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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: #f8fafc;
    color: #1e293b;
    line-height: 1.6;
}

.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Navigation */
.sidebar {
    width: 260px;
    background: white;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 100;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);
}

.sidebar-header {
    padding: 20px;
    margin-bottom: 10px;
}

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

.logo-icon {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 8px;
    position: relative;
}

.logo-icon::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 16px;
    height: 16px;
    background: white;
    border-radius: 2px;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
}

.nav-menu {
    list-style: none;
    padding: 20px 0;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    margin: 8px 12px;
    cursor: pointer;
    transition: all 0.2s ease;
    border-radius: 12px;
    background: transparent;
    border: none;
    width: calc(100% - 24px);
    text-align: left;
}

.nav-item:hover {
    background-color: #667eea1a;
}

.nav-item.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.2);
}

.nav-icon {
    width: 20px;
    height: 20px;
    border-radius: 4px;
    position: relative;
}

.dashboard-icon {
    background: currentColor;
    mask: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='currentColor'%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2H5a2 2 0 00-2-2z'/%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m8 5l4-4 4 4'/%3e%3c/svg%3e") no-repeat center;
    -webkit-mask: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='currentColor'%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2H5a2 2 0 00-2-2z'/%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='m8 5l4-4 4 4'/%3e%3c/svg%3e") no-repeat center;
}

.courses-icon::before {
    content: '📚';
    position: absolute;
    font-size: 16px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.detail-icon::before {
    content: '📖';
    position: absolute;
    font-size: 16px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.performance-icon::before {
    content: '📊';
    position: absolute;
    font-size: 16px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.profile-icon::before {
    content: '👤';
    position: absolute;
    font-size: 16px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.nav-text {
    font-weight: 500;
    font-size: 14px;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 260px;
    display: flex;
    flex-direction: column;
}

/* Top Bar */
.top-bar {
    background: white;
    padding: 16px 24px;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 90;
}

.search-bar {
    position: relative;
    flex: 1;
    max-width: 400px;
}

.search-input {
    width: 100%;
    padding: 10px 40px 10px 14px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 14px;
    background-color: #f8fafc;
    transition: all 0.2s ease;
}

.search-input:focus {
    outline: none;
    border-color: #667eea;
    background-color: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-btn {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
}

.search-btn::before {
    content: '🔍';
    font-size: 16px;
}

.top-bar-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.notification-btn {
    position: relative;
    background: none;
    border: none;
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.notification-btn:hover {
    background-color: #f1f5f9;
}

.notification-icon::before {
    content: '🔔';
    font-size: 20px;
}

.notification-badge {
    position: absolute;
    top: 4px;
    right: 4px;
    background: #ef4444;
    color: white;
    font-size: 11px;
    font-weight: 600;
    padding: 2px 6px;
    border-radius: 10px;
    min-width: 18px;
    text-align: center;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: 8px;
    transition: background-color 0.2s ease;
}

.user-menu:hover {
    background-color: #f1f5f9;
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
}

.user-name {
    font-size: 14px;
    font-weight: 500;
    color: #374151;
}

/* Page Content */
.page-content {
    padding: 24px;
    flex: 1;
    display: none;
}

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

.page-header {
    margin-bottom: 32px;
}

.page-title {
    font-size: 28px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 8px;
}

.page-subtitle {
    font-size: 16px;
    color: #64748b;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.courses-stat {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.courses-stat::before {
    content: '📚';
    color: white;
}

.time-stat {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.time-stat::before {
    content: '⏰';
    color: white;
}

.score-stat {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.score-stat::before {
    content: '🎯';
    color: white;
}

.streak-stat {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.streak-stat::before {
    content: '🔥';
    color: white;
}

.stat-content {
    flex: 1;
}

.stat-number {
    font-size: 24px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: #64748b;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
    margin-bottom: 32px;
}

.card-header {
    display: flex;
    justify-content: between;
    align-items: center;
    margin-bottom: 20px;
    gap: 16px;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    flex: 1;
}

.time-filter, .view-all-btn {
    padding: 6px 12px;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    font-size: 14px;
    background: white;
    cursor: pointer;
}

.view-all-btn {
    color: #667eea;
    border-color: #667eea;
    transition: all 0.2s ease;
}

.view-all-btn:hover {
    background: #667eea;
    color: white;
}

/* Upcoming Classes */
.upcoming-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.upcoming-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: #f8fafc;
    border-radius: 8px;
}

.upcoming-time {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 60px;
}

.time {
    font-size: 14px;
    font-weight: 600;
    color: #1e293b;
}

.date {
    font-size: 12px;
    color: #64748b;
}

.upcoming-content {
    flex: 1;
}

.upcoming-content h4 {
    font-size: 14px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 2px;
}

.upcoming-content p {
    font-size: 12px;
    color: #64748b;
}

.join-btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.join-btn:not(.outline) {
    background: #667eea;
    color: white;
}

.join-btn:not(.outline):hover {
    background: #5a67d8;
}

.join-btn.outline {
    background: white;
    color: #667eea;
    border: 1px solid #667eea;
}

.join-btn.outline:hover {
    background: #667eea;
    color: white;
}

/* Progress Section */
.progress-section {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.section-title {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 20px;
}

.progress-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.progress-item {
    display: flex;
    align-items: center;
    gap: 16px;
}

.progress-info {
    flex: 1;
}

.progress-info h4 {
    font-size: 14px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 4px;
}

.progress-text {
    font-size: 12px;
    color: #64748b;
}

.progress-bar {
    flex: 2;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.progress-percent {
    font-size: 14px;
    font-weight: 600;
    color: #667eea;
    min-width: 40px;
    text-align: right;
}

/* Course List */
.filters-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    gap: 16px;
}

.filter-tabs {
    display: flex;
    gap: 8px;
}

.filter-tab {
    padding: 8px 16px;
    border: none;
    background: white;
    color: #64748b;
    border-radius: 6px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-tab.active,
.filter-tab:hover {
    background: #667eea;
    color: white;
}

.filter-controls {
    display: flex;
    gap: 12px;
}

.filter-select,
.sort-btn {
    padding: 8px 16px;
    border: 1px solid #e2e8f0;
    border-radius: 6px;
    font-size: 14px;
    background: white;
    cursor: pointer;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.course-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.course-image {
    position: relative;
    height: 180px;
    overflow: hidden;
}

.course-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.course-status {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
}

.course-status.in-progress {
    background: #fbbf24;
    color: #92400e;
}

.course-status.completed {
    background: #34d399;
    color: #065f46;
}

.course-status.not-started {
    background: #e5e7eb;
    color: #374151;
}

.course-content {
    padding: 20px;
}

.course-category {
    font-size: 12px;
    color: #667eea;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.course-title {
    font-size: 16px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 6px;
}

.course-instructor {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 16px;
}

.course-progress {
    margin-bottom: 16px;
}

.course-progress .progress-text {
    font-size: 12px;
    color: #64748b;
    margin-top: 8px;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: #64748b;
}

.course-rating {
    color: #fbbf24;
}

/* Course Detail */
.course-detail-header {
    margin-bottom: 32px;
}

.back-btn {
    background: none;
    border: none;
    color: #667eea;
    font-size: 14px;
    cursor: pointer;
    margin-bottom: 16px;
    padding: 8px 0;
}

.course-detail-title {
    font-size: 32px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 8px;
}

.course-detail-instructor {
    font-size: 16px;
    color: #64748b;
    margin-bottom: 12px;
}

.course-detail-meta {
    display: flex;
    gap: 24px;
    font-size: 14px;
    color: #64748b;
}

.course-detail-content {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 32px;
}

.video-section {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.video-player {
    aspect-ratio: 16/9;
    background: #000;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-placeholder {
    text-align: center;
    color: white;
}

.play-button {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 50%;
    margin: 0 auto 16px;
    position: relative;
    cursor: pointer;
}

.play-button::before {
    content: '▶';
    position: absolute;
    top: 50%;
    left: 55%;
    transform: translate(-50%, -50%);
    font-size: 32px;
    color: #000;
}

.video-placeholder h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.video-placeholder p {
    font-size: 14px;
    opacity: 0.8;
}

.video-controls {
    padding: 20px;
}

.video-progress {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.video-progress-bar {
    flex: 1;
    height: 6px;
    background: #e2e8f0;
    border-radius: 3px;
    overflow: hidden;
}

.video-progress-fill {
    height: 100%;
    background: #667eea;
    border-radius: 3px;
}

.video-time {
    font-size: 12px;
    color: #64748b;
    font-weight: 500;
}

.video-actions {
    display: flex;
    gap: 12px;
}

.video-btn {
    padding: 8px 16px;
    border: 1px solid #e2e8f0;
    background: white;
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.video-btn:hover {
    background: #f8fafc;
}

.video-btn.play {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.course-sidebar {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.course-progress-card {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.course-progress-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 16px;
}

.circular-progress {
    margin-bottom: 16px;
}

.progress-circle {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: conic-gradient(#667eea 0deg 241deg, #e2e8f0 241deg 360deg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    position: relative;
}

.progress-circle::before {
    content: '';
    width: 70px;
    height: 70px;
    background: white;
    border-radius: 50%;
    position: absolute;
}

.progress-number {
    font-size: 24px;
    font-weight: 700;
    color: #1e293b;
    position: relative;
    z-index: 1;
}

.continue-btn {
    padding: 12px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease;
}

.continue-btn:hover {
    background: #5a67d8;
}

.course-modules {
    background: white;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.modules-header {
    padding: 20px;
    border-bottom: 1px solid #e2e8f0;
}

.modules-header h3 {
    font-size: 16px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 4px;
}

.modules-count {
    font-size: 12px;
    color: #64748b;
}

.module-list {
    max-height: 400px;
    overflow-y: auto;
}

.module-item {
    border-bottom: 1px solid #f1f5f9;
}

.module-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.module-header:hover {
    background: #f8fafc;
}

.module-icon {
    width: 16px;
    height: 16px;
    border: 2px solid #cbd5e1;
    border-radius: 2px;
    position: relative;
    transition: all 0.2s ease;
}

.module-icon.expanded {
    background: #667eea;
    border-color: #667eea;
}

.module-icon.expanded::before {
    content: '-';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 12px;
    font-weight: bold;
}

.module-icon:not(.expanded)::before {
    content: '+';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #64748b;
    font-size: 12px;
    font-weight: bold;
}

.module-title {
    flex: 1;
    font-size: 14px;
    font-weight: 500;
    color: #1e293b;
}

.module-duration {
    font-size: 12px;
    color: #64748b;
}

.lesson-list {
    background: #f8fafc;
    padding: 0 0 0 48px;
}

.lesson-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px 12px 0;
    border-bottom: 1px solid #e2e8f0;
    cursor: pointer;
    transition: background 0.2s ease;
}

.lesson-item:hover {
    background: #f1f5f9;
}

.lesson-item.active {
    background: #ede9fe;
    color: #667eea;
}

.lesson-status {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    border: 2px solid #cbd5e1;
    background: white;
    position: relative;
}

.lesson-item.completed .lesson-status {
    background: #10b981;
    border-color: #10b981;
}

.lesson-item.completed .lesson-status::before {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 10px;
    font-weight: bold;
}

.lesson-item.active .lesson-status {
    background: #667eea;
    border-color: #667eea;
}

.lesson-item.active .lesson-status::before {
    content: '▶';
    position: absolute;
    top: 50%;
    left: 55%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 8px;
}

.lesson-title {
    flex: 1;
    font-size: 13px;
    color: #374151;
}

.lesson-duration {
    font-size: 11px;
    color: #64748b;
}

/* Performance */
.performance-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 32px;
    background: white;
    padding: 4px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.tab-btn {
    flex: 1;
    padding: 12px 20px;
    border: none;
    background: transparent;
    color: #64748b;
    font-size: 14px;
    font-weight: 500;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.tab-btn.active,
.tab-btn:hover {
    background: #667eea;
    color: white;
}

.performance-overview {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    margin-bottom: 32px;
}

.performance-stats {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.performance-stat {
    display: flex;
    align-items: center;
    gap: 20px;
}

.stat-chart {
    flex-shrink: 0;
}

.donut-chart {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: conic-gradient(#667eea 0deg calc(var(--progress) * 3.6deg), #e2e8f0 calc(var(--progress) * 3.6deg) 360deg);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.donut-chart::before {
    content: '';
    width: 50px;
    height: 50px;
    background: white;
    border-radius: 50%;
    position: absolute;
}

.donut-text {
    font-size: 16px;
    font-weight: 700;
    color: #1e293b;
    position: relative;
    z-index: 1;
}

.stat-info h3 {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 4px;
}

.stat-info p {
    font-size: 14px;
    color: #64748b;
}

.activity-heatmap {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.activity-heatmap h3 {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 20px;
}

.heatmap-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.heatmap-months {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #64748b;
    padding: 0 8px;
}

.heatmap-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 4px;
}

.heatmap-cell {
    width: 20px;
    height: 20px;
    background: #e2e8f0;
    border-radius: 2px;
}

.heatmap-cell.low {
    background: #ddd6fe;
}

.heatmap-cell.medium {
    background: #a78bfa;
}

.heatmap-cell.high {
    background: #667eea;
}

.heatmap-legend {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 12px;
    color: #64748b;
}

.legend-scale {
    display: flex;
    gap: 2px;
}

.legend-cell {
    width: 12px;
    height: 12px;
    background: #e2e8f0;
    border-radius: 1px;
}

.legend-cell.low {
    background: #ddd6fe;
}

.legend-cell.medium {
    background: #a78bfa;
}

.legend-cell.high {
    background: #667eea;
}

.quiz-scores {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.quiz-scores h3 {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 20px;
}

.scores-chart {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.score-item {
    display: flex;
    align-items: center;
    gap: 16px;
}

.score-info {
    flex: 1;
}

.score-info h4 {
    font-size: 14px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 2px;
}

.score-date {
    font-size: 12px;
    color: #64748b;
}

.score-bar {
    flex: 2;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
}

.score-fill {
    height: 100%;
    background: linear-gradient(135deg, #10b981 0%, #34d399 100%);
    border-radius: 4px;
}

.score-value {
    font-size: 14px;
    font-weight: 600;
    color: #10b981;
    min-width: 40px;
    text-align: right;
}

/* Profile */
.profile-header {
    background: white;
    padding: 32px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    margin-bottom: 32px;
    display: flex;
    gap: 32px;
    align-items: start;
}

.profile-avatar-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.profile-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid #e2e8f0;
}

.avatar-edit-btn {
    padding: 8px 16px;
    border: 1px solid #e2e8f0;
    background: white;
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.avatar-edit-btn:hover {
    background: #f8fafc;
    border-color: #667eea;
}

.profile-info {
    flex: 1;
}

.profile-name {
    font-size: 28px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 4px;
}

.profile-title {
    font-size: 16px;
    color: #667eea;
    font-weight: 500;
    margin-bottom: 16px;
}

.profile-bio {
    font-size: 14px;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 24px;
}

.profile-stats {
    display: flex;
    gap: 32px;
}

.profile-stat {
    text-align: center;
}

.profile-stat .stat-number {
    font-size: 24px;
    font-weight: 700;
    color: #1e293b;
    display: block;
}

.profile-stat .stat-label {
    font-size: 12px;
    color: #64748b;
    text-transform: uppercase;
    font-weight: 500;
}

.profile-content {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.badges-section, .certificates-section, .profile-settings {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.badges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.badge-item {
    padding: 20px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    text-align: center;
    transition: all 0.2s ease;
}

.badge-item.earned {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0e7ff 100%);
    border-color: #667eea;
}

.badge-item.locked {
    opacity: 0.5;
}

.badge-item:hover:not(.locked) {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.15);
}

.badge-icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 0 auto 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.badge-icon.javascript {
    background: linear-gradient(135deg, #f7df1e 0%, #ffeb3b 100%);
}

.badge-icon.javascript::before {
    content: 'JS';
    font-weight: bold;
    color: #000;
    font-size: 16px;
}

.badge-icon.streak {
    background: linear-gradient(135deg, #ff6b35 0%, #f7931e 100%);
}

.badge-icon.streak::before {
    content: '🔥';
}

.badge-icon.quiz {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.badge-icon.quiz::before {
    content: '🎯';
}

.badge-icon.react {
    background: linear-gradient(135deg, #61dafb 0%, #21d4fd 100%);
}

.badge-icon.react::before {
    content: '⚛';
    color: #000;
}

.badge-icon.mentor {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

.badge-icon.mentor::before {
    content: '👥';
}

.badge-icon.perfectionist {
    background: linear-gradient(135deg, #ffeaa7 0%, #fab1a0 100%);
}

.badge-icon.perfectionist::before {
    content: '⭐';
}

.badge-item h4 {
    font-size: 16px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 8px;
}

.badge-item p {
    font-size: 14px;
    color: #64748b;
}

.certificates-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.certificate-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.certificate-item:hover {
    border-color: #667eea;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.1);
}

.certificate-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 8px;
    position: relative;
}

.certificate-icon::before {
    content: '🎓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 24px;
}

.certificate-info {
    flex: 1;
}

.certificate-info h4 {
    font-size: 16px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 4px;
}

.certificate-info p {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 4px;
}

.certificate-id {
    font-size: 12px;
    color: #9ca3af;
    font-family: monospace;
}

.download-btn {
    padding: 8px 16px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.download-btn:hover {
    background: #5a67d8;
}

.settings-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: #374151;
}

.form-input, .form-textarea {
    padding: 10px 14px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 14px;
    transition: all 0.2s ease;
}

.form-input:focus, .form-textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    padding-top: 20px;
    border-top: 1px solid #e2e8f0;
}

.btn-primary, .btn-secondary {
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary {
    background: #667eea;
    color: white;
    border: none;
}

.btn-primary:hover {
    background: #5a67d8;
}

.btn-secondary {
    background: white;
    color: #374151;
    border: 1px solid #d1d5db;
}

.btn-secondary:hover {
    background: #f9fafb;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .sidebar {
        width: 80px;
    }
    
    .main-content {
        margin-left: 80px;
    }
    
    .nav-text, .logo-text {
        display: none;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .course-detail-content {
        grid-template-columns: 1fr;
    }
    
    .performance-overview {
        grid-template-columns: 1fr;
    }
    
    .profile-header {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        z-index: 200;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .top-bar {
        padding: 12px 16px;
    }
    
    .search-bar {
        max-width: 200px;
    }
    
    .user-name {
        display: none;
    }
    
    .page-content {
        padding: 16px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    .filters-bar {
        flex-direction: column;
        gap: 16px;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .badges-grid {
        grid-template-columns: 1fr;
    }
    
    .profile-stats {
        flex-direction: column;
        gap: 16px;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        padding: 16px;
    }
    
    .page-title {
        font-size: 24px;
    }
    
    .course-detail-title {
        font-size: 24px;
    }
    
    .profile-name {
        font-size: 24px;
    }
}

/* Animation Keyframes */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.page-content.active-page {
    animation: fadeIn 0.3s ease-in-out;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}