/* =========================================================
       GRADES MANAGEMENT & STUDENT GRADES SYSTEM
    ========================================================= */
    .gradebook-page-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      padding: 20px 24px;
      background: var(--card-bg, #111827);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    [data-theme="light"] .gradebook-page-header {
      background: #ffffff;
      border-color: #e2e8f0;
    }

    .gradebook-header-title {
      margin: 0 0 4px;
      font-size: 22px;
      font-weight: 800;
      color: var(--ink);
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .gradebook-header-subtitle {
      margin: 0;
      font-size: 13.5px;
      color: var(--muted);
      font-weight: 500;
    }

    .gradebook-header-actions {
      display: flex;
      align-items: center;
      gap: 10px;
      flex-wrap: wrap;
    }

    .grade-header-status-pill {
      display: inline-flex;
      align-items: center;
      gap: 7px;
      padding: 6px 14px;
      border-radius: 999px;
      font-size: 12.5px;
      font-weight: 700;
      transition: all 0.2s ease;
      user-select: none;
    }

    .grade-header-status-pill.saved {
      background: rgba(16, 185, 129, 0.1);
      color: #10b981;
      border: 1px solid rgba(16, 185, 129, 0.3);
    }

    [data-theme="light"] .grade-header-status-pill.saved {
      background: #ecfdf5;
      color: #059669;
      border-color: #a7f3d0;
    }

    .grade-header-status-pill.saving {
      background: rgba(99, 102, 241, 0.1);
      color: #818cf8;
      border: 1px solid rgba(99, 102, 241, 0.3);
    }

    [data-theme="light"] .grade-header-status-pill.saving {
      background: #eef2ff;
      color: #4f46e5;
      border-color: #c7d2fe;
    }

    .grade-header-status-pill.dirty {
      background: rgba(245, 158, 11, 0.1);
      color: #fbbf24;
      border: 1px solid rgba(245, 158, 11, 0.3);
    }

    [data-theme="light"] .grade-header-status-pill.dirty {
      background: #fffbeb;
      color: #d97706;
      border-color: #fde68a;
    }

    .grade-header-status-pill.error {
      background: rgba(239, 68, 68, 0.1);
      color: #f87171;
      border: 1px solid rgba(239, 68, 68, 0.3);
    }

    [data-theme="light"] .grade-header-status-pill.error {
      background: #fef2f2;
      color: #dc2626;
      border-color: #fecaca;
    }

    .grade-spinner-sm {
      width: 13px;
      height: 13px;
      border: 2px solid rgba(99, 102, 241, 0.3);
      border-top-color: var(--brand-indigo, #6366f1);
      border-radius: 50%;
      animation: spin 0.8s linear infinite;
    }

    .grade-status-dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
    }

    .pulse-blue {
      background: #6366f1;
      box-shadow: 0 0 6px #6366f1;
    }

    .pulse-amber {
      background: #f59e0b;
      box-shadow: 0 0 6px #f59e0b;
    }

    .week-today-btn {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      font-weight: 700;
      padding: 6px 12px;
    }

    .week-today-btn.active {
      background: rgba(99, 102, 241, 0.15) !important;
      color: var(--brand-indigo, #6366f1) !important;
      border-color: var(--brand-indigo, #6366f1) !important;
    }

    .teacher-filter-card {
      padding: 18px 20px;
      background: var(--card-bg, #111827);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
    }

    .teacher-filter-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 16px;
      align-items: end;
    }

    @media (max-width: 860px) {
      .teacher-filter-grid {
        grid-template-columns: 1fr;
        gap: 12px;
      }
    }

    .teacher-filter-field {
      display: flex;
      flex-direction: column;
      gap: 6px;
      min-width: 0;
    }

    .teacher-filter-label {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 12px;
      font-weight: 700;
      color: var(--muted);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    /* Responsive Views */
    .grades-desktop-view {
      display: block;
      width: 100%;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
    }

    .grades-mobile-view {
      display: none;
    }

    @media (max-width: 768px) {
      .grades-desktop-view {
        display: none !important;
      }

      .grades-mobile-view {
        display: flex !important;
        flex-direction: column;
        gap: 12px;
        padding: 14px;
      }
    }

    .grades-table-wrap {
      width: 100%;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      background: var(--card-bg, #111827);
    }

    [data-theme="light"] .grades-table-wrap {
      background: #ffffff;
      border-color: #e2e8f0;
    }

    .grades-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      font-size: 13.5px;
      text-align: left;
    }

    .grades-table th {
      padding: 12px 16px;
      font-size: 11.5px;
      font-weight: 800;
      color: var(--muted);
      text-transform: uppercase;
      letter-spacing: 0.6px;
      background: rgba(15, 23, 42, 0.6);
      border-bottom: 1px solid var(--card-border);
      white-space: nowrap;
    }

    [data-theme="light"] .grades-table th {
      background: #f8fafc;
      border-color: #e2e8f0;
      color: #64748b;
    }

    .grades-table td {
      padding: 14px 16px;
      border-bottom: 1px solid var(--card-border);
      vertical-align: middle;
      color: var(--ink);
      transition: background 0.15s;
    }

    .grades-table tr:last-child td {
      border-bottom: none;
    }

    .grades-table tr:hover td {
      background: rgba(99, 102, 241, 0.04);
    }

    .grade-student-avatar {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: rgba(99, 102, 241, 0.15);
      border: 1px solid rgba(99, 102, 241, 0.3);
      color: #818cf8;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 12px;
      flex-shrink: 0;
    }

    .grade-input-field {
      width: 80px;
      box-sizing: border-box;
      padding: 8px 10px;
      border-radius: var(--radius-md);
      border: 1px solid var(--input-border);
      background: var(--input-bg);
      color: var(--ink);
      font-size: 14px;
      font-weight: 800;
      font-family: 'JetBrains Mono', monospace;
      text-align: center;
      outline: none;
      transition: all 0.2s ease;
    }

    .grade-input-field:focus {
      border-color: var(--brand-indigo);
      box-shadow: 0 0 0 3px var(--brand-indigo-light);
      background: var(--card-bg);
    }

    /* Mobile Card Layout */
    .grade-student-card {
      background: var(--card-bg-subtle, rgba(15, 23, 42, 0.5));
      border: 1px solid var(--card-border);
      border-radius: var(--radius-md);
      padding: 14px 16px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      transition: border-color 0.2s, transform 0.2s;
    }

    [data-theme="light"] .grade-student-card {
      background: #ffffff;
      border-color: #e2e8f0;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    }

    .grade-student-card:hover {
      border-color: rgba(99, 102, 241, 0.35);
    }

    .grade-student-card-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 10px;
      flex-wrap: wrap;
    }

    .grade-student-card-body {
      display: grid;
      grid-template-columns: 100px 1fr;
      gap: 10px;
      align-items: center;
    }

    @media (max-width: 480px) {
      .grade-student-card-body {
        grid-template-columns: 1fr;
      }
    }

    .grade-student-card-footer {
      display: flex;
      justify-content: flex-end;
      align-items: center;
      padding-top: 4px;
    }

    .grades-summary-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 16px;
    }

    .grades-summary-card {
      background: var(--card-bg, #111827);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 18px 20px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      position: relative;
      overflow: hidden;
    }

    [data-theme="light"] .grades-summary-card {
      background: #ffffff;
      border-color: #e2e8f0;
    }

    .grades-summary-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 4px;
      height: 100%;
      background: linear-gradient(180deg, var(--brand-indigo), var(--brand-cyan));
    }

    .grades-progress-bar-wrap {
      width: 100%;
      height: 8px;
      background: rgba(148, 163, 184, 0.15);
      border-radius: 999px;
      overflow: hidden;
    }

    .grades-progress-bar-fill {
      height: 100%;
      border-radius: 999px;
      background: linear-gradient(90deg, #6366f1, #38bdf8);
      transition: width 0.5s cubic-bezier(0.16, 1, 0.3, 1);
    }

    .grade-pill-badge {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      padding: 4px 10px;
      border-radius: var(--radius-full, 999px);
      font-size: 12px;
      font-weight: 700;
      font-family: 'JetBrains Mono', monospace;
      white-space: nowrap;
    }

    .grade-pill-high {
      background: rgba(16, 185, 129, 0.15);
      border: 1px solid rgba(16, 185, 129, 0.3);
      color: #34d399;
    }

    .grade-pill-mid {
      background: rgba(56, 189, 248, 0.15);
      border: 1px solid rgba(56, 189, 248, 0.3);
      color: #38bdf8;
    }

    .grade-pill-low {
      background: rgba(245, 158, 11, 0.15);
      border: 1px solid rgba(245, 158, 11, 0.3);
      color: #fbbf24;
    }

    .grade-pill-bad {
      background: rgba(239, 68, 68, 0.15);
      border: 1px solid rgba(239, 68, 68, 0.3);
      color: #f87171;
    }

    .grade-pill-empty {
      background: rgba(148, 163, 184, 0.1);
      border: 1px solid var(--card-border);
      color: var(--muted);
    }

    .badge-indigo {
      background: rgba(99, 102, 241, 0.15);
      border: 1px solid rgba(99, 102, 241, 0.3);
      color: #a5b4fc;
    }

    [data-theme="light"] .badge-indigo {
      background: rgba(79, 70, 229, 0.1);
      border-color: rgba(79, 70, 229, 0.25);
      color: #4f46e5;
    }

    /* =========================================================
       DAILY GRADEBOOK STYLES (Student × Date × Grade)
    ========================================================= */

    .grade-date-range-badge {
      display: inline-flex;
      align-items: center;
      padding: 9px 14px;
      border-radius: var(--radius-md);
      background: var(--input-bg);
      border: 1px solid var(--input-border);
      color: var(--ink);
      font-size: 13px;
      font-weight: 700;
      font-family: 'JetBrains Mono', monospace;
      letter-spacing: -0.2px;
      user-select: none;
    }

    .gradebook-tabs-nav {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 4px;
      background: var(--card-bg-subtle, rgba(15, 23, 42, 0.5));
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      width: fit-content;
    }

    .gradebook-tab-btn {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 16px;
      border-radius: var(--radius-md);
      background: transparent;
      border: none;
      color: var(--muted);
      font-size: 13px;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .gradebook-tab-btn:hover {
      color: var(--ink);
      background: rgba(99, 102, 241, 0.08);
    }

    .gradebook-tab-btn.active {
      background: var(--card-bg);
      color: var(--brand-indigo, #6366f1);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--card-border);
    }

    [data-theme="light"] .gradebook-tab-btn.active {
      background: #ffffff;
      color: #4f46e5;
      border-color: #cbd5e1;
    }

    /* Horizontal Date Navigation Bar & Weekly System */
    .grade-date-nav-wrap {
      display: flex;
      flex-direction: column;
      gap: 12px;
      width: 100%;
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 12px 16px;
      box-shadow: var(--shadow-sm);
    }

    .grade-week-nav-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 12px;
      width: 100%;
      padding-bottom: 10px;
      border-bottom: 1px solid var(--card-border);
      flex-wrap: wrap;
    }

    .week-nav-btn {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 7px 14px;
      font-size: 13px;
      font-weight: 700;
      border-radius: var(--radius-md);
      cursor: pointer;
      transition: all 0.15s ease;
      user-select: none;
    }

    .week-nav-btn:disabled {
      opacity: 0.4;
      cursor: not-allowed;
      transform: none;
    }

    .week-nav-current-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 18px;
      background: rgba(99, 102, 241, 0.1);
      border: 1px solid rgba(99, 102, 241, 0.25);
      border-radius: var(--radius-full, 999px);
      color: var(--ink);
      font-size: 14px;
      font-weight: 800;
      letter-spacing: 0.2px;
    }

    .grade-date-nav-arrow {
      width: 36px;
      height: 36px;
      border-radius: 50%;
      background: var(--card-bg-subtle, rgba(15, 23, 42, 0.4));
      border: 1px solid var(--card-border);
      color: var(--ink);
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      flex-shrink: 0;
      transition: all 0.2s ease;
    }

    .grade-date-nav-arrow:hover {
      border-color: var(--brand-indigo);
      color: var(--brand-indigo);
      transform: scale(1.05);
    }

    .grade-date-nav-arrow:disabled {
      opacity: 0.35;
      cursor: not-allowed;
      transform: none;
    }

    .grade-date-nav-scroll {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: none;
      width: 100%;
      padding: 2px 0;
    }

    .grade-date-nav-scroll::-webkit-scrollbar {
      display: none;
    }

    .grade-date-pill {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 6px 14px;
      min-width: 68px;
      border-radius: var(--radius-md);
      background: var(--card-bg-subtle, rgba(15, 23, 42, 0.4));
      border: 1.5px solid var(--card-border);
      cursor: pointer;
      transition: all 0.2s ease;
      user-select: none;
      flex-shrink: 0;
    }

    .grade-date-pill:hover {
      border-color: var(--brand-indigo);
      transform: translateY(-1px);
    }

    .grade-date-pill .pill-date {
      font-size: 13px;
      font-weight: 800;
      font-family: 'JetBrains Mono', monospace;
      color: var(--ink);
    }

    .grade-date-pill .pill-day {
      font-size: 11px;
      font-weight: 700;
      color: var(--muted);
      margin-top: 2px;
    }

    .grade-date-pill.active {
      background: rgba(99, 102, 241, 0.15);
      border-color: var(--brand-indigo, #6366f1);
      box-shadow: 0 0 0 1px var(--brand-indigo);
    }

    .grade-date-pill.active .pill-date,
    .grade-date-pill.active .pill-day {
      color: var(--brand-indigo, #6366f1);
    }

    [data-theme="light"] .grade-date-pill.active {
      background: rgba(79, 70, 229, 0.1);
      border-color: #4f46e5;
      box-shadow: 0 0 0 1px #4f46e5;
    }

    .grade-date-pill.is-today {
      position: relative;
    }

    .grade-date-pill.is-today::after {
      content: '';
      position: absolute;
      top: 4px;
      right: 4px;
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: var(--brand-cyan, #06b6d4);
      box-shadow: 0 0 6px var(--brand-cyan);
    }

    .grade-date-pill.is-weekend {
      opacity: 0.65;
    }

    /* Selected Day Context Banner */
    .grade-day-context-card {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      padding: 16px 20px;
      background: linear-gradient(135deg, rgba(99, 102, 241, 0.08), rgba(6, 182, 212, 0.04));
      border: 1px solid rgba(99, 102, 241, 0.25);
      border-radius: var(--radius-lg);
    }

    [data-theme="light"] .grade-day-context-card {
      background: #f8fafc;
      border-color: #cbd5e1;
    }

    .grade-day-context-left {
      display: flex;
      flex-direction: column;
      gap: 3px;
    }

    .grade-day-context-date {
      font-size: 15.5px;
      font-weight: 800;
      color: var(--ink);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .grade-day-context-topic {
      font-size: 13px;
      color: var(--muted);
      font-weight: 600;
    }

    .grade-day-context-attendance {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-wrap: wrap;
    }

    .att-stat-chips {
      display: flex;
      align-items: center;
      gap: 8px;
      flex-wrap: wrap;
    }

    .att-stat-pill {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      padding: 4px 10px;
      border-radius: var(--radius-md, 6px);
      font-size: 12px;
      font-weight: 600;
      border: 1px solid var(--card-border);
      background: var(--card-bg);
      user-select: none;
    }

    .att-stat-pill.present {
      color: #10b981;
      border-color: rgba(16, 185, 129, 0.3);
      background: rgba(16, 185, 129, 0.06);
    }

    [data-theme="light"] .att-stat-pill.present {
      background: #ecfdf5;
      color: #047857;
      border-color: #a7f3d0;
    }

    .att-stat-pill.absent {
      color: #ef4444;
      border-color: rgba(239, 68, 68, 0.3);
      background: rgba(239, 68, 68, 0.06);
    }

    [data-theme="light"] .att-stat-pill.absent {
      background: #fef2f2;
      color: #dc2626;
      border-color: #fecaca;
    }

    .att-stat-pill.late {
      color: #f59e0b;
      border-color: rgba(245, 158, 11, 0.3);
      background: rgba(245, 158, 11, 0.06);
    }

    [data-theme="light"] .att-stat-pill.late {
      background: #fffbeb;
      color: #d97706;
      border-color: #fde68a;
    }

    .att-stat-pill.unmarked {
      color: var(--muted);
      border-color: var(--card-border);
      background: rgba(148, 163, 184, 0.06);
    }

    .grade-day-context-right {
      display: flex;
      align-items: center;
      gap: 10px;
      flex-wrap: wrap;
    }

    .grade-day-stat-pill {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 5px 14px;
      border-radius: 999px;
      background: rgba(99, 102, 241, 0.12);
      border: 1px solid rgba(99, 102, 241, 0.25);
      color: var(--brand-indigo, #6366f1);
      font-size: 12.5px;
      font-weight: 700;
    }

    /* Attendance Column & Quick Toggle Button */
    .col-attendance-th,
    .col-attendance-td {
      width: 105px;
      min-width: 105px;
      text-align: center;
      vertical-align: middle;
    }

    .att-cycle-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 5px;
      padding: 5px 10px;
      border-radius: var(--radius-md, 6px);
      font-size: 12px;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.15s ease;
      border: 1px solid transparent;
      min-width: 72px;
      user-select: none;
    }

    .att-cycle-btn.att-present {
      background: rgba(16, 185, 129, 0.12);
      border-color: rgba(16, 185, 129, 0.35);
      color: #10b981;
    }
    [data-theme="light"] .att-cycle-btn.att-present {
      background: #ecfdf5;
      border-color: #a7f3d0;
      color: #047857;
    }

    .att-cycle-btn.att-absent {
      background: rgba(239, 68, 68, 0.12);
      border-color: rgba(239, 68, 68, 0.35);
      color: #f87171;
    }
    [data-theme="light"] .att-cycle-btn.att-absent {
      background: #fef2f2;
      border-color: #fecaca;
      color: #dc2626;
    }

    .att-cycle-btn.att-late {
      background: rgba(245, 158, 11, 0.12);
      border-color: rgba(245, 158, 11, 0.35);
      color: #fbbf24;
    }
    [data-theme="light"] .att-cycle-btn.att-late {
      background: #fffbeb;
      border-color: #fde68a;
      color: #d97706;
    }

    .att-cycle-btn.att-unmarked {
      background: rgba(148, 163, 184, 0.08);
      border-color: rgba(148, 163, 184, 0.2);
      color: var(--muted, #94a3b8);
    }

    /* Gradebook Daily Table & Sticky Column */
    .gradebook-table-scroll {
      width: 100%;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      border-radius: var(--radius-lg);
      border: 1px solid var(--card-border);
      background: var(--card-bg);
      box-shadow: var(--shadow-sm);
    }

    .gradebook-daily-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      font-size: 13.5px;
      text-align: left;
    }

    .gradebook-daily-table th {
      padding: 12px 14px;
      font-size: 11.5px;
      font-weight: 800;
      color: var(--muted);
      text-transform: uppercase;
      letter-spacing: 0.5px;
      background: rgba(15, 23, 42, 0.6);
      border-bottom: 1px solid var(--card-border);
      white-space: nowrap;
      text-align: center;
      user-select: none;
    }

    [data-theme="light"] .gradebook-daily-table th {
      background: #f8fafc;
      border-color: #e2e8f0;
      color: #64748b;
    }

    .gradebook-daily-table th.col-student-th {
      text-align: left;
      min-width: 220px;
    }

    .gradebook-daily-table th.col-date-th {
      min-width: 80px;
      cursor: pointer;
      transition: background 0.15s ease;
    }

    .gradebook-daily-table th.col-date-th:hover {
      background: rgba(99, 102, 241, 0.12);
    }

    .gradebook-daily-table th.col-date-th.col-selected-day {
      background: rgba(99, 102, 241, 0.18);
      color: var(--brand-indigo, #6366f1);
      border-bottom: 2px solid var(--brand-indigo, #6366f1);
    }

    .gradebook-daily-table th.col-date-th.col-current-day {
      border-top: 2px solid var(--brand-cyan, #06b6d4);
    }

    /* Weekend Column Headers & Cells */
    .gradebook-daily-table th.col-date-th.col-weekend-th {
      background: rgba(239, 68, 68, 0.06);
      color: #ef4444;
      border-bottom: 1px solid rgba(239, 68, 68, 0.2);
    }

    .gradebook-daily-table th.col-date-th.col-weekend-th:hover {
      background: rgba(239, 68, 68, 0.12);
    }

    .gradebook-daily-table th.col-date-th.col-weekend-th.col-selected-day {
      background: rgba(239, 68, 68, 0.16);
      color: #ef4444;
      border-bottom: 2px solid #ef4444;
    }

    .gradebook-daily-table th.col-date-th.col-weekend-th.col-current-day {
      border-top: 2px solid var(--brand-indigo, #6366f1);
      box-shadow: inset 0 2px 0 var(--brand-indigo, #6366f1);
    }

    .col-weekend-date,
    .col-weekend-day {
      color: #ef4444 !important;
    }

    .gradebook-daily-table td.col-date-td.col-weekend-td {
      background: rgba(239, 68, 68, 0.02);
    }

    .gradebook-daily-table td {
      padding: 10px 12px;
      border-bottom: 1px solid var(--card-border);
      vertical-align: middle;
      text-align: center;
      transition: background 0.15s ease;
    }

    .gradebook-daily-table tr:last-child td {
      border-bottom: none;
    }

    .gradebook-daily-table tr:hover td {
      background: rgba(99, 102, 241, 0.03);
    }

    /* Disabled cell when no lesson or other teacher or future date */
    .grade-daily-input.grade-cell-disabled,
    .grade-daily-input:disabled {
      background: rgba(148, 163, 184, 0.08) !important;
      border-color: rgba(148, 163, 184, 0.18) !important;
      color: var(--muted, #94a3b8) !important;
      cursor: not-allowed !important;
      pointer-events: none !important;
      opacity: 0.65;
    }

    .col-future-day-th {
      opacity: 0.7;
    }

    .col-future-day-cell {
      opacity: 0.7;
      cursor: not-allowed;
    }

    .grade-date-pill.is-future {
      opacity: 0.65;
    }

    .grade-date-pill.is-weekend {
      border-color: rgba(239, 68, 68, 0.28);
    }

    .grade-date-pill.is-weekend .pill-date,
    .grade-date-pill.is-weekend .pill-day {
      color: #ef4444;
    }


    /* Sticky columns */
    .col-sticky-idx {
      position: sticky;
      left: 0;
      z-index: 4;
      background: var(--card-bg);
      width: 44px;
      min-width: 44px;
      text-align: center;
      font-weight: 700;
      color: var(--muted);
      border-right: 1px solid var(--card-border);
    }

    .col-sticky-student {
      position: sticky;
      left: 44px;
      z-index: 4;
      background: var(--card-bg);
      text-align: left !important;
      min-width: 200px;
      border-right: 1px solid var(--card-border);
      box-shadow: 3px 0 6px rgba(0, 0, 0, 0.06);
    }

    .gradebook-daily-table th.col-sticky-idx {
      z-index: 6;
      background: rgba(15, 23, 42, 0.85);
    }

    .gradebook-daily-table th.col-sticky-student {
      z-index: 6;
      background: rgba(15, 23, 42, 0.85);
      text-align: left !important;
    }

    [data-theme="light"] .col-sticky-idx,
    [data-theme="light"] .col-sticky-student {
      background: #ffffff;
      border-color: #e2e8f0;
    }

    [data-theme="light"] .gradebook-daily-table th.col-sticky-idx,
    [data-theme="light"] .gradebook-daily-table th.col-sticky-student {
      background: #f1f5f9;
      border-color: #e2e8f0;
    }

    /* Daily Input Field */
    .grade-daily-input {
      width: 58px;
      height: 38px;
      box-sizing: border-box;
      padding: 4px 6px;
      border-radius: var(--radius-md);
      border: 1.5px solid var(--input-border);
      background: var(--input-bg);
      color: var(--ink);
      font-size: 13.5px;
      font-weight: 800;
      font-family: 'JetBrains Mono', monospace;
      text-align: center;
      outline: none;
      transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
      -moz-appearance: textfield;
    }

    .grade-daily-input:focus {
      border-color: var(--brand-indigo, #6366f1);
      box-shadow: 0 0 0 2.5px rgba(99, 102, 241, 0.25);
      background: var(--card-bg);
      /* transform: scale removed to eliminate scroll jump and layout re-anchoring */
    }

    /* Suppress native number spinners */
    .grade-daily-input::-webkit-outer-spin-button,
    .grade-daily-input::-webkit-inner-spin-button {
      -webkit-appearance: none;
      margin: 0;
    }

    .grade-daily-input.has-grade {
      background: rgba(16, 185, 129, 0.08);
      border-color: rgba(16, 185, 129, 0.35);
      color: #34d399;
    }

    [data-theme="light"] .grade-daily-input.has-grade {
      background: rgba(16, 185, 129, 0.08);
      border-color: #10b981;
      color: #047857;
    }

    .grade-daily-input.is-dirty {
      border-color: #f59e0b !important;
      background: rgba(245, 158, 11, 0.1) !important;
      color: #fbbf24 !important;
    }

    .col-selected-day-cell {
      background: rgba(99, 102, 241, 0.05);
    }

    .col-current-day-cell {
      background: rgba(6, 182, 212, 0.03);
    }

    /* Average & General Count Badges */
    .grade-avg-badge {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 3px 8px;
      border-radius: var(--radius-md);
      font-size: 12.5px;
      font-weight: 800;
      font-family: 'JetBrains Mono', monospace;
      min-width: 44px;
    }

    .grade-count-badge {
      font-size: 12.5px;
      font-weight: 700;
      font-family: 'JetBrains Mono', monospace;
      color: var(--muted);
    }

    /* Batch Save Bar */
    .gradebook-batch-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
      padding: 14px 20px;
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
    }

    .gradebook-batch-status {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 13px;
      font-weight: 600;
      color: var(--muted);
    }

    .gradebook-batch-status.dirty {
      color: #f59e0b;
      font-weight: 700;
    }

    /* Mobile Adaptations */
    @media (max-width: 768px) {
      .grade-date-nav-wrap {
        padding: 6px 8px;
      }

      .grade-date-pill {
        padding: 6px 10px;
        min-width: 58px;
      }

      .grade-daily-input {
        width: 54px;
        min-height: 48px;
        font-size: 14px;
      }

      .col-sticky-student {
        min-width: 150px;
        max-width: 160px;
      }

      .col-sticky-student .student-full-name {
        max-width: 100px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
      }

      .gradebook-daily-table th.col-date-th {
        min-width: 70px;
      }
    }

    /* Duplicate student account indicators for audit and manual review */
    .grade-dup-flag {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 1px 6px;
      background: rgba(245, 158, 11, 0.15);
      border: 1px solid rgba(245, 158, 11, 0.35);
      color: #f59e0b;
      border-radius: 4px;
      font-size: 10px;
      font-weight: 700;
      letter-spacing: 0.02em;
      user-select: none;
      cursor: help;
    }

    [data-theme="light"] .grade-dup-flag {
      background: #fef3c7;
      border-color: #fcd34d;
      color: #b45309;
    }

    .grade-dup-id-tag {
      font-family: monospace;
      font-size: 10px;
      padding: 1px 4px;
      border-radius: 3px;
      background: rgba(107, 114, 128, 0.15);
      color: var(--muted);
    }

    .grade-dup-notice-banner {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 10px 14px;
      background: rgba(245, 158, 11, 0.08);
      border: 1px solid rgba(245, 158, 11, 0.25);
      border-radius: var(--radius-md);
      font-size: 12.5px;
      font-weight: 600;
      color: var(--ink);
      margin-bottom: 2px;
    }

    [data-theme="light"] .grade-dup-notice-banner {
      background: #fffbeb;
      border-color: #fde68a;
      color: #92400e;
    }