:root{color-scheme:light;--paper:#f4f7fb;--surface:#fff;--ink:#15283d;--muted:#465c74;--line:#d5e1ed;--accent:#235d94;--on-accent:#fff;--wash:#e5effa;--bad:#8d362c;--focus:#305fc4}
*{box-sizing:border-box}
[hidden]{display:none!important}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.5 system-ui,sans-serif}
button,input,select,textarea{font:inherit;color:inherit}
button,select,input,textarea{border:1px solid var(--line);border-radius:8px;background:var(--surface);padding:8px 12px;min-height:44px}
button{cursor:pointer;font-weight:650}
button:hover{border-color:var(--accent)}
button:active{background-color:var(--wash)}
button:disabled{cursor:wait;opacity:.65}
button:focus-visible,select:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible,a:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.primary{background:var(--accent);color:var(--on-accent);border-color:var(--accent)}
.primary:active{background:var(--accent)}
.skip-link{position:absolute;top:8px;left:12px;z-index:5;padding:8px 12px;background:var(--surface);transform:translateY(-160%)}
.skip-link:focus{transform:none}
::selection{background:var(--wash);color:var(--ink)}
.frame{width:min(100% - 48px, 940px);margin-inline:auto}
.masthead{border-bottom:1px solid var(--line);background:var(--surface)}
.masthead-row,.toolbar,.brand,.tabs,.actions,.page-head,.week-control,.week,.legend{display:flex;align-items:center;gap:12px}
.masthead-row,.page-head{justify-content:space-between}
.masthead-row{min-height:64px;gap:8px}
.brand{flex:none;font-weight:760;letter-spacing:-.025em;color:var(--accent)}
.toolbar{font-size:14px;gap:4px;justify-content:flex-end;min-width:0}
#groups{min-width:0;max-width:180px;font-weight:650}
#environment{color:var(--muted)}
.icon-button{flex:none;width:44px;padding:0;display:inline-grid;place-items:center}
.quick-menu{position:relative;margin:0}
.quick-menu summary{display:grid;place-items:center;width:44px;height:44px;padding:0;list-style:none;border-radius:8px}
.quick-menu summary::-webkit-details-marker{display:none}
.quick-menu[open] summary,.quick-menu summary:hover{background:var(--wash)}
.quick-menu-panel{position:absolute;z-index:3;right:0;top:calc(100% + 8px);min-width:224px;max-width:calc(100vw - 24px);display:grid;padding:4px;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.quick-menu-panel button{border:0;text-align:left;background:transparent}
.quick-menu-panel button:hover,.quick-menu-panel button:focus-visible{background:var(--wash)}
.quick-menu-panel #environment:not(:empty){padding:4px 12px}
.tabs{flex-wrap:wrap;gap:4px 20px;border-bottom:1px solid var(--line)}
.tabs button{flex:none;border:0;border-radius:0;background:transparent;padding:12px 0;color:var(--muted)}
.tabs button[aria-current=page]{box-shadow:inset 0 -2px var(--accent);color:var(--accent)}
.tabs button:focus-visible{outline-offset:-2px}
.period-tabs{margin-top:8px}
main{padding-block:28px 56px}
h1,h2,h3,p{margin:0}
h1{font-size:1.875rem;font-weight:700;line-height:1.15;letter-spacing:-.03em}
h2{font-size:22px;letter-spacing:-.025em}
h3{font-size:17px}
.page-head{align-items:flex-end;margin-bottom:24px}
.page-head p,.muted,.meta{color:var(--muted)}
.page-head p{margin-top:4px}
.actions,.legend{flex-wrap:wrap}
.calendar{background:var(--surface);border:1px solid var(--line);border-radius:12px;margin-bottom:24px;padding:8px}
.week-control{justify-content:space-between;gap:4px;padding-left:4px;margin-bottom:4px}
.week-control .actions{gap:0;flex-wrap:nowrap}
.week-control button{border-color:transparent;font-size:13px;padding-inline:8px}
.week-control button:hover{background:var(--wash)}
.week-range{font-size:13px;font-weight:650;color:var(--muted);font-variant-numeric:tabular-nums}
.week{gap:2px}
.week button{flex:1;min-width:0;min-height:52px;border:0;padding:4px 0;display:grid;place-content:center;font-size:12px;font-weight:550;color:var(--muted);background:transparent}
.week button:hover,.week button[aria-current=date]{background:var(--wash);color:var(--accent)}
.week button strong{font-size:19px;font-variant-numeric:tabular-nums}
.week button[aria-pressed=true]{background:var(--accent);color:var(--on-accent)}
.day-heading{display:flex;align-items:baseline;justify-content:space-between;gap:8px;margin-bottom:8px}
.day-heading h2{font-size:1.125rem;line-height:1.3}
.day-heading h2::first-letter{text-transform:uppercase}
.day-heading .meta{white-space:nowrap;font-variant-numeric:tabular-nums}
.section-head{margin-bottom:8px}
.list{border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 16px}
.row>*{min-width:0}
.row+.row{border-top:1px solid var(--line)}
.lesson{display:grid;grid-template-columns:66px minmax(0,1fr) auto}
.lesson-info .meta:empty{display:none}
.lesson-source{margin-top:4px}
.lesson-homework{margin-top:8px;font-size:14px}
.shared-section{margin-top:20px}
.shared-section h2{margin-bottom:8px}
.shared-section .list+.list{margin-top:12px}
.shared-actions{margin-bottom:8px}
.lesson-actions{gap:4px}
.lesson-actions button{font-size:13px;padding-inline:8px;border-color:transparent;background:transparent}
.lesson-actions button[data-action=journal]{background:var(--wash);color:var(--accent)}
.lesson-actions button:hover{border-color:var(--line);background:var(--wash)}
.source-status{margin-top:12px}
.time{font-variant-numeric:tabular-nums;font-weight:750;align-self:start;color:var(--accent)}
.time small{display:block;color:var(--muted);font-weight:500}
.meta{font-size:14px;overflow-wrap:anywhere}
.row h3,.row p{overflow-wrap:anywhere}
.posts{white-space:pre-wrap;margin-top:4px}
.tag{display:inline-block;padding:2px 8px;background:var(--wash);color:var(--accent);border-radius:4px;font-size:13px}
.cancelled .tag{color:var(--bad)}
.empty{padding:24px 16px;border:1px dashed var(--line);color:var(--muted);border-radius:8px}
.journal{margin-top:24px}
.legend{gap:8px;margin:12px 0}
.legend span{padding:6px 10px;border-radius:4px;background:var(--wash);font-size:14px}
#journal label{overflow-wrap:anywhere}
#journal .list{margin-top:12px}
#journal>.meta + button{margin-top:8px}
.mark{width:min(50%,240px);flex:none}
dialog{max-width:min(480px,calc(100% - 24px));width:100%;max-height:calc(100dvh - 24px);border:1px solid var(--line);border-radius:12px;background:var(--surface);color:var(--ink);padding:24px}
dialog::backdrop{background:#122640b3}
form{display:grid;gap:12px;margin-top:16px}
label{display:grid;gap:4px;font-weight:600;font-size:14px}
form input,form select,form textarea{width:100%;min-width:0;font-size:16px}
textarea{min-height:104px;resize:vertical}
.fields{display:grid;gap:8px;grid-template-columns:1fr 1fr}
.notice{position:fixed;z-index:2;right:12px;bottom:12px;max-width:min(440px,calc(100% - 24px));background:var(--ink);color:var(--paper);padding:12px 16px;border-radius:8px}
.error{color:var(--bad)}
details{margin:16px 0}
summary{cursor:pointer;color:var(--accent);padding:8px 0;font-weight:650}
a{color:var(--accent)}
@media (max-width:560px), (horizontal-viewport-segments:2){
  .frame{width:calc(100% - 24px)}
  main{padding-top:20px}
  .masthead-row{min-height:56px}
  .brand{gap:8px}
  #groups{max-width:94px;padding-inline:4px;font-size:13px}
  .tabs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:4px;padding-block:4px}
  .tabs button{padding:6px 4px;border-radius:8px;font-size:14px;line-height:1.25;overflow-wrap:anywhere}
  .tabs button[aria-current=page]{background:var(--wash);box-shadow:none}
  .page-head{align-items:flex-start;flex-direction:column;gap:12px;margin-bottom:16px}
  main:has(.calendar) > .page-head{align-items:center;flex-direction:row;flex-wrap:wrap;gap:8px}
  main:has(.calendar) > .page-head h1{font-size:1.625rem}
  .row{padding:12px;gap:8px}
  .student-row,#journal .row{flex-direction:column;align-items:stretch}
  .student-row .actions{gap:8px}
  .mark{width:100%}
  .lesson{grid-template-columns:48px minmax(0,1fr)}
  .lesson .actions{grid-column:2;gap:4px}
}
@media(prefers-color-scheme:dark){
  :root{color-scheme:dark;--paper:#121e2c;--surface:#19293b;--ink:#edf5ff;--muted:#b8cae0;--line:#354b62;--accent:#a6d2ff;--on-accent:#132a43;--wash:#263e58;--bad:#ffaca0;--focus:#bed8ff}
  .brand svg path{stroke:var(--on-accent)}
}
.schedule-preview{max-height:38vh;overflow:auto;overscroll-behavior:contain}

.schedule-tools{margin-block:16px 0}
.schedule-tools summary{min-height:44px}
.setting-toggle{display:flex;align-items:center;gap:12px;min-height:40px}
.setting-toggle input{width:20px;min-height:20px;height:20px;accent-color:var(--accent)}

.admin-stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(136px,1fr));gap:8px;margin:12px 0}
.admin-stats div{background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:12px}
.admin-stats dt{font-size:.875rem;color:var(--muted)}
.admin-stats dd{margin:4px 0 0;font-size:1.5rem;font-weight:700;font-variant-numeric:tabular-nums}

.gradebook-controls{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:12px}
.gradebook-controls label{min-width:0}
.gradebook-controls select{max-width:min(100%, 320px)}
.gradebook-hint{margin-bottom:8px}
.gradebook-scroll{overflow:auto;border:1px solid var(--line);border-radius:12px;background:var(--surface)}
.gradebook-scroll:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.gradebook{border-spacing:0;min-width:100%;font-size:14px;font-variant-numeric:tabular-nums}
.gradebook th,.gradebook td{padding:4px 8px;text-align:center;border-bottom:1px solid var(--line)}
.gradebook thead th{white-space:nowrap;background:var(--wash)}
.gradebook th:first-child{position:sticky;left:0;z-index:1;text-align:left;min-width:124px;max-width:176px;border-right:1px solid var(--line);overflow-wrap:anywhere;white-space:normal}
.gradebook tbody th{background:var(--surface)}
.gradebook th small{display:block;font-weight:500;color:var(--muted)}
.gradebook td button{min-width:44px;padding-inline:4px;border-color:transparent;background:transparent}
.gradebook td button:hover,.gradebook td button:focus-visible{background:var(--wash)}
.gradebook td button:focus-visible{outline-offset:-2px}
.grade-origin{display:block;white-space:nowrap;color:var(--muted);font-weight:500}
.gradebook tbody tr:last-child>*{border-bottom:0}
.gradebook-average{font-weight:700;color:var(--accent);background:var(--wash)}
.personal-grade-table{width:100%;border-spacing:0;font-size:14px;font-variant-numeric:tabular-nums}
.personal-grade-table th,.personal-grade-table td{padding:8px;border-bottom:1px solid var(--line);text-align:left;overflow-wrap:anywhere}
.personal-grade-table thead th{background:var(--wash)}
.personal-grade-table tbody tr:last-child>*{border-bottom:0}
.personal-grade-table small{display:block;color:var(--muted);font-weight:400}
.personal-grade-table button{padding-inline:8px}
.attendance-calendar{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:4px;text-align:center}
.attendance-calendar button{padding:4px 0;font-size:14px}
.attendance-calendar button.marked-date{background:var(--wash);font-weight:750}
.attendance-calendar button.marked-date::after{content:"";display:block;width:5px;height:5px;margin:2px auto 0;border-radius:50%;background:var(--accent)}