:root{--bg:#EEF1EA;--paper:var(--bg);--surface:#fff;--ink:#1B2A22;--muted:#5C6B62;--line:#D5DCD3;--accent:#2E6B46;--accent-soft:#DDEBE1;--amber:#D89A2B;--amber-soft:#F7ECD3;--red:#B8322A;--red-soft:#F4DCDA;--blue:#2E86AB;--light:#EDF0E3;--dark:#839C83;--error:var(--red);--warn:#fff6d8;--radius:10px;--r:12px;--rb:10px;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;color:var(--ink);background:var(--paper)}
*{box-sizing:border-box}
body{margin:0;min-height:100svh;background:var(--paper)}
[hidden]{display:none!important}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:var(--accent)}
h1,h2,h3{overflow-wrap:anywhere}
.primary{background:var(--accent);color:#fff;border:0;border-radius:var(--radius);padding:12px 18px;font-weight:650;min-height:46px}
.outline{background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:var(--radius);padding:9px 14px;min-height:40px}
.text-button{background:none;border:0;color:var(--accent);padding:8px;min-height:40px}
.danger{color:var(--error)}
.muted{color:var(--muted)}
.error{color:var(--error)}
.small{min-height:34px;padding:5px 10px;font-size:14px}
a.outline{text-decoration:none;display:inline-flex;align-items:center}
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);width:max-content;background:#22262e;color:#fff;padding:12px 18px;border-radius:8px;z-index:100;max-width:min(90vw,480px)}
dialog{border:1px solid var(--line);border-radius:14px;padding:20px;width:min(92vw,560px);max-width:92vw;max-height:90vh;overflow-y:auto;color:var(--ink);background:var(--surface)}
dialog::backdrop{background:#0006}
label{display:grid;gap:6px;font-weight:600}
input,select{border:1px solid var(--line);border-radius:8px;padding:10px 12px;background:#fff;min-height:44px;min-width:0;width:100%}
.form-actions,.dialog-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:14px;align-items:center}

/* Page frame */
.page-header{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:6px 16px;padding:12px 16px;background:var(--surface);border-bottom:1px solid var(--line)}
.page-header strong{font-size:18px}
.page-header nav{display:flex;flex-wrap:wrap;gap:4px 12px;align-items:center}
.page-header a{font-weight:650}
.page-main{display:grid;gap:16px;padding:16px;max-width:1100px;margin:0 auto}
.panel{background:var(--surface);border-radius:14px;padding:16px;box-shadow:0 2px 10px #0000000d;min-width:0}
.panel h1,.panel h2{margin:0 0 12px}
.panel p{margin:0 0 8px}
.card-form{display:grid;gap:14px}
.card-form p{margin:0}
.note{margin:0;padding:8px 12px;background:var(--warn);border-radius:8px}
.success{color:var(--accent);font-weight:650}

/* Login */
.login-card{width:min(100% - 32px,400px);margin:10vh auto;background:var(--surface);padding:24px;border-radius:16px;box-shadow:0 6px 24px #0001}
.login-brand{text-align:center;margin:0 0 18px}
.login-logo{display:block;width:96px;height:auto;margin:0 auto 10px}
.login-card h1{margin:0}
.login-site{text-align:center}
.login-card form{display:grid;gap:14px}
.login-card p{margin:14px 0 0}

/* Home */
.set-list{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,240px),1fr));gap:12px}
.set-card{border:1px solid var(--line);border-radius:12px;padding:12px 14px;display:grid;gap:2px;min-width:0}
.set-card strong{overflow-wrap:anywhere}

/* Admin */
.tabs{display:flex;gap:6px}
.tabs button{flex:1 1 0;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);min-height:44px;font-weight:650;color:var(--ink)}
.tabs button[aria-selected=true]{background:var(--accent);border-color:var(--accent);color:#fff}
.filters{display:grid;grid-template-columns:minmax(0,1fr);gap:10px;margin-bottom:14px}
.student-row{cursor:pointer}
.student-row:hover{background:var(--paper)}
.missing{display:block;font-size:13px;color:var(--error)}
.status-pill{font-size:13px;padding:3px 10px;border-radius:999px;background:#eee;white-space:nowrap}
.status-pill.on{background:#d9f2df;color:#1d6b34}
.status-pill.ok{background:#d9f2df;color:#1d6b34}
.status-pill.bad{background:#f6d9d5;color:var(--error)}

/* Table that becomes stacked cards on narrow screens */
.table{width:100%;border-collapse:collapse;font-size:15px}
.table th,.table td{text-align:left;padding:8px 6px;border-bottom:1px solid var(--line);vertical-align:top}
@media(max-width:639px){
  .table,.table tbody,.table tr,.table td{display:block;width:100%}
  .table thead{display:none}
  .table tr{border:1px solid var(--line);border-radius:12px;padding:8px 12px;margin-bottom:10px;background:var(--surface)}
  .table td{border:0;padding:4px 0;display:grid;grid-template-columns:minmax(90px,38%) minmax(0,1fr);gap:8px;overflow-wrap:anywhere}
  .table td::before{content:attr(data-label);color:var(--muted);font-size:13px;font-weight:600}
}
@media(min-width:640px){.filters{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}}
.filters .check{display:flex;align-items:center;gap:8px;align-self:end;min-height:44px}
.filters .check input{width:18px;height:18px;min-height:0;padding:0;margin:0;flex:none;accent-color:var(--accent)}
.count{margin:0 0 8px;font-size:14px}
.table .sort{background:none;border:0;padding:0;font:inherit;font-weight:600;color:inherit;text-align:left}
.table th[aria-sort="ascending"] .sort::after{content:" ▲";font-size:10px}
.table th[aria-sort="descending"] .sort::after{content:" ▼";font-size:10px}
.table .pw-col{display:none}
.table.show-passwords .pw-col{display:table-cell}
.secret{font-size:14px;padding:2px 6px;border-radius:6px;background:#EDEFEA;cursor:copy}
@media(max-width:639px){.table.show-passwords td.pw-col{display:grid}}
@media print{.page-header,.tabs,.filters,.count,#sync-warning{display:none}.table th,.table td{font-size:12px;padding:4px}}

/* Student card dialog */
.card-heading{display:flex;justify-content:space-between;align-items:start;gap:8px;margin-bottom:8px}
.card-heading h2{margin:0}
.card-list{display:grid;gap:8px;margin:0}
.card-list div{display:grid;grid-template-columns:minmax(0,1fr);gap:0 8px;overflow-wrap:anywhere}
@media(min-width:480px){.card-list div{grid-template-columns:150px minmax(0,1fr)}}
.card-list dt{overflow-wrap:normal;word-break:keep-all;color:var(--muted);font-size:14px;font-weight:600}
.card-list dd{margin:0}
.secret{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.secret code{font-size:17px;font-weight:700;background:var(--paper);padding:4px 8px;border-radius:6px;user-select:all}
.guardian{margin:0 0 6px}
.events{list-style:none;padding:0;margin:0;display:grid;gap:4px;font-size:14px}
.card-section{margin:16px 0 0;font-size:16px}

/* «Σύνδεση ως» ribbon on every page */
.acting{position:sticky;top:0;z-index:40;display:flex;align-items:center;justify-content:space-between;gap:10px;padding:8px 16px;background:var(--amber-soft);border-bottom:1px solid #E8D3A2;color:#5A3D08;font-size:13px;font-weight:600;line-height:1.35}
.acting span{flex:1 1 0;min-width:0}
.acting .outline{flex:none;min-height:44px;padding:8px 12px;font-weight:700}

/* Student pages */
body.app{display:flex;flex-direction:column;min-height:100svh;background:var(--bg);line-height:1.4}
.app .toast{bottom:calc(96px + env(safe-area-inset-bottom))}
.app .outline{min-height:46px;padding:11px 16px;font-weight:600;border-radius:var(--rb)}
.app .primary{border-radius:var(--rb);font-weight:700}
.app button:disabled:not(.right):not(.wrong){opacity:.45;cursor:default}
a.primary{text-decoration:none;display:inline-flex;align-items:center;justify-content:center}
.top{display:flex;align-items:center;gap:10px;width:100%;max-width:720px;margin:0 auto;min-height:58px;padding:10px 16px 6px;background:var(--bg)}
.top h1{flex:1;min-width:0;margin:0;font-size:20px;font-weight:800;letter-spacing:-.01em;line-height:1.2;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.knight{flex:none;width:30px;height:30px;border-radius:50%;background:var(--accent);display:grid;place-items:center}
.knight img{width:22px;height:22px;filter:invert(1) brightness(2)}
.score{flex:none;font-weight:800;color:var(--accent);background:var(--accent-soft);padding:4px 10px;border-radius:999px;font-size:15px;white-space:nowrap}
.pos{flex:none;color:var(--muted);font-size:14px;font-weight:600;white-space:nowrap}
.icon{width:46px;height:46px;border-radius:var(--rb);border:1px solid var(--line);background:var(--surface);display:grid;place-items:center;padding:0;color:var(--ink);flex:none}
.icon svg{width:24px;height:24px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.top .icon{width:44px;height:44px;border:0;background:transparent;margin-left:-10px}
.app-main{flex:1;width:100%;max-width:720px;margin:0 auto;padding:0 16px 20px;min-width:0}
.app-main h2{font-size:17px;font-weight:700;margin:18px 0 8px}
.hello{margin:6px 0 10px;font-size:24px;font-weight:800;letter-spacing:-.01em;overflow-wrap:anywhere}
.empty{color:var(--muted);margin:12px 2px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:14px;min-width:0}
nav.tabs{position:sticky;bottom:0;z-index:20;display:flex;justify-content:space-around;gap:0;border-top:1px solid var(--line);background:var(--surface);padding:6px max(4px,calc(50% - 360px)) calc(8px + env(safe-area-inset-bottom))}
nav.tabs a{flex:1 1 0;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;min-width:0;min-height:48px;padding:4px 2px;font-size:11px;color:var(--muted);text-decoration:none;text-align:center}
nav.tabs a span{white-space:nowrap}
@media(max-width:380px){nav.tabs a{font-size:10px}}
@media(max-width:340px){nav.tabs a{font-size:9px}}
nav.tabs svg{width:24px;height:24px;fill:none;stroke:currentColor;stroke-width:1.9;stroke-linecap:round;stroke-linejoin:round}
nav.tabs a.on{color:var(--accent);font-weight:700}

/* Home and category lists */
.resume{display:flex;gap:14px;background:var(--surface);border-radius:var(--r);padding:12px;border:1px solid var(--line);min-width:0}
.mini{width:110px;flex:none;align-self:flex-start}
.mini.board-frame{--coord-gutter:0px;width:110px}
.mini .board{box-shadow:none;border-radius:6px}
.mini .board-coordinates{display:none}
.resume-text{display:flex;flex-direction:column;gap:2px;min-width:0}
.resume-text small{color:var(--muted);font-size:13px}
.resume-text strong{font-size:16px;overflow-wrap:anywhere}
.resume-text span{color:var(--muted);font-size:14px}
.resume-text .primary{margin-top:auto;align-self:flex-start;padding:9px 16px;min-height:44px}
.cats{display:flex;flex-direction:column;background:var(--surface);border-radius:var(--r);border:1px solid var(--line);overflow:hidden}
.cat{display:flex;align-items:center;justify-content:space-between;gap:10px;min-height:56px;padding:12px 14px;border-top:1px solid var(--line);color:inherit;text-decoration:none}
.cat:first-child{border-top:0}
/* Library: covers in a grid, the text under each cover. */
.books{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,150px),1fr));gap:18px 14px}
.book{display:flex;flex-direction:column;gap:8px;color:inherit;text-decoration:none;min-width:0}
.book img{display:block;width:100%;aspect-ratio:17/24;object-fit:cover;object-position:top;border-radius:6px;border:1px solid var(--line);background:var(--surface);box-shadow:0 4px 14px #1b2a2218}
.book:focus-visible img,.book:hover img{border-color:var(--accent)}
.book-text{display:flex;flex-direction:column;gap:2px;min-width:0}
.book-text strong{font-size:15px;line-height:1.25;overflow-wrap:anywhere}
.book-text small{color:var(--accent);font-size:12px;font-weight:650}
.book-about{color:var(--muted);font-size:13px;line-height:1.35}
.cat-row{display:flex;align-items:stretch;border-top:1px solid var(--line)}
.cat-row:first-child{border-top:0}
.cat-go{flex:1 1 auto;display:flex;align-items:center;justify-content:space-between;gap:10px;min-width:0;min-height:56px;padding:12px 14px;border:0;border-radius:0;background:none;color:inherit;text-align:left}
.cat-go:disabled{cursor:default}
.cat-go:disabled .cat-text strong{color:var(--muted)}
.cat-list{flex:none;display:flex;align-items:center;padding:0 14px;border-left:1px solid var(--line);color:var(--accent);font-weight:650;font-size:14px;text-decoration:none}
.hint{margin:-4px 0 10px;color:var(--muted);font-size:14px}
.cat-text{display:flex;flex-direction:column;min-width:0}
.cat-text strong{font-size:15px;font-weight:600;overflow-wrap:anywhere}
.cat-text small{color:var(--muted);font-size:13px}
.rank{display:inline-grid;grid-template-columns:repeat(8,12px);flex:none;border:1px solid #0002;border-radius:3px;overflow:hidden;vertical-align:middle}
.rank i{display:block;height:12px}
.rank i.l{background:var(--light)}
.rank i.d{background:var(--dark)}
.rank i.on{background:var(--accent)}
.rank i.on.l{background:#3f8a5b}
.admin-link{margin-top:18px}

/* Unit page */
.unit-head h2{margin:8px 0 2px;font-size:22px;font-weight:800}
.unit-head p{margin:0;color:var(--muted);display:flex;flex-wrap:wrap;align-items:center;gap:6px 10px;font-size:14px}
.row{display:flex;gap:10px;margin:12px 0}
.row .primary,.row .outline{flex:1;min-width:0}
.chips{display:flex;gap:8px;overflow-x:auto;padding:2px 0 6px;scrollbar-width:none;margin:0 -16px;padding-left:16px;padding-right:16px}
.chips::-webkit-scrollbar{display:none}
.chip{flex:none;min-height:44px;border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:0 14px;font-size:14px;font-weight:600;color:var(--muted)}
.chip[aria-pressed=true]{background:var(--ink);color:#fff;border-color:var(--ink)}
.legend{display:flex;gap:6px 12px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin:6px 0 10px}
.legend em,.tile em{font-style:normal;font-weight:800}
.tiles{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:8px}
.tile{position:relative;aspect-ratio:1;min-width:0;border-radius:var(--rb);background:var(--surface);border:1px solid var(--line);display:flex;flex-direction:column;align-items:center;justify-content:center;color:inherit;text-decoration:none}
.tile b{font-size:17px;font-weight:700;font-variant-numeric:tabular-nums}
.tile em{font-size:12px;line-height:1;margin-top:2px;min-height:12px}
.tile.solved{background:var(--accent-soft);border-color:#B9D4C2}
.tile.solved em,.legend .solved{color:var(--accent)}
.tile.seen{background:#EDEFEA}
.tile.seen em,.legend .seen{color:var(--muted)}
.tile.wrong{background:var(--amber-soft);border-color:#E8D3A2}
.tile.wrong em,.legend .wrong{color:#9A6A10}
.tile.skipped em,.legend .skipped{color:var(--muted)}
.tile .fav{position:absolute;top:4px;right:5px;width:9px;height:9px;background:var(--amber);clip-path:polygon(50% 0,61% 35%,98% 35%,68% 57%,79% 91%,50% 70%,21% 91%,32% 57%,2% 35%,39% 35%)}
.tile.mini-tile{width:44px;flex:none}
.tile.mini-tile em{font-size:18px;margin:0}

/* Board, from the mat app with the colours of the courses design */
.board-wrap,.board-frame{--coord-gutter:clamp(32px,6vw,44px)}
.board-frame{display:grid;grid-template-columns:var(--coord-gutter) minmax(0,1fr);grid-template-rows:auto var(--coord-gutter);width:100%}
.board-surface{position:relative;grid-column:2;grid-row:1;min-width:0}
.board-coordinates{display:grid;align-items:center;justify-items:center;color:var(--ink);font-size:clamp(22px,4vw,30px);font-weight:800;line-height:1;user-select:none;-webkit-user-select:none;pointer-events:none}
.board-ranks{grid-column:1;grid-row:1;grid-template-rows:repeat(8,minmax(0,1fr))}
.board-files{grid-column:2;grid-row:2;grid-template-columns:repeat(8,minmax(0,1fr))}
.coordinates-hidden{visibility:hidden}
.board-frame[data-orientation=b] .board-arrows{transform:rotate(180deg)}
.board{display:grid;grid-template-columns:repeat(8,1fr);aspect-ratio:1;width:100%;border-radius:4px;overflow:hidden;box-shadow:0 3px 12px #0002;user-select:none;-webkit-user-select:none;touch-action:none}
.square{position:relative;display:flex;align-items:center;justify-content:center;aspect-ratio:1;min-width:0;min-height:0;border:0;padding:0;border-radius:0;background:var(--light)}
.square.dark{background:var(--dark)}
.square.selected{background:#cbd579}
.square.last-move{background:#d4dfa3}
.square.dark.last-move{background:#a9bd77}
.square.flash-right{background:#7fd18b!important}
.square.flash-wrong{background:#e07a6a!important}
.square img{width:88%;height:88%;object-fit:contain;pointer-events:none;filter:drop-shadow(0 1px 1px #0003)}
.square.dragging img{opacity:.25}
.square.legal-target:after{content:"";width:24%;height:24%;border-radius:50%;position:absolute;background:#293e3140}
.square.legal-target:has(img):after{width:88%;height:88%;background:none;border:5px solid #293e3140}
.square.mark-mark{--mark:var(--blue)}
.square.mark-right{--mark:#2f8f4e}
.square.mark-wrong{--mark:var(--red)}
.square.mark-missing{--mark:var(--muted)}
.square:is(.mark-mark,.mark-right,.mark-wrong,.mark-missing):after{content:"";position:absolute;width:38%;height:38%;border-radius:50%;background:var(--mark);box-sizing:border-box}
.square.mark-missing:after{background:none;border:5px solid var(--mark)}
.square:is(.mark-mark,.mark-right,.mark-wrong):has(img):after{width:88%;height:88%;background:none;border:6px solid var(--mark)}
.board.locked{filter:grayscale(.6) brightness(.92)}
.board.square-selection{touch-action:manipulation}
.board-arrows{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}
.arrow-right{fill:#2f8f4e;fill-opacity:.75}
.arrow-wrong{fill:var(--red);fill-opacity:.75}
.arrow-reply{fill:var(--blue);fill-opacity:.7}
.drag-ghost{position:fixed;pointer-events:none;z-index:50;filter:drop-shadow(0 4px 6px #0004)}
.promotion-choices{display:flex;gap:6px;margin:12px 0}
.promotion-choices button{padding:4px;border:1px solid var(--line);border-radius:8px;background:#fff}
.promotion-choices img{width:56px;height:56px}

/* Exercise page */
.play-page{touch-action:pan-x pan-y}
.play{display:flex;flex-direction:column;gap:6px;padding-top:2px}
.play-col{width:min(100%,560px);margin:0 auto;display:flex;flex-direction:column;gap:6px;min-width:0}
.play-col .board-wrap{width:min(100%,max(280px,calc(100svh - 340px)));margin:0 auto}
.play-col:has(.coordinate-pieces:not([hidden])) .board-wrap,.play-col:has(.note:not([hidden])) .board-wrap{width:min(100%,max(280px,calc(100svh - 430px)))}
.task{margin:0;font-size:19px;font-weight:700;line-height:1.25;overflow-wrap:anywhere}
.task.coordinate{font-size:clamp(36px,8vw,48px);line-height:1.1}
.stage{margin:0;color:var(--muted);font-size:14px;overflow-wrap:anywhere}
.value{display:inline-block;margin-left:8px;padding:2px 8px;border-radius:999px;background:var(--amber-soft);color:#7A5410;font-weight:700;font-size:12px;vertical-align:middle;white-space:nowrap}
.help{margin:0;color:var(--muted);font-size:15px}
.play .note{font-size:15px}
.moves{margin:0;font-size:15px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}
.moves .turn{color:var(--accent);font-weight:700;margin-left:6px}
.feedback{margin:2px 0 0;min-height:22px;font-size:15px;color:var(--muted)}
.feedback.right{color:var(--accent);font-weight:700}
.feedback.wrong{color:var(--red);font-weight:700}
.feedback.info{color:var(--ink)}
.board-wrap{position:relative}
.points-bubble{position:absolute;left:calc(50% + var(--coord-gutter)/2);top:40%;font-size:56px;font-weight:800;white-space:nowrap;z-index:7;pointer-events:none;animation:float-up 1.2s ease-out forwards;text-shadow:0 2px 8px #0004}
.points-bubble.long{font-size:34px}
.points-bubble.plus{color:#2f8f4e}
@keyframes float-up{from{opacity:0;transform:translate(-50%,-30%) scale(.7)}20%{opacity:1;transform:translate(-50%,-50%) scale(1.1)}to{opacity:0;transform:translate(-50%,-120%) scale(1)}}
@media(prefers-reduced-motion:reduce){.points-bubble{animation:none}}
.coordinate-pieces{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:6px}
.piece-choice{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;min-width:0;min-height:64px;padding:4px;border:2px solid var(--line);border-radius:8px;background:var(--surface);color:var(--ink);font-weight:700}
.piece-choice img{width:40px;height:40px;pointer-events:none}
.piece-choice[aria-pressed=true]{border-color:var(--accent);background:var(--accent-soft);box-shadow:0 0 0 1px var(--accent)}
.choice-actions{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:8px}
.choice-actions button{min-height:52px;font-size:19px;font-weight:700;border:2px solid var(--line);border-radius:var(--rb);background:var(--surface);color:var(--ink)}
.choice-actions button.right{background:#2f8f4e;color:#fff;border-color:#2f8f4e}
.choice-actions button.wrong{background:var(--red);color:#fff;border-color:var(--red);cursor:default}
.solution{display:grid;gap:6px;padding:8px 10px;background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}
.solution-controls{display:flex;align-items:center;justify-content:space-between;gap:8px}
.solution-controls .outline{min-height:44px;padding:8px 14px}
.solution-controls span{color:var(--muted);font-size:14px;font-variant-numeric:tabular-nums;text-align:center}
.solution-steps{display:flex;flex-wrap:wrap;gap:2px 4px;margin:0;padding:0;list-style:none}
.solution-steps button{border:0;background:none;min-height:40px;padding:4px 8px;font-weight:700;color:var(--ink);border-radius:8px;font-variant-numeric:tabular-nums}
.solution-steps button.active{background:var(--accent-soft);color:var(--accent)}
.actions{position:sticky;bottom:0;z-index:20;background:var(--surface);border-top:1px solid var(--line);padding:10px 12px calc(12px + env(safe-area-inset-bottom))}
.actions-row{display:flex;gap:8px;max-width:560px;margin:0 auto}
/* The exercise actions sit on top of the usual bottom bar, and the two stay together at the bottom of the screen. */
.dock{position:sticky;bottom:0;z-index:20}
.dock .actions{position:static;padding-bottom:10px}
.dock nav.tabs{position:static}
.actions .outline,.actions .primary{flex:1 1 0;min-width:0;padding-left:6px;padding-right:6px;font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.actions #solution-button,.actions #restart-button{flex-grow:1.25}
.actions #solution-button.playing{flex-grow:1.9;font-size:14px}
.actions .primary.wide{flex-grow:1.6}
.actions .icon{width:44px}
.icon.star svg{stroke:var(--amber)}
.icon.star[aria-pressed=true] svg{fill:var(--amber)}
.connection{position:fixed;top:12px;left:50%;transform:translateX(-50%);background:var(--red);color:#fff;padding:8px 14px;border-radius:999px;white-space:nowrap;z-index:60;font-size:14px}
.message{font-size:18px;text-align:center;margin:18vh 0 0}
.menu-dialog{padding:8px 0;width:min(92vw,420px)}
.menu-dialog h2{margin:8px 20px 6px;font-size:17px}
.menu-item{display:flex;align-items:center;width:100%;min-height:50px;padding:10px 20px;border:0;border-top:1px solid var(--line);background:none;color:var(--ink);font-weight:600;text-align:left}
.menu-item:first-of-type{border-top:0}
.menu-item.muted{color:var(--muted)}
.report-form{display:grid;gap:12px}
.report-form h2{margin:0;font-size:19px}
.report-form p{margin:0;color:var(--muted);font-size:15px}
textarea{font:inherit;border:1px solid var(--line);border-radius:8px;padding:10px 12px;min-height:110px;width:100%;resize:vertical;background:#fff;color:var(--ink)}
.end-dialog{text-align:center;width:min(92vw,400px)}
.end-dialog h2{margin:4px 0 16px;font-size:22px}
.end-dialog .dialog-actions{display:grid;gap:10px}
.end-dialog .outline{justify-content:center}

/* Leaderboard */
.seg{display:inline-flex;border:1px solid var(--line);border-radius:999px;overflow:hidden;align-self:flex-start;background:var(--surface)}
.seg button{border:0;background:var(--surface);min-height:44px;padding:7px 14px;font-weight:600;color:var(--muted)}
.seg button[aria-pressed=true]{background:var(--ink);color:#fff}
.seg.full{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));width:100%;margin:6px 0 10px}
.seg.full button{padding:9px 6px}
label.select{display:flex;align-items:center;gap:10px;font-weight:600;font-size:14px;margin-bottom:10px}
label.select select{flex:1;width:auto;min-width:0;border-radius:var(--rb);background:var(--surface)}
.lead{list-style:none;margin:0;padding:0;background:var(--surface);border:1px solid var(--line);border-radius:var(--r);overflow:hidden}
.lead li{display:grid;grid-template-columns:34px minmax(0,1fr) auto;align-items:center;gap:10px;padding:11px 14px;border-top:1px solid var(--line)}
.lead li:first-child{border-top:0}
.lead li b{font-size:16px;color:var(--muted)}
.lead li.top3 b{color:var(--amber);font-size:18px}
.lead li span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lead li strong{font-variant-numeric:tabular-nums;white-space:nowrap}
.lead li.me{background:var(--accent-soft)}
.lead li.me span{font-weight:800}
.lead li.gap{justify-items:center;color:var(--muted);grid-template-columns:1fr;padding:4px}
.hint{color:var(--muted);font-size:13px;margin:10px 2px 0}

/* Favorites */
.fav-list .cat{justify-content:flex-start;gap:12px}

/* «Εγώ» */
.profile h2{margin:4px 0 2px;font-size:22px;font-weight:800}
.profile p{margin:0;color:var(--muted)}
.stat-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}
.stat-grid div{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:10px;display:flex;flex-direction:column;gap:2px;min-width:0}
.stat-grid b{font-size:24px;font-weight:800;letter-spacing:-.02em;font-variant-numeric:tabular-nums}
.stat-grid span{font-size:12px;color:var(--muted);line-height:1.2}
.bycat{width:100%;border-collapse:collapse;font-size:14px}
.bycat th{text-align:right;font-weight:600;color:var(--muted);padding:6px 4px;border-bottom:1px solid var(--line);font-size:12px}
.bycat th:first-child{text-align:left}
.bycat td{padding:9px 4px;border-bottom:1px solid var(--line);vertical-align:middle}
.bycat td:first-child{font-weight:600}
.bycat td:first-child .rank{display:grid;width:max-content;margin-top:4px}
.bycat td:not(:first-child){text-align:right;font-variant-numeric:tabular-nums;width:64px}
.attempt-list{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.attempt-list li{background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}
.attempt-list a,.attempt-list .attempt-body{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:2px 10px;align-items:center;padding:10px 14px;color:inherit;text-decoration:none;min-height:56px}
.attempt-list small{grid-column:1;color:var(--muted);font-size:13px}
.attempt-list strong{grid-column:1;font-size:14px;font-weight:600;overflow-wrap:anywhere}
.attempt-list .pill{grid-column:2;grid-row:1 / span 2}
.pill{display:inline-block;padding:3px 10px;border-radius:999px;background:#EDEFEA;font-size:13px;font-weight:600;color:var(--ink);white-space:nowrap}
.pill.ok{background:var(--accent-soft);color:var(--accent)}
.pill.wrong{background:var(--amber-soft);color:#9A6A10}
.pill.skip{background:#EDEFEA;color:var(--muted)}
.pill.draw{background:#E4E8F5;color:#3B4C8A}
.pill.loss{background:var(--red-soft);color:var(--red)}
.byadmin{font-style:normal;font-weight:600;font-size:12px;color:var(--muted);margin-left:6px;background:#EDEFEA;padding:1px 6px;border-radius:999px}
.more-button{width:100%;margin-top:10px}
.me-actions{margin-top:18px}
.me-actions .outline{width:100%}

/* Admin, stage 2. Tabs, the student card as a side panel, replay, reports, exercises and admins */
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
div.tabs{flex-wrap:wrap}
div.tabs button{flex:1 1 auto;padding:0 14px;display:inline-flex;align-items:center;justify-content:center;gap:6px}
.badge{display:inline-block;min-width:22px;padding:0 7px;border-radius:999px;background:var(--amber);color:#fff;font-size:12px;font-weight:800;line-height:20px;text-align:center;font-variant-numeric:tabular-nums}
div.tabs button[aria-selected=true] .badge{background:#fff;color:var(--accent)}
.chip .badge{margin-left:6px;background:var(--line);color:var(--ink)}
.chip[aria-pressed=true] .badge{background:#fff;color:var(--ink)}
.filter-chips{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:14px}
.outline.super{border-color:var(--accent);color:var(--accent);font-weight:650}
.meta{margin:4px 0 0;display:flex;flex-wrap:wrap;gap:6px 10px;align-items:center;color:var(--muted);font-size:14px}
.meta code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:14px;color:var(--ink);background:var(--bg);padding:2px 6px;border-radius:6px;overflow-wrap:anywhere}
.meta .missing{display:inline}

dialog.side-panel{padding:0;width:100%;max-width:100%;height:100%;max-height:100%;margin:0;border:0;border-radius:0;overflow-y:auto;overscroll-behavior:contain;background:var(--surface)}
@media(min-width:900px){dialog.side-panel{width:min(880px,calc(100% - 80px));margin:0 0 0 auto;border-left:1px solid var(--line);box-shadow:-10px 0 34px #0000002e}}
.side-panel .card-heading{position:sticky;top:0;z-index:8;margin:0;padding:14px 16px 12px;background:var(--surface);border-bottom:1px solid var(--line)}
.side-panel .card-heading h2{font-size:22px;font-weight:800;letter-spacing:-.01em;line-height:1.2}
.card-who{min-width:0}
.card-body{display:grid;gap:22px;padding:16px 16px 32px;min-width:0}
@media(min-width:900px){.side-panel .card-heading{padding:18px 24px 14px}.card-body{padding:18px 24px 36px}}
.card-top{display:grid;gap:12px;min-width:0}
.cred{display:grid;gap:6px;background:var(--bg);border-radius:var(--r);padding:8px 12px;max-width:480px;min-width:0}
.cred div{display:grid;grid-template-columns:72px minmax(0,1fr) auto;align-items:center;gap:8px}
.cred small{color:var(--muted);font-size:13px}
.cred code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:15px;font-weight:600;background:var(--surface);padding:4px 8px;border-radius:6px;border:1px solid var(--line);overflow-wrap:anywhere;user-select:all;justify-self:start}
.card-actions{margin-top:0}
.card-stats{display:grid;gap:12px;min-width:0}
.stats-head{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px}
.score-big{font-weight:800;color:var(--accent);background:var(--accent-soft);padding:6px 12px;border-radius:999px;white-space:nowrap;font-variant-numeric:tabular-nums}
.card-counters div,.exercise-counts div{background:var(--bg);border:0}
.card-counters small{font-size:11px;font-weight:700;color:#9A6A10}
@media(min-width:900px){.card-counters{grid-template-columns:repeat(6,minmax(0,1fr))}}
.card-attempts{min-width:0}
.attempts-head{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;margin-bottom:10px}
.attempts-head h3{margin:0;font-size:17px}
.attempts-head select{width:auto;max-width:100%}
.card-bottom{display:grid;gap:4px;min-width:0}
.card-bottom .card-section{margin-top:12px}

/* Expandable rows of attempts and reports */
.admin-list{list-style:none;margin:0;padding:0;display:grid;gap:8px;min-width:0}
.attempt{border:1px solid var(--line);border-radius:var(--r);background:var(--surface);min-width:0}
.attempt.open{border-color:#B9D4C2;box-shadow:0 0 0 1px #B9D4C2}
.attempt-row{display:grid;grid-template-columns:110px minmax(0,1fr) auto;gap:4px 12px;align-items:center;width:100%;min-height:48px;padding:10px 14px;border:0;border-radius:var(--r);background:none;color:inherit;font-size:14px;text-align:left}
.attempt-row:hover{background:var(--paper)}
.attempt.open .attempt-row{border-radius:var(--r) var(--r) 0 0}
.attempt-row .when{color:var(--muted);font-variant-numeric:tabular-nums}
.attempt-row strong{font-weight:600;overflow-wrap:anywhere}
.attempt-row .pill{justify-self:end}
.report-main{display:grid;gap:1px;min-width:0}
.report-main span{overflow-wrap:anywhere}
.report-main .excerpt{color:var(--muted);font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
@media(max-width:599px){
  .attempt-row{grid-template-columns:minmax(0,1fr) auto}
  .attempt-row .when{grid-column:1 / -1;font-size:13px}
}

/* Replay, report position and solution boards */
.replay,.report-detail{display:grid;grid-template-columns:260px minmax(0,1fr);gap:16px;align-items:start;padding:4px 14px 14px;min-width:0}
.stepper{display:grid;gap:8px;min-width:0}
.replay-board.board-frame{--coord-gutter:0px;width:100%}
.replay-board .board-coordinates{display:none}
.replay-board .board{box-shadow:none;touch-action:auto}
.replay-controls{display:flex;align-items:center;justify-content:space-between;gap:8px;color:var(--muted);font-size:14px;font-variant-numeric:tabular-nums;text-align:center}
.replay-controls .outline{min-height:40px}
.replay-controls button:disabled{opacity:.45;cursor:default}
.replay-steps{list-style:none;margin:0;padding:0;display:grid;gap:2px;font-size:14px;min-width:0}
.replay-steps button{display:flex;flex-wrap:wrap;align-items:baseline;gap:2px 10px;width:100%;min-height:40px;padding:7px 10px;border:0;border-radius:8px;background:none;color:inherit;text-align:left}
.replay-steps button:hover{background:var(--paper)}
.replay-steps button[aria-current=step]{background:var(--accent-soft)}
.replay-steps time{color:var(--muted);font-size:13px;font-variant-numeric:tabular-nums}
.replay-steps em{font-style:normal;font-weight:700}
.replay-steps em.solved{color:var(--accent)}
.replay-steps em.wrong{color:#9A6A10}
.replay-steps em.seen{color:var(--muted)}
.replay-steps .reply{color:var(--blue)}
.replay-steps .reason{flex-basis:100%;color:var(--muted);font-size:13px}
.report-side{display:grid;gap:10px;min-width:0}
.report-side p{margin:0}
.report-comment{white-space:pre-wrap;overflow-wrap:anywhere;background:var(--bg);border-radius:var(--rb);padding:10px 12px}
.report-edit{display:grid;gap:12px}
.report-edit textarea{min-height:90px}
.report-edit .form-actions{margin-top:0}
@media(max-width:599px){.replay,.report-detail{grid-template-columns:minmax(0,1fr);padding:4px 12px 12px}}

/* Exercises tab */
.lookup{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px;align-items:end}
.panel .hint{margin:8px 0 0}
#lookup-result:not(:empty){margin-top:16px}
.exercise-layout{display:grid;grid-template-columns:300px minmax(0,1fr);grid-template-rows:auto 1fr;grid-template-areas:"board head" "board rest";gap:14px 20px;align-items:start}
.exercise-layout>.stepper{grid-area:board}
.exercise-head{grid-area:head;min-width:0}
.exercise-rest{grid-area:rest;display:grid;gap:14px;min-width:0}
.exercise-head h2{margin:0;font-size:20px}
.exercise-prompt{font-weight:700;margin:8px 0 0}
.exercise-head .muted{margin:6px 0 0}
.exercise-counts{grid-template-columns:repeat(2,minmax(0,1fr));max-width:420px}
.exercise-solution .card-section{margin:0 0 6px}
@media(max-width:699px){.exercise-layout{grid-template-columns:minmax(0,1fr);grid-template-rows:none;grid-template-areas:"head" "board" "rest"}}