:root{
  --bg:#f4f6fb; --card:#fff; --ink:#1f2733; --muted:#7a8699;
  --line:#e6eaf2; --accent:#4f66f6; --accent-d:#3b50d6;
  --shadow:0 1px 3px rgba(20,30,60,.08),0 6px 20px rgba(20,30,60,.06);
  --red:#e5484d; --orange:#f5a623; --yellow:#f2d024; --green:#30a46c; --blue:#3b82f6; --purple:#8b5cf6;
}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased}
body[data-admin="0"] .admin-only{display:none !important}

/* ---------- top bar ---------- */
.topbar{display:flex;align-items:center;justify-content:space-between;background:#fff;padding:12px 18px;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30;gap:10px}
.brand{font-weight:700;font-size:17px;display:flex;align-items:center;gap:8px;white-space:nowrap}
.brand-icon{font-size:19px}
.top-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.badge-sample{background:#fff4d6;color:#8a6100;font-size:10px;font-weight:700;padding:4px 8px;border-radius:20px;letter-spacing:.04em}
.btn-ghost{border:1px solid var(--line);background:#fff;color:var(--accent);font-weight:600;font-size:13px;padding:7px 11px;border-radius:8px;cursor:pointer}
.btn-ghost:hover{background:#eef1ff;border-color:var(--accent)}

/* ---------- stats ---------- */
.stats-bar{display:flex;gap:10px;padding:14px 18px 2px;flex-wrap:wrap}
.stat{background:#fff;border:1px solid var(--line);border-radius:12px;padding:10px 16px;min-width:78px;box-shadow:var(--shadow);flex:1 0 auto}
.stat-num{display:block;font-size:22px;font-weight:700;line-height:1.1}
.stat-label{font-size:11px;color:var(--muted)}
.stat-hero{background:linear-gradient(135deg,#4f66f6,#7c3aed);border-color:transparent}
.stat-hero .stat-num{color:#fff}
.stat-hero .stat-label{color:rgba(255,255,255,.85)}

/* ---------- submission summary ---------- */
.summary-wrap{padding:8px 18px 0}
.summary-toggle{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;background:#fff;border:1px solid var(--line);border-radius:12px;padding:11px 16px;font-size:14px;font-weight:600;color:var(--ink);cursor:pointer;box-shadow:var(--shadow)}
.summary-toggle:hover{border-color:var(--accent);color:var(--accent)}
.summary-caret{transition:transform .18s;color:var(--muted)}
.summary-toggle.open .summary-caret{transform:rotate(180deg)}
.summary-body{margin-top:10px}
.summary-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow)}
.summary-table{border-collapse:collapse;width:100%;font-size:14px;min-width:360px}
.summary-table th,.summary-table td{padding:10px 14px;text-align:center;border-bottom:1px solid var(--line);white-space:nowrap}
.summary-table thead th{background:#f2f4fa;color:var(--ink);font-weight:700;font-size:13px;position:sticky;top:0}
.summary-table .sticky-col{text-align:left;font-weight:600;position:sticky;left:0;background:#fff;z-index:1}
.summary-table thead .sticky-col{background:#f2f4fa;z-index:2}
.summary-table .grade-cell{color:var(--ink)}
.summary-table td.zero{color:#c3c9d6}
.summary-table .col-total{font-weight:700;background:#f8f9fd}
.summary-table thead .col-total{background:#eef1ff;color:var(--accent-d)}
.summary-table tfoot td{font-weight:700;background:#f2f4fa;border-top:2px solid var(--line);border-bottom:0}
.summary-table tfoot .grand{background:var(--accent);color:#fff;border-radius:0 0 8px 0}
.summary-table tbody tr:hover td{background:#fbfcff}
.summary-table tbody tr:hover .col-total{background:#eef1ff}

/* ---------- category tabs ---------- */
.tabs{display:flex;gap:8px;padding:12px 18px 4px;overflow-x:auto;-webkit-overflow-scrolling:touch;scrollbar-width:thin;position:sticky;top:56px;background:var(--bg);z-index:20}
.tabs::-webkit-scrollbar{height:5px}
.tabs::-webkit-scrollbar-thumb{background:#cfd8ee;border-radius:5px}
.tab{border:1px solid var(--line);background:#fff;color:var(--ink);font-size:13px;font-weight:600;padding:7px 14px;border-radius:20px;cursor:pointer;white-space:nowrap;flex:0 0 auto}
.tab:hover{border-color:var(--accent);color:var(--accent)}
.tab.active{background:var(--accent);color:#fff;border-color:var(--accent)}
.tab-add{border-style:dashed;color:var(--muted)}

/* ---------- toolbar ---------- */
.toolbar{display:flex;gap:8px;padding:8px 18px 6px;flex-wrap:wrap}
.search-wrap{flex:1 1 220px;min-width:160px}
#search{width:100%;padding:10px 14px;border:1px solid var(--line);border-radius:10px;font-size:14px;background:#fff}
.toolbar select{padding:10px 12px;border:1px solid var(--line);border-radius:10px;font-size:14px;background:#fff;cursor:pointer;flex:1 1 auto;min-width:120px}
#search:focus,.toolbar select:focus,input:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(79,102,246,.12)}

/* ---------- cards ---------- */
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;padding:8px 18px 60px}
.card{position:relative;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px 16px 12px;box-shadow:var(--shadow);overflow:hidden;transition:transform .12s,box-shadow .12s}
.card:hover{transform:translateY(-2px);box-shadow:0 6px 24px rgba(20,30,60,.12)}
.flag-strip{position:absolute;left:0;top:0;bottom:0;width:6px;background:transparent}
.card.is-unread{border-color:#cfd8ee;background:#fbfcff}
.card.is-unread .card-name{font-weight:700}
.dot-unread{width:10px;height:10px;border-radius:50%;background:var(--accent);flex:0 0 auto;margin-top:5px}
.card.is-read .dot-unread{background:transparent;border:2px solid var(--line)}
.card-head{display:flex;justify-content:space-between;gap:10px;align-items:flex-start}
.card-headmain{min-width:0}
.card-name{margin:0;font-size:16px;word-break:break-word}
.card-class{color:var(--muted);font-size:13px;margin-top:2px}
.card-cats{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.chip{font-size:11px;background:#eef1ff;color:var(--accent-d);padding:3px 9px;border-radius:20px;font-weight:600}
.card-message{margin:10px 0;font-size:14px;line-height:1.5;max-height:150px;overflow:auto;word-break:break-word}
.muted{color:var(--muted);font-style:italic}
.card-meta{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:10px}
.meta-item{font-size:11.5px;color:var(--muted);background:#f2f4fa;padding:3px 8px;border-radius:20px;word-break:break-all}
.willing-yes{background:#e5f6ee;color:#1a7a4c}
.willing-no{background:#fdecec;color:#a23a3d}
.card-actions{display:flex;gap:6px;align-items:center;flex-wrap:wrap}
.act{border:1px solid var(--line);background:#fff;border-radius:8px;padding:7px 11px;font-size:13px;font-weight:600;cursor:pointer;color:var(--ink)}
.act:hover{border-color:var(--accent);color:var(--accent)}
.act-view{margin-left:auto;background:var(--accent);color:#fff;border-color:var(--accent)}
.act-view:hover{background:var(--accent-d);color:#fff}
.lbl-mark-unread{display:none}
.card.is-read .lbl-mark-read{display:none}
.card.is-read .lbl-mark-unread{display:inline}

/* done button + state */
.act-done{color:#1a7a4c;border-color:#bfe6cf}
.act-done:hover{background:#e5f6ee;color:#1a7a4c;border-color:#1a7a4c}
.lbl-undone{display:none}
.card.is-done .lbl-done{display:none}
.card.is-done .lbl-undone{display:inline}
.card.is-done{opacity:.72;background:#f7fbf8}
.card.is-done .card-name{text-decoration:none}
.done-badge{display:none;color:#30a46c;font-size:15px;margin-top:2px;margin-right:4px}
.card.is-done .done-badge{display:inline}
.card.is-done .dot-unread{display:none}

/* flag picker */
.flag-picker{position:relative}
.flag-menu{position:absolute;bottom:110%;left:0;background:#fff;border:1px solid var(--line);border-radius:10px;padding:8px;display:none;gap:6px;box-shadow:var(--shadow);z-index:5;flex-wrap:wrap;width:130px}
.flag-picker.open .flag-menu{display:flex}
.fc{width:22px;height:22px;border-radius:50%;cursor:pointer;border:2px solid rgba(0,0,0,.08);display:inline-flex;align-items:center;justify-content:center;font-size:12px;color:#666}
.fc-red{background:var(--red)}.fc-orange{background:var(--orange)}.fc-yellow{background:var(--yellow)}
.fc-green{background:var(--green)}.fc-blue{background:var(--blue)}.fc-purple{background:var(--purple)}
.fc-clear{background:#fff}
.fc:hover{transform:scale(1.15)}
.flag-red .flag-strip{background:var(--red)}.flag-orange .flag-strip{background:var(--orange)}
.flag-yellow .flag-strip{background:var(--yellow)}.flag-green .flag-strip{background:var(--green)}
.flag-blue .flag-strip{background:var(--blue)}.flag-purple .flag-strip{background:var(--purple)}

.empty{text-align:center;color:var(--muted);padding:50px 20px;font-size:15px}

/* ---------- modals ---------- */
.modal{position:fixed;inset:0;z-index:60;display:none;align-items:center;justify-content:center;padding:16px}
.modal.is-open{display:flex}
.modal[hidden]{display:none !important}
.modal-backdrop{position:absolute;inset:0;background:rgba(20,28,50,.5)}
.modal-box{position:relative;background:#fff;border-radius:16px;max-width:620px;width:100%;max-height:88vh;overflow:auto;padding:24px 22px 20px;box-shadow:0 30px 70px rgba(0,0,0,.35)}
.modal-sm{max-width:420px}
.modal-box .flag-strip{border-radius:16px 0 0 16px}
.modal-close{position:absolute;top:12px;right:14px;border:0;background:#f2f4fa;width:32px;height:32px;border-radius:50%;cursor:pointer;font-size:15px;z-index:2}
.modal-close:hover{background:#e6eaf2}
#mName{margin:0 0 2px;font-size:21px;padding-right:36px;word-break:break-word}
.modal-class{color:var(--muted);font-size:14px;margin-bottom:10px}
.modal-cats{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:12px}
.modal-message{font-size:15px;line-height:1.6;word-break:break-word;background:#f8f9fd;border:1px solid var(--line);border-radius:12px;padding:15px;margin-bottom:14px}
.modal-meta{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}
.modal-actions{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.modal-actions.right{justify-content:flex-end}
.modal-box h3{margin:0 0 6px;font-size:19px;padding-right:36px}
.hint{color:var(--muted);font-size:12.5px;line-height:1.5;margin:4px 0 12px}
.fld-label{display:block;font-size:12px;font-weight:700;color:var(--muted);text-transform:uppercase;letter-spacing:.04em;margin:6px 0}
.modal-box input[type=text],.modal-box input[type=password]{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:10px;font-size:14px;margin-bottom:8px}
.modal-box hr{border:0;border-top:1px solid var(--line);margin:18px 0 14px}
.login-error{background:#fdecec;color:#c0292d;border-radius:8px;padding:9px 12px;font-size:13px;margin-bottom:10px}
.settings-msg{background:#e5f6ee;color:#1a7a4c;border-radius:8px;padding:9px 12px;font-size:13px;margin:8px 0}

/* category assign checklist */
.cat-checklist{display:flex;flex-direction:column;gap:8px;margin-bottom:14px;max-height:220px;overflow:auto}
.cat-check{display:flex;align-items:center;gap:9px;font-size:14px;padding:8px 10px;border:1px solid var(--line);border-radius:9px;cursor:pointer}
.cat-check input{width:17px;height:17px}
.cat-add-row{display:flex;gap:8px;margin-bottom:14px}
.cat-add-row input{flex:1;margin:0}
.cat-manage{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:10px}
.chip-del{cursor:pointer;background:#f2f4fa;color:var(--ink)}
.chip-del b{color:var(--red);margin-left:2px}
.chip-del:hover{background:#fdecec}

/* ---------- mobile ---------- */
@media(max-width:640px){
  .topbar{padding:10px 12px}
  .brand{font-size:15px}
  .stats-bar{padding:10px 12px 2px;gap:8px}
  .stat{min-width:0;padding:9px 10px}
  .stat-num{font-size:19px}
  .tabs{padding:10px 12px 4px;top:52px}
  .toolbar{padding:8px 12px 4px}
  .toolbar select{flex:1 1 100%}
  .cards{grid-template-columns:1fr;padding:8px 12px 60px;gap:12px}
  .modal{padding:0;align-items:flex-end}
  .modal-box{max-width:100%;border-radius:18px 18px 0 0;max-height:92vh;padding:22px 16px 18px}
  .modal-sm{border-radius:18px 18px 0 0}
  .act{padding:9px 12px;font-size:13.5px}
}