/* =============================================================
   theEducator.ai — Teacher Dashboard Design System
   class-management.css
   Modern, premium, production-ready SaaS educational platform
   ============================================================= */

/* ----------------------------------------------------------
   DESIGN TOKENS
   ---------------------------------------------------------- */
:root {
  /* Brand palette */
  --eai-blue-50:  #eff6ff;
  --eai-blue-100: #dbeafe;
  --eai-blue-200: #bfdbfe;
  --eai-blue-500: #3b82f6;
  --eai-blue-600: #2563eb;
  --eai-blue-700: #1d4ed8;

  /* Neutrals */
  --eai-gray-50:  #f8fafc;
  --eai-gray-100: #f1f5f9;
  --eai-gray-200: #e2e8f0;
  --eai-gray-300: #cbd5e1;
  --eai-gray-400: #94a3b8;
  --eai-gray-500: #64748b;
  --eai-gray-600: #475569;
  --eai-gray-700: #334155;
  --eai-gray-800: #1e293b;
  --eai-gray-900: #0f172a;

  /* Semantic colours */
  --eai-success-bg:   #d1fae5;
  --eai-success-text: #065f46;
  --eai-success-border: #10b981;
  --eai-warning-bg:   #fefce8;
  --eai-warning-text: #854d0e;
  --eai-warning-border: #eab308;
  --eai-danger-bg:    #fee2e2;
  --eai-danger-text:  #991b1b;
  --eai-danger-border: #ef4444;
  --eai-info-bg:      #eff6ff;
  --eai-info-text:    #1e40af;
  --eai-info-border:  #3b82f6;

  /* Score colours */
  --eai-score-green-bg:   #d1fae5;
  --eai-score-green-text: #065f46;
  --eai-score-amber-bg:   #fef3c7;
  --eai-score-amber-text: #92400e;
  --eai-score-red-bg:     #fee2e2;
  --eai-score-red-text:   #991b1b;
  --eai-score-unknown-bg: #f1f5f9;
  --eai-score-unknown-text: #475569;

  /* Surfaces */
  --eai-surface:        #ffffff;
  --eai-surface-raised: #ffffff;
  --eai-bg-page:        #f0f4f8;

  /* Shadows */
  --eai-shadow-sm:  0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --eai-shadow-md:  0 4px 12px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.05);
  --eai-shadow-lg:  0 10px 30px rgba(0,0,0,0.10), 0 4px 12px rgba(0,0,0,0.06);
  --eai-shadow-xl:  0 20px 50px rgba(0,0,0,0.14), 0 8px 20px rgba(0,0,0,0.08);
  --eai-shadow-modal: 0 25px 60px rgba(0,0,0,0.18);

  /* Radii */
  --eai-radius-sm:  6px;
  --eai-radius-md:  10px;
  --eai-radius-lg:  14px;
  --eai-radius-xl:  20px;
  --eai-radius-pill: 999px;

  /* Spacing scale */
  --eai-space-1: 4px;
  --eai-space-2: 8px;
  --eai-space-3: 12px;
  --eai-space-4: 16px;
  --eai-space-5: 20px;
  --eai-space-6: 24px;
  --eai-space-8: 32px;
  --eai-space-10: 40px;
  --eai-space-12: 48px;

  /* Typography */
  --eai-font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', Roboto, sans-serif;
  --eai-font-mono:   'SFMono-Regular', Consolas, 'Liberation Mono', monospace;

  /* Transitions */
  --eai-transition: 0.18s ease;
  --eai-transition-slow: 0.3s ease;
}

/* ----------------------------------------------------------
   NAVIGATION SEPARATORS (preserved original selectors)
   ---------------------------------------------------------- */
.menu-item-eai[data-category="dashboard"] {
    position: relative;
}

.menu-item-eai[data-category="dashboard"]::after {
    content: "";
    position: absolute;
    top: 10%;
    right: -10px;
    height: 80%;
    width: 1px;
    background-color: var(--eai-gray-300);
}

/* Classes Direct Link Styling */
.classes-direct-link {
    position: relative;
}

.classes-direct-link::before {
    content: "";
    position: absolute;
    top: 10%;
    left: -10px;
    height: 80%;
    width: 1px;
    background-color: var(--eai-gray-300);
}

.classes-direct-link:hover {
    background-color: var(--eai-blue-50);
    border-radius: var(--eai-radius-sm);
}

/* =============================================================
   STUDENT SIGN UP FORM
   ============================================================= */

.csuk-auth-wrapper {
    max-width: 480px;
    margin: var(--eai-space-8) auto;
}

.csuk-auth-panel {
    border: 1px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-8);
    background: var(--eai-surface);
    box-shadow: var(--eai-shadow-md);
}

.signup-message {
    margin-bottom: var(--eai-space-4);
}

.signup-error {
    background: var(--eai-danger-bg);
    color: var(--eai-danger-text);
    padding: var(--eai-space-3) var(--eai-space-4);
    border: 1px solid var(--eai-danger-border);
    border-left: 4px solid var(--eai-danger-border);
    border-radius: var(--eai-radius-md);
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: var(--eai-space-4);
}

.eai-coder-custom-form label {
    display: block;
    font-weight: 600;
    color: var(--eai-gray-700);
    margin-bottom: var(--eai-space-1);
    font-size: 0.875rem;
}

.eai-coder-custom-form input[type="text"],
.eai-coder-custom-form input[type="email"],
.eai-coder-custom-form input[type="password"] {
    width: 100%;
    padding: 10px 14px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-md);
    font-size: 0.95rem;
    background: var(--eai-gray-50);
    color: var(--eai-gray-800);
    transition: border-color var(--eai-transition), box-shadow var(--eai-transition);
    box-sizing: border-box;
    margin-bottom: var(--eai-space-4);
}

.eai-coder-custom-form input[type="text"]:focus,
.eai-coder-custom-form input[type="email"]:focus,
.eai-coder-custom-form input[type="password"]:focus {
    border-color: var(--eai-blue-500);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.12);
    outline: none;
    background: var(--eai-surface);
}

#signup-submit-button {
    width: 100%;
    padding: 12px;
    background: var(--eai-blue-600);
    color: #fff;
    border: none;
    border-radius: var(--eai-radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--eai-transition), transform var(--eai-transition);
    margin-top: var(--eai-space-2);
}

#signup-submit-button:hover {
    background: var(--eai-blue-700);
    transform: translateY(-1px);
}

#signup-submit-button:disabled {
    background: var(--eai-gray-400);
    cursor: not-allowed;
    transform: none;
}

/* =============================================================
   MEMBERSHIP ACCESS BOX
   ============================================================= */

.csuk-membership-access-box {
    text-align: center;
    max-width: 560px;
    margin: var(--eai-space-10) auto;
    background: var(--eai-surface);
    padding: var(--eai-space-8) var(--eai-space-10);
    border-radius: var(--eai-radius-xl);
    box-shadow: var(--eai-shadow-lg);
    border: 1px solid var(--eai-gray-200);
}

.csuk-membership-title {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--eai-gray-800);
    margin-bottom: var(--eai-space-3);
}

.csuk-membership-message {
    font-size: 1rem;
    color: var(--eai-gray-500);
    margin-bottom: var(--eai-space-6);
    line-height: 1.6;
}

.csuk-membership-button {
    display: inline-block;
    margin: var(--eai-space-2) var(--eai-space-2);
    padding: 12px 24px;
    border: none;
    border-radius: var(--eai-radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
    box-shadow: var(--eai-shadow-sm);
}

.csuk-membership-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--eai-shadow-md);
}

.csuk-membership-button.trial {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.csuk-membership-button.pro {
    background: linear-gradient(135deg, var(--eai-blue-500) 0%, var(--eai-blue-700) 100%);
    color: white;
}

.csuk-membership-note {
    font-size: 0.825rem;
    color: var(--eai-gray-400);
    margin-top: -4px;
    margin-bottom: var(--eai-space-3);
}

.csuk-membership-or {
    font-weight: 600;
    color: var(--eai-gray-400);
    margin: var(--eai-space-3) 0;
    font-size: 0.85rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

/* =============================================================
   CREATE GROUP FORM
   ============================================================= */

#create-group-form {
    background: var(--eai-surface);
    border: 1px solid var(--eai-gray-200);
    padding: var(--eai-space-8);
    border-radius: var(--eai-radius-lg);
    max-width: 720px;
    margin: 0 auto;
    box-shadow: var(--eai-shadow-md);
    display: flex;
    flex-direction: column;
    gap: var(--eai-space-5);
}

#create-group-form input[type="text"],
#create-group-form input[type="number"],
#create-group-form input[type="password"],
#create-group-form input[type="email"] {
    width: 100%;
    padding: 11px 14px;
    font-size: 0.95rem;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-md);
    background: var(--eai-gray-50);
    color: var(--eai-gray-800);
    transition: border-color var(--eai-transition), box-shadow var(--eai-transition);
    box-sizing: border-box;
}

#create-group-form input:focus {
    border-color: var(--eai-blue-500);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.12);
    outline: none;
    background: var(--eai-surface);
}

#create-group-form input[type="submit"] {
    background: linear-gradient(135deg, var(--eai-blue-500) 0%, var(--eai-blue-600) 100%);
    color: #fff;
    padding: 13px var(--eai-space-8);
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--eai-radius-md);
    cursor: pointer;
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
    box-shadow: 0 4px 14px rgba(59,130,246,0.30);
    letter-spacing: 0.01em;
}

#create-group-form input[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59,130,246,0.40);
}

#create-group-form input[type="submit"]:disabled {
    background: var(--eai-gray-400);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

#create-group-form p {
    font-weight: 500;
    color: var(--eai-gray-600);
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: var(--eai-space-2);
}

#group-message {
    margin-top: var(--eai-space-4);
    text-align: center;
}

#group-message p {
    padding: var(--eai-space-3) var(--eai-space-5);
    border-radius: var(--eai-radius-md);
    font-size: 0.9rem;
    font-weight: 500;
}

#group-message p[style*="color: green;"] {
    background: var(--eai-success-bg);
    color: var(--eai-success-text);
    border-left: 4px solid var(--eai-success-border);
}

#group-message p[style*="color: red;"] {
    background: var(--eai-danger-bg);
    color: var(--eai-danger-text);
    border-left: 4px solid var(--eai-danger-border);
}

.create-group-header {
    text-align: center;
    margin-bottom: var(--eai-space-6);
}

.create-group-header h2 {
    margin: 0 0 var(--eai-space-2);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--eai-gray-800);
    letter-spacing: -0.02em;
}

.create-group-header p {
    margin: 0;
    color: var(--eai-gray-500);
    font-size: 0.95rem;
    line-height: 1.6;
    max-width: 560px;
    margin: 0 auto;
}

#create-group-form label {
    font-weight: 600;
    margin-bottom: var(--eai-space-1);
    display: block;
    color: var(--eai-gray-700);
    font-size: 0.875rem;
}

#create-group-form input[type="number"] {
    width: 50%;
    max-width: 200px;
}

/* =============================================================
   TEACHER DASHBOARD — MAIN CONTAINER
   ============================================================= */

.class-dashboard {
    background: var(--eai-bg-page);
    padding: var(--eai-space-6) var(--eai-space-5);
    border-radius: var(--eai-radius-lg);
    font-family: var(--eai-font-family);
}

.class-dashboard h2 {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--eai-gray-800);
    margin: 0 0 var(--eai-space-6);
    letter-spacing: -0.025em;
    line-height: 1.2;
}

.class-dashboard h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--eai-gray-700);
    margin: var(--eai-space-6) 0 var(--eai-space-4);
    display: flex;
    align-items: center;
    gap: var(--eai-space-2);
    letter-spacing: -0.01em;
}

.class-dashboard h3::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 1.1em;
    background: var(--eai-blue-500);
    border-radius: 2px;
    flex-shrink: 0;
}

.empty-class-message {
    background: var(--eai-surface);
    padding: var(--eai-space-10) var(--eai-space-8);
    border-radius: var(--eai-radius-lg);
    border: 1.5px dashed var(--eai-gray-300);
    text-align: center;
    color: var(--eai-gray-500);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* =============================================================
   TASK TABLE
   ============================================================= */

.dashboard-table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--eai-radius-lg);
    box-shadow: var(--eai-shadow-md);
    background: var(--eai-surface);
}

.dashboard-table {
    width: 100%;
    border-collapse: collapse;
    margin: 0;
    background: var(--eai-surface);
    border-radius: var(--eai-radius-lg);
    overflow: hidden;
    font-size: 0.875rem;
}

.dashboard-table thead {
    position: sticky;
    top: 0;
    z-index: 10;
}

.dashboard-table th {
    background: var(--eai-gray-800);
    color: var(--eai-gray-100);
    font-weight: 600;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 13px 16px;
    text-align: left;
    white-space: nowrap;
    border-bottom: none;
}

.dashboard-table td {
    padding: 13px 16px;
    border-bottom: 1px solid var(--eai-gray-100);
    color: var(--eai-gray-700);
    vertical-align: middle;
    line-height: 1.5;
}

.dashboard-table tbody tr {
    transition: background-color var(--eai-transition);
}

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

.dashboard-table tbody tr:hover {
    background-color: var(--eai-blue-50);
}

.dashboard-table th:nth-child(1),
.dashboard-table td:nth-child(1) {
    width: 36%;
}

.dashboard-table th:nth-child(n+2),
.dashboard-table td:nth-child(n+2) {
    width: 11%;
}

/* Task title link */
.csuk-open-assessment-modal {
    cursor: pointer;
    color: var(--eai-blue-600) !important;
    font-weight: 500;
    text-decoration: none !important;
    transition: color var(--eai-transition);
    display: inline-block;
}

.csuk-open-assessment-modal:hover {
    color: var(--eai-blue-700) !important;
    text-decoration: underline !important;
}

/* Score pill */
.avg-score {
    font-weight: 600;
    font-size: 0.8rem;
    padding: 4px 10px;
    border-radius: var(--eai-radius-pill);
    display: inline-flex;
    align-items: center;
    cursor: default;
    white-space: nowrap;
    letter-spacing: 0.01em;
}

.avg-score.score-green {
    background-color: var(--eai-score-green-bg);
    color: var(--eai-score-green-text);
}

.avg-score.score-amber {
    background-color: var(--eai-score-amber-bg);
    color: var(--eai-score-amber-text);
}

.avg-score.score-red {
    background-color: var(--eai-score-red-bg);
    color: var(--eai-score-red-text);
}

.avg-score.score-unknown {
    background-color: var(--eai-score-unknown-bg);
    color: var(--eai-score-unknown-text);
}

/* Tooltip */
.avg-score[title]:hover::after {
    content: attr(title);
    white-space: pre;
    background: var(--eai-gray-900);
    color: #fff;
    padding: var(--eai-space-2) var(--eai-space-3);
    border-radius: var(--eai-radius-md);
    position: absolute;
    z-index: 999;
    font-size: 0.8rem;
    line-height: 1.5;
    transform: translateY(-110%);
    max-width: 280px;
    box-shadow: var(--eai-shadow-lg);
    pointer-events: none;
}

/* Monitor icon button */
.view-task-details {
    font-size: 1.1rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity var(--eai-transition), transform var(--eai-transition);
    display: inline-block;
    padding: 4px 6px;
    border-radius: var(--eai-radius-sm);
}

.view-task-details:hover {
    opacity: 1;
    transform: scale(1.15);
    background: var(--eai-blue-50);
}

/* Delete assignment button */
.csuk-delete-assignment {
    background: none;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-sm);
    padding: 4px 8px;
    font-size: 0.95rem;
    cursor: pointer;
    color: var(--eai-gray-500);
    transition: background var(--eai-transition), color var(--eai-transition), border-color var(--eai-transition);
    line-height: 1;
}

.csuk-delete-assignment:hover {
    background: var(--eai-danger-bg);
    color: var(--eai-danger-text);
    border-color: var(--eai-danger-border);
}

.csuk-delete-assignment:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

/* Inline date editing */
.csuk-editable-date {
    cursor: pointer;
    border-bottom: 1.5px dashed var(--eai-gray-400);
    transition: background var(--eai-transition), color var(--eai-transition);
    border-radius: 2px;
    padding: 1px 3px;
    color: var(--eai-gray-700);
    font-size: 0.825rem;
}

.csuk-editable-date:hover {
    background: var(--eai-blue-50);
    color: var(--eai-blue-700);
    border-color: var(--eai-blue-400);
}

.csuk-inline-dt {
    font-size: 0.825rem;
    border: 1.5px solid var(--eai-blue-500);
    border-radius: var(--eai-radius-sm);
    padding: 3px 6px;
    background: var(--eai-surface);
    color: var(--eai-gray-800);
    max-width: 200px;
}

/* =============================================================
   PERFORMANCE INSIGHTS CARDS
   ============================================================= */

.student-performance-insights {
    margin-bottom: var(--eai-space-8);
}

.student-performance-insights h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--eai-gray-700);
    margin: 0 0 var(--eai-space-4);
    display: flex;
    align-items: center;
    gap: var(--eai-space-2);
}

.student-performance-insights h3::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 1.1em;
    background: var(--eai-blue-500);
    border-radius: 2px;
}

.csuk-insights-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--eai-space-4);
}

.csuk-insight-card {
    background: var(--eai-surface);
    border: 1px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-5) var(--eai-space-4);
    box-shadow: var(--eai-shadow-sm);
    transition: box-shadow var(--eai-transition-slow), transform var(--eai-transition-slow);
    min-width: 0;
}

.csuk-insight-card:hover {
    box-shadow: var(--eai-shadow-md);
    transform: translateY(-2px);
}

.csuk-card-inner {
    display: flex;
    flex-direction: column;
    gap: var(--eai-space-3);
}

.csuk-insight-card h4 {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--eai-gray-500);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin: 0;
}

.csuk-stat-line {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--eai-space-2);
}

.csuk-stat-label {
    font-size: 0.8rem;
    color: var(--eai-gray-500);
    font-weight: 500;
}

.csuk-circle {
    font-size: 0.8rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--eai-radius-pill);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    letter-spacing: 0.01em;
}

.csuk-insight-assigned {
    background: var(--eai-gray-100);
    color: var(--eai-gray-700);
}

.csuk-insight-attempted {
    background: var(--eai-blue-100);
    color: var(--eai-blue-700);
}

.average_score_sc {
    font-size: 0.8rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--eai-radius-pill);
    display: inline-flex;
    align-items: center;
    min-width: 40px;
    justify-content: center;
}

.average_score_sc.score-green {
    background: var(--eai-score-green-bg);
    color: var(--eai-score-green-text);
}

.average_score_sc.score-amber {
    background: var(--eai-score-amber-bg);
    color: var(--eai-score-amber-text);
}

.average_score_sc.score-red {
    background: var(--eai-score-red-bg);
    color: var(--eai-score-red-text);
}

.average_score_sc.score-unknown {
    background: var(--eai-score-unknown-bg);
    color: var(--eai-score-unknown-text);
}

/* =============================================================
   DASHBOARD ACTION BUTTONS (GROUP TOOLS)
   ============================================================= */

.dashboard-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: var(--eai-space-4);
    margin: var(--eai-space-6) 0;
    max-width: 800px;
}

.dashboard-button {
    background: var(--eai-surface);
    border: 1.5px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-5) var(--eai-space-3);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--eai-space-2);
    box-shadow: var(--eai-shadow-sm);
    transition: transform var(--eai-transition-slow), box-shadow var(--eai-transition-slow), border-color var(--eai-transition-slow), background var(--eai-transition-slow);
    cursor: pointer;
    text-align: center;
    min-height: 110px;
}

.dashboard-button:hover {
    transform: translateY(-4px);
    box-shadow: var(--eai-shadow-lg);
    border-color: var(--eai-blue-300);
    background: var(--eai-blue-50) !important;
}

.dashboard-button img {
    width: 48px;
    height: 48px;
    object-fit: contain;
    transition: transform var(--eai-transition);
}

.dashboard-button:hover img {
    transform: scale(1.08);
}

.dashboard-button span {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--eai-gray-700);
    line-height: 1.3;
}

.dashboard-button.danger {
    background: var(--eai-danger-bg);
    border-color: var(--eai-danger-border);
    color: var(--eai-danger-text);
}

.dashboard-button.danger:hover {
    background: #fca5a5 !important;
    border-color: var(--eai-danger-border);
    transform: translateY(-3px);
}

/* =============================================================
   DASHBOARD MODALS (TOOL PANELS)
   ============================================================= */

.dashboard-modal-wrapper {
    display: none;
    position: fixed;
    z-index: 9999;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    justify-content: center;
    align-items: center;
    animation: eai-backdrop-in var(--eai-transition-slow) ease;
}

@keyframes eai-backdrop-in {
    from { opacity: 0; }
    to   { opacity: 1; }
}

.dashboard-modal {
    background: var(--eai-surface);
    border-radius: var(--eai-radius-xl);
    box-shadow: var(--eai-shadow-modal);
    position: relative;
    overflow-y: auto;
    width: calc(100vw - 48px);
    height: calc(100vh - 48px);
    max-width: 1480px;
    max-height: calc(100vh - 48px);
    margin: auto;
    animation: eai-modal-in 0.22s cubic-bezier(0.34, 1.56, 0.64, 1);
    padding: var(--eai-space-8);
}

@keyframes eai-modal-in {
    from { opacity: 0; transform: scale(0.96) translateY(10px); }
    to   { opacity: 1; transform: scale(1) translateY(0); }
}

/* Close button — shared between modal types */
.dashboard-modal-close,
.eai-modal-close-mb,
.csuk-modal-close,
#csuk-modal-close {
    position: sticky;
    top: 0;
    float: right;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--eai-gray-800);
    color: #fff;
    font-size: 20px;
    font-weight: 700;
    border-radius: var(--eai-radius-pill);
    cursor: pointer;
    z-index: 20;
    transition: background var(--eai-transition), transform var(--eai-transition);
    line-height: 1;
    margin-left: auto;
    border: none;
    flex-shrink: 0;
}

.dashboard-modal-close:hover,
.eai-modal-close-mb:hover,
.csuk-modal-close:hover,
#csuk-modal-close:hover {
    background: var(--eai-danger-border);
    transform: scale(1.08);
}

/* =============================================================
   MARKBOOK TABLE
   ============================================================= */

.eai_markbook_table {
    overflow: auto;
    width: 100%;
    max-height: 800px;
    display: block;
    padding-right: 4px;
    border-radius: var(--eai-radius-lg);
    box-shadow: var(--eai-shadow-md);
    background: var(--eai-surface);
}

.eai_markbook_table table {
    border-collapse: collapse;
    width: 100%;
    font-size: 10px;
    border: none;
}

.eai_markbook_table thead {
    position: sticky !important;
    top: 0;
    height: 150px;
    z-index: 50;
    background: var(--eai-surface);
}

.eai_markbook_table thead tr {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--eai-surface);
}

.eai_markbook_table th,
.eai_markbook_table td {
    border: 1px solid var(--eai-gray-200);
    text-align: center;
    white-space: nowrap;
    color: var(--eai-gray-800) !important;
}

.eai_markbook_table th {
    color: var(--eai-gray-700) !important;
    border: none;
    z-index: 1 !important;
    cursor: pointer;
}

.eai_markbook_table tr th:first-child,
.eai_markbook_table tr td:first-child {
    min-width: 110px;
    text-align: left;
    position: sticky;
    left: 0;
    background-color: var(--eai-surface);
    color: var(--eai-gray-800) !important;
    z-index: 2;
    font-weight: 600;
    padding-left: var(--eai-space-3);
}

.eai_markbook_table tr th:not(:first-child),
.eai_markbook_table tr td:not(:first-child) {
    max-width: 46px;
    min-width: 46px;
    width: 46px;
    height: 32px;
    padding: 0;
    vertical-align: middle;
}

.eai_markbook_table th:not(:first-child) {
    height: 108px;
    position: relative;
    padding: 0;
}

.eai_markbook_table th:not(:first-child) > div {
    transform: translate(5px, 73px) rotate(-45deg);
    width: 30px;
    pointer-events: none;
}

.eai_markbook_table th:not(:first-child) > div > span {
    padding: 7px 10px 5px 25px;
    border-top: 1px solid var(--eai-gray-200);
    box-sizing: border-box;
    font-size: 8px;
    color: var(--eai-gray-600);
    pointer-events: none;
}

/* Markbook score cell colours */
.eai_markbook_table td.green  { background: var(--eai-score-green-bg); }
.eai_markbook_table td.amber  { background: var(--eai-score-amber-bg); }
.eai_markbook_table td.red    { background: var(--eai-score-red-bg); }
.eai_markbook_table td.neutral { background: var(--eai-score-unknown-bg); }

.eai_markbook_table td.green span  { color: var(--eai-score-green-text) !important; font-weight: 600; }
.eai_markbook_table td.amber span  { color: var(--eai-score-amber-text) !important; font-weight: 600; }
.eai_markbook_table td.red span    { color: var(--eai-score-red-text) !important; font-weight: 600; }
.eai_markbook_table td.neutral span { color: var(--eai-score-unknown-text) !important; }

.eai_markbook_table td.student-row {
    cursor: pointer;
    transition: background var(--eai-transition);
}

.eai_markbook_table td.student-row:hover {
    background-color: var(--eai-blue-50);
}

/* Sortable headers */
th.sortable {
    cursor: pointer;
    position: relative;
    user-select: none;
}

th.sortable:hover {
    background-color: var(--eai-gray-100);
}

th.sorted-asc::after {
    content: "â–²";
    position: absolute;
    right: 6px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 10px;
    color: var(--eai-blue-500);
    opacity: 0.8;
}

th.sorted-desc::after {
    content: "â–¼";
    position: absolute;
    right: 6px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 10px;
    color: var(--eai-blue-500);
    opacity: 0.8;
}

/* Markbook CSV export button */
#export-markbook-csv {
    display: inline-flex;
    align-items: center;
    gap: var(--eai-space-2);
    margin: var(--eai-space-3) 0;
    padding: 9px 18px;
    font-size: 0.875rem;
    font-weight: 600;
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    border: none;
    border-radius: var(--eai-radius-md);
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(16,185,129,0.3);
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
}

#export-markbook-csv:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(16,185,129,0.4);
}

/* =============================================================
   MARKBOOK TASK REVIEW MODAL (eai-modal-mb)
   ============================================================= */

.eai-modal-mb {
    display: none;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    box-sizing: border-box;
    padding: 16px 0;
    overflow-y: auto;
}

.eai-modal-mb.active {
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.eai-modal-content-mb {
    margin-top: var(--eai-space-10);
    background: var(--eai-surface);
    padding: var(--eai-space-6);
    border: none;
    width: 84%;
    max-width: 1400px;
    border-radius: var(--eai-radius-xl);
    box-shadow: var(--eai-shadow-modal);
    max-height: calc(100vh - 80px);
    overflow-y: auto;
    position: relative;
    animation: eai-modal-in 0.22s cubic-bezier(0.34,1.56,0.64,1);
}

/* =============================================================
   ASSESSMENT REVIEW MODAL (split-pane)
   ============================================================= */

#assessment-review-modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 92%;
    max-width: 1500px;
    height: 90%;
    background: var(--eai-surface);
    border-radius: var(--eai-radius-xl);
    z-index: 9999;
    box-shadow: var(--eai-shadow-modal);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.csuk-modal-content {
    display: flex;
    flex-direction: row;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

/* Left panel */
#assessment-student-list {
    width: 260px;
    min-width: 220px;
    border-right: 1px solid var(--eai-gray-200);
    padding: var(--eai-space-5) var(--eai-space-4);
    background: var(--eai-gray-50);
    overflow-y: auto;
    flex-shrink: 0;
}

#assessment-student-list h4 {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--eai-gray-500);
    margin: 0 0 var(--eai-space-3);
    padding-bottom: var(--eai-space-2);
    border-bottom: 1px solid var(--eai-gray-200);
}

#assessment-student-list table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

#assessment-student-list td {
    padding: 7px 6px;
    border-bottom: 1px solid var(--eai-gray-200);
    font-size: 0.825rem;
    color: var(--eai-gray-700);
}

#assessment-student-list td:first-child {
    font-weight: 500;
}

#assessment-student-list td.student-score {
    cursor: pointer;
    text-align: center;
    width: 48px;
    transition: background var(--eai-transition);
    border-radius: var(--eai-radius-sm);
    font-weight: 600;
    font-size: 0.8rem;
}

#assessment-student-rows .student-score {
    text-align: center;
    width: 48px;
    height: 32px;
    padding: 4px 6px;
    border-radius: var(--eai-radius-sm);
}

/* Right panel */
#assessment-detail-panel {
    flex: 1;
    padding: var(--eai-space-6);
    overflow-y: auto;
    box-sizing: border-box;
}

#assessment-detail-panel h4 {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--eai-gray-500);
    margin: 0 0 var(--eai-space-4);
    padding-bottom: var(--eai-space-2);
    border-bottom: 1px solid var(--eai-gray-200);
}

#assessment-detail-content {
    width: 100%;
    box-sizing: border-box;
}

/* Modal overlay */
#modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.55);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
    z-index: 999;
}

/* Student score cells */
.student-score {
    cursor: pointer;
    color: var(--eai-gray-800);
    transition: background var(--eai-transition);
    border-radius: var(--eai-radius-sm);
}

.selected-student-score {
    border: 2px solid var(--eai-blue-500) !important;
    box-shadow: 0 0 0 2px rgba(59,130,246,0.25);
}

/* Score cells colour */
.student-score.score-green  { background: var(--eai-score-green-bg); color: var(--eai-score-green-text); }
.student-score.score-amber  { background: var(--eai-score-amber-bg); color: var(--eai-score-amber-text); }
.student-score.score-red    { background: var(--eai-score-red-bg);   color: var(--eai-score-red-text); }
.student-score.score-unknown { background: var(--eai-score-unknown-bg); color: var(--eai-score-unknown-text); }

/* =============================================================
   ASSESSMENT / MCQ PREVIEW MODAL
   ============================================================= */

#csuk-assessment-modal {
    display: none;
    position: fixed;
    z-index: 9999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.csuk-assessment-content {
    background: var(--eai-surface);
    margin: 4% auto;
    padding: var(--eai-space-6);
    border-radius: var(--eai-radius-xl);
    width: 92%;
    max-width: 1400px;
    max-height: 88vh;
    overflow-y: auto;
    box-shadow: var(--eai-shadow-modal);
    position: relative;
    animation: eai-modal-in 0.22s cubic-bezier(0.34,1.56,0.64,1);
}

.csuk-close-wrapper {
    position: sticky;
    top: 0;
    display: flex;
    justify-content: flex-end;
    z-index: 20;
    padding: 0;
    margin-bottom: -44px;
}

#csuk-assessment-loader {
    text-align: center;
    padding: var(--eai-space-8);
    color: var(--eai-gray-500);
    font-size: 0.95rem;
}

/* =============================================================
   QUESTION REVIEW CONTENT
   ============================================================= */

.question-content {
    margin-bottom: var(--eai-space-4);
    font-style: italic;
    color: var(--eai-gray-600);
    line-height: 1.6;
    font-size: 0.95rem;
}

.marking-block ul {
    padding-left: var(--eai-space-5);
}

.marking-block ul li {
    margin-bottom: var(--eai-space-2);
    font-size: 0.9rem;
    color: var(--eai-gray-700);
    line-height: 1.5;
}

.assessment-summary {
    margin-top: var(--eai-space-8);
    background: var(--eai-info-bg);
    padding: var(--eai-space-5);
    border-radius: var(--eai-radius-md);
    font-weight: 600;
    border-left: 4px solid var(--eai-info-border);
    color: var(--eai-info-text);
    font-size: 0.95rem;
}

.review-heading {
    margin-bottom: var(--eai-space-5);
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--eai-gray-800);
}

/* =============================================================
   GROUP MANAGEMENT — TEACHER ENROLMENT FORM
   ============================================================= */

.current-students-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    margin-top: var(--eai-space-3);
    border-radius: var(--eai-radius-md);
    overflow: hidden;
    box-shadow: var(--eai-shadow-sm);
}

.current-students-table th,
.current-students-table td {
    border-bottom: 1px solid var(--eai-gray-200);
    padding: 10px 14px;
    text-align: left;
}

.current-students-table th {
    background: var(--eai-gray-800);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--eai-gray-100);
    border-bottom: none;
}

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

.current-students-table tr:nth-child(even) {
    background-color: var(--eai-gray-50);
}

.current-students-table tr:hover {
    background-color: var(--eai-blue-50);
    transition: background-color var(--eai-transition);
}

.csuk-current-students {
    background: var(--eai-surface);
    border: 1px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-5);
    margin-bottom: var(--eai-space-5);
    box-shadow: var(--eai-shadow-sm);
}

.csuk-current-students h4 {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--eai-gray-700);
    margin: 0 0 var(--eai-space-4);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* =============================================================
   ENROLMENT SUB-TABS
   ============================================================= */

.csuk-enrolment-subtabs {
    display: flex;
    margin-top: var(--eai-space-5);
    margin-bottom: var(--eai-space-5);
    gap: 0;
    border-bottom: 2px solid var(--eai-gray-200);
}

.csuk-subtab {
    padding: 10px 20px;
    cursor: pointer;
    border: 1.5px solid var(--eai-gray-200);
    border-bottom: none;
    background: var(--eai-gray-100);
    border-radius: var(--eai-radius-md) var(--eai-radius-md) 0 0;
    margin-right: 4px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--eai-gray-600);
    transition: background var(--eai-transition), color var(--eai-transition);
    position: relative;
    bottom: -2px;
}

.csuk-subtab:hover {
    background: var(--eai-gray-200);
    color: var(--eai-gray-800);
}

.csuk-subtab.active {
    background: var(--eai-surface);
    border-top: 2.5px solid var(--eai-blue-500);
    font-weight: 700;
    color: var(--eai-blue-600);
    border-color: var(--eai-gray-200);
    border-bottom-color: var(--eai-surface);
}

.csuk-subtab-content {
    background: var(--eai-surface);
    padding: var(--eai-space-5);
    border: 1px solid var(--eai-gray-200);
    border-radius: 0 var(--eai-radius-md) var(--eai-radius-md) var(--eai-radius-md);
}

/* =============================================================
   MANUAL SIGNUP TABLE
   ============================================================= */

.manual-signup-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    border-radius: var(--eai-radius-md);
    overflow: hidden;
}

.manual-signup-table td,
.manual-signup-table th {
    border: 1px solid var(--eai-gray-200);
    padding: 8px 10px;
}

.manual-signup-table th {
    background: var(--eai-gray-100);
    font-weight: 600;
    color: var(--eai-gray-700);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.manual-signup-table input[type="text"],
.manual-signup-table input[type="email"],
.manual-signup-table input[type="password"] {
    width: 100%;
    padding: 7px 10px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-sm);
    font-size: 0.85rem;
    background: var(--eai-gray-50);
    color: var(--eai-gray-800);
    box-sizing: border-box;
    transition: border-color var(--eai-transition);
}

.manual-signup-table input:focus {
    border-color: var(--eai-blue-500);
    outline: none;
    background: var(--eai-surface);
}

.submit_teacher_manual_signup {
    display: inline-flex;
    align-items: center;
    padding: 10px 24px;
    background: linear-gradient(135deg, var(--eai-blue-500) 0%, var(--eai-blue-600) 100%);
    color: #fff;
    border: none;
    border-radius: var(--eai-radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(59,130,246,0.3);
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
}

.submit_teacher_manual_signup:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(59,130,246,0.4);
}

/* =============================================================
   EDIT STUDENTS TABLE
   ============================================================= */

.edit-students-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
    margin-top: var(--eai-space-3);
    border-radius: var(--eai-radius-md);
    overflow: hidden;
}

.edit-students-table th,
.edit-students-table td {
    border-bottom: 1px solid var(--eai-gray-200);
    padding: 9px 12px;
    text-align: center;
    vertical-align: middle;
}

.edit-students-table th {
    background: var(--eai-gray-800);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--eai-gray-100);
    border-bottom: none;
}

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

.edit-students-table tr:nth-child(even) {
    background-color: var(--eai-gray-50);
}

.edit-students-table tr:hover {
    background-color: var(--eai-blue-50);
    transition: background-color var(--eai-transition);
}

.edit-students-table .with-divider {
    border-right: 3px solid var(--eai-gray-300);
}

.edit-students-table input[type="text"],
.edit-students-table input[type="email"],
.edit-students-table input[type="password"] {
    width: 100%;
    padding: 6px 10px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-sm);
    font-size: 0.85rem;
    background: var(--eai-gray-50);
    color: var(--eai-gray-800);
    box-sizing: border-box;
    transition: border-color var(--eai-transition);
}

.edit-students-table input:focus {
    border-color: var(--eai-blue-500);
    outline: none;
    background: var(--eai-surface);
}

.edit-students-table select {
    padding: 5px 8px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-sm);
    font-size: 0.8rem;
    background: var(--eai-gray-50);
    color: var(--eai-gray-700);
    cursor: pointer;
}

.edit-students-table button[type="submit"] {
    padding: 5px 12px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-sm);
    font-size: 0.8rem;
    background: var(--eai-gray-100);
    color: var(--eai-gray-700);
    cursor: pointer;
    transition: background var(--eai-transition), border-color var(--eai-transition);
    margin: 2px;
}

.edit-students-table button[name="move_student"]:hover {
    background: var(--eai-blue-50);
    border-color: var(--eai-blue-400);
    color: var(--eai-blue-700);
}

.edit-students-table button[name="remove_student"]:hover {
    background: var(--eai-danger-bg);
    border-color: var(--eai-danger-border);
    color: var(--eai-danger-text);
}

.save_student_edits {
    display: inline-flex;
    align-items: center;
    padding: 10px 24px;
    background: linear-gradient(135deg, var(--eai-blue-500) 0%, var(--eai-blue-600) 100%);
    color: #fff;
    border: none;
    border-radius: var(--eai-radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(59,130,246,0.3);
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
    margin-top: var(--eai-space-4);
}

.save_student_edits:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(59,130,246,0.4);
}

/* =============================================================
   GROUP MANAGEMENT TABS (csuk-group-tabs)
   ============================================================= */

.csuk-group-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 0;
    border-bottom: 2px solid var(--eai-gray-200);
    padding: 0;
    flex-wrap: wrap;
}

.csuk-tab {
    padding: 10px 18px;
    background: var(--eai-gray-100);
    border: 1.5px solid var(--eai-gray-200);
    border-bottom: none;
    border-radius: var(--eai-radius-md) var(--eai-radius-md) 0 0;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--eai-gray-600);
    transition: background var(--eai-transition), color var(--eai-transition);
    position: relative;
    bottom: -2px;
}

.csuk-tab:hover {
    background: var(--eai-gray-200);
    color: var(--eai-gray-800);
}

.csuk-tab.active {
    background: var(--eai-surface);
    border-top: 2.5px solid var(--eai-blue-500);
    font-weight: 700;
    color: var(--eai-blue-600);
    border-color: var(--eai-gray-200);
    border-bottom-color: var(--eai-surface);
}

.csuk-tab-content {
    background: var(--eai-surface);
    padding: var(--eai-space-6);
    border: 1px solid var(--eai-gray-200);
    border-radius: 0 var(--eai-radius-md) var(--eai-radius-md) var(--eai-radius-md);
    margin-top: 0;
}

/* =============================================================
   INTERNAL AI TOOL TABS (ai-tab-buttons)
   ============================================================= */

.ai-tab-buttons {
    display: flex;
    gap: 0;
    border-bottom: 2px solid var(--eai-gray-200);
    margin-left: 12px;
    margin-right: 12px;
    overflow-x: auto;
}

.ai-tab-btn {
    background: var(--eai-gray-100);
    border: 1.5px solid var(--eai-gray-200);
    border-bottom: none;
    padding: 10px 12px 8px;
    cursor: pointer;
    border-radius: var(--eai-radius-md) var(--eai-radius-md) 0 0;
    transition: background var(--eai-transition), color var(--eai-transition);
    flex: 1 1 auto;
    min-width: 90px;
    text-align: center;
    font-weight: 500;
    font-size: 0.8rem;
    color: var(--eai-gray-600);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    position: relative;
    bottom: -2px;
    white-space: nowrap;
}

.ai-tab-btn img {
    width: 28px;
    height: 28px;
    object-fit: contain;
}

.ai-tab-btn.active {
    background: var(--eai-blue-50);
    border-top: 2.5px solid var(--eai-blue-500);
    color: var(--eai-blue-700);
    font-weight: 700;
    border-color: var(--eai-gray-200);
    border-bottom-color: var(--eai-blue-50);
}

.ai-tab-btn:hover {
    background: var(--eai-blue-50);
    color: var(--eai-blue-600);
}

/* =============================================================
   CLASSES DASHBOARD (eai-classes-dashboard)
   ============================================================= */

.eai-classes-dashboard {
    margin: 0 auto;
    font-family: var(--eai-font-family);
}

/* Tab Navigation */
.eai-classes-tabs {
    display: flex;
    gap: var(--eai-space-1);
    border-bottom: 2px solid var(--eai-blue-500);
    padding: var(--eai-space-4) var(--eai-space-3) 0;
    margin-bottom: 0;
    flex-wrap: wrap;
    background: var(--eai-gray-50);
    border-radius: var(--eai-radius-lg) var(--eai-radius-lg) 0 0;
}

.eai-tab-button {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 10px 18px;
    background: var(--eai-gray-200);
    border: none;
    border-radius: var(--eai-radius-md) var(--eai-radius-md) 0 0;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--eai-gray-600);
    transition: all var(--eai-transition-slow);
    position: relative;
    bottom: -2px;
    white-space: nowrap;
    flex-shrink: 0;
}

.eai-tab-button:hover {
    background: var(--eai-gray-300);
    color: var(--eai-gray-800);
}

.eai-tab-button.active {
    background: var(--eai-blue-600);
    color: #fff;
    border-bottom: 2px solid var(--eai-blue-600);
    font-weight: 600;
    box-shadow: 0 -2px 8px rgba(37,99,235,0.18);
}

.eai-tab-icon {
    width: 18px;
    height: 18px;
    object-fit: contain;
    opacity: 0.85;
}

.eai-tab-button.active .eai-tab-icon {
    opacity: 1;
    filter: brightness(0) invert(1);
}

/* Tab Content */
.eai-classes-content {
    background: var(--eai-surface);
    border-radius: 0 0 var(--eai-radius-lg) var(--eai-radius-lg);
    min-height: 500px;
    padding: var(--eai-space-6);
    border: 1px solid var(--eai-gray-200);
    border-top: none;
    box-shadow: var(--eai-shadow-md);
}

.eai-tab-panel {
    display: none;
    animation: eai-panel-in 0.25s ease;
}

.eai-tab-panel.active {
    display: block;
}

@keyframes eai-panel-in {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* =============================================================
   CREATE GROUP TAB (inside classes dashboard)
   ============================================================= */

.create-group-container {
    max-width: 680px;
    margin: 0 auto;
    padding: var(--eai-space-8) var(--eai-space-6);
}

.create-group-header {
    text-align: center;
    margin-bottom: var(--eai-space-8);
}

.create-group-header h2 {
    color: var(--eai-gray-800);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--eai-space-3);
    letter-spacing: -0.02em;
}

.create-group-header p {
    color: var(--eai-gray-500);
    font-size: 0.95rem;
    line-height: 1.65;
    max-width: 540px;
    margin: 0 auto;
}

.seat-limit-info {
    background: var(--eai-info-bg);
    border-left: 4px solid var(--eai-info-border);
    padding: 14px 18px;
    margin-bottom: var(--eai-space-6);
    border-radius: 0 var(--eai-radius-md) var(--eai-radius-md) 0;
    font-size: 0.9rem;
    color: var(--eai-info-text);
}

.eai-form {
    background: var(--eai-gray-50);
    border: 1.5px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-8);
}

.form-field {
    margin-bottom: var(--eai-space-5);
}

.form-field label {
    display: block;
    font-weight: 600;
    color: var(--eai-gray-700);
    margin-bottom: var(--eai-space-2);
    font-size: 0.875rem;
}

.form-field input[type="text"],
.form-field input[type="number"] {
    width: 100%;
    padding: 11px 14px;
    border: 1.5px solid var(--eai-gray-300);
    border-radius: var(--eai-radius-md);
    font-size: 0.95rem;
    background: var(--eai-surface);
    color: var(--eai-gray-800);
    transition: border-color var(--eai-transition), box-shadow var(--eai-transition);
    box-sizing: border-box;
}

.form-field input[type="text"]:focus,
.form-field input[type="number"]:focus {
    border-color: var(--eai-blue-500);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.12);
    outline: none;
}

.field-hint {
    display: block;
    color: var(--eai-gray-400);
    font-size: 0.8rem;
    margin-top: var(--eai-space-2);
    line-height: 1.4;
}

.form-actions {
    margin-top: var(--eai-space-8);
}

.eai-button-primary {
    background: linear-gradient(135deg, var(--eai-blue-500) 0%, var(--eai-blue-600) 100%);
    color: white;
    border: none;
    padding: 13px var(--eai-space-8);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--eai-radius-md);
    cursor: pointer;
    transition: transform var(--eai-transition), box-shadow var(--eai-transition);
    box-shadow: 0 4px 14px rgba(59,130,246,0.30);
    letter-spacing: 0.01em;
    display: inline-flex;
    align-items: center;
}

.eai-button-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59,130,246,0.40);
}

.eai-button-primary:disabled {
    background: var(--eai-gray-400);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Status messages */
.eai-success {
    background: var(--eai-success-bg);
    color: var(--eai-success-text);
    padding: 14px 18px;
    border-radius: var(--eai-radius-md);
    border-left: 4px solid var(--eai-success-border);
    font-size: 0.9rem;
    font-weight: 500;
}

.eai-error {
    background: var(--eai-danger-bg);
    color: var(--eai-danger-text);
    padding: 14px 18px;
    border-radius: var(--eai-radius-md);
    border-left: 4px solid var(--eai-danger-border);
    font-size: 0.9rem;
    font-weight: 500;
}

/* Loading state */
.eai-group-loading {
    text-align: center;
    padding: var(--eai-space-12) var(--eai-space-5);
    color: var(--eai-gray-400);
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--eai-space-3);
}

.eai-group-loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--eai-gray-200);
    border-top-color: var(--eai-blue-500);
    border-radius: 50%;
    animation: eai-spin 0.9s linear infinite;
    flex-shrink: 0;
}

@keyframes eai-spin {
    to { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* =============================================================
   SEAT CONTROL TAB
   ============================================================= */

.group-seats-container {
    background: var(--eai-surface);
    border: 1px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-lg);
    padding: var(--eai-space-6);
    box-shadow: var(--eai-shadow-sm);
}

.group-seats-container h5 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--eai-gray-800);
    margin: 0 0 var(--eai-space-3);
}

.group-seats-container p {
    color: var(--eai-gray-600);
    font-size: 0.9rem;
    line-height: 1.65;
    margin-bottom: var(--eai-space-5);
}

.seat-info {
    background: var(--eai-gray-50);
    border: 1px solid var(--eai-gray-200);
    border-radius: var(--eai-radius-md);
    padding: var(--eai-space-4) var(--eai-space-5);
    display: flex;
    flex-direction: column;
    gap: var(--eai-space-2);
}

.seat-info p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--eai-gray-700);
    font-weight: 500;
}

.seat-quota {
    display: inline-flex;
    align-items: center;
    gap: var(--eai-space-1);
    font-weight: 700;
    color: var(--eai-blue-600);
    cursor: pointer;
    border-bottom: 1.5px dashed var(--eai-blue-400);
    padding: 1px 3px;
    border-radius: 2px;
    transition: background var(--eai-transition);
}

.seat-quota:hover {
    background: var(--eai-blue-50);
}

/* =============================================================
   DELETE GROUP TAB
   ============================================================= */

.csuk-tab-content form[onsubmit] {
    background: var(--eai-danger-bg);
    border: 1.5px solid var(--eai-danger-border);
    border-radius: var(--eai-radius-md);
    padding: var(--eai-space-5);
}

.csuk-tab-content form[onsubmit] p {
    color: var(--eai-danger-text);
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: var(--eai-space-4);
}

input.danger,
button.danger,
.csuk-tab-content form[onsubmit] input[type="submit"] {
    background: var(--eai-danger-border);
    color: #fff;
    border: none;
    padding: 10px 22px;
    border-radius: var(--eai-radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--eai-transition), transform var(--eai-transition);
}

input.danger:hover,
button.danger:hover,
.csuk-tab-content form[onsubmit] input[type="submit"]:hover {
    background: #dc2626;
    transform: translateY(-1px);
}

/* Warning / error messages */
.csuk-warning {
    background: var(--eai-danger-bg);
    color: var(--eai-danger-text);
    border-left: 4px solid var(--eai-danger-border);
    padding: var(--eai-space-3) var(--eai-space-4);
    border-radius: var(--eai-radius-md);
    font-size: 0.875rem;
    margin-bottom: var(--eai-space-4);
}

.csuk-membership-warning {
    background: var(--eai-warning-bg);
    color: var(--eai-warning-text);
    border-left: 4px solid var(--eai-warning-border);
    padding: var(--eai-space-4) var(--eai-space-5);
    border-radius: var(--eai-radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    margin: var(--eai-space-6) 0;
}

/* =============================================================
   RESPONSIVE LAYOUT
   ============================================================= */

@media (max-width: 900px) {
    .csuk-modal-content {
        flex-direction: column;
    }

    #assessment-student-list {
        width: 100%;
        min-width: unset;
        border-right: none;
        border-bottom: 1px solid var(--eai-gray-200);
        max-height: 220px;
    }

    #assessment-detail-panel {
        width: 100%;
    }
}

@media (max-width: 800px) {
    .dashboard-buttons {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
        gap: var(--eai-space-3);
    }

    .dashboard-button {
        min-height: 90px;
        padding: var(--eai-space-3);
    }

    .dashboard-button img {
        width: 34px !important;
        height: 34px !important;
    }

    .dashboard-button span {
        font-size: 0.75rem !important;
    }

    .csuk-insight-card {
        padding: var(--eai-space-4) !important;
    }

    .csuk-stat-line {
        flex-direction: row;
        justify-content: space-between;
    }

    .csuk-circle,
    .average_score_sc {
        font-size: 0.75rem !important;
        padding: 3px 8px !important;
    }

    .dashboard-table-wrapper {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .dashboard-table {
        min-width: 640px;
        font-size: 0.8rem;
    }

    .eai-classes-tabs {
        overflow-x: auto;
        flex-wrap: nowrap;
        -webkit-overflow-scrolling: touch;
    }

    .eai-tab-button {
        padding: 9px 14px;
        font-size: 0.8rem;
    }

    .csuk-insights-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .class-dashboard {
        padding: var(--eai-space-4) var(--eai-space-3);
    }

    .class-dashboard h2 {
        font-size: 1.25rem;
    }

    .dashboard-modal {
        width: calc(100vw - 16px);
        height: calc(100vh - 16px);
        border-radius: var(--eai-radius-lg);
        padding: var(--eai-space-4);
    }

    .eai-modal-content-mb {
        width: 96%;
        padding: var(--eai-space-4);
    }

    .csuk-assessment-content {
        width: 96%;
        margin: 2% auto;
        padding: var(--eai-space-4);
    }

    .csuk-insights-cards {
        grid-template-columns: 1fr 1fr;
        gap: var(--eai-space-3);
    }

    .eai-classes-content {
        padding: var(--eai-space-4);
    }

    .create-group-container {
        padding: var(--eai-space-4);
    }

    .eai-form {
        padding: var(--eai-space-5);
    }

    #assessment-review-modal {
        width: 98%;
        height: 96%;
        border-radius: var(--eai-radius-md);
    }
}