/* Ascendia — base layout + components (design/02_components.md). Tokens: theme.css. Only transform/opacity are animated. */
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:var(--lg-font);font-size:17px;line-height:1.6;color:var(--bp-ink);min-height:100vh}
button,input,select{font:inherit;color:inherit}
img,svg{max-width:100%}
[hidden]{display:none!important}
.wrap{width:min(1180px,calc(100% - 32px));margin:0 auto}
@media(min-width:561px){.wrap{width:min(1180px,calc(100% - 48px))}}
@media(min-width:1024px){.wrap{width:min(1180px,calc(100% - 64px))}}
h1,h2,h3{font-family:var(--lg-font-display);color:var(--bp-ink);margin:0;text-wrap:balance}
h1{font-size:clamp(28px,2.8vw,36px);font-weight:650;line-height:1.15;letter-spacing:-.02em}
h2{font-size:22px;line-height:1.3;font-weight:600;letter-spacing:-.01em}
h3{font-size:18px;line-height:1.35;font-weight:600;letter-spacing:-.01em}
p{margin:0}
.muted{color:var(--bp-ink-2)}.faint{color:var(--bp-ink-3);font-size:14px;font-weight:500;line-height:1.45}.strong{font-weight:600}.small{font-size:14px}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.between{justify-content:space-between}.end{justify-content:flex-end}.grow{flex:1}
.stack{display:flex;flex-direction:column;gap:14px}.mt{margin-top:28px}.mt-auto{margin-top:auto}.maxw{max-width:720px}.w220{width:220px;max-width:100%}
.ic{flex:none;vertical-align:-.2em}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
:focus-visible{outline:3px solid var(--bp-focus);outline-offset:2px}

/* ---- cards ---- */
.card{background:var(--bp-paper);border:1px solid var(--bp-line);border-radius:var(--bp-r-card);box-shadow:var(--bp-shadow-1);padding:20px}
@media(min-width:561px){.card{padding:24px}}

/* ---- header ---- */
.app-nav{position:sticky;top:calc(env(safe-area-inset-top,0px) + 12px);z-index:50;display:flex;align-items:center;gap:10px;width:min(1180px,calc(100% - 24px));margin:12px auto 0;padding:8px 8px 8px 12px;border-radius:999px}
.brand{display:flex;align-items:center;gap:10px;min-height:44px;font:650 17px/1 var(--lg-font-display);color:var(--bp-ink);text-decoration:none;white-space:nowrap}
.brand-mark{width:34px;height:34px;border-radius:11px}
.nav-search{flex:0 1 360px;display:flex;align-items:center;gap:8px;min-height:44px;padding:0 16px;border-radius:999px;background:var(--bp-paper-2);border:1px solid var(--bp-line);color:var(--bp-ink-3);position:relative}
.nav-search input{flex:1;min-width:0;border:0;background:none;font-size:15px;color:var(--bp-ink);outline:none}
.nav-search input::placeholder{color:var(--bp-ink-3)}
.nav-search:focus-within{outline:3px solid var(--bp-focus);outline-offset:2px}
.btn.nav-search-btn{display:none;width:44px;padding:0}
.nav-links{display:flex;gap:4px}
.nav-links a{display:inline-flex;align-items:center;gap:8px;min-height:44px;padding:0 14px;border-radius:999px;color:var(--bp-ink-2);font:600 15px var(--lg-font);text-decoration:none}
.nav-links a[aria-current="page"]{background:var(--bp-tint-soft);color:var(--bp-tint-ink)}
.avatar-btn{position:relative;width:48px;height:48px;border:0;border-radius:50%;background:none;padding:0;cursor:pointer;flex:none}
.avatar-btn .initials{position:absolute;inset:6px;border-radius:50%;display:grid;place-items:center;font:700 14px/1 var(--lg-font);color:#fff;background:linear-gradient(145deg,#2470E0,#1A5BC4)}
.avatar-btn .lvl{position:absolute;right:-2px;bottom:-2px;min-width:20px;height:20px;padding:0 5px;border-radius:999px;font:700 11px/20px var(--lg-font);color:var(--bp-on-primary);background:var(--bp-tint);box-shadow:0 0 0 2px var(--bp-paper);text-align:center}
.avatar-btn:active{transform:scale(.94)}.avatar-btn.bump{animation:bp-bump var(--bp-t-pop) var(--bp-ease)}
@keyframes bp-bump{50%{transform:scale(1.08)}}
.ring{display:block}.ring .trk{stroke:var(--bp-track)}.ring .val{stroke-linecap:round}
.ring-wrap{position:relative;display:inline-grid;place-items:center;flex:none}.ring-wrap .rt{position:absolute;font:700 16px/1 var(--lg-font-display);font-variant-numeric:tabular-nums}
@media(max-width:820px){.nav-search{display:none}.btn.nav-search-btn{display:inline-flex}}
@media(max-width:560px){.app-nav{border-radius:22px}.brand .txt{font-size:15px}}

/* ---- buttons ---- */
.btn{position:relative;overflow:hidden;isolation:isolate;display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:0 20px;border:0;border-radius:999px;font:600 15px/1 var(--lg-font);cursor:pointer;text-decoration:none;background:var(--bp-paper-2);color:var(--bp-ink);box-shadow:inset 0 0 0 1px var(--bp-line);transition:transform var(--bp-t-press) var(--bp-ease);white-space:nowrap}
.btn.sm{padding:0 14px;font-size:14px}.btn.block{width:100%}
.btn.pri{background:var(--bp-primary);color:var(--bp-on-primary,#fff);box-shadow:var(--bp-glow),inset 0 1px 0 rgba(255,255,255,.35)}
.btn.glass{background:var(--bp-lite);box-shadow:var(--bp-spec),inset 0 0 0 1px var(--bp-lite-line)}
.btn.plain{background:none;box-shadow:none;color:var(--bp-tint);padding:0 12px}
.btn:active{transform:scale(.97)}
.btn.pri::before{content:"";position:absolute;inset:0;z-index:-1;background:rgba(0,24,72,.14);opacity:0;transition:opacity var(--bp-t-hover)}
@media(hover:hover){.btn:hover{transform:translateY(-1px)}.btn.plain:hover{text-decoration:underline}.btn.pri:hover::before{opacity:1}}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.62;cursor:not-allowed;transform:none}
/* contrast sweep 22/10: a faded white-on-blue primary was 1.5:1; disabled primary = solid pale chip + navy text (7.7:1) */
.btn.pri:disabled,.btn.pri[aria-disabled="true"]{opacity:1;background:#C3D3EA;color:#1E3358;box-shadow:none}
.btn svg{width:18px;height:18px;flex:none}
.neg-text{color:var(--bp-neg)!important}
.btn::after,.tile::after,.keypad button::after{content:"";position:absolute;left:var(--rx,50%);top:var(--ry,50%);width:var(--rs,160px);height:var(--rs,160px);margin:calc(var(--rs,160px)/-2) 0 0 calc(var(--rs,160px)/-2);border-radius:50%;background:currentColor;opacity:0;transform:scale(0);pointer-events:none;z-index:-1}

@keyframes bp-ripple{0%{transform:scale(0);opacity:.18}100%{transform:scale(1);opacity:0}}

/* ---- pills, badges ---- */
.pill{display:inline-flex;align-items:center;gap:5px;min-height:26px;padding:0 10px;border-radius:999px;font:600 12.5px/1 var(--lg-font);white-space:nowrap}
.pill svg{width:14px;height:14px}
.pill.pos{background:var(--bp-pos-soft);color:var(--bp-pos)}.pill.neg{background:var(--bp-neg-soft);color:var(--bp-neg)}.pill.warn{background:var(--bp-warn-soft);color:var(--bp-warn)}.pill.info{background:var(--bp-info-soft);color:var(--bp-info)}.pill.neu{background:var(--bp-neu-soft);color:var(--bp-neu)}
.pill.glow{box-shadow:0 0 0 1px color-mix(in srgb,currentColor 22%,transparent),0 4px 14px -4px color-mix(in srgb,currentColor 35%,transparent)}
.badge3d{position:relative;display:inline-grid;place-items:center;flex:none;width:40px;height:40px;border-radius:12px;color:#fff;text-shadow:0 1px 2px rgba(0,24,72,.55);font:700 19px/1 var(--lg-font-display);background:radial-gradient(120% 90% at 30% 15%,rgba(255,255,255,.32),rgba(255,255,255,0) 46%),linear-gradient(145deg,var(--h1),var(--h2));box-shadow:inset 0 -4px 10px rgba(0,0,0,.18),inset 0 1.5px 0 rgba(255,255,255,.6),0 8px 18px -8px var(--h2)}
.badge3d svg{width:22px;height:22px}.badge3d.sm{width:32px;height:32px;border-radius:10px;font-size:16px}.badge3d.sm svg{width:18px;height:18px}
.badge3d.lg{width:56px;height:56px;border-radius:16px;font-size:24px}.badge3d.lg svg{width:28px;height:28px}
.badge3d.neu{--h1:#E7EAF6;--h2:#CDD3EA;color:var(--bp-ink-2);box-shadow:inset 0 1.5px 0 rgba(255,255,255,.8)}
:root[data-theme="dark"] .badge3d.neu{--h1:#2A3266;--h2:#222A58}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]) .badge3d.neu{--h1:#2A3266;--h2:#222A58}}
.hue-blue,.hue-cyan,.hue-violet,.hue-coral{--h1:#2F7FE8;--h2:#1A5BC4}.hue-green{--h1:#23885A;--h2:#1A6E43}

/* ---- progress ---- */
.prog{height:8px;border-radius:999px;background:var(--bp-track);overflow:hidden}
.prog i{display:block;height:100%;border-radius:inherit;background:linear-gradient(90deg,#5EE3F0,#2F7FE6 60%,#1A66D9);transform:scaleX(var(--p,0));transform-origin:left;transition:transform var(--bp-t-pop) var(--bp-ease)}
.prog.ok i{background:linear-gradient(90deg,#34D399,#11703A)}.prog.sm{height:6px}
.prog i::after{content:"";display:block;height:45%;margin:1px 4px 0;border-radius:999px;background:rgba(255,255,255,.45)}

/* ---- tabs, segmented ---- */
.tabbar{position:sticky;top:calc(env(safe-area-inset-top,0px) + 80px);z-index:40;display:inline-flex;gap:4px;padding:4px;border-radius:999px;margin:6px 0 18px}
.tabbar a{display:inline-flex;align-items:center;gap:8px;min-height:44px;padding:0 18px;border-radius:999px;font:600 15px/1 var(--lg-font);color:var(--bp-ink-2);text-decoration:none}
.tabbar a[aria-current="page"]{background:var(--bp-primary);color:var(--bp-on-primary,#fff);box-shadow:var(--bp-glow)}
.tabbar a .n{font:700 12px/1 var(--lg-font);opacity:.8}
@media(max-width:560px){.tabbar{display:flex}.tabbar a{flex:1;justify-content:center;padding:0 10px}}
.seg{display:inline-grid;grid-auto-flow:column;padding:4px;border-radius:999px;background:var(--bp-paper-2);border:1px solid var(--bp-line)}
.seg button{min-height:44px;padding:0 16px;border:0;border-radius:999px;background:none;font:500 15px var(--lg-font);color:var(--bp-ink-2);cursor:pointer;white-space:nowrap}
.seg button[aria-pressed="true"]{background:var(--bp-paper);color:var(--bp-ink);font-weight:650;box-shadow:var(--bp-shadow-1)}

/* ---- stats panel ---- */
.statpanel{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));border-radius:var(--bp-r-card);overflow:hidden}
.stat3{display:grid;grid-template-columns:auto 1fr;gap:4px 14px;align-items:center;padding:18px 20px;min-height:96px}
.stat3+.stat3{border-left:1px solid var(--bp-glass-line)}.stat3 .badge3d{grid-row:span 2}
.stat3 b{font:700 32px/1 var(--lg-font-display);letter-spacing:-.02em;font-variant-numeric:tabular-nums;color:var(--bp-ink)}
.stat3 .lab{font:500 15px/1.3 var(--lg-font);color:var(--bp-ink-2)}.stat3 .sub{grid-column:2;font:500 13px/1.3 var(--lg-font);color:var(--bp-ink-3)}
@media(max-width:700px){.statpanel{grid-template-columns:1fr}.stat3+.stat3{border-left:0;border-top:1px solid var(--bp-glass-line)}.stat3{min-height:72px;padding:14px 16px}.stat3 b{font-size:26px}}

/* ---- tiles ---- */
.tiles{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:14px;margin-top:14px}
.tile{position:relative;overflow:hidden;isolation:isolate;display:flex;flex-direction:column;gap:8px;min-height:164px;padding:16px;border-radius:var(--bp-r-tile);color:inherit;text-decoration:none;cursor:pointer;transition:transform var(--bp-t-hover) var(--bp-ease)}
.tile .top{display:flex;align-items:center;justify-content:space-between;gap:8px}
.tile .eyebrow,.eyebrow{font:700 12px/1 var(--lg-font);letter-spacing:.06em;text-transform:uppercase;color:var(--bp-ink-3)}
.tile h3{font-size:17px}.tile .ref{font-size:13px;color:var(--bp-ink-3)}
.tile .foot{margin-top:auto;display:flex;flex-direction:column;gap:8px}.tile .foot .row{justify-content:space-between}
@media(hover:hover){a.tile:hover{transform:translateY(-3px)}}
.tile:active{transform:scale(.98)}
.tile.done{box-shadow:var(--bp-spec),0 0 0 2px color-mix(in srgb,var(--bp-pos) 45%,transparent),var(--bp-shadow-1)}
.tile.locked{background:var(--bp-paper-2);box-shadow:none;cursor:default}.tile.locked .badge3d{opacity:.55}.tile.locked:active{transform:none}.tile.locked::after{display:none}
.tile.big{min-height:180px}
@media(max-width:560px){.tiles{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.tile{min-height:150px;padding:14px}}

/* ---- question card (solid) ---- */
.q-card{background:var(--bp-paper);border:1px solid var(--bp-line);border-radius:var(--bp-r-card);padding:20px 22px;margin:14px 0;box-shadow:var(--bp-shadow-1)}
.q-head{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:10px}.q-id{margin-left:auto;font-size:13px;color:var(--bp-ink-3)}
.q-stem{font-size:17px;line-height:1.55;color:var(--bp-ink)}.ptext{font:19px/1.5 var(--math)}
.part{display:grid;grid-template-columns:40px minmax(0,1fr);gap:4px 10px;margin-top:14px;padding-top:14px;border-top:1px solid var(--bp-line)}
.part .lab{font:700 15px/1.6 var(--lg-font);color:var(--bp-tint)}
.ans-row{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:8px}
.ans{flex:1 1 180px;min-width:0;min-height:48px;padding:0 18px;border-radius:999px;border:1px solid var(--bp-field-line);background:var(--bp-field);font:500 17px var(--lg-font);color:var(--bp-ink)}
.ans::placeholder{color:var(--bp-ink-3)}.ans:focus-visible{outline:3px solid var(--bp-focus);outline-offset:2px;border-color:var(--bp-focus)}
.part.ok .ans{border-color:var(--bp-pos)}.part.no .ans{border-color:var(--bp-neg)}
.fb{display:flex;align-items:center;flex-wrap:wrap;gap:6px;font:600 14px/1.4 var(--lg-font);margin-top:8px;color:var(--bp-ink-2)}.fb svg{width:18px;height:18px}
.fb.ok{color:var(--bp-pos)}.fb.no{color:var(--bp-neg)}.fb.ok svg{animation:bp-pop var(--bp-t-pop) var(--bp-spring)}
@keyframes bp-pop{from{transform:scale(.6);opacity:0}}
.xp-chip{font:700 12px/1 var(--lg-font);color:var(--bp-info);background:var(--bp-info-soft);padding:4px 8px;border-radius:999px;animation:bp-rise 900ms var(--bp-ease) both}
@keyframes bp-rise{from{transform:translateY(6px);opacity:0}}
.sol{margin-top:10px;background:var(--bp-paper-2);border-radius:var(--bp-r-inner);padding:14px 16px;font-size:15px}.sol ol,.sol-steps{margin:6px 0 6px 18px;padding:0}.ms{color:var(--bp-ink-2);font-size:14px;margin-top:6px}
.hint{display:flex;gap:8px;margin-top:8px;padding:10px 14px;border-radius:var(--bp-r-inner);background:var(--bp-warn-soft);color:var(--bp-warn);font-size:14px}
.diagram{margin:10px 0}.dg{width:min(380px,100%);height:auto;color:var(--bp-ink)}

/* ---- keypad, dock, menu, sheet, toast ---- */
.keypad{display:grid;grid-template-columns:repeat(10,52px);gap:8px;justify-content:center}
.keypad button{position:relative;overflow:hidden;isolation:isolate;min-width:52px;min-height:52px;border:0;border-radius:var(--bp-r-inner);background:var(--bp-paper);color:var(--bp-ink);font:500 21px var(--math);box-shadow:0 1px 0 var(--bp-line),inset 0 0 0 1px var(--bp-line);cursor:pointer}
.keypad button:active{transform:scale(.94)}.keypad button[data-k="⌫"]{grid-column:span 2;font-family:var(--lg-font)}
.kp-dock{position:fixed;left:50%;bottom:calc(12px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);z-index:45;width:min(720px,calc(100% - 24px));padding:12px;border-radius:28px}
body.has-dock main{padding-bottom:220px}
@media(max-width:560px){.keypad{grid-template-columns:repeat(6,minmax(0,1fr));gap:6px}.keypad button{min-width:0}}
.menu{position:absolute;z-index:60;min-width:260px;padding:8px;border-radius:20px;animation:bp-in var(--bp-t-enter) var(--bp-ease)}
.menu a,.menu button.mi{display:flex;align-items:center;gap:10px;width:100%;min-height:44px;padding:0 12px;border:0;border-radius:12px;background:none;text-align:left;font:500 15px var(--lg-font);color:var(--bp-ink);text-decoration:none;cursor:pointer}
@media(hover:hover){.menu a:hover,.menu button.mi:hover{background:var(--bp-neu-soft)}}
.menu .mhead{display:flex;gap:10px;align-items:center;padding:8px 12px 10px}.menu hr{border:0;border-top:1px solid var(--bp-line);margin:6px 0}
dialog.sheet{border:0;padding:16px;border-radius:24px;width:min(560px,calc(100% - 24px));color:var(--bp-ink);margin:12px auto auto}
dialog.sheet::backdrop{background:rgba(10,15,38,.28)}dialog.sheet[open]{animation:bp-in var(--bp-t-enter) var(--bp-ease)}
@keyframes bp-in{from{transform:translateY(12px);opacity:0}}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));z-index:99;display:flex;align-items:center;gap:8px;min-height:44px;padding:0 18px;border-radius:999px;font:600 15px var(--lg-font);color:var(--bp-ink);transform:translateX(-50%);animation:bp-toast var(--bp-t-enter) var(--bp-ease)}
@keyframes bp-toast{from{transform:translate(-50%,12px);opacity:0}}
body.has-dock .toast{bottom:240px}

/* ---- video, solver, empty, skeleton ---- */
.video,.novideo{width:100%;aspect-ratio:16/9;border-radius:20px;background:#0B1736;border:1px solid rgba(160,170,255,.18);box-shadow:var(--bp-shadow-2);display:block}
.novideo{display:grid;place-items:center;text-align:center;padding:16px;color:#F3F6FF}.novideo .sub{color:#C3CDE6;font-size:14px}.novideo .badge3d{margin:0 auto 10px}
.solver .ans{min-height:48px}.steps-out{list-style:none;margin:12px 0 0;padding:0}
.steps-out li{display:grid;grid-template-columns:32px 1fr;gap:2px 10px;padding:10px 0;border-top:1px solid var(--bp-line)}
.steps-out li:first-child{border-top:0}.steps-out .nb{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:var(--bp-info-soft);color:var(--bp-info);font:700 13px/1 var(--lg-font)}
.steps-out .eqn{font-size:19px;overflow-x:auto}.steps-out .why{grid-column:2;font-size:15px;color:var(--bp-ink-2)}
.empty{display:flex;flex-direction:column;align-items:center;text-align:center;gap:10px;padding:28px 12px}
.skeleton{border-radius:inherit;background:var(--bp-paper-2);position:relative;overflow:hidden}
.skeleton::after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent,rgba(255,255,255,.55),transparent);transform:translateX(-100%);animation:bp-shimmer 1.2s infinite}
:root[data-theme="dark"] .skeleton::after{background:linear-gradient(90deg,transparent,rgba(255,255,255,.06),transparent)}
@keyframes bp-shimmer{to{transform:translateX(100%)}}
.sk-line{height:14px;border-radius:8px;margin:8px 0}.sk-card{height:164px;border-radius:var(--bp-r-tile)}

/* ---- forms, tables, notes, misc ---- */
label{display:flex;flex-direction:column;gap:6px;font-size:14px;font-weight:600;color:var(--bp-ink-2)}label.row{flex-direction:row;font-size:15px;font-weight:500;color:var(--bp-ink);min-height:44px}
.form{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:12px}
.form input,.login input:not([type=checkbox]),select,input[type=date]{min-height:48px;border-radius:14px;border:1px solid var(--bp-field-line);background:var(--bp-field);padding:0 14px;font-size:16px;color:var(--bp-ink);max-width:100%}
input[type=checkbox]{accent-color:#2F5BEA;width:22px;height:22px}
.note{display:flex;gap:10px;background:var(--bp-info-soft);color:var(--bp-info);border-radius:var(--bp-r-inner);padding:12px 14px;font-size:14px}
.note.err{background:var(--bp-neg-soft);color:var(--bp-neg)}.note pre{margin:8px 0;font:15px var(--lg-font-mono);white-space:pre-wrap}
.tbl{overflow-x:auto}table{width:100%;border-collapse:collapse}
th{text-align:left;font-size:12px;color:var(--bp-ink-3);font-weight:700;padding:8px 12px;text-transform:uppercase;letter-spacing:.06em}
td{padding:14px 12px;border-top:1px solid var(--bp-line);vertical-align:middle;font-size:15px}
tr.click{cursor:pointer;min-height:56px}@media(hover:hover){tr.click:hover td{background:var(--bp-paper-2)}}tr.click:active td{background:var(--bp-paper-2)}
.toast-host{position:fixed;inset:0;pointer-events:none}
.foot{padding:34px 0 50px;font-size:13px;color:var(--bp-ink-3)}

/* ---- touch-target fixes (>= 44px hit areas) ---- */
.nav-search input{min-height:44px;align-self:stretch}
.btn.nav-search-btn{flex:none}
.crumb a{min-height:44px;display:inline-flex;align-items:center}
.crumb{padding-top:10px}
input[type=checkbox]{appearance:none;-webkit-appearance:none;width:44px;height:44px;margin:0;display:inline-grid;place-items:center;cursor:pointer;flex:none;background:none;border:0;border-radius:12px}
input[type=checkbox]::before{content:"";width:24px;height:24px;box-sizing:border-box;border-radius:7px;border:2px solid var(--bp-field-line);background:var(--bp-field);transition:transform var(--bp-t-press) var(--bp-ease)}
input[type=checkbox]:checked::before{background:#2F5BEA url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7.5'/%3E%3C/svg%3E") center/16px no-repeat;border-color:#2F5BEA}
input[type=checkbox]:active::before{transform:scale(.9)}input[type=checkbox]:disabled{opacity:.5;cursor:not-allowed}
label.row input[type=checkbox]{margin:0 -6px 0 -10px}
input[type=file]{min-height:48px;padding:0 6px;width:100%;border-radius:999px;border:1px dashed var(--bp-field-line);background:var(--bp-field);color:var(--bp-ink-2);font-size:15px}
input[type=file]::file-selector-button{min-height:36px;margin:6px 12px 6px 4px;padding:0 16px;border:0;border-radius:999px;background:var(--bp-primary);color:var(--bp-on-primary,#fff);font:600 14px var(--lg-font);cursor:pointer}

/* ---- maths answer field (MathLive) ---- */
math-field.mf{display:block;flex:1 1 220px;min-width:0;min-height:48px;padding:2px 16px;border-radius:999px;border:1px solid var(--bp-field-line);background:var(--bp-field);color:var(--bp-ink);font-size:24px;--caret-color:var(--bp-tint);--selection-background-color:transparent;--selection-background-color-focused:transparent;--selection-color:inherit;--contains-highlight-background-color:transparent;--contains-highlight-color:inherit;--placeholder-color:var(--bp-ink-3)}
math-field.mf ::selection{background:transparent;color:inherit}
math-field.mf:focus-within{outline:3px solid var(--bp-focus);outline-offset:2px;border-color:var(--bp-focus)}
math-field.mf::part(menu-toggle){display:none}
.part.ok math-field.mf{border-color:var(--bp-pos)}.part.no math-field.mf{border-color:var(--bp-neg)}
.tip{display:flex;align-items:center;gap:6px;margin-top:10px}
:root{--keyboard-accent-color:#2F5BEA}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]){--keyboard-background:#141a3c;--keyboard-toolbar-text:#c9ceea;--keyboard-key-background-color:#232b5e}}
:root[data-theme="dark"]{--keyboard-background:#141a3c;--keyboard-toolbar-text:#c9ceea}

/* ---- scratchpad ---- */
.pad-btn{position:relative}.pad-dot{width:8px;height:8px;border-radius:50%;background:var(--bp-tint);display:inline-block;margin-left:2px}
.pad{margin:12px 0;border:1px solid var(--bp-line);border-radius:var(--bp-r-inner);background:var(--bp-paper-2);overflow:hidden}
.pad-bar{display:flex;align-items:center;flex-wrap:wrap;gap:6px 10px;padding:6px 8px;border-bottom:1px solid var(--bp-line);background:var(--bp-paper)}
.pad-group{display:flex;gap:4px}
.pad-tool,.pad-page{min-width:44px;min-height:44px;border:0;border-radius:12px;background:none;color:var(--bp-ink-2);display:inline-grid;place-items:center;cursor:pointer;font:600 15px var(--lg-font)}
.pad-tool[aria-pressed="true"],.pad-page[aria-pressed="true"]{background:var(--bp-tint-soft);color:var(--bp-tint-ink)}
.pad-tool:active,.pad-page:active{transform:scale(.94)}
.pad-color{width:44px;height:44px;border:0;background:none;border-radius:12px;display:grid;place-items:center;cursor:pointer}
.pad-color::before{content:"";width:22px;height:22px;border-radius:50%;background:var(--ink);box-shadow:0 0 0 2px var(--bp-paper),0 0 0 3.5px var(--bp-field-line)}
.pad-color[aria-pressed="true"]::before{box-shadow:0 0 0 2px var(--bp-paper),0 0 0 4px var(--bp-tint)}
.pad-pages{display:flex;gap:2px}
.pad-pen{margin-left:4px}.pad-pen input{margin:0 -8px 0 -6px}
.pad-stage{position:relative;padding:0}
.pad-canvas{display:block;width:100%;touch-action:none;background-image:radial-gradient(var(--bp-line) 1.2px,transparent 1.2px);background-size:24px 24px;background-position:12px 12px}
.pad-note{padding:6px 12px 8px}
.pad.full{position:fixed;inset:0;z-index:80;margin:0;border-radius:0;display:flex;flex-direction:column;background:var(--bp-paper)}
.pad.full .pad-stage{flex:1;display:grid;align-items:start;overflow:auto}
body.pad-open{overflow:hidden}

.novideo h3{color:#F3F6FF}.novideo p.sub{color:#C3CDE6;margin-top:4px}
/* virtual keyboard: keep the focused field visible above it */
body.kb-open main{padding-bottom:calc(var(--kb-h,320px) + 24px)}
@media(max-width:560px){.pad-pen{font-size:13px}.pad-bar{gap:2px 6px}}
/* release a11y 22/10: global reduced-motion floor. One-shot animations (banners, speech, toasts) keep their timing so messages still show
   and hide; every LOOPING animation (sparkle, glow, bob, pulse, map rings) plays once and stops; smooth scrolling off. Per-component
   reduce rules above stay (they swap motion for a still state). */
@media (prefers-reduced-motion: reduce){*,*::before,*::after{animation-iteration-count:1!important;scroll-behavior:auto!important}}

.pad-q{padding:10px 14px;border-bottom:1px solid var(--bp-line);background:var(--bp-paper);font-weight:600;max-height:24vh;overflow:auto}.pad{scroll-margin-top:150px}.pad-q-part{margin-top:6px;font-weight:500}

.obq .pad-q{display:none}   /* game cards already show the question right above the pad */

.q-pin{position:fixed;z-index:9998;max-height:30vh;overflow:auto;padding:8px 12px;border-radius:14px;background:rgba(255,255,255,.96);border:1px solid var(--bp-line);box-shadow:0 6px 24px rgba(10,30,70,.22);font-weight:600;font-size:15px;line-height:1.35;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}
.q-pin[hidden]{display:none}.q-pin-part{margin-top:4px;font-weight:500}.q-pin-fig svg{max-height:90px;width:auto}

/* LITE MODE (js/lite.js): the glass blur and big shadows are the costliest paint on iPad Safari */
html.lite *,html.lite *::before,html.lite *::after{-webkit-backdrop-filter:none!important;backdrop-filter:none!important}
html.lite .glass3,html.lite .card{box-shadow:0 2px 8px rgba(10,30,70,.10)!important}

/* 28/10 input parity: taps never wait for a double-tap-zoom decision (no 300 ms) and never select text by accident on controls; pinch-zoom of the page itself stays available */
a, button, [role="button"], summary, label, select, input:not([type="text"]):not([type="search"]):not([type="number"]) { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
/* 30/10 teacher: on a phone the top bar was 43px wider than the screen (the avatar stuck out, page scrolled sideways): tighter gaps and smaller icon buttons */
@media(max-width:430px){.app-nav{gap:4px;padding-left:8px;padding-right:8px}.app-nav>.btn.sm{min-width:38px;width:38px;padding-left:0;padding-right:0}.app-nav .avatar-btn{width:44px;height:44px}}