html {
    overflow-x: hidden;
    overflow-y: auto;
}
body {
    margin: 0;
    overflow-x: hidden;
}

#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding-top: 78px;
}

#main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 2px solid var(--accent);
    display: flex;
    flex-direction: column;
    z-index: 100;
    box-shadow: var(--shadow);
}
.header-main-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 20px;
}
.header-credit {
    text-align: right;
    font-size: 12px;
    color: #f59e0b;
    letter-spacing: 0.5px;
    opacity: 0.7;
    line-height: 1;
    padding: 1px 0 3px;
    border-top: 1px solid var(--border);
    margin: 0 20px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.logo-container {
    width: 48px;
    height: 48px;
    border-radius: var(--radius);
    overflow: hidden;
    flex-shrink: 0;
}

.logo-container img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.logo-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent);
    color: var(--bg);
    font-weight: 700;
    font-size: 18px;
    border-radius: var(--radius);
}

.header-info h1 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
    line-height: 1.2;
}

.header-info .tagline {
    font-size: 12px;
    color: var(--accent);
    font-weight: 500;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-date {
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--bg-input);
    padding: 6px 12px;
    border-radius: var(--radius);
}

#main-content {
    flex: 1;
    display: flex;
    margin-left: 165px;
    padding: 20px;
    min-height: 100vh;
}

.sidebar {
    position: fixed;
    left: 0;
    top: 78px;
    width: 165px;
    height: calc(100vh - 78px);
    background: var(--bg-card);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    overflow-x: hidden;
    padding: 20px 0 12px;
    z-index: 50;
}

.nav-section {
    margin-bottom: 4px;
}

.nav-section:not(:first-child) {
    margin-top: 10px;
}

.nav-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--accent);
    padding: 0 16px 5px;
    margin-bottom: 3px;
    font-weight: 700;
    border-bottom: 1px solid var(--border);
}

.nav-tab {
    display: flex;
    align-items: center;
    gap: 0;
    padding: 7px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    border-left: 3px solid transparent;
    position: relative;
}

.nav-tab::before {
    content: '';
    display: inline-block;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--text-muted);
    opacity: 0.5;
    margin-right: 12px;
    flex-shrink: 0;
    transition: var(--transition);
}

.nav-tab:hover {
    background: var(--bg-hover);
    color: var(--text);
}

.nav-tab:hover::before {
    opacity: 0.85;
    background: var(--accent);
}

.nav-tab.active {
    background: var(--bg-input);
    color: var(--accent);
    border-left-color: var(--accent);
}

.nav-tab.active::before {
    opacity: 1;
    background: var(--accent);
    box-shadow: 0 0 6px 2px var(--accent);
}

.nav-text {
    flex: 1;
}

.nav-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 18px;
    height: 18px;
    padding: 0 5px;
    border-radius: 9px;
    background: var(--danger);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    line-height: 1;
    margin-left: auto;
}

.nav-icon {
    display: none;
}

.screen {
    display: none;
    width: 100%;
}

.screen.active {
    display: block;
}

.screen-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 12px;
}

.screen-header h2 {
    font-size: 20px;
    font-weight: 700;
}

.screen-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    margin-bottom: 4px;
    font-weight: 600;
}

.stat-value {
    font-size: 22px;
    font-weight: 800;
    color: var(--text);
}

.dashboard-grid {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.dashboard-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 16px;
}

.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 16px;
    box-shadow: var(--shadow);
}

.card h3 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--accent);
    border-bottom: 1px solid var(--border);
    padding-bottom: 8px;
}

.table-container {
    overflow-x: auto;
    max-width: 100%;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
    table-layout: auto;
}

.data-table th {
    background: var(--bg-input);
    padding: 8px 6px;
    text-align: left;
    font-weight: 600;
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    border-bottom: 2px solid var(--accent);
    white-space: nowrap;
    width: auto;
}

.data-table td {
    padding: 8px 6px;
    border-bottom: 1px solid var(--border);
    vertical-align: middle;
    white-space: nowrap;
}

.data-table td:last-child, .data-table th:last-child {
    width: 1%;
    white-space: nowrap;
}

.data-table .btn {
    padding: 3px 6px;
    font-size: 10px;
    margin: 0 1px;
    display: inline-block;
}

.data-table button, .data-table .btn {
    white-space: nowrap;
    min-width: auto;
}

.data-table tbody tr:hover {
    background: var(--bg-hover);
}

#screen-quizzes .data-table th:nth-child(3),
#screen-quizzes .data-table td:nth-child(3) {
    width: 12%;
}

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

.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
}

.badge-success { background: rgba(5,150,105,0.2); color: var(--success-light); }
.badge-warning { background: rgba(217,119,6,0.2); color: var(--warning); }
.badge-danger { background: rgba(220,38,38,0.2); color: var(--danger-light); }
.badge-info { background: rgba(59,130,246,0.2); color: var(--primary-light); }
.badge-secondary { background: rgba(100,116,139,0.2); color: #94a3b8; }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    border: none;
    border-radius: var(--radius);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: var(--accent);
    color: var(--bg);
}

.btn-primary:hover {
    background: var(--accent-light);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.btn-outline:hover {
    background: var(--bg-input);
    color: var(--text);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: var(--danger-light);
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-success:hover {
    background: var(--success-light);
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: var(--radius);
    font-size: 16px;
}

.btn-sm {
    padding: 4px 10px;
    font-size: 11px;
}

.search-input, .filter-select, .date-input {
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-input);
    color: var(--text);
    font-size: 13px;
    transition: var(--transition);
}

.search-input {
    min-width: 200px;
}

.search-input:focus, .filter-select:focus, .date-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(245,158,11,0.2);
}

.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-input);
    color: var(--text);
    font-size: 13px;
}

.form-group textarea {
    resize: vertical;
    min-height: 60px;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
}

.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.6);
    z-index: 10001;
    align-items: center;
    justify-content: center;
}

.modal-overlay.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.modal-header h3 {
    font-size: 16px;
    font-weight: 700;
    color: var(--accent);
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 20px;
    cursor: pointer;
    padding: 4px;
    line-height: 1;
}

.modal-close:hover {
    color: var(--danger);
}

.modal-actions {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
    margin-top: 16px;
}

.toast {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--bg-card);
    color: var(--text);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--accent);
    box-shadow: var(--shadow-lg);
    z-index: 300;
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s ease;
    font-size: 13px;
    max-width: 380px;
    min-width: 280px;
    overflow: hidden;
    padding: 0;
}
.toast.show { transform: translateY(0); opacity: 1; }
.toast-success { border-left-color: var(--success); }
.toast-danger { border-left-color: var(--danger); }
.toast-warning { border-left-color: var(--warning); }
.toast-info { border-left-color: var(--primary-light); }
.toast-inner { display: flex; align-items: flex-start; gap: 0; padding: 12px 14px; }
.toast-content { flex: 1; min-width: 0; }
.toast-message { font-weight: 600; margin-bottom: 2px; }
.toast-title { font-weight: 700; font-size: 13px; margin-bottom: 3px; color: var(--text-primary); }
.toast-details { font-size: 11px; color: var(--text-muted); line-height: 1.4; margin-top: 2px; }
.toast-action-btn { display: block; width: 100%; padding: 8px; background: var(--bg-input); border: none; border-top: 1px solid var(--border); color: var(--accent); font-size: 12px; font-weight: 600; cursor: pointer; text-align: center; }
.toast-action-btn:hover { background: var(--bg-hover); }
.toast-progress { height: 3px; background: var(--accent); position: absolute; bottom: 0; left: 0; animation: toast-progress linear forwards; }
@keyframes toast-progress { from { width: 100%; } to { width: 0%; } }

.tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    padding: 8px 16px;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.tab-btn.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

.tab-btn:hover:not(.active) {
    color: var(--text-secondary);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 16px;
}

.logo-upload {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-upload .logo-placeholder {
    width: 64px;
    height: 64px;
    font-size: 12px;
}

.attendance-sheet, .grades-sheet {
    padding: 8px 0;
}

.attendance-row, .grade-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 8px;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    align-items: center;
}

.attendance-row:last-child, .grade-row:last-child {
    border-bottom: none;
}

.attendance-header, .grade-header {
    font-weight: 600;
    font-size: 11px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.attendance-radio {
    display: flex;
    gap: 4px;
}

.attendance-radio label {
    display: flex;
    align-items: center;
    gap: 2px;
    font-size: 12px;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--radius);
    transition: var(--transition);
}

.attendance-radio input[type="radio"] {
    display: none;
}

.attendance-radio label.selected {
    background: var(--accent);
    color: var(--bg);
}

.grade-input {
    width: 80px;
    padding: 4px 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-input);
    color: var(--text);
    font-size: 13px;
    text-align: center;
}

.calendar {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 2px;
    margin-bottom: 16px;
}

.calendar-header {
    text-align: center;
    padding: 8px;
    font-weight: 600;
    font-size: 11px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.calendar-day {
    padding: 8px;
    min-height: 80px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 12px;
}

.calendar-day.today {
    border-color: var(--accent);
}

.calendar-day .day-number {
    font-weight: 700;
    margin-bottom: 4px;
}

.calendar-day .event-dot {
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    display: inline-block;
    margin-right: 2px;
}

.events-list {
    max-height: 300px;
    overflow-y: auto;
}

.event-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    font-size: 13px;
}

.event-item:last-child {
    border-bottom: none;
}

.schedule-grid {
    display: grid;
    gap: 2px;
}

.schedule-header {
    background: var(--bg-input);
    padding: 8px;
    text-align: center;
    font-weight: 600;
    font-size: 11px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.schedule-cell {
    background: var(--bg-card);
    padding: 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 12px;
}

.schedule-cell .course-name {
    font-weight: 600;
    color: var(--accent);
}

.schedule-cell .course-time {
    color: var(--text-muted);
    font-size: 11px;
}

.smart-search-container { position: relative; width: 300px; }
.smart-search-input { width: 100%; padding: 8px 12px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-input); color: var(--text); font-size: 13px; }
.smart-search-input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px rgba(245,158,11,0.2); }
.smart-search-results { position: absolute; top: 100%; left: 0; right: 0; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); max-height: 400px; overflow-y: auto; z-index: 200; box-shadow: var(--shadow-lg); display: none; }
.smart-search-results.active { display: block; }
.smart-search-item { padding: 10px 14px; border-bottom: 1px solid var(--border); cursor: pointer; transition: background 0.15s; }
.smart-search-item:hover, .smart-search-item.active { background: var(--bg-hover); }
.smart-search-item:last-child { border-bottom: none; }
.smart-search-item .search-item-label { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; color: var(--accent); }
.smart-search-item .search-item-text { font-size: 13px; font-weight: 600; color: var(--text); }
.smart-search-item .search-item-sub { font-size: 11px; color: var(--text-muted); }
.smart-search-category { padding: 6px 14px; font-size: 9px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: var(--text-muted); background: var(--bg-input); border-bottom: 1px solid var(--border); }
.smart-search-empty { padding: 20px; text-align: center; color: var(--text-muted); font-size: 13px; }

.wa-dropdown { display: inline-block; position: relative; }
.wa-drop-menu { display: none; position: absolute; right: 0; top: 100%; background: var(--bg-card); border: 1px solid var(--border); border-radius: 6px; padding: 4px; min-width: 180px; z-index: 50; box-shadow: var(--shadow-lg); }
.wa-drop-item { padding: 8px 12px; font-size: 12px; cursor: pointer; border-radius: 4px; transition: background 0.15s; white-space: nowrap; }
.wa-drop-item:hover { background: var(--bg-hover); }

.menu-toggle {
    display: none;
    font-size: 20px;
    padding: 4px 8px;
    cursor: pointer;
}

@media (max-width: 768px) {
    html, body {
        overflow-x: hidden;
        max-width: 100vw;
    }

    .sidebar {
        display: flex;
        flex-direction: column;
        transform: translateX(-100%);
        transition: transform 0.25s ease;
        z-index: 200;
    }
    .sidebar.open {
        transform: translateX(0);
    }

    #main-content {
        margin-left: 0;
        padding: 12px;
        width: 100%;
        box-sizing: border-box;
    }

    .menu-toggle {
        display: flex !important;
    }

    .screen-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .screen-actions {
        width: 100%;
        flex-wrap: wrap;
    }

    .screen-actions .search-input,
    .screen-actions .filter-select {
        width: 100%;
        min-width: unset;
    }

    .search-input {
        min-width: 100%;
        width: 100%;
    }

    .dashboard-cards {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .table-container {
        overflow-x: auto;
        width: 100%;
        box-sizing: border-box;
    }
    .table-container table {
        width: 100%;
        min-width: 0;
    }

    .data-table th,
    .data-table td {
        padding: 6px 4px;
        font-size: 10px;
        white-space: nowrap;
    }

    .data-table th:last-child, 
    .data-table td:last-child {
        width: auto;
        white-space: nowrap;
    }

    .data-table .btn, 
    .data-table button {
        padding: 3px 5px;
        font-size: 9px;
    }

    .header-date {
        display: none;
    }

    .header-info h1 {
        font-size: 14px;
    }
    .header-info .tagline {
        font-size: 10px;
    }

    #main-header .header-main-row {
        padding: 6px 12px;
    }
    #main-header .header-credit {
        margin: 0 12px;
        font-size: 10px;
    }

    .logo-container {
        width: 36px;
        height: 36px;
    }

    .modal-content {
        width: 95%;
        margin: 10px auto;
        padding: 16px;
        max-width: calc(100vw - 20px);
        box-sizing: border-box;
    }

    .smart-search-container {
        display: none;
    }

    .stats-row {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }
    .stat-card {
        padding: 12px;
    }
    .stat-value {
        font-size: 18px;
    }

    .card {
        padding: 12px;
        overflow-x: hidden;
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .btn {
        padding: 8px 14px;
        font-size: 12px;
    }

    #user-name-display {
        display: none;
    }

    .header-right {
        gap: 6px;
    }

    .dashboard-grid .dashboard-cards {
        grid-template-columns: 1fr;
    }

    .event-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .nav-tab {
        padding: 10px 14px;
        font-size: 13px;
    }

    .screen-actions button {
        width: 100%;
        justify-content: center;
    }

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

    .tab-btn {
        white-space: nowrap;
        padding: 8px 12px;
    }

    .wa-dropdown {
        position: static;
    }

    .wa-drop-menu {
        position: fixed;
        left: 10px;
        right: 10px;
        width: auto;
    }

    .alert-dropdown {
        position: fixed;
        left: 10px;
        right: 10px;
        width: auto;
        max-width: none;
    }

    .user-badge {
        padding: 4px 8px;
    }

    .login-screen {
        padding: 16px;
    }

    .login-card {
        padding: 24px 16px;
        width: 100%;
        max-width: 100%;
    }
}

/* Extra small devices */
@media (max-width: 480px) {
    html, body {
        overflow-x: hidden;
    }

    .stats-row {
        grid-template-columns: 1fr 1fr;
    }

    .modal-content {
        padding: 12px;
        font-size: 13px;
        width: calc(100vw - 16px);
    }

    .data-table th,
    .data-table td {
        padding: 4px 6px;
        font-size: 10px;
    }

    .btn {
        padding: 6px 10px;
        font-size: 11px;
    }

    .logo-container {
        width: 30px;
        height: 30px;
    }

    .header-info h1 {
        font-size: 12px;
    }

    #main-content {
        padding: 8px;
    }

    .stat-card {
        padding: 10px;
    }

    .stat-value {
        font-size: 16px;
    }

    .screen-header h2 {
        font-size: 18px;
    }

    .card {
        padding: 10px;
    }

    .form-group input,
    .form-group select,
    .form-group textarea {
        font-size: 14px;
        padding: 10px 12px;
    }

    .badge {
        font-size: 10px;
        padding: 2px 6px;
    }

    .nav-tab {
        padding: 8px 12px;
        font-size: 12px;
    }

    .header-right {
        gap: 4px;
    }

    .btn-icon {
        width: 32px;
        height: 32px;
        font-size: 14px;
    }
}

.sig-upload { display: flex; align-items: center; gap: 8px; }
.sig-preview { max-height: 40px; border: 1px solid var(--border); border-radius: 4px; padding: 2px; background: #fff; }
.sig-placeholder { padding: 8px 16px; background: var(--bg-input); border: 1px dashed var(--border); border-radius: 4px; font-size: 11px; color: var(--text-muted); cursor: pointer; }
.sig-upload input[type="file"] { display: none; }
.sig-placeholder:hover { border-color: var(--accent); color: var(--accent); }
.diploma-sig-img { max-height: 35px; display: block; margin: 0 auto 2px; }
.transcript-sig-img { max-height: 30px; display: block; margin: 0 auto 2px; }
.btn-warning { background: #f59e0b; color: #fff; border: none; padding: 6px 12px; border-radius: 6px; cursor: pointer; font-size: 12px; font-weight: 600; }
.btn-warning:hover { background: #d97706; }

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}