:root{
    --primary:#2383e2; --primary-soft:#e8f1fc; --primary-dark:#1a6cc0;
    --green:#0f9d58; --green-soft:#e3f5ec;
    --amber:#d9820b; --amber-soft:#fdf1dd;
    --red:#e03e3e; --red-soft:#fbe4e4;
    --text:#37352f; --text-2:#6b6a65; --muted:#9b9a97;
    --bg:#ffffff; --bg-2:#f7f7f5; --bg-3:#efeeec;
    --border:#e9e9e7; --border-2:#dcdbd8;
    --radius:6px; --radius-lg:10px;
    --shadow:0 1px 2px rgba(15,15,15,.05);
    --shadow-md:0 4px 14px rgba(15,15,15,.10);
    --shadow-lg:0 12px 34px rgba(15,15,15,.16);
    --font:-apple-system,BlinkMacSystemFont,"Segoe UI","Hiragino Kaku Gothic ProN","Hiragino Sans","Noto Sans JP",Meiryo,sans-serif;
  }
  *{box-sizing:border-box}
  html,body{margin:0;padding:0}
  body{font-family:var(--font);color:var(--text);background:var(--bg-2);font-size:15px;line-height:1.7;-webkit-font-smoothing:antialiased}
  .hidden{display:none!important}
  .sr-only{position:absolute!important;width:1px!important;height:1px!important;padding:0!important;margin:-1px!important;overflow:hidden!important;clip:rect(0,0,0,0)!important;white-space:nowrap!important;border:0!important}
  .skip-link{position:fixed;top:8px;left:8px;z-index:3000;padding:8px 14px;border-radius:var(--radius);background:var(--text);color:#fff;transform:translateY(-150%)}
  .skip-link:focus{transform:translateY(0)}
  a{color:var(--primary);text-decoration:none}
  button{font-family:inherit}
  button:focus-visible,a:focus-visible,[tabindex]:focus-visible,.inp:focus-visible,.ta:focus-visible,.sel:focus-visible,.search:focus-visible{outline:3px solid var(--primary);outline-offset:2px}

  /* ---------- Buttons ---------- */
  .btn{display:inline-flex;align-items:center;gap:6px;padding:8px 14px;border-radius:var(--radius);border:1px solid var(--border-2);
       background:var(--bg);color:var(--text);font-size:14px;font-weight:500;cursor:pointer;transition:.12s;white-space:nowrap}
  .btn:hover{background:var(--bg-2)}
  .btn-primary{background:var(--primary);border-color:var(--primary);color:#fff}
  .btn-primary:hover{background:var(--primary-dark)}
  .btn-primary:disabled{background:var(--bg-3);border-color:var(--border);color:var(--muted);cursor:not-allowed}
  .btn-ghost{border-color:transparent;background:transparent;color:var(--text-2)}
  .btn-ghost:hover{background:var(--bg-3)}
  .btn-sm{padding:5px 10px;font-size:13px}
  .btn-block{width:100%;justify-content:center}
  .btn-lg{padding:11px 20px;font-size:15px}

  /* ---------- Shell ---------- */
  .topbar{height:52px;background:var(--bg);border-bottom:1px solid var(--border);display:flex;align-items:center;
          padding:0 18px;gap:10px;position:sticky;top:0;z-index:50}
  .brand{display:flex;align-items:center;gap:9px;font-weight:600;font-size:15px}
  .brand .logo{width:24px;height:24px;border-radius:6px;background:var(--text);color:#fff;display:flex;align-items:center;justify-content:center;font-size:14px}
  .topbar .spacer{flex:1}
  .role-pill{font-size:12px;color:var(--text-2);background:var(--bg-3);padding:3px 10px;border-radius:20px}
  .demo-flag{font-size:11px;color:var(--amber);background:var(--amber-soft);padding:3px 9px;border-radius:20px;font-weight:600}

  .wrap{max-width:820px;margin:0 auto;padding:36px 20px 80px}
  .wrap-wide{max-width:1160px}

  /* ---------- Landing ---------- */
  .landing{max-width:760px;margin:0 auto;padding:70px 20px}
  .landing h1{font-size:26px;margin:0 0 6px;letter-spacing:-.01em}
  .landing .sub{color:var(--text-2);margin:0 0 34px}
  .role-cards{display:grid;grid-template-columns:1fr 1fr;gap:16px}
  .role-card{width:100%;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:26px;color:var(--text);font:inherit;cursor:pointer;transition:.14s;text-align:left}
  .role-card:hover{border-color:var(--primary);box-shadow:var(--shadow-md);transform:translateY(-1px)}
  .role-card .ic{width:40px;height:40px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-size:20px;margin-bottom:14px}
  .role-card h3{margin:0 0 4px;font-size:17px}
  .role-card p{margin:0;color:var(--text-2);font-size:13px}
  @media(max-width:640px){.role-cards{grid-template-columns:1fr}}

  /* ---------- Card / panel ---------- */
  .card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:24px;margin-bottom:18px;box-shadow:var(--shadow)}
  .card h2{margin:0 0 4px;font-size:18px}
  .card .lead{color:var(--text-2);margin:0 0 18px;font-size:13px}
  .section-title{font-size:12px;font-weight:700;letter-spacing:.06em;color:var(--muted);text-transform:uppercase;margin:0 0 12px}

  /* ---------- Forms ---------- */
  .fg{margin-bottom:16px}
  .lbl{display:block;font-size:13px;font-weight:600;margin-bottom:6px}
  .req{color:var(--red);font-weight:700}
  .inp,.ta,.sel{width:100%;padding:10px 12px;border:1px solid var(--border-2);border-radius:var(--radius);font-size:14px;font-family:inherit;background:var(--bg);transition:.12s;color:var(--text)}
  .inp:focus,.ta:focus,.sel:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
  .ta{resize:vertical;min-height:90px;line-height:1.7}
  .hint{font-size:12px;color:var(--muted);margin-top:5px}
  .row{display:flex;gap:12px;flex-wrap:wrap}
  .row>.fg{flex:1;min-width:180px}

  /* ---------- Assignment box ---------- */
  .assignment{background:var(--bg-2);border:1px solid var(--border);border-left:3px solid var(--primary);border-radius:var(--radius);padding:16px 18px;margin-bottom:18px;white-space:pre-wrap;font-size:14px}
  .assignment .cap{font-size:11px;font-weight:700;letter-spacing:.06em;color:var(--muted);text-transform:uppercase;margin-bottom:6px}
  .meta-line{display:flex;flex-wrap:wrap;gap:14px;font-size:12px;color:var(--text-2);margin-bottom:16px}
  .meta-line b{color:var(--text)}

  /* ---------- Editor ---------- */
  .editor-shell{border:1px solid var(--border-2);border-radius:var(--radius);overflow:hidden;transition:.12s}
  .editor-shell:focus-within{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
  .editor{width:100%;min-height:320px;border:none;padding:16px;font-size:15px;line-height:1.9;font-family:inherit;resize:vertical;color:var(--text)}
  .editor:focus{outline:none}
  .editor-bar{display:flex;align-items:center;gap:14px;padding:9px 14px;background:var(--bg-2);border-top:1px solid var(--border)}
  .count-wrap{flex:1;display:flex;align-items:center;gap:10px}
  .count-num{font-size:13px;font-weight:600;font-variant-numeric:tabular-nums}
  .count-num .ok{color:var(--green)}
  .count-num .no{color:var(--amber)}
  .pbar{flex:1;max-width:260px;height:6px;background:var(--bg-3);border-radius:20px;overflow:hidden}
  .pbar>i{display:block;height:100%;background:var(--amber);width:0;transition:.2s}
  .pbar>i.done{background:var(--green)}
  .lock-note{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--muted)}
  .draft-note{font-size:12px;color:var(--muted);margin-top:8px;display:flex;align-items:center;gap:6px}
  body.writing-active{overflow:hidden;background:#eef0f3}
  body.writing-active .topbar{display:none}
  #view-student .wrap.writing-mode{max-width:none;height:100vh;padding:0}
  .writing-card{height:100vh;min-width:960px;margin:0;padding:0;border:0;border-radius:0;box-shadow:none;display:flex;flex-direction:column;overflow:hidden}
  .writing-head{height:64px;flex:none;display:flex;align-items:center;gap:18px;padding:0 22px;border-bottom:1px solid var(--border);background:var(--bg);z-index:2}
  .writing-head .backlink{margin:0;padding-right:18px;border-right:1px solid var(--border)}
  .writing-title{font-size:15px;font-weight:700;white-space:nowrap}
  .writing-head .meta-line{margin:0;gap:10px;font-size:12px}
  .writing-head-spacer{flex:1}
  .writing-save{font-size:12px;color:var(--muted);white-space:nowrap}
  .writing-save.saving{color:var(--amber)}
  .writing-save.save-error{color:var(--red)}
  .writing-grid{display:grid;grid-template-columns:370px minmax(0,1fr);flex:1;min-height:0}
  .writing-sidebar{display:flex;flex-direction:column;min-height:0;border-right:1px solid #dfe3e8;background:#f7f8fa}
  .writing-grid .assignment{flex:1;min-height:0;margin:0;padding:32px 28px;border:0;border-radius:0;background:transparent;overflow:auto;white-space:normal;font-size:16px;line-height:2}
  .writing-grid .assignment .cap{display:flex;align-items:center;gap:10px;margin-bottom:12px;padding:0;color:#303943;font-size:15px;font-weight:700;letter-spacing:.02em}
  .writing-grid .assignment .cap::before{content:"";display:block;width:4px;height:21px;border-radius:3px;background:var(--primary)}
  .writing-grid #wAssignment{padding:20px;border:1px solid #dde2e8;border-radius:8px;background:#fff;box-shadow:0 1px 3px rgba(15,15,15,.05);white-space:pre-wrap;font-size:16px;font-weight:500;line-height:2;color:#2f343b}
  .deadline-card{margin-top:14px;padding:14px 16px;border:1px solid #f0cc85;border-radius:8px;background:var(--amber-soft);color:#76500d}
  .deadline-label{font-size:11px;font-weight:700;letter-spacing:.06em;color:#a06408}
  #wDeadline{margin-top:2px;font-size:15px}
  #wDeadline b{font-size:16px;color:#6f4600}
  .previous-submission{margin-top:14px;padding:14px 16px;border:1px solid #b9dfcb;border-radius:8px;background:var(--green-soft);color:#17623d}
  .previous-submission .cap{margin:0 0 3px;padding:0;color:#26734c;font-size:11px;letter-spacing:.06em}
  .previous-submission .cap::before{display:none}
  .previous-submission .meta{font-size:13px;font-weight:700}
  .previous-submission .note{margin:4px 0 0;font-size:11px;line-height:1.5;color:#367457}
  .writing-sidebar .editor-bar{display:block;flex:none;width:auto;margin:0;padding:18px 24px;border:0;border-top:1px solid #dfe3e8;border-radius:0;background:#fff;box-shadow:none}
  .writing-sidebar .count-wrap{gap:12px}
  .writing-sidebar .count-num{font-size:14px;white-space:nowrap}
  .writing-sidebar .pbar{max-width:none}
  .writing-sidebar .submit-hint{display:block;margin-top:9px;font-size:12px;line-height:1.6;color:var(--text-2);white-space:normal}
  .writing-sidebar .lock-note{margin-top:7px;font-size:11px}
  .writing-main{display:flex;flex-direction:column;align-items:center;min-width:0;min-height:0;padding:0 34px;background:#fff;overflow-y:auto}
  .writing-main .editor-shell{width:100%;max-width:900px;flex:none;margin:0 auto;display:block;min-height:calc(100vh - 64px);border:0;border-radius:0;background:#fff;box-shadow:none;overflow:visible}
  .writing-main .editor-shell:focus-within{border-color:transparent;box-shadow:none}
  .writing-main .editor{display:block;width:100%;min-height:calc(100vh - 64px);height:auto;padding:58px 72px 100px;overflow:hidden;resize:none;font-size:17px;line-height:2;color:#292824;background:transparent}
  .writing-main .editor::placeholder{color:#b6b4af}

  /* ---------- Done / receipt ---------- */
  .done-hero{text-align:center;padding:22px 0 8px}
  .done-hero .big{width:66px;height:66px;border-radius:50%;background:var(--green-soft);color:var(--green);display:flex;align-items:center;justify-content:center;font-size:34px;margin:0 auto 14px}
  .done-hero h2{margin:0 0 4px}
  .done-hero p{color:var(--text-2);margin:0}
  .receipt{background:var(--bg-2);border:1px solid var(--border);border-radius:var(--radius);padding:16px 18px;margin:20px 0}
  .receipt dl{display:grid;grid-template-columns:auto 1fr;gap:8px 18px;margin:0}
  .receipt dt{color:var(--text-2);font-size:13px}
  .receipt dd{margin:0;font-size:13px;font-weight:600;font-variant-numeric:tabular-nums}

  /* ---------- Badges ---------- */
  .badge{display:inline-flex;align-items:center;gap:5px;padding:3px 10px;border-radius:20px;font-size:12px;font-weight:600;white-space:nowrap}
  .b-submitted{background:var(--primary-soft);color:var(--primary-dark)}
  .b-graded{background:var(--green-soft);color:var(--green)}
  .b-pending{background:var(--bg-3);color:var(--text-2)}
  .b-late{background:var(--red-soft);color:var(--red)}
  .b-ai{background:#f0e9fb;color:#7b4fc0}

  /* ---------- Tabs ---------- */
  .tabs{display:flex;gap:2px;border-bottom:1px solid var(--border);margin-bottom:22px}
  .tab{padding:9px 16px;cursor:pointer;font-size:14px;color:var(--text-2);border:0;border-bottom:2px solid transparent;background:transparent;margin-bottom:-1px;font-weight:500}
  .tab:hover{color:var(--text)}
  .tab.active{color:var(--text);border-bottom-color:var(--primary);font-weight:600}

  /* ---------- Stats ---------- */
  .stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:22px}
  .stat{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:16px 18px}
  .stat .v{font-size:26px;font-weight:700;font-variant-numeric:tabular-nums}
  .stat .l{font-size:12px;color:var(--text-2);margin-top:2px}
  .stat.hl{border-color:var(--primary)}

  /* ---------- Toolbar ---------- */
  .toolbar{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:16px}
  .search{flex:1;min-width:180px;max-width:340px;padding:8px 12px;border:1px solid var(--border-2);border-radius:var(--radius);font-size:14px;font-family:inherit}
  .search:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
  .seg{display:flex;border:1px solid var(--border-2);border-radius:var(--radius);overflow:hidden}
  .seg button{padding:7px 12px;border:none;background:var(--bg);cursor:pointer;font-size:13px;color:var(--text-2);display:flex;align-items:center;gap:5px}
  .seg button.active{background:var(--text);color:#fff}

  /* ---------- Table ---------- */
  .tbl-wrap{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden}
  table.tbl{width:100%;border-collapse:collapse}
  table.tbl th{text-align:left;padding:11px 16px;font-size:11px;font-weight:700;letter-spacing:.04em;color:var(--muted);text-transform:uppercase;border-bottom:1px solid var(--border);background:var(--bg-2)}
  table.tbl td{padding:11px 16px;font-size:14px;border-bottom:1px solid var(--border)}
  table.tbl tbody tr{cursor:pointer;transition:.1s}
  table.tbl tbody tr:hover{background:var(--primary-soft)}
  table.tbl tbody tr:last-child td{border-bottom:none}
  .table-action{padding:4px 9px}
  #manageList .tbl-wrap{overflow-x:auto}
  #manageList table.tbl{min-width:820px}
  #manageList table.tbl th,#manageList table.tbl td{white-space:nowrap}
  .mono{font-variant-numeric:tabular-nums;color:var(--text-2)}

  /* ---------- Card grid ---------- */
  .grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px}
  .scard{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);padding:16px;cursor:pointer;transition:.14s}
  button.scard{display:block;width:100%;font:inherit;color:inherit;text-align:left}
  .scard:hover{border-color:var(--primary);box-shadow:var(--shadow-md);transform:translateY(-1px)}
  .scard .top{display:flex;justify-content:space-between;align-items:flex-start;gap:8px;margin-bottom:10px}
  .scard .nm{font-weight:600}
  .scard .id{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}
  .scard .foot{display:flex;justify-content:space-between;align-items:center;margin-top:12px;font-size:12px;color:var(--text-2)}

  .empty{text-align:center;padding:50px 20px;color:var(--muted)}
  .empty .ic{font-size:34px;margin-bottom:8px}

  /* ---------- Roster preview ---------- */
  .roster-tbl{max-height:280px;overflow:auto;border:1px solid var(--border);border-radius:var(--radius);margin-top:12px}
  .roster-tbl table{width:100%;border-collapse:collapse}
  .roster-tbl td{padding:7px 14px;font-size:13px;border-bottom:1px solid var(--border)}
  .roster-tbl tr:last-child td{border-bottom:none}
  .drop{border:1.5px dashed var(--border-2);border-radius:var(--radius);padding:22px;text-align:center;color:var(--text-2);cursor:pointer;transition:.12s;background:var(--bg-2)}
  .drop:hover,.drop.over{border-color:var(--primary);background:var(--primary-soft);color:var(--primary-dark)}

  /* ---------- Modal / drawer ---------- */
  .overlay{position:fixed;inset:0;background:rgba(15,15,15,.4);z-index:900;display:none}
  .overlay.active{display:block}
  .drawer{position:fixed;top:0;right:0;height:100%;width:900px;max-width:94vw;background:#e9eaec;z-index:901;
          box-shadow:var(--shadow-lg);transform:translateX(100%);visibility:hidden;transition:transform .22s ease,visibility 0s linear .22s;display:flex;flex-direction:column}
  .drawer.active{transform:translateX(0);visibility:visible;transition-delay:0s}
  .drawer-head{padding:16px 20px;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:12px}
  .drawer-head .nm{font-weight:600;font-size:16px}
  .drawer-head .id{font-size:12px;color:var(--muted)}
  .drawer-body{flex:1;overflow:auto;padding:30px 44px 48px}
  .drawer-foot{padding:14px 20px;border-top:1px solid var(--border);display:flex;gap:10px;justify-content:flex-end;background:var(--bg-2)}
  .report-text{max-width:760px;min-height:980px;margin:0 auto 28px;background:#fff;border:0;border-radius:2px;padding:64px 70px;white-space:pre-wrap;font-family:var(--font);font-size:16px;line-height:2.05;color:#242424;box-shadow:0 3px 18px rgba(15,15,15,.13)}
  .drawer-body>.kv,.drawer-body>.section-title,.drawer-body>#dwAiSection,.drawer-body>.divider,.drawer-body>.grade-row{max-width:760px;margin-left:auto;margin-right:auto}
  .kv{display:flex;gap:14px;flex-wrap:wrap;font-size:12px;color:var(--text-2);margin:10px 0 18px}
  .kv b{color:var(--text)}
  .grade-row{display:flex;gap:12px;align-items:flex-end}
  .score-in{width:110px}
  .ai-box{background:#faf7ff;border:1px solid #ece2fb;border-radius:var(--radius);padding:14px 16px;margin-top:8px;font-size:13px}
  .ai-box h4{margin:0 0 8px;font-size:13px;color:#7b4fc0;display:flex;align-items:center;gap:6px}
  .ai-score{display:inline-block;font-weight:700;font-size:15px}
  .ai-list{margin:6px 0 0;padding-left:18px}
  .ai-list li{margin-bottom:3px}

  /* ---------- Toast ---------- */
  .toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(10px);background:var(--text);color:#fff;
         padding:11px 20px;border-radius:8px;font-size:14px;box-shadow:var(--shadow-lg);z-index:2000;opacity:0;pointer-events:none;transition:.2s}
  .toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
  .toast.err{background:var(--red)}

  .backlink{display:inline-flex;align-items:center;gap:6px;padding:0;border:0;background:transparent;color:var(--text-2);font-size:13px;cursor:pointer;margin-bottom:16px}
  .backlink:hover{color:var(--text)}
  .divider{height:1px;background:var(--border);margin:20px 0}
  .callout{background:var(--amber-soft);border:1px solid #f2dfb8;border-radius:var(--radius);padding:12px 14px;font-size:13px;color:#8a5a08;display:flex;gap:9px}
  code.k{background:var(--bg-3);padding:1px 6px;border-radius:4px;font-size:12px}

  @media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}

  /* ---------- Print (PDF) ---------- */
  @media print{
    body *{visibility:hidden}
    #printArea,#printArea *{visibility:visible}
    #printArea{position:absolute;inset:0;padding:40px 46px}
  }
  #printArea{display:none}
  .print-doc{width:186mm;max-width:100%;margin:0 auto;color:#111;font-size:14px;line-height:1.9}
  .print-doc h1{font-size:19px;border-bottom:2px solid #333;padding-bottom:8px;margin:0 0 16px}
  .print-meta{display:grid;grid-template-columns:auto 1fr;gap:4px 18px;font-size:13px;margin-bottom:18px;break-inside:avoid;page-break-inside:avoid}
  .print-meta dt{color:#555}.print-meta dd{margin:0;font-weight:600}
  .print-assign{max-width:100%;background:#f4f4f2;border-left:3px solid #666;padding:10px 14px;font-size:12px;white-space:pre-wrap;overflow-wrap:anywhere;word-break:break-all;margin-bottom:16px;break-inside:avoid;page-break-inside:avoid}
  .print-body{max-width:100%;overflow-wrap:anywhere;word-break:break-all}
  .print-block{margin:0;white-space:pre-wrap;break-inside:avoid;page-break-inside:avoid}
  .print-block-empty{height:1.9em}