* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: #f5f7fa;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.container-mobile {
    max-width: 480px;
    margin: 0 auto;
    padding: 15px;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px;
}

.header h1 {
    font-size: 20px;
    margin-bottom: 5px;
}

.header p {
    font-size: 14px;
    opacity: 0.9;
}

.header-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a6fd6;
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-block {
    width: 100%;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

.card {
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    padding: 20px;
    margin-bottom: 15px;
}

.form-group {
    margin-bottom: 15px;
}

.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: #444;
}

.form-input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s;
}

.form-input:focus {
    border-color: #667eea;
}

.form-select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 14px;
    outline: none;
    background: white;
}

.form-textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 14px;
    outline: none;
    min-height: 100px;
    resize: vertical;
    font-family: inherit;
}

.char-count {
    float: right;
    font-size: 12px;
    color: #888;
    font-weight: normal;
}

.char-count.over-limit {
    color: #e74c3c;
    font-weight: bold;
}

.follow-record {
    margin-bottom: 12px;
    padding: 10px;
    background: #f9f9f9;
    border-radius: 6px;
}

.follow-record:not(:last-child) {
    border-bottom: 1px solid #eee;
}

.student-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: white;
    border-radius: 10px;
    margin-bottom: 10px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
    cursor: pointer;
    transition: transform 0.2s;
}

.student-item:hover {
    transform: translateX(5px);
}

.student-info {
    flex: 1;
}

.student-name {
    font-size: 17px;
    font-weight: 600;
    color: #333;
}

.student-meta {
    font-size: 13px;
    color: #888;
    margin-top: 4px;
}

.status-badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.status-pending {
    background: #fff3cd;
    color: #856404;
}

.status-in_progress {
    background: #cce5ff;
    color: #004085;
}

.status-completed {
    background: #d4edda;
    color: #155724;
}

.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 15px;
    margin-top: 8px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
}

.checkbox-item input {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.section-title {
    font-size: 16px;
    font-weight: 600;
    color: #333;
    margin: 20px 0 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid #667eea;
}

.sub-section {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 12px;
}

.sub-section-title {
    font-size: 14px;
    font-weight: 600;
    color: #555;
    margin-bottom: 10px;
}

.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
}

.login-card {
    background: white;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
}

.login-title {
    text-align: center;
    font-size: 24px;
    font-weight: 700;
    color: #333;
    margin-bottom: 8px;
}

.login-subtitle {
    text-align: center;
    color: #888;
    margin-bottom: 30px;
}

.logout-btn {
    background: rgba(255,255,255,0.2);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

.logout-btn:hover {
    background: rgba(255,255,255,0.3);
}

.table-container {
    overflow-x: auto;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
}

.admin-table th,
.admin-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.admin-table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #555;
}

.admin-table tr:hover {
    background: #f8f9fa;
}

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.modal {
    background: white;
    border-radius: 12px;
    width: 100%;
    max-width: 900px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 20px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-body {
    padding: 20px;
}

.modal-close {
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: #888;
    line-height: 1;
}

.modal-close:hover {
    color: #333;
}

.progress-overview {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.progress-card {
    background: white;
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
}

.progress-number {
    font-size: 32px;
    font-weight: 700;
    color: #667eea;
}

.progress-label {
    color: #888;
    font-size: 14px;
    margin-top: 5px;
}

.comment-templates {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 8px;
}

.comment-tag {
    background: #e9ecef;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.comment-tag:hover {
    background: #667eea;
    color: white;
}

.nav-tabs {
    display: flex;
    background: white;
    padding: 0 20px;
    border-bottom: 1px solid #eee;
}

.nav-tab {
    padding: 15px 20px;
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all 0.2s;
}

.nav-tab:hover {
    background: #f8f9fa;
}

.nav-tab.active {
    border-bottom-color: #667eea;
    color: #667eea;
    font-weight: 500;
}

.hidden {
    display: none !important;
}

.alert {
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 15px;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
}

.alert-success {
    background: #d4edda;
    color: #155724;
}

.admin-layout {
    display: flex;
    min-height: 100vh;
    background: #f5f7fa;
}

.admin-sidebar {
    width: 240px;
    background: #2c3e50;
    color: white;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 25px 20px;
    border-bottom: 1px solid #34495e;
}

.sidebar-header h2 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 5px;
}

.sidebar-header p {
    font-size: 12px;
    opacity: 0.7;
}

.sidebar-menu {
    flex: 1;
    padding: 15px 0;
}

.menu-item {
    display: block;
    width: 100%;
    padding: 12px 20px;
    text-align: left;
    background: none;
    border: none;
    color: #ecf0f1;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.menu-item:hover {
    background: #34495e;
}

.menu-item.active {
    background: #34495e;
    border-left-color: #667eea;
    color: white;
}

.sidebar-footer {
    padding: 15px 20px;
    border-top: 1px solid #34495e;
}

.sidebar-footer .logout-btn {
    width: 100%;
    background: #e74c3c;
    color: white;
    padding: 10px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

.sidebar-footer .logout-btn:hover {
    background: #c0392b;
}

.admin-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.content-header {
    background: white;
    padding: 20px 30px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.content-header h1 {
    font-size: 22px;
    font-weight: 600;
    color: #333;
}

.header-info {
    color: #888;
    font-size: 14px;
}

.content-body {
    flex: 1;
    padding: 30px;
    overflow-y: auto;
}

.table-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.actions {
    white-space: nowrap;
}

.actions .btn {
    margin-right: 5px;
}

.actions .btn:last-child {
    margin-right: 0;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    cursor: pointer;
}

.form-check input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.form-check span {
    font-size: 14px;
    color: #444;
}

.mobile-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.mobile-header h1 {
    font-size: 18px;
    font-weight: 600;
}

.search-bar {
    margin-bottom: 15px;
}

.search-bar input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 14px;
}

.stats-row {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.stat-item {
    flex: 1;
    background: white;
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 1px 4px rgba(0,0,0,0.05);
}

.stat-number {
    font-size: 24px;
    font-weight: 700;
    color: #667eea;
}

.stat-label {
    font-size: 12px;
    color: #888;
    margin-top: 5px;
}

.filter-row {
    margin-bottom: 15px;
}

.filter-row select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 14px;
    background: white;
}

.login-box {
    background: white;
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
}

.login-box h2 {
    text-align: center;
    font-size: 22px;
    font-weight: 600;
    color: #333;
    margin-bottom: 30px;
}