/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-bg: #0f172a;
    --dark-card: #1e293b;
    --dark-hover: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--dark-bg);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* Navbar */
.navbar {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-brand i {
    color: var(--primary-color);
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s;
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--text-primary);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--dark-card);
    border-radius: 8px;
    font-weight: 500;
}

/* Buttons */
.btn-primary, .btn-outline, .btn-secondary, .btn-large {
    padding: 0.625rem 1.25rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
    font-size: 0.9375rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

.btn-outline:hover {
    background: var(--dark-hover);
}

.btn-secondary {
    background: var(--dark-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--dark-hover);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(139, 92, 246, 0.15) 0%, transparent 50%);
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 50px;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-bottom: 3rem;
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* Sections */
.section {
    padding: 6rem 0;
}

.section-dark {
    background: rgba(30, 41, 59, 0.5);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--dark-card);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.feature-icon i {
    font-size: 1.75rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Target Audience */
.target-audience {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.audience-item {
    text-align: center;
    padding: 2rem;
}

.audience-item i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.audience-item h4 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.audience-item p {
    color: var(--text-secondary);
}

/* Process Steps */
.process-steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 4rem;
}

.step {
    background: var(--dark-card);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    flex: 1;
    min-width: 200px;
    max-width: 250px;
    text-align: center;
}

.step-number {
    width: 50px;
    height: 50px;
    background: var(--gradient-1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
    margin: 0 auto 1rem;
}

.step h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.step p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.step-arrow {
    color: var(--primary-color);
    font-size: 1.5rem;
}

/* CTA Box */
.cta-box {
    background: var(--gradient-1);
    padding: 4rem 2rem;
    border-radius: 16px;
    text-align: center;
}

.cta-box h3 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.cta-box p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* Footer */
.footer {
    background: var(--dark-card);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-section p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.footer-section i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
}

/* Form Container */
.page-container {
    min-height: calc(100vh - 200px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 3rem 1rem;
}

.form-container {
    width: 100%;
    max-width: 600px;
    background: var(--dark-card);
    border-radius: 16px;
    padding: 3rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-xl);
}

.form-container-small {
    max-width: 450px;
}

.form-header {
    text-align: center;
    margin-bottom: 2rem;
}

.form-header i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.form-header h1 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

.form-header p {
    color: var(--text-secondary);
}

/* Form Styles */
.form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group label i {
    color: var(--primary-color);
}

.form-group input,
.form-group select,
.form-group textarea {
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group small {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.private-badge {
    background: rgba(139, 92, 246, 0.1);
    color: var(--secondary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-left: 0.5rem;
}

.form-notice {
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.3);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    gap: 0.75rem;
}

.form-notice i {
    color: var(--primary-color);
    flex-shrink: 0;
    margin-top: 0.125rem;
}

.form-notice p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.5;
}

.form-footer {
    text-align: center;
    color: var(--text-secondary);
    margin-top: 1rem;
}

.form-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.form-footer a:hover {
    text-decoration: underline;
}

/* Message */
.message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 8px;
    display: none;
}

.message.show {
    display: block;
}

.message.success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: var(--success-color);
}

.message.error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--danger-color);
}

/* Dashboard Layout */
.dashboard-container {
    display: flex;
    min-height: calc(100vh - 70px);
}

.sidebar {
    width: 250px;
    background: var(--dark-card);
    border-right: 1px solid var(--border-color);
    padding: 2rem 0;
}

.sidebar-menu {
    display: flex;
    flex-direction: column;
}

.menu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s;
    border-left: 3px solid transparent;
}

.menu-item:hover {
    background: var(--dark-hover);
    color: var(--text-primary);
}

.menu-item.active {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

.menu-item i {
    font-size: 1.125rem;
}

.dashboard-main {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

.dashboard-section {
    display: none;
}

.dashboard-section.active {
    display: block;
}

.section-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 2rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--dark-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s;
}

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

.stat-card-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.stat-card-icon i {
    font-size: 1.5rem;
    color: white;
}

.stat-card-icon.rank-icon {
    background: var(--gradient-1);
}

.stat-card-icon.score-icon {
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
}

.stat-card-icon.ranking-icon {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
}

.stat-card-icon.progress-icon {
    background: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
}

.stat-card-content {
    flex: 1;
}

.stat-card-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.stat-card-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
}

/* Card */
.card {
    background: var(--dark-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.card-title {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

/* Assignments */
.assignments-list,
.assignments-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.assignments-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
}

.assignment-card {
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    transition: all 0.3s;
}

.assignment-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.assignment-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.assignment-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.assignment-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
}

.assignment-badge.pending {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.assignment-badge.submitted {
    background: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
}

.assignment-badge.graded {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.assignment-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.assignment-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.assignment-meta {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.assignment-meta i {
    margin-right: 0.375rem;
    color: var(--primary-color);
}

/* Videos Grid */
.videos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.video-card {
    background: var(--dark-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.video-thumbnail {
    background: var(--gradient-1);
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-thumbnail i {
    font-size: 4rem;
    color: white;
    opacity: 0.9;
}

.video-info {
    padding: 1.5rem;
}

.video-info h3 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.video-info p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 0.9375rem;
}

.video-duration {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
}

/* Leaderboard */
.leaderboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.leaderboard-header h2 {
    font-size: 1.375rem;
    font-weight: 700;
}

.leaderboard-legend {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
}

.leaderboard-legend span {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.leaderboard-table {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.leaderboard-row {
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: all 0.3s;
}

.leaderboard-row:hover {
    background: var(--dark-hover);
}

.leaderboard-row.current-user {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

.leaderboard-rank {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-secondary);
    width: 40px;
    text-align: center;
}

.rank-1 { color: #fbbf24; }
.rank-2 { color: #94a3b8; }
.rank-3 { color: #cd7f32; }

.leaderboard-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient-1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.leaderboard-info {
    flex: 1;
}

.leaderboard-name {
    font-weight: 700;
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
}

.leaderboard-rank-badge {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.leaderboard-score {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    font-size: 1.125rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.75);
    z-index: 2000;
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--dark-card);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
}

.modal-content-large {
    max-width: 800px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 800;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    transition: all 0.3s;
}

.modal-close:hover {
    background: var(--dark-hover);
    color: var(--text-primary);
}

.modal-body {
    padding: 2rem;
}

/* Admin Styles */
.admin-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    gap: 1rem;
}

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

.search-box i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-box input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 3rem;
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

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

.admin-table {
    width: 100%;
    border-collapse: collapse;
}

.admin-table th,
.admin-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    font-weight: 700;
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.admin-table td {
    color: var(--text-primary);
}

.admin-table tbody tr {
    transition: all 0.3s;
}

.admin-table tbody tr:hover {
    background: var(--dark-hover);
}

.loading-row {
    text-align: center !important;
    color: var(--text-secondary);
}

.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.btn-small {
    padding: 0.375rem 0.75rem;
    font-size: 0.875rem;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
}

.btn-edit {
    background: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
}

.btn-edit:hover {
    background: rgba(59, 130, 246, 0.2);
}

.btn-delete {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.btn-delete:hover {
    background: rgba(239, 68, 68, 0.2);
}

.btn-grade {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.btn-grade:hover {
    background: rgba(16, 185, 129, 0.2);
}

.rank-badge {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.875rem;
}

.rank-평민 { background: rgba(148, 163, 184, 0.1); color: #94a3b8; }
.rank-기사 { background: rgba(59, 130, 246, 0.1); color: #3b82f6; }
.rank-남작 { background: rgba(34, 197, 94, 0.1); color: #22c55e; }
.rank-백작 { background: rgba(168, 85, 247, 0.1); color: #a855f7; }
.rank-후작 { background: rgba(245, 158, 11, 0.1); color: #f59e0b; }
.rank-공작 { background: rgba(249, 115, 22, 0.1); color: #f97316; }
.rank-왕 { background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%); color: white; }

/* English rank names */
.rank-Commoner { background: rgba(148, 163, 184, 0.1); color: #94a3b8; }
.rank-Knight { background: rgba(59, 130, 246, 0.1); color: #3b82f6; }
.rank-Baron { background: rgba(34, 197, 94, 0.1); color: #22c55e; }
.rank-Viscount { background: rgba(168, 85, 247, 0.1); color: #a855f7; }
.rank-Count { background: rgba(245, 158, 11, 0.1); color: #f59e0b; }
.rank-Marquis { background: rgba(249, 115, 22, 0.1); color: #f97316; }
.rank-Duke { background: rgba(251, 146, 60, 0.1); color: #fb923c; }
.rank-King { background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%); color: white; }

.assignments-manage-list,
.submissions-review-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.assignment-manage-card,
.submission-card {
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
}

.submission-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.submission-user {
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--primary-color);
}

.submission-content {
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
    color: var(--text-secondary);
    line-height: 1.6;
    white-space: pre-wrap;
}

.rank-distribution {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.rank-dist-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--dark-bg);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.rank-dist-count {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.rank-dist-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-stats {
        gap: 2rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .dashboard-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 1rem 0;
    }

    .sidebar-menu {
        flex-direction: row;
        overflow-x: auto;
    }

    .menu-item {
        border-left: none;
        border-bottom: 3px solid transparent;
        white-space: nowrap;
    }

    .menu-item.active {
        border-left-color: transparent;
        border-bottom-color: var(--primary-color);
    }

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

    .assignments-grid,
    .videos-grid {
        grid-template-columns: 1fr;
    }

    .admin-toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        max-width: 100%;
    }

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

    .admin-table {
        min-width: 800px;
    }
}

/* Loading Animation */
@keyframes spin {
    to { transform: rotate(360deg); }
}

.fa-spinner {
    animation: spin 1s linear infinite;
}