:root{font-family:Inter,"Noto Sans TC","Microsoft JhengHei",system-ui,sans-serif;color-scheme:light;--bg:#f5f8fb;--surface:#fff;--surface2:#edf5fa;--text:#0b2144;--muted:#667891;--line:#dce7ef;--blue:#087db0;--blue2:#257ee7;--blue-light:#e5f5fc;--shadow:0 10px 30px rgba(14,48,82,.07);--danger:#df4249;--green:#128965}
:root[data-theme=dark]{color-scheme:dark;--bg:#101a2a;--surface:#18283d;--surface2:#20364d;--text:#eff6ff;--muted:#a7bad0;--line:#34516a;--blue:#3eb8e4;--blue2:#4b91f5;--blue-light:#173b52;--shadow:0 10px 30px rgba(0,0,0,.18);--danger:#ff7278;--green:#62d0a4}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text)}button,input,select{font:inherit}button{cursor:pointer}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,[contenteditable]:focus-visible,summary:focus-visible{outline:3px solid var(--blue2);outline-offset:2px}.hidden{display:none!important}.muted,.hint{color:var(--muted)}.small{font-size:.83rem}.hint{font-size:.78rem;line-height:1.45;margin:.35rem 0 0}.eyebrow{letter-spacing:.16em;color:var(--blue);font-size:.7rem;font-weight:800;margin:0 0 .25rem}.topbar{height:82px;background:var(--surface);border-bottom:1px solid var(--line);display:flex;align-items:center;gap:18px;padding:0 clamp(18px,2.5vw,46px);position:sticky;top:0;z-index:20}.brand{text-decoration:none;font-size:clamp(1.3rem,2.1vw,2rem);font-weight:850;letter-spacing:.02em;white-space:nowrap}.brand-mark{display:inline-grid;place-items:center;color:var(--blue2);font-size:1.1em;margin-right:.25em}.searchbox{display:flex;align-items:center;gap:12px;background:var(--bg);border:1px solid var(--line);border-radius:14px;padding:0 18px;flex:1;max-width:900px;height:48px;margin-left:auto;color:var(--muted);font-size:1.4rem}.searchbox input{border:0;background:transparent;color:var(--text);outline:0;width:100%;font-size:1rem}.searchbox input::placeholder,input::placeholder{color:var(--muted);opacity:.9}.icon-btn{width:44px;height:44px;display:inline-grid;place-items:center;border:1px solid var(--line);border-radius:12px;background:var(--surface);color:var(--text);font-size:1.35rem}.icon-btn:hover,.secondary-btn:hover,.ghost-btn:hover{background:var(--blue-light)}.primary-btn,.small-primary,.pill-btn{background:linear-gradient(120deg,var(--blue),var(--blue2));color:#fff;border:0;border-radius:12px;font-weight:750;box-shadow:0 4px 12px rgba(20,112,180,.14)}.primary-btn{padding:13px 20px}.primary-btn:hover,.small-primary:hover,.pill-btn:hover{filter:brightness(1.08)}.secondary-btn{display:inline-flex;justify-content:center;align-items:center;gap:7px;background:var(--surface);color:var(--text);border:1px solid var(--line);border-radius:11px;padding:11px 14px;text-decoration:none;font-weight:650}.ghost-btn{border:0;background:transparent;color:var(--muted);padding:8px 10px;border-radius:9px}.danger-text{color:var(--danger)}.small-primary{font-size:.82rem;padding:9px 12px}.pill-btn{padding:9px 15px;border-radius:999px}
.student-layout{display:grid;grid-template-columns:240px minmax(0,1fr);min-height:calc(100vh - 82px)}.category-nav{border-right:1px solid var(--line);background:var(--surface);padding:24px 14px;position:sticky;top:82px;height:calc(100vh - 82px);overflow:auto}.category-btn{display:flex;align-items:center;gap:12px;width:100%;text-align:left;border:0;background:transparent;color:var(--muted);padding:14px 15px;border-radius:13px;font-weight:700;margin-bottom:5px}.category-btn.active{background:linear-gradient(120deg,var(--blue),#2896c4);color:white}.category-btn:hover:not(.active){background:var(--blue-light);color:var(--text)}.category-btn .cat-icon{font-size:1.25rem}.student-main{width:min(100%,1400px);margin:0 auto;padding:22px clamp(18px,2vw,38px) 80px}.section-heading{display:flex;align-items:end;justify-content:space-between;margin:10px 2px 22px}.section-heading h1{font-size:clamp(1.5rem,2.4vw,2.2rem);margin:0}.live-badge{color:var(--green);background:rgba(18,137,101,.1);border-radius:999px;padding:8px 12px;font-size:.8rem;font-weight:700}.spotlight-bar{background:var(--blue-light);border-radius:16px;color:var(--text);display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 18px;margin-bottom:18px;font-weight:700}.message-list{display:grid;gap:17px}.message-card{display:grid;grid-template-columns:142px minmax(0,1fr) 132px;gap:18px;align-items:start;background:var(--surface);border:1px solid var(--line);border-radius:19px;box-shadow:var(--shadow);padding:22px;scroll-margin-top:120px}.message-card.spotlit{border:2px solid var(--blue);animation:glow 1.3s ease-in-out 2}@keyframes glow{50%{box-shadow:0 0 0 8px rgba(30,168,214,.2)}}.message-number{font-size:clamp(3.7rem,5.5vw,5.6rem);line-height:1;letter-spacing:-.06em;font-weight:900;color:var(--text);font-variant-numeric:tabular-nums}.message-main{min-width:0}.message-meta{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:12px}.category-tag{display:inline-block;background:var(--blue-light);color:var(--blue);border-radius:10px;padding:6px 11px;font-size:.82rem;font-weight:750}.time{font-size:.79rem;color:var(--muted)}.message-content{font-size:1.1rem;line-height:1.65;overflow-wrap:anywhere}.message-content p{margin:0 0 .7em}.message-content p:last-child{margin-bottom:0}.message-content a,.note-content a{color:var(--blue2);text-decoration:underline}.message-content img{display:block;width:min(100%,900px);max-height:350px;object-fit:cover;border-radius:12px;cursor:zoom-in}.message-content iframe{width:min(100%,860px);aspect-ratio:16/9;border:0;border-radius:12px}.note-content{font-size:.96rem;line-height:1.6;margin-top:12px;overflow-wrap:anywhere}.message-copy{align-self:center;min-width:115px}.locked-message{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.locked-message input{min-width:180px;max-width:280px;flex:1;border:1px solid var(--line);border-radius:10px;padding:11px;background:var(--surface);color:var(--text)}.locked-message .lock-label{font-weight:700}.empty-state{text-align:center;background:var(--surface);color:var(--muted);border:1px dashed var(--line);border-radius:16px;padding:50px 20px}
.modal{border:1px solid var(--line);border-radius:20px;background:var(--surface);color:var(--text);box-shadow:0 25px 100px rgba(0,0,0,.25);width:min(92vw,550px);padding:28px;text-align:center}.modal::backdrop{background:rgba(6,20,39,.65)}.modal h2{margin:5px 0 8px}.modal p{color:var(--muted)}.modal-close{position:absolute;right:17px;top:12px;border:0;background:transparent;color:var(--muted);font-size:1.9rem}.qr-code{min-height:280px;display:grid;place-items:center;background:#fff;border-radius:12px;padding:20px;width:max-content;max-width:100%;margin:18px auto}.qr-code img,.qr-code canvas{max-width:100%;height:auto}.qr-url{display:block;color:var(--blue2);overflow-wrap:anywhere;font-size:.88rem}.modal-actions{display:flex;gap:10px;justify-content:center;margin-top:20px}.toast{position:fixed;bottom:24px;left:50%;transform:translate(-50%,30px);background:#10243d;color:white;padding:12px 20px;border-radius:10px;box-shadow:var(--shadow);opacity:0;pointer-events:none;transition:.2s;z-index:100}.toast.show{opacity:1;transform:translate(-50%,0)}
.admin-topbar{justify-content:space-between}.header-actions{display:flex;align-items:center;gap:9px}.admin-layout{display:grid;grid-template-columns:235px minmax(0,1fr) minmax(0,1fr);gap:14px;padding:16px;min-height:calc(100vh - 82px)}.panel{background:var(--surface);border:1px solid var(--line);border-radius:16px;min-width:0;box-shadow:var(--shadow)}.admin-categories{padding:16px 11px}.admin-editor,.admin-list{padding:16px;align-self:start}.panel-title{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:17px}.panel-title h2{font-size:1.45rem;margin:0}.admin-category-list{display:grid;gap:4px}.admin-cat-row{display:flex;align-items:center;gap:3px;border-radius:11px;padding:5px}.admin-cat-row.active{background:var(--blue-light)}.admin-cat-name{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;text-align:left;flex:1;border:0;background:transparent;color:var(--text);font-weight:650;padding:9px 5px}.mini-icon{border:0;background:transparent;color:var(--muted);border-radius:8px;width:28px;height:30px;display:grid;place-items:center}.mini-icon:hover{background:var(--surface2);color:var(--text)}.mini-icon.danger:hover{color:var(--danger)}.panel-foot{border-top:1px solid var(--line);margin-top:20px;padding-top:10px;display:flex;justify-content:space-between}.type-tabs{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:15px}.type-tabs button{border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:10px;padding:10px 5px;font-weight:700}.type-tabs button.active{background:var(--blue-light);border-color:#9ed9ed;color:var(--blue)}.label{display:block;font-size:.9rem;font-weight:750;margin:15px 0 7px}.field{display:block;font-size:.9rem;font-weight:750;margin:13px 0}.field input,.list-tools input,.list-tools select{display:block;width:100%;padding:11px 12px;margin-top:7px;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:10px}.richbox{border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--surface)}.format-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:3px;padding:7px;border-bottom:1px solid var(--line)}.format-toolbar button,.format-toolbar select{border:0;background:transparent;color:var(--text);height:32px;min-width:32px;border-radius:6px;font-weight:750}.format-toolbar button:hover,.format-toolbar select:hover{background:var(--blue-light)}.format-toolbar select{border:1px solid var(--line);margin-right:5px;min-width:67px}.rich-editor{min-height:135px;max-height:330px;overflow:auto;padding:12px;line-height:1.55;outline:none;overflow-wrap:anywhere}.rich-editor:empty:before{content:attr(data-placeholder);color:var(--muted)}.rich-editor.note-editor{min-height:65px;max-height:180px}.rich-editor a{color:var(--blue2)}.selected-categories{display:flex;gap:5px;flex-wrap:wrap;min-height:30px}.selected-chip{display:inline-flex;align-items:center;gap:3px;color:var(--blue);background:var(--blue-light);padding:5px 8px;border-radius:8px;font-size:.85rem;font-weight:700}.selected-chip button{border:0;background:none;color:inherit;font-size:1.1rem;line-height:1}.picker{position:relative;margin-top:7px}.picker summary{list-style:none;width:max-content;cursor:pointer;border:1px solid var(--line);border-radius:9px;padding:8px 11px;font-weight:650}.picker summary::-webkit-details-marker{display:none}.picker-options{position:absolute;top:100%;left:0;z-index:10;min-width:220px;max-height:280px;overflow:auto;background:var(--surface);border:1px solid var(--line);border-radius:10px;box-shadow:var(--shadow);padding:9px}.picker-options label{display:flex;align-items:center;gap:8px;padding:6px;cursor:pointer}.password-block{border:1px solid var(--line);border-radius:12px;padding:10px 13px;margin-top:15px}.switch-row{display:flex;align-items:center;gap:10px;font-weight:750;cursor:pointer}.switch-row input{position:absolute;opacity:0}.switch-ui{height:23px;width:43px;background:#a4b3c0;border-radius:20px;position:relative;margin-left:auto}.switch-ui:after{content:"";position:absolute;background:#fff;width:17px;height:17px;top:3px;left:3px;border-radius:50%;transition:.2s}.switch-row input:checked+.switch-ui{background:var(--blue)}.switch-row input:checked+.switch-ui:after{left:23px}.publish-actions{display:flex;gap:9px;margin-top:12px}.publish-actions .primary-btn{flex:1}.paste-zone{position:relative;border:2px dashed var(--line);background:var(--bg);border-radius:12px;min-height:145px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;font-size:1.5rem;color:var(--blue);cursor:pointer}.paste-zone strong{font-size:.9rem}.paste-zone span{font-size:.75rem;color:var(--muted)}.paste-zone input{position:absolute;inset:0;opacity:0;cursor:pointer;width:100%}.media-preview{margin:10px 0}.media-preview img{max-width:100%;max-height:200px;border-radius:10px}.media-preview iframe{width:100%;aspect-ratio:16/9;border:0;border-radius:10px}.list-tools{display:flex;gap:8px;margin-bottom:14px}.list-tools input{margin:0;flex:1;min-width:0}.list-tools select{margin:0;width:140px}.count-badge{font-size:.78rem;color:var(--muted);background:var(--surface2);padding:5px 8px;border-radius:99px}.admin-message-list{display:grid;gap:10px;max-height:calc(100vh - 190px);overflow:auto;padding:2px}.admin-msg{border:1px solid var(--line);border-radius:13px;padding:12px;background:var(--surface);display:grid;grid-template-columns:58px minmax(0,1fr);gap:11px}.admin-msg.dragging{opacity:.4}.admin-msg-number{font-size:2.6rem;font-weight:900;letter-spacing:-.06em;line-height:1.1}.admin-msg-body{min-width:0}.admin-msg-top{display:flex;justify-content:space-between;align-items:start;gap:7px}.admin-msg-tags{display:flex;flex-wrap:wrap;gap:4px}.admin-msg-preview{font-size:.86rem;color:var(--muted);line-height:1.45;max-height:4.35em;overflow:hidden;overflow-wrap:anywhere;margin:6px 0}.admin-msg-preview img{height:80px;max-width:160px;object-fit:cover;border-radius:7px}.admin-actions{display:flex;gap:4px;margin-left:auto;flex-wrap:wrap;justify-content:flex-end}.admin-actions button{height:30px;width:30px;display:grid;place-items:center;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:7px}.admin-actions button:hover{background:var(--blue-light)}.admin-actions button.focus-action{background:var(--blue);color:#fff;border-color:var(--blue)}.admin-actions button.delete-action{color:var(--danger)}.admin-msg-lock{font-size:.73rem;color:var(--muted)}.auth-screen{min-height:100vh;display:grid;place-items:center;padding:20px}.auth-card{width:min(100%,430px);background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:32px;box-shadow:var(--shadow)}.auth-symbol{font-size:2.6rem;color:var(--blue2)}.auth-card h1{margin:10px 0 4px}.auth-card p{color:var(--muted)}.auth-card .wide{width:100%;margin-top:10px}.form-error{color:var(--danger)!important;min-height:1.3em}.admin-mobile-tabs{display:none}
@media(max-width:1100px){.admin-layout{grid-template-columns:200px minmax(0,1fr) minmax(0,1fr);gap:9px;padding:9px}.admin-editor,.admin-list{padding:12px}.admin-categories{padding:12px 5px}.panel-title h2{font-size:1.18rem}.admin-msg-top{display:block}.admin-actions{margin:7px 0 0;justify-content:flex-start}.header-actions .secondary-btn{font-size:.82rem;padding:9px}.student-layout{grid-template-columns:195px minmax(0,1fr)}.message-card{grid-template-columns:100px minmax(0,1fr) 105px}}
@media(max-width:780px){.topbar{height:auto;min-height:66px;flex-wrap:wrap;padding:9px 14px;gap:8px}.brand{font-size:1.35rem}.searchbox{order:3;max-width:none;flex-basis:100%;height:42px}.student-layout{display:block}.category-nav{position:sticky;top:105px;height:auto;padding:9px 12px;overflow-x:auto;z-index:9}.category-nav>div{display:flex;gap:7px;width:max-content}.category-btn{margin:0;white-space:nowrap;width:auto;padding:10px 13px}.student-main{padding:15px 12px 60px}.section-heading{margin-top:12px}.message-card{grid-template-columns:74px minmax(0,1fr);gap:10px;padding:16px}.message-number{font-size:3.7rem}.message-copy{grid-column:2;justify-self:end;min-width:105px}.message-content{font-size:1rem}.message-content img{max-height:300px}.spotlight-bar{font-size:.84rem}.admin-topbar .brand{flex:1}.header-actions{gap:4px}.header-actions .secondary-btn{font-size:0;width:37px;height:37px;padding:0}.header-actions .secondary-btn::first-letter{font-size:1rem}.header-actions .ghost-btn{font-size:.78rem}.admin-mobile-tabs{display:flex;position:sticky;top:56px;z-index:15;background:var(--surface);border-bottom:1px solid var(--line)}.admin-mobile-tabs button{flex:1;padding:12px 5px;border:0;background:transparent;color:var(--muted);font-weight:700}.admin-mobile-tabs button.active{color:var(--blue);border-bottom:3px solid var(--blue)}.admin-layout{display:block;padding:10px}.admin-layout>.panel{display:none}.admin-layout>.panel.mobile-active{display:block}.admin-message-list{max-height:none}.admin-categories{min-height:60vh}.admin-list{min-height:60vh}}
@media(max-width:460px){.message-card{grid-template-columns:62px minmax(0,1fr);padding:13px}.message-number{font-size:3.2rem}.message-meta{align-items:start;flex-direction:column;gap:3px}.spotlight-bar{flex-wrap:wrap}.list-tools select{width:105px}.modal-actions{flex-direction:column}}

/* Classroom card layout and persistent Spotlight state */
.message-card{grid-template-columns:auto minmax(0,1fr);gap:10px 18px}
.message-number{grid-column:1;grid-row:1;color:var(--blue2)}
.student-page .message-card.pinned .message-number{color:#b86c00}
:root[data-theme=dark] .student-page .message-card.pinned .message-number{color:#ffc36a}
.message-main{display:contents}
.message-meta{grid-column:2;grid-row:1;justify-content:flex-end;align-self:start;flex-wrap:wrap;margin:0}
.message-tags{display:inline-flex;flex-wrap:wrap;gap:5px;margin-right:auto}
.copy-count{color:var(--muted);font-size:.82rem;white-space:nowrap}
.message-content,.note-content,.locked-message{grid-column:1/-1;min-width:0}
.message-content img{width:auto;max-width:100%;max-height:480px;object-fit:contain}
.message-content iframe{width:min(100%,960px)}
.message-footer{grid-column:1/-1;display:flex;align-items:end;justify-content:space-between;gap:10px;min-height:34px;margin-top:8px}
.message-copy{align-self:end;min-width:105px;margin-left:auto}
.message-card.spotlit,.admin-msg.spotlit{border:2px solid #a45cff;box-shadow:inset 0 0 12px rgba(149,77,255,.2),0 0 18px rgba(149,77,255,.7);animation:purpleGlow 1.75s ease-in-out infinite}
@keyframes purpleGlow{0%,100%{box-shadow:inset 0 0 10px rgba(149,77,255,.2),0 0 0 2px rgba(149,77,255,.35),0 0 16px rgba(149,77,255,.65)}50%{box-shadow:inset 0 0 16px rgba(149,77,255,.3),0 0 0 4px rgba(149,77,255,.4),0 0 25px rgba(149,77,255,.9)}}
.admin-actions button.focus-action.active{background:#8b4ee5;border-color:#8b4ee5;color:#fff}
.clear-spotlight{width:100%;margin:-4px 0 12px;color:#7a35cf;border-color:#a45cff}

/* Keep every category action inside its own panel. */
@media(min-width:1101px){.admin-layout{width:100%;grid-template-columns:clamp(270px,20vw,320px) minmax(0,1fr) minmax(0,1fr);gap:16px;padding:16px}.admin-categories{padding:16px 12px}}
.admin-cat-row{display:grid;grid-template-columns:minmax(0,1fr) 100px;width:100%;min-width:0;overflow:visible;gap:8px;align-items:center}
.admin-cat-name{min-width:0;max-width:100%;white-space:normal;overflow-wrap:anywhere;text-overflow:clip;line-height:1.4;padding:9px 2px}
.admin-cat-actions,.admin-cat-row>div{display:grid;grid-template-columns:repeat(3,32px);width:100px;align-items:center;gap:2px}
.admin-cat-actions button,.admin-cat-row>div>button{width:32px;min-width:0;max-width:32px;height:32px;flex:0 0 32px;padding:0;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:7px;display:grid;place-items:center}
.admin-cat-actions button:hover{background:var(--surface2)}
.admin-cat-actions button.danger:hover{color:var(--danger)}
.picker summary{width:100%;text-align:left}
.picker-options{left:0;right:0;width:100%;min-width:0;max-width:none}
.picker-options label{display:grid;grid-template-columns:22px minmax(0,1fr);justify-items:start;text-align:left;white-space:normal;overflow-wrap:anywhere;gap:10px}
.picker-options input{margin:0}
.admin-list .list-tools select{width:165px}

/* Searchable emoji palette for both rich text editors. */
.emoji-picker{width:min(92vw,720px);max-height:min(80vh,680px);border:1px solid var(--line);border-radius:18px;background:var(--surface);color:var(--text);box-shadow:0 25px 100px rgba(0,0,0,.28);padding:16px}
.emoji-picker::backdrop{background:rgba(6,20,39,.48)}
.emoji-head{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:1.05rem;margin-bottom:10px}
.emoji-close{border:0;background:transparent;color:var(--muted);font-size:1.8rem;line-height:1}
.emoji-tabs{display:flex;justify-content:space-between;gap:3px;border-bottom:1px solid var(--line);overflow:auto}
.emoji-tabs button{min-width:43px;padding:9px 5px;border:0;border-bottom:3px solid transparent;background:transparent;color:var(--muted);font-size:1.15rem}
.emoji-tabs button.active{border-bottom-color:var(--green);color:var(--text)}
.emoji-search{width:100%;margin:12px 0;padding:11px 13px;border:1px solid var(--line);border-radius:10px;background:var(--surface);color:var(--text)}
.emoji-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(43px,1fr));gap:3px;max-height:350px;overflow:auto;align-content:start}
.emoji-grid button{height:43px;border:0;border-radius:8px;background:transparent;font-size:1.65rem;line-height:1}
.emoji-grid button:hover,.emoji-grid button:focus-visible{background:var(--blue-light)}

@media(max-width:1100px) and (min-width:781px){.admin-mobile-tabs{display:flex;position:sticky;top:82px;z-index:15;background:var(--surface);border-bottom:1px solid var(--line)}.admin-mobile-tabs button{flex:1;padding:12px 5px;border:0;background:transparent;color:var(--muted);font-weight:700}.admin-mobile-tabs button.active{color:var(--blue);border-bottom:3px solid var(--blue)}.admin-layout{display:block;padding:12px}.admin-layout>.panel{display:none}.admin-layout>.panel.mobile-active{display:block}.admin-categories,.admin-editor,.admin-list{padding:18px}.admin-message-list{max-height:none}}
@media(max-width:780px){.message-card{grid-template-columns:74px minmax(0,1fr)}.message-meta{flex-direction:column;align-items:flex-end}.message-tags{margin:0}.message-copy{grid-column:auto}.emoji-picker{padding:10px}.emoji-tabs button{min-width:36px}.emoji-grid{grid-template-columns:repeat(auto-fill,minmax(39px,1fr))}}
.admin-layout>.panel{max-width:100%;min-width:0}
.admin-editor .type-tabs{min-width:0}
.admin-list .panel-title{flex-wrap:wrap}
.admin-list .list-tools{flex-wrap:wrap}
.admin-list .list-tools input{flex:1 1 160px}
.admin-list .list-tools select{flex:0 1 165px;max-width:100%}
.admin-message-list{padding:10px;gap:18px}
.admin-posted{margin:8px 0;line-height:1.5}
.pinned-tag{display:inline-flex;align-items:center;gap:4px;padding:5px 9px;border-radius:9px;background:#fff1c9;color:#80520a;font-size:.78rem;font-weight:750}
.admin-actions button.pin-action.active{background:#fff1c9;border-color:#e7b448;color:#80520a}
:root[data-theme=dark] .pinned-tag,:root[data-theme=dark] .admin-actions button.pin-action.active{background:#493911;color:#ffe29b}

/* Category groups and classroom controls */
.mobile-search-toggle,.mobile-category-toggle{display:none}
.hide-all-categories{width:100%;margin:-2px 0 12px}
.group-toolbar{display:flex;justify-content:space-between;align-items:center;gap:8px;padding:10px 5px;border-top:1px solid var(--line);color:var(--muted)}
.admin-group{border:1px solid var(--line);border-radius:10px;background:var(--surface);min-width:0;margin-bottom:4px}
.admin-group summary{display:flex;align-items:center;justify-content:space-between;gap:5px;padding:6px;cursor:pointer;font-weight:750;list-style:none}
.admin-group summary::-webkit-details-marker,.student-group summary::-webkit-details-marker{display:none}
.admin-group summary:before{content:'▸';color:var(--muted);margin-right:3px}
.admin-group[open] summary:before{content:'▾'}
.group-name{flex:1;min-width:0;overflow-wrap:anywhere}
.group-name small{color:var(--muted);font-weight:600}
.group-actions{display:grid;grid-template-columns:repeat(3,29px);gap:2px;flex:0 0 auto}
.group-actions button{width:29px;height:29px;border:1px solid var(--line);background:var(--surface);color:var(--text);border-radius:7px;display:grid;place-items:center;padding:0}
.group-actions button:hover{background:var(--blue-light)}
.admin-group-list{padding:4px 3px 7px 9px;border-top:1px solid var(--line)}
.group-empty{font-size:.77rem;color:var(--muted);padding:8px}
.group-picker-dialog{width:min(94vw,600px)}
.group-picker-options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px;max-height:50vh;overflow:auto;text-align:left;margin:15px 0}
.group-picker-options label{display:flex;align-items:center;gap:8px;padding:8px;border:1px solid var(--line);border-radius:8px;cursor:pointer;min-width:0;overflow-wrap:anywhere}
.group-picker-options input{accent-color:var(--blue)}
.student-group{border-radius:12px;margin:6px 0}
.student-group summary{list-style:none;display:flex;align-items:center;justify-content:space-between;padding:12px 15px;cursor:pointer;color:var(--text);font-weight:800;background:var(--surface2);border-radius:10px}
.student-group summary:after{content:'▸';color:var(--muted)}
.student-group[open] summary:after{content:'▾'}
.student-group-list{border-left:2px solid var(--line);margin:7px 0 10px 14px;padding-left:7px}
.student-group-list .category-btn{padding:10px 9px}
.bulk-actions{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin:-4px 0 12px}
.bulk-actions .secondary-btn{width:100%;margin:0;padding:10px 5px;min-width:0;text-align:center}
.bulk-actions button:disabled{opacity:.45;cursor:default}

/* Message card heading, separator and top-right copy action */
.message-card{grid-template-columns:auto minmax(0,1fr) auto;grid-template-rows:auto auto auto auto auto;column-gap:14px;row-gap:10px}
.message-card::before{content:'';grid-column:1/-1;grid-row:2;border-bottom:1px solid #b7bec8;align-self:center}
.message-number{grid-column:1;grid-row:1;align-self:center}
.message-meta{grid-column:2;grid-row:1;align-self:start;justify-content:flex-start}
.message-tags{margin:0}
.message-card-tools{grid-column:3;grid-row:1;display:flex;flex-direction:column;align-items:flex-end;gap:8px;min-width:105px}
.message-card-tools .copy-count{font-size:.8rem}
.message-card-tools .message-copy{margin:0;min-width:105px;padding:10px 12px}
.message-content,.locked-message{grid-column:1/-1;grid-row:3}
.note-content{grid-column:1/-1;grid-row:4;margin-top:0}
.message-footer{grid-column:1/-1;grid-row:5;margin-top:0}
@media(max-width:780px){.category-nav{max-height:230px;overflow-y:auto}.category-nav>div{display:block;width:auto}.category-btn{width:100%;text-align:left}.student-group-list .category-btn{width:100%}.message-card{grid-template-columns:auto minmax(0,1fr) auto}.message-number{font-size:clamp(2.7rem,11vw,3.7rem)}.message-meta{align-items:flex-start}.message-card-tools{min-width:80px}.message-card-tools .message-copy{min-width:80px;padding:8px 9px}.message-card-tools .copy-count{font-size:.72rem}.group-picker-options{grid-template-columns:1fr}}
@media(max-width:780px){
  .student-page .topbar{min-height:66px;gap:7px}
  .student-page .brand{font-size:clamp(1.05rem,5vw,1.35rem);margin-right:auto}
  .student-page .icon-btn{width:39px;height:39px;flex:0 0 39px}
  .student-page .mobile-search-toggle{display:inline-grid}
  .student-page .searchbox{display:none;order:5;flex:0 0 100%;margin:2px 0 4px}
  .student-page.mobile-search-open .searchbox{display:flex}
  .student-page .category-nav{top:66px;max-height:min(75vh,620px);padding:8px 12px;overflow:auto;border-right:0;border-bottom:1px solid var(--line)}
  .student-page.mobile-search-open .category-nav{top:116px}
  .student-page .mobile-category-toggle{display:flex;width:100%;align-items:center;justify-content:space-between;gap:12px;padding:11px 14px;border:1px solid var(--line);border-radius:11px;background:var(--surface2);color:var(--text);font-weight:750;text-align:left}
  .mobile-category-arrow{font-size:1.7rem;line-height:1;transition:transform .15s}
  .mobile-categories-open .mobile-category-arrow{transform:rotate(90deg)}
  .student-page .category-nav #categories{display:none;width:100%;padding-top:8px}
  .student-page.mobile-categories-open .category-nav #categories{display:block}
  .student-page .category-btn{white-space:normal;margin-bottom:3px}
  .student-page .student-main{padding-top:10px}
  .student-page .section-heading{margin:4px 2px 15px;align-items:center}
}
@media(max-width:360px){.student-page .brand{font-size:1rem}.student-page .icon-btn{width:34px;height:34px;flex-basis:34px}.student-page .topbar{padding-left:9px;padding-right:9px}}

/* Shared visual theme switcher. The original theme is this stylesheet alone. */
.visual-theme-picker{position:relative;flex:none;z-index:50}
.visual-theme-picker summary{width:44px;height:44px;display:flex;align-items:center;justify-content:center;gap:3px;list-style:none;cursor:pointer;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow)}
.visual-theme-picker summary::-webkit-details-marker{display:none}
.visual-theme-picker[open] summary,.visual-theme-picker summary:hover{border-color:var(--blue2)}
.theme-dot{display:block;width:7px;height:7px;border-radius:50%;box-shadow:0 0 0 1px rgba(20,35,75,.12)}
.dot-classic{background:#2787d8}.dot-glass{background:linear-gradient(135deg,#785aff,#61ccf6)}.dot-clay{background:#f2a879}
.visual-theme-options{position:absolute;right:0;top:calc(100% + 9px);min-width:190px;padding:7px;background:var(--surface);border:1px solid var(--line);border-radius:15px;box-shadow:0 14px 38px rgba(12,30,65,.2);display:grid;gap:3px;color:var(--text)}
.visual-theme-options button{display:flex;align-items:center;gap:10px;text-align:left;width:100%;padding:10px 11px;border:0;border-radius:9px;background:transparent;color:var(--text);font-size:.88rem;font-weight:700;white-space:nowrap}
.visual-theme-options button:hover,.visual-theme-options button.active{background:var(--blue-light)}
.visual-theme-options button.active:after{content:'✓';margin-left:auto;color:var(--blue)}
.theme-swatch{width:17px;height:17px;border-radius:50%;flex:none;box-shadow:inset 0 1px 2px rgba(255,255,255,.5),0 0 0 1px rgba(20,35,75,.13)}
@media(max-width:780px){.visual-theme-picker summary{width:39px;height:39px}.student-page .visual-theme-picker{order:0}}
@media(max-width:360px){.student-page .visual-theme-picker summary{width:34px;height:34px}.student-page .topbar{gap:4px}.student-page .brand{margin-right:auto}}