:root{
  --paper:#FFFFFF; --page:#F3F6FB; --rule:#D9E3F2; --ink:#2342A8; --ink-soft:#E6ECFA;
  --margin:#D7263D; --margin-soft:#FCE7EA; --text:#1B2333; --muted:#5A667D; --hl:#FFE45C; --hl-text:#1B2333;
  --ok:#1E7A4C; --ok-soft:#E3F3EA; --late:#B26A00; --late-soft:#FFF1D6;
  --head:"Bricolage Grotesque","Segoe UI",system-ui,sans-serif;
  --body:"Atkinson Hyperlegible","Segoe UI",system-ui,-apple-system,sans-serif;
  box-sizing:border-box;
  padding-top:env(safe-area-inset-top,0px); padding-bottom:env(safe-area-inset-bottom,0px);
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --paper:#131C2E; --page:#0D1422; --rule:#26344F; --ink:#8FB1FF; --ink-soft:#1C2A49;
    --margin:#FF6B7A; --margin-soft:#3A1D27; --text:#E8EDF7; --muted:#9AA7BF; --hl:#E8C93A; --hl-text:#1B2333;
    --ok:#6BD39B; --ok-soft:#173326; --late:#F2B45A; --late-soft:#3A2C12;
  }
}
*,*::before,*::after{box-sizing:inherit}
html{height:100%;scroll-padding-top:env(safe-area-inset-top,0px)}
body{margin:0;min-height:100%;background:var(--page);color:var(--text);font-family:var(--body);font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased}
button,input,select,textarea{font:inherit;color:inherit}
a{color:var(--ink)}
:focus-visible{outline:3px solid var(--ink);outline-offset:2px;border-radius:4px}
h1,h2,h3{font-family:var(--head);line-height:1.15;margin:0}
[hidden]{display:none !important}

/* top bar */
.top{position:sticky;top:env(safe-area-inset-top,0px);z-index:5;background:var(--page);border-bottom:1px solid var(--rule)}
.top-inner{max-width:1040px;margin:0 auto;padding:10px 20px;display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.brand{font-family:var(--head);font-weight:800;font-size:1.2rem;letter-spacing:-.01em;color:var(--ink);display:flex;align-items:center;gap:9px;text-decoration:none}
.brand svg{flex:none}
.centre-name{color:var(--muted);font-size:.9rem;max-width:220px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.top-right{margin-left:auto;display:flex;gap:8px;align-items:center}
.top-right select{min-height:36px;padding:4px 8px;width:auto}
nav.tabs{display:flex;gap:2px;flex-wrap:wrap;width:100%}
nav.tabs a{padding:7px 13px;border-radius:999px;color:var(--muted);font-weight:700;text-decoration:none}
nav.tabs a[aria-current="page"]{background:var(--ink);color:var(--paper)}
@media (max-width:760px){
  nav.tabs{position:fixed;left:0;right:0;bottom:0;z-index:6;background:var(--paper);border-top:1px solid var(--rule);flex-wrap:nowrap;overflow-x:auto;padding:6px 6px calc(6px + env(safe-area-inset-bottom,0px))}
  nav.tabs a{flex:1 0 auto;text-align:center;font-size:.85rem;padding:9px 10px}
  main{padding-bottom:100px !important}
  .centre-name{display:none}
}

main{max-width:1040px;margin:0 auto;padding:22px 20px 48px}
.banner{background:var(--margin-soft);color:var(--text);border-left:4px solid var(--margin);padding:10px 14px;border-radius:8px;margin-bottom:16px}
.banner.info{background:var(--ink-soft);border-color:var(--ink)}
.view-head{display:flex;align-items:flex-end;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:16px}
.view-head h1{font-size:clamp(1.6rem,4vw,2.2rem);font-weight:800;letter-spacing:-.02em}
.lede{color:var(--muted);margin:6px 0 0;max-width:68ch}
.lede a{font-weight:700}

.btn{border:2px solid var(--ink);background:var(--ink);color:var(--paper);padding:8px 15px;border-radius:10px;font-weight:700;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;gap:6px;white-space:nowrap;line-height:1.3}
.btn.ghost{background:transparent;color:var(--ink)}
.btn.small{padding:4px 10px;font-size:.87rem;border-radius:8px}
.btn.danger{border-color:var(--margin);background:transparent;color:var(--margin)}
.btn.ok{border-color:var(--ok);background:transparent;color:var(--ok)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.linkbtn{background:none;border:0;padding:0;color:var(--ink);font-weight:700;cursor:pointer;text-decoration:underline}

.controls{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-bottom:14px}
input[type=date],input[type=text],input[type=email],input[type=tel],input[type=number],input[type=time],input[type=search],input[type=password],select,textarea{
  background:var(--paper);border:1.5px solid var(--rule);border-radius:10px;padding:8px 12px;min-height:44px;width:100%}
.controls input,.controls select{width:auto}
.field-inline{display:flex;align-items:center;gap:8px;color:var(--muted);font-size:.9rem}

.chips{display:flex;gap:8px;overflow-x:auto;padding-bottom:4px;margin-bottom:14px}
.chip{border:1.5px solid var(--rule);background:var(--paper);border-radius:999px;padding:7px 14px;cursor:pointer;white-space:nowrap;font-weight:700;color:var(--text)}
.chip small{font-weight:400;color:var(--muted);margin-left:6px}
.chip[aria-pressed="true"]{border-color:var(--ink);background:var(--ink-soft);color:var(--ink)}

/* register: the ruled exercise-book page */
.register{background:var(--paper);border:1px solid var(--rule);border-radius:4px 14px 14px 4px;overflow:hidden;position:relative}
.register::before{content:"";position:absolute;top:0;bottom:0;left:52px;width:2px;background:var(--margin);opacity:.75;pointer-events:none}
.reg-head{display:grid;grid-template-columns:54px 1fr auto;align-items:center;padding:14px 14px 10px 0;border-bottom:2px solid var(--rule);gap:4px 0}
.reg-head .title{grid-column:2;padding-left:14px}
.reg-head h2{font-size:1.25rem}
.reg-head .meta{color:var(--muted);font-size:.9rem}
.reg-head .act{grid-column:3}
.row{display:grid;grid-template-columns:54px 1fr auto;align-items:center;min-height:60px;border-bottom:1px solid var(--rule);padding-right:12px}
.row:last-child{border-bottom:0}
.num{font-family:var(--head);font-weight:700;color:var(--margin);text-align:center;font-size:.95rem}
.who{padding:8px 14px;min-width:0}
.who strong{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.who span{color:var(--muted);font-size:.87rem}
.marks{display:flex;gap:6px}
.mark{width:44px;height:44px;border-radius:50%;border:2px solid var(--rule);background:transparent;font-family:var(--head);font-weight:800;font-size:1rem;cursor:pointer;color:var(--muted);transition:transform .12s}
.mark:active{transform:scale(.92)}
.mark.p[aria-pressed="true"]{border-color:var(--ink);color:var(--ink);background:var(--ink-soft)}
.mark.l[aria-pressed="true"]{border-color:var(--late);color:var(--late);background:var(--late-soft)}
.mark.a[aria-pressed="true"]{border-color:var(--margin);color:var(--margin);background:var(--margin-soft)}
.reg-foot{color:var(--muted);font-size:.9rem;margin-top:10px}

.hl{background:linear-gradient(transparent 12%,var(--hl) 12%,var(--hl) 88%,transparent 88%);color:var(--hl-text);padding:0 5px;font-weight:700;border-radius:2px}
.paid{color:var(--ok);font-weight:700}

.inv-row{display:grid;grid-template-columns:54px 1fr auto;gap:4px 0;align-items:center;border-bottom:1px solid var(--rule);padding:10px 12px 10px 0}
.inv-row:last-child{border-bottom:0}
.inv-row .who{padding:0 14px}
.inv-row .amt{white-space:nowrap;text-align:right}
.inv-actions{grid-column:2 / -1;padding-left:14px;display:flex;gap:6px;flex-wrap:wrap}
@media (min-width:761px){
  .inv-row{grid-template-columns:54px 1fr 150px auto}
  .inv-actions{grid-column:auto;justify-content:flex-end}
}
.status{display:inline-block;font-size:.78rem;font-weight:700;border-radius:6px;padding:1px 7px;margin-left:6px;vertical-align:1px}
.status.open{background:var(--margin-soft);color:var(--margin)}
.status.partial{background:var(--late-soft);color:var(--late)}
.status.paid{background:var(--ok-soft);color:var(--ok)}
.status.void{background:var(--rule);color:var(--muted)}
.status.overdue{background:var(--margin);color:#fff}
.section-label{font-family:var(--head);font-weight:700;font-size:1rem;margin:22px 0 8px}

.summary{display:flex;gap:28px;flex-wrap:wrap;margin:4px 0 18px}
.summary div{display:flex;flex-direction:column}
.summary b{font-family:var(--head);font-size:1.45rem;font-weight:800}
.summary span{color:var(--muted);font-size:.88rem}

.list-card{background:var(--paper);border:1px solid var(--rule);border-radius:14px;overflow:hidden}
.item{display:flex;align-items:center;gap:10px;padding:13px 16px;border-bottom:1px solid var(--rule);flex-wrap:wrap}
.item:last-child{border-bottom:0}
.item .grow{flex:1;min-width:190px}
.item strong{display:block}
.sub{color:var(--muted);font-size:.87rem}
.tag{display:inline-block;border:1px solid var(--rule);border-radius:6px;padding:1px 7px;font-size:.8rem;margin:3px 4px 0 0;color:var(--muted)}

.table-wrap{overflow-x:auto;background:var(--paper);border:1px solid var(--rule);border-radius:14px}
table{border-collapse:collapse;width:100%;font-size:.92rem}
th,td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-weight:700;color:var(--muted);font-size:.84rem;white-space:nowrap}
tr:last-child td{border-bottom:0}
td.num-cell,th.num-cell{text-align:right;white-space:nowrap}
tr.clickable{cursor:pointer}
tr.clickable:hover td{background:var(--ink-soft)}

.empty{background:var(--paper);border:1.5px dashed var(--rule);border-radius:14px;padding:30px 24px;text-align:center}
.empty h2{font-size:1.3rem;margin-bottom:6px}
.empty p{color:var(--muted);margin:0 auto 16px;max-width:50ch}
.btns{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}

dialog{border:0;border-radius:16px;padding:0;width:min(580px,calc(100vw - 20px));max-height:calc(100% - 30px);background:var(--paper);color:var(--text);box-shadow:0 20px 60px rgba(10,20,50,.35)}
dialog::backdrop{background:rgba(13,20,34,.55)}
dialog form{padding:22px 22px 18px;display:flex;flex-direction:column;gap:14px}
dialog h2{font-size:1.3rem}
label.f{display:flex;flex-direction:column;gap:5px;font-weight:700;font-size:.92rem}
label.f small,.hint{font-weight:400;color:var(--muted);font-size:.85rem}
.checks{display:flex;flex-wrap:wrap;gap:8px}
.checks label,.toggle{display:flex;align-items:center;gap:8px;border:1.5px solid var(--rule);border-radius:8px;padding:6px 10px;font-weight:400;cursor:pointer}
.checks input,.toggle input{width:18px;height:18px;margin:0;accent-color:var(--ink);flex:none}
.toggle{border:0;padding:4px 0}
.enr{display:grid;grid-template-columns:1fr 130px;gap:8px;align-items:center;border:1.5px solid var(--rule);border-radius:8px;padding:6px 10px}
.enr label{display:flex;gap:8px;align-items:center;font-weight:400;cursor:pointer}
.enr input[type=checkbox]{width:18px;height:18px;accent-color:var(--ink)}
.enr input[type=number]{min-height:36px;padding:4px 8px}
.dlg-actions{display:flex;gap:8px;justify-content:flex-end;flex-wrap:wrap;margin-top:6px}
.dlg-actions .left{margin-right:auto}
.form-err{color:var(--margin);font-size:.9rem;margin:0}
.two{display:grid;grid-template-columns:1fr 1fr;gap:12px}
@media (max-width:520px){.two{grid-template-columns:1fr}}
.kv{display:grid;grid-template-columns:auto 1fr;gap:4px 14px;font-size:.93rem}
.kv dt{color:var(--muted)}
.kv dd{margin:0;font-weight:700}
.copy{display:flex;gap:6px}
.copy input{font-size:.85rem}

.settings{display:grid;gap:18px;max-width:720px}
.panel{background:var(--paper);border:1px solid var(--rule);border-radius:14px;padding:20px;display:flex;flex-direction:column;gap:14px}
.panel h2{font-size:1.15rem}
.note{color:var(--muted);font-size:.9rem;margin:0}

.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:var(--text);color:var(--paper);padding:10px 18px;border-radius:10px;font-weight:700;z-index:20;opacity:0;pointer-events:none;transition:opacity .2s;max-width:calc(100vw - 30px);text-align:center}
.toast.show{opacity:1}
.toast.err{background:var(--margin);color:#fff}
@media (max-width:760px){.toast{bottom:calc(92px + env(safe-area-inset-bottom,0px))}}

/* login */
.auth{min-height:100vh;display:grid;place-items:center;padding:24px}
.auth-card{width:min(420px,100%);background:var(--paper);border:1px solid var(--rule);border-radius:4px 16px 16px 4px;padding:30px 28px 26px 44px;position:relative}
.auth-card::before{content:"";position:absolute;top:0;bottom:0;left:22px;width:2px;background:var(--margin);opacity:.75}
.auth-card form{display:flex;flex-direction:column;gap:14px;margin-top:18px}
.auth-card .brand{font-size:1.4rem}
.loading{color:var(--muted);padding:60px 0;text-align:center}
@media (prefers-reduced-motion:reduce){*{transition:none !important}}

/* portal */
.portal main{max-width:760px}
.portal .head{margin-bottom:18px}
.portal .head h1{font-size:clamp(1.6rem,5vw,2.2rem)}
.att-p{color:var(--ink);font-weight:700}.att-a{color:var(--margin);font-weight:700}.att-l{color:var(--late);font-weight:700}
.att-counts{display:flex;gap:12px;white-space:nowrap;margin-left:auto}
fieldset.panel{margin:0;border:1px solid var(--rule)}
.legend{font-weight:700;font-size:.95rem;padding:0 4px}
.note-body{white-space:pre-line;background:var(--page);border-radius:10px;padding:12px 14px;line-height:1.55}
.note-preview{margin-top:2px}
details.msg{display:block}
details.msg summary{display:flex;flex-direction:column;gap:2px;cursor:pointer;list-style:none}
details.msg summary::-webkit-details-marker{display:none}
details.msg[open] summary{margin-bottom:10px}
details.msg .btns{margin-top:10px}
details summary.linkbtn{display:inline}
.refcard{background:var(--paper);border:1px solid var(--rule);border-left:4px solid var(--margin);border-radius:4px 14px 14px 4px;padding:20px 22px;display:flex;flex-direction:column;gap:10px;max-width:620px}
.refcode{font-family:var(--head);font-weight:800;font-size:clamp(2.2rem,8vw,3.4rem);letter-spacing:.12em;color:var(--ink);line-height:1}
.sr-default{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none;border:0;padding:0}
.install-wrap{max-width:1040px;margin:0 auto;padding:12px 20px 0}
.install-wrap .banner{margin:0}
.install-hint{display:flex;gap:10px;align-items:center;justify-content:space-between;flex-wrap:wrap}
.install-hint[hidden]{display:none}
.auth-card .install-hint{margin:0}
@media (display-mode: standalone){ .top{padding-top:4px} }
.parent-entry{border-top:1px solid var(--rule);padding-top:14px;margin-top:4px;display:flex;flex-direction:column;gap:8px;color:var(--muted);font-size:.92rem}