/* =========================================================================
     ROSTER — design tokens
     Concept: a teacher's roll-call ledger, rebuilt as software. Ruled lines,
     a hand-stamped attendance mark, and a grade-book numeral face for stats.
     ========================================================================= */
  :root{
    --ink:        #1C2333;
    --ink-soft:   #4A5268;
    --paper:      #F5F6F1;
    --paper-raised:#FFFFFF;
    --rule:       #D8D9CE;
    --ledger:     #1B2A4A;   /* deep register-book navy */
    --ledger-soft:#2E3F63;
    --chalk:      #3F6B4F;   /* chalkboard green — primary accent */
    --chalk-soft: #E4EEE7;
    --gold:       #B8862F;   /* streak / highlight gold */
    --stamp-red:  #A93B2E;
    --stamp-red-soft:#F3E2DF;
    --stamp-green:#2F7A4A;
    --stamp-green-soft:#E1EFE4;
    --amber-soft: #FBF0DC;
    --shadow:     0 1px 2px rgba(28,35,51,.06), 0 6px 20px rgba(28,35,51,.06);
    --radius-s:   4px;
    --radius-m:   8px;
    --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
    --font-sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --font-num:   "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  }

  *{ box-sizing:border-box; }
  html,body{ margin:0; padding:0; }
  body{
    background:var(--paper);
    color:var(--ink);
    font-family:var(--font-sans);
    font-size:15px;
    line-height:1.5;
    -webkit-font-smoothing:antialiased;
  }
  h1,h2,h3,h4{ font-family:var(--font-serif); font-weight:600; margin:0; color:var(--ink); }
  p{ margin:0; }
  a{ color:inherit; }
  button{ font-family:inherit; cursor:pointer; }
  ::selection{ background:var(--chalk-soft); }

  /* ---------- layout shell ---------- */
  .app-shell{ display:flex; min-height:100vh; }
  .sidebar{
    width:232px; flex-shrink:0; background:var(--ledger); color:#EDEFE6;
    display:flex; flex-direction:column; padding:22px 0;
  }
  .sidebar .brand{
    font-family:var(--font-serif); font-size:20px; font-weight:700;
    padding:0 22px 20px; letter-spacing:.2px; border-bottom:1px solid rgba(255,255,255,.12);
    margin-bottom:10px; display:flex; align-items:baseline; gap:8px;
  }
  .sidebar .brand .mark{ color:var(--gold); font-family:var(--font-num); font-size:15px; }
  .sidebar nav{ display:flex; flex-direction:column; gap:2px; padding:6px 12px; flex:1; }
  .sidebar nav button{
    text-align:left; background:none; border:none; color:#C9CDD8;
    padding:10px 14px; border-radius:var(--radius-s); font-size:14px; font-weight:500;
    display:flex; align-items:center; gap:10px; transition:background .15s, color .15s;
  }
  .sidebar nav button:hover{ background:rgba(255,255,255,.06); color:#fff; }
  .sidebar nav button.active{ background:var(--chalk); color:#fff; }
  .sidebar .who{
    padding:14px 22px 4px; margin-top:auto; border-top:1px solid rgba(255,255,255,.12);
    font-size:12.5px; color:#B7BCCB;
  }
  .sidebar .who strong{ display:block; color:#fff; font-size:14px; font-weight:600; }
  .sidebar .signout{
    margin:10px 12px 0; background:none; border:1px solid rgba(255,255,255,.22); color:#EDEFE6;
    padding:8px 14px; border-radius:var(--radius-s); font-size:13px; text-align:center;
  }
  .sidebar .signout:hover{ background:rgba(255,255,255,.08); }

  .main{ flex:1; padding:30px 40px 60px; max-width:1180px; }
  .topline{ display:flex; justify-content:space-between; align-items:baseline; margin-bottom:26px; flex-wrap:wrap; gap:10px; }
  .topline h1{ font-size:26px; }
  .topline .date{ font-family:var(--font-num); color:var(--ink-soft); font-size:13px; }

  /* ---------- stat cards ---------- */
  .stat-row{ display:grid; grid-template-columns:repeat(auto-fit, minmax(150px,1fr)); gap:14px; margin-bottom:28px; }
  .stat-card{
    background:var(--paper-raised); border:1px solid var(--rule); border-radius:var(--radius-m);
    padding:16px 18px; box-shadow:var(--shadow);
  }
  .stat-card .num{ font-family:var(--font-num); font-size:28px; font-weight:600; color:var(--ledger); line-height:1; }
  .stat-card .label{ margin-top:6px; font-size:12.5px; color:var(--ink-soft); }
  .stat-card.accent .num{ color:var(--chalk); }
  .stat-card.warn .num{ color:var(--stamp-red); }

  /* ---------- section blocks ---------- */
  .section{ margin-bottom:34px; }
  .section-head{ display:flex; justify-content:space-between; align-items:center; margin-bottom:14px; }
  .section-head h2{ font-size:18px; }
  .section-head .hint{ font-size:12.5px; color:var(--ink-soft); }

  .card{
    background:var(--paper-raised); border:1px solid var(--rule); border-radius:var(--radius-m);
    box-shadow:var(--shadow); padding:20px;
  }

  /* ---------- today's activity ledger entry ---------- */
  .activity-entry{
    background:var(--paper-raised); border:1px solid var(--rule); border-left:4px solid var(--chalk);
    border-radius:var(--radius-m); padding:18px 20px; margin-bottom:14px; box-shadow:var(--shadow);
  }
  .activity-entry.state-missed{ border-left-color:var(--stamp-red); }
  .activity-entry.state-completed{ border-left-color:var(--stamp-green); opacity:.85; }
  .activity-entry .meta{ display:flex; gap:10px; align-items:center; font-size:12px; color:var(--ink-soft); margin-bottom:6px; font-family:var(--font-num); }
  .activity-entry h3{ font-size:17px; margin-bottom:4px; }
  .activity-entry .desc{ color:var(--ink-soft); font-size:14px; margin:8px 0 14px; }
  .badge{
    display:inline-block; font-size:11px; font-weight:600; padding:2px 9px; border-radius:20px;
    font-family:var(--font-num); letter-spacing:.2px;
  }
  .badge.new{ background:var(--amber-soft); color:var(--gold); }
  .badge.pending{ background:var(--chalk-soft); color:var(--chalk); }
  .badge.completed{ background:var(--stamp-green-soft); color:var(--stamp-green); }
  .badge.missed{ background:var(--stamp-red-soft); color:var(--stamp-red); }

  .response-row{ display:flex; gap:10px; flex-wrap:wrap; }
  .btn{
    border:1px solid var(--rule); background:var(--paper-raised); padding:9px 16px;
    border-radius:var(--radius-s); font-size:13.5px; font-weight:600; color:var(--ink);
    transition:transform .1s, box-shadow .1s;
  }
  .btn:hover{ box-shadow:0 2px 8px rgba(28,35,51,.12); transform:translateY(-1px); }
  .btn.full{ background:var(--stamp-green); border-color:var(--stamp-green); color:#fff; }
  .btn.half{ background:var(--gold); border-color:var(--gold); color:#fff; }
  .btn.none{ background:var(--stamp-red); border-color:var(--stamp-red); color:#fff; }
  .btn.primary{ background:var(--ledger); border-color:var(--ledger); color:#fff; }
  .btn.ghost{ background:transparent; }
  .btn:disabled{ opacity:.5; cursor:not-allowed; transform:none; }

  /* ---------- course cards ---------- */
  .course-grid{ display:grid; grid-template-columns:repeat(auto-fill, minmax(230px,1fr)); gap:16px; }
  .course-card{
    background:var(--paper-raised); border:1px solid var(--rule); border-radius:var(--radius-m);
    padding:18px; box-shadow:var(--shadow); cursor:pointer; transition:border-color .15s;
  }
  .course-card:hover{ border-color:var(--chalk); }
  .course-card h3{ font-size:16px; margin-bottom:12px; }
  .course-card .row{ display:flex; justify-content:space-between; font-size:13px; color:var(--ink-soft); margin-bottom:4px; }
  .course-card .row b{ font-family:var(--font-num); color:var(--ink); }
  .course-card .bar{ height:5px; background:var(--rule); border-radius:3px; margin-top:10px; overflow:hidden; }
  .course-card .bar span{ display:block; height:100%; background:var(--chalk); }

  /* ---------- tables (register book) ---------- */
  table.register{ width:100%; border-collapse:collapse; font-size:13.5px; }
  table.register th{
    text-align:left; font-family:var(--font-sans); font-weight:600; color:var(--ink-soft);
    font-size:11.5px; text-transform:uppercase; letter-spacing:.4px;
    padding:8px 12px; border-bottom:2px solid var(--ink);
  }
  table.register td{ padding:10px 12px; border-bottom:1px solid var(--rule); }
  table.register tr:hover td{ background:var(--paper); }
  table.register td.num{ font-family:var(--font-num); }

  /* ---------- forms ---------- */
  label{ display:block; font-size:13px; font-weight:600; color:var(--ink-soft); margin-bottom:5px; margin-top:14px; }
  label:first-child{ margin-top:0; }
  input, select, textarea{
    width:100%; padding:9px 11px; border:1px solid var(--rule); border-radius:var(--radius-s);
    font-family:inherit; font-size:14px; background:#fff; color:var(--ink);
  }
  input:focus, select:focus, textarea:focus{ outline:2px solid var(--chalk); outline-offset:1px; border-color:var(--chalk); }
  textarea{ min-height:90px; resize:vertical; }

  .grid-2{ display:grid; grid-template-columns:1fr 1fr; gap:0 16px; }

  /* ---------- login ---------- */
  .login-wrap{
    min-height:100vh; display:flex; align-items:center; justify-content:center;
    background:
      linear-gradient(var(--rule) 1px, transparent 1px) 0 0/100% 34px,
      var(--paper);
  }
  .login-card{
    width:380px; background:var(--paper-raised); border:1px solid var(--rule); border-radius:var(--radius-m);
    box-shadow:0 2px 4px rgba(28,35,51,.06), 0 20px 44px rgba(28,35,51,.12); padding:36px 34px;
  }
  .login-card .brand{ font-family:var(--font-serif); font-size:24px; font-weight:700; color:var(--ledger); margin-bottom:2px; }
  .login-card .tag{ font-size:13px; color:var(--ink-soft); margin-bottom:26px; }
  .login-card .err{ background:var(--stamp-red-soft); color:var(--stamp-red); font-size:13px; padding:8px 12px; border-radius:var(--radius-s); margin-top:14px; display:none; }
  .login-card .err.show{ display:block; }
  .role-toggle{ display:flex; border:1px solid var(--rule); border-radius:var(--radius-s); overflow:hidden; margin-bottom:18px; }
  .role-toggle button{ flex:1; background:var(--paper); border:none; padding:9px; font-size:13px; font-weight:600; color:var(--ink-soft); }
  .role-toggle button.active{ background:var(--ledger); color:#fff; }

  /* ---------- chart containers ---------- */
  .chart-row{ display:grid; grid-template-columns:1fr 1fr; gap:18px; }
  .chart-box{ background:var(--paper-raised); border:1px solid var(--rule); border-radius:var(--radius-m); padding:18px; box-shadow:var(--shadow); }
  .chart-box h3{ font-size:14px; margin-bottom:10px; color:var(--ink-soft); font-weight:600; }
  .chart-box canvas{ max-height:230px; }

  .streak-pill{
    display:inline-flex; align-items:center; gap:6px; background:var(--amber-soft); color:var(--gold);
    font-family:var(--font-num); font-size:12.5px; font-weight:700; padding:4px 12px; border-radius:20px;
  }

  .empty{ text-align:center; padding:40px 20px; color:var(--ink-soft); }
  .loader{ text-align:center; padding:60px 20px; color:var(--ink-soft); font-family:var(--font-num); font-size:13px; }

  select#reportRange{ width:auto; display:inline-block; }
  .toolbar{ display:flex; gap:10px; align-items:center; flex-wrap:wrap; margin-bottom:16px; }
  .toolbar select{ width:auto; min-width:160px; }

  .tabs{ display:flex; gap:4px; border-bottom:1px solid var(--rule); margin-bottom:20px; }
  .tabs button{ background:none; border:none; padding:10px 16px; font-size:14px; font-weight:600; color:var(--ink-soft); border-bottom:2px solid transparent; }
  .tabs button.active{ color:var(--ledger); border-bottom-color:var(--chalk); }

  @media (max-width: 900px){
    .app-shell{ flex-direction:column; }
    .sidebar{ width:100%; flex-direction:row; align-items:center; padding:12px 16px; overflow-x:auto; }
    .sidebar .brand{ border:none; padding:0 14px 0 0; margin:0; }
    .sidebar nav{ flex-direction:row; padding:0; }
    .sidebar .who, .sidebar .signout{ display:none; }
    .main{ padding:22px 18px 50px; }
    .chart-row{ grid-template-columns:1fr; }
    .grid-2{ grid-template-columns:1fr; }
  }

  @media (prefers-reduced-motion: reduce){
    .btn, .course-card{ transition:none; }
  }