:100vw!important;max-height:100dvh!important;height:100dvh;border-radius:0;max-width:100vw}.report-dialog #reportBody{padding:56px 14px 24px}}

/* Báo cáo: bảng không bị cắt cột, cuộn ngang trong .report-scroll */
.report-scroll{overflow-x:auto;overflow-y:hidden;max-width:100%;width:100%}
#reportQuestions{min-width:560px}
#reportStudents{min-width:560px}
#reportQuestions th:nth-child(2),#reportQuestions td:nth-child(2){min-width:56px}
#reportQuestions th:nth-child(3),#reportQuestions td:nth-child(3){min-width:84px}
#reportQuestions th:nth-child(4),#reportQuestions td:nth-child(4),#reportQuestions th:nth-child(5),#reportQuestions td:nth-child(5){min-width:64px}
#reportQuestions th:nth-child(6),#reportQuestions td:nth-child(6){min-width:96px}
#reportQuestions td:first-child,#reportQuestions th:first-child{min-width:130px;max-width:170px;white-space:normal;overflow-wrap:anywhere}
#reportStudents td:first-child{white-space:normal}
@media(max-width:720px){
 .report-table th,.report-table td{padding:8px 12px}
 /* inspector mở: loại bỏ nội dung xuyên nền mờ */
 .lesson-app:has(.inspector-backdrop.is-visible) .slide-reorder,
 .lesson-app:has(.inspector-backdrop.is-visible) .lesson-block-tools,
 .lesson-app:has(.inspector-backdrop.is-visible) .inspector-toggle{display:none!important}
 .inspector-backdrop.is-visible{background:rgba(16,24,40,.6)}
 .lesson-app:has(.inspector-panel.is-open) ~ .toast-region,.lesson-app:has(.inspector-backdrop.is-visible) ~ .toast-region{z-index:10;opacity:.0;pointer-events:none}
 .lesson-app:has(.inspector-backdrop.is-visible) .slide-panel{position:relative;z-index:1}
}
/* N3c — nhóm kiến thức (cây LQS) trong bảng thuộc tính và báo cáo */
.lesson-taxonomy{margin:14px 0 4px}
.lesson-taxonomy-panel{margin:12px 0;padding:12px;border:1px solid var(--line,#e4e7ec);border-radius:10px;background:#fcfcfd;font-size:13px}
.lesson-taxonomy-panel__status{margin:0 0 8px;font-size:12px;color:#667085}
.lesson-taxonomy-panel__status[hidden]{display:none}
.lesson-taxonomy-panel[data-state="error"] .lesson-taxonomy-panel__status{color:#b42318}
.lesson-taxonomy-panel__retry{margin-left:6px;padding:4px 10px;font-size:12px}
.inspector-section .lesson-taxonomy-panel .lt-taxchip-input{margin-top:0}
.inspector-section .lesson-taxonomy-panel .lt-taxchip-text{max-width:min(60vw,200px)}
.report-taxonomy{margin-top:18px}
#reportTaxonomyTable{min-width:560px}
#reportTaxonomyTable tr[data-weak="true"] td:first-child{color:#b42318;font-weight:700}
.report-taxonomy__note{font-size:13px;color:#475467;margin:10px 0 0}

/* ===== YC-17/22: thống nhất giao diện giáo viên (xanh cobalt, logo lopta.vn, focus rõ) ===== */
.lesson-header{grid-template-columns:minmax(0,auto) 1fr auto}
.lesson-brand{gap:12px;min-width:0}
.back-to-teacher{display:inline-flex;align-items:center;min-height:36px;padding:0 12px;border:1px solid var(--lt-color-border-input,#cbd5e1);border-radius:9px;color:var(--lt-color-cobalt-700,#2142ab);background:#fff;font-weight:700;font-size:14px;text-decoration:none;white-space:nowrap}
.back-to-teacher:hover{background:var(--lt-color-cobalt-50,#eaf0fe);border-color:var(--lt-color-cobalt-300,#7d9cf0)}
.brand-logo{height:26px;width:auto;display:block;flex:none}
.brand-product{font-size:12px;color:var(--muted);padding-left:12px;border-left:1px solid var(--line);white-space:nowrap}
.avatar-button{cursor:default;user-select:none}
.primary-button:hover{background:var(--brand-dark)}
.primary-button:focus-visible{box-shadow:0 0 0 2px #fff}
.inspector-tabs button.active{color:var(--brand);box-shadow:inset 0 -2px var(--brand)}
.lesson-confirm-dialog.is-danger .lesson-confirm-dialog__actions .primary-button{background:var(--lt-color-red-500,#d13c3c)}
/* Ô tìm kiếm: viền focus nằm trên khung, không để input tự bỏ outline */
.search-field input{outline:0}
.search-field:focus-within{outline:3px solid var(--focus);outline-offset:2px;border-color:var(--focus)}
.search-field input:focus-visible{outline:0}
:where(button,a,input,textarea,select,summary,[tabindex],[role=button]):focus-visible{outline:3px solid var(--focus);outline-offset:2px}
.lesson-title-field input:focus-visible{outline:3px solid var(--focus);outline-offset:1px}
@media(max-width:720px){
 .lesson-header{grid-template-columns:minmax(0,1fr) auto}
 .brand-product{display:none}
 .back-to-teacher{padding:0 10px;font-size:13px}
 .brand-logo{height:22px}
 .lesson-brand{flex-wrap:nowrap}
}
@media(max-width:420px){.back-to-teacher{font-size:12px;padding:0 8px}.brand-logo{display:none}}

/* ===== YC-35/36: thư viện (skeleton, thẻ xem trước), breadcrumb đầu trang, lỗi xuất bản ===== */
/* Thanh đầu trang: "← Trang giáo viên / ← Thư viện" + breadcrumb lopta.vn › Bài giảng › [tên] */
.lesson-app[data-view="editor"] .library-only{display:none}
.lesson-crumbs{display:flex;align-items:center;gap:8px;min-width:0;color:var(--muted);font-size:13px}
.lesson-crumbs .crumb{white-space:nowrap;font-weight:600;color:#344054}
.lesson-crumbs .crumb-sep{color:#98a2b3}
button.back-to-teacher{font:inherit;font-weight:700;font-size:14px;cursor:pointer}
.lesson-title-field input{text-align:left;font-size:16px}
.lesson-title-field{width:min(520px,45vw)}
.header-center{gap:0}
@media(max-width:720px){
 .lesson-brand{gap:8px}
 .lesson-brand .lesson-crumbs .crumb,.lesson-brand .lesson-crumbs .crumb-sep{display:inline}
 .lesson-title-field{width:100%}
 .lesson-title-field input{text-align:left}
 button.back-to-teacher{min-height:44px;padding:0 10px;font-size:13px}
}
@media(max-width:420px){button.back-to-teacher{font-size:12px;padding:0 8px}}
/* Trạng thái "đang kiểm tra quyền": một dòng mảnh, tự biến mất khi xong (:empty) */
.global-status.is-loading{padding:4px 24px;font-size:12px;background:transparent;color:var(--muted);text-align:left}
.global-status.is-loading::before{content:"";display:inline-block;width:10px;height:10px;margin-right:8px;border:2px solid #b2c4f5;border-top-color:var(--brand);border-radius:50%;vertical-align:-1px;animation:ls-spin .8s linear infinite}
@keyframes ls-spin{to{transform:rotate(360deg)}}

/* Skeleton thẻ bài giảng khi đang tải */
.draft-card.is-skeleton{pointer-events:none}
.draft-card.is-skeleton:hover{transform:none;box-shadow:none;border-color:var(--line)}
.draft-card.is-skeleton .draft-cover,.sk{background:linear-gradient(90deg,#eef1f6 25%,#f8fafc 50%,#eef1f6 75%);background-size:200% 100%;animation:ls-shimmer 1.3s linear infinite}
.sk{display:block;border-radius:6px}
.sk-title{height:16px;width:70%;margin-bottom:12px}.sk-meta{height:11px;width:45%;margin-bottom:18px}.sk-button{height:38px;width:100%;border-radius:9px}
@keyframes ls-shimmer{to{background-position:-200% 0}}

/* Thẻ bài giảng: xem trước tối giản, bấm cả thẻ để soạn */
.draft-card.is-clickable{cursor:pointer}
.draft-cover{height:96px;padding:12px}
.draft-cover-icon{font-size:38px;line-height:1;color:var(--brand);opacity:.85}
.draft-cover-slide{width:78%;max-height:100%;overflow:hidden;background:#fff;border-radius:6px;box-shadow:0 5px 14px rgba(16,24,40,.12);padding:12px 14px;font-weight:800;font-size:15px;line-height:1.3;color:var(--ink);display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow-wrap:anywhere}
.draft-card-actions .primary-button,.draft-card-actions .ghost-button{min-height:40px}
@media(max-width:720px){.draft-card-actions .primary-button,.draft-card-actions .ghost-button{min-height:44px}}

/* Hộp thoại xuất bản: danh sách lỗi có nút "Đi tới khối" */
.publish-problems{margin-top:12px;padding:12px 14px;border:1px solid #fecdca;border-left:4px solid #d92d20;border-radius:10px;background:#fef3f2;color:#7a271a;font-size:13px}
.publish-problems>strong{display:block;margin-bottom:6px;color:#b42318;font-size:14px}
.publish-problems ul{margin:0;padding:0;list-style:none;display:grid;gap:8px;max-height:min(40vh,320px);overflow:auto}
.publish-problems li{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:6px 12px;padding:6px 0;border-top:1px solid #fecdca;line-height:1.45}
.publish-problems li:first-child{border-top:0}
.publish-problems li>span{flex:1 1 220px;min-width:0;overflow-wrap:anywhere}
.issue-goto{flex:none;min-height:36px;padding:0 12px;border:1px solid #d92d20;border-radius:8px;background:#fff;color:#b42318;font-weight:700;font-size:13px}
.issue-goto:hover{background:#fff3f2}
@media(max-width:720px){.issue-goto{min-height:44px}}
#removeEmptyBlocks{margin-top:10px}
@media(max-width:560px){.lesson-app[data-view="editor"] .lesson-crumbs{display:none!important}}

/* YC-45 — hộp thoại Xuất bản & Giao bài */
#confirmAssignment{margin-top:22px}
.assign-form-fields{display:block}
.assignment-section.is-assigned .assign-form-fields,.assignment-section.is-assigned #publishedBanner{display:none}
.assigned-card{display:flex;flex-direction:column;gap:12px;padding:14px 16px;font-size:15px}
.assigned-card__text small{display:block;margin-top:3px;font-size:12px;font-weight:500;color:#475467;overflow-wrap:anywhere}
.assigned-card__actions{display:flex;flex-wrap:wrap;gap:8px}
.assigned-card__actions button{flex:1 1 auto;min-height:40px}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid #2f5fe0;outline-offset:2px}

/* YC-46 — nhóm bài và huy hiệu trạng thái trong thư viện */
.draft-group-title{grid-column:1/-1;margin:10px 0 0;font-size:15px;color:#344054;letter-spacing:.01em;border-bottom:1px solid #e4e7ec;padding-bottom:6px}
.draft-group-title:first-child{margin-top:0}
.status-badge{display:inline-block;padding:2px 9px;border-radius:999px;font-size:12px;font-weight:700;background:#f2f4f7;color:#475467}
.status-badge--assigned{background:#ecfdf3;color:#067647}
.status-badge--published{background:#eaf0fe;color:#2142ab}