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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
}

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

.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.logo {
    font-size: 1.8rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-tabs {
    display: flex;
    gap: 1rem;
}

.tab-button {
    padding: 0.75rem 1.5rem;
    border: none;
    background: transparent;
    color: #666;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.tab-button.active {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.tab-button:not(.active):hover {
    background: rgba(102, 126, 234, 0.1);
    color: #667eea;
}

.main-content {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.create-quiz-container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: white;
}

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

.form-select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    background: white;
    cursor: pointer;
}

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

.difficulty-btn {
    padding: 0.5rem 1rem;
    border: 2px solid #e1e5e9;
    background: white;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.difficulty-btn.active {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border-color: transparent;
}

.difficulty-btn:hover:not(.active) {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.05);
}

.generate-btn {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-width: 150px;
    justify-content: center;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

.generate-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.quiz-display {
    margin-top: 2rem;
}

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

.quiz-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.quiz-meta {
    color: #666;
    font-size: 1.1rem;
}

.question-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.question-number {
    color: #667eea;
    font-weight: 600;
    margin-bottom: 1rem;
}

.question-text {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.options-grid {
    display: grid;
    gap: 0.75rem;
}

.option-button {
    padding: 1rem;
    border: 2px solid #e1e5e9;
    background: white;
    text-align: left;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.option-button:hover {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.05);
}

.option-button.selected {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

.option-button.correct {
    border-color: #10b981;
    background: rgba(16, 185, 129, 0.1);
}

.option-button.incorrect {
    border-color: #ef4444;
    background: rgba(239, 68, 68, 0.1);
}

.quiz-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

.action-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.action-btn.primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.action-btn.secondary {
    background: white;
    color: #667eea;
    border: 2px solid #667eea;
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

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

.quiz-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    cursor: pointer;
}

.quiz-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

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

.quiz-card-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #333;
}

.quiz-card-meta {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.owner-username {
    color: #3b82f6 !important;
    font-weight: 700;
}

.owner-badge {
    background: linear-gradient(135deg, #ffd700, #ffed4a);
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 8px;
    font-size: 0.7rem;
    font-weight: 600;
    margin-left: 0.5rem;
    display: inline-block;
}

.highlighted-quiz-section {
    background: linear-gradient(135deg, #ffd700, #ffed4a);
    border-radius: 20px;
    padding: 2rem;
    border: 3px solid #ffd700;
    box-shadow: 0 10px 30px rgba(255, 215, 0, 0.3);
    margin-bottom: 2rem;
}

.highlighted-quiz-title {
    color: #ffd700;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-align: center;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.search-section {
    background: rgba(255,255,255,0.95);
    border-radius: 15px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.search-toggle {
    display: flex;
    gap: 0.5rem;
}

.search-toggle-btn {
    padding: 0.5rem 1rem;
    border: 2px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.search-toggle-btn.active {
    background: #667eea;
    color: white;
}

.search-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid #e1e5e9;
    border-radius: 25px;
    font-size: 1rem;
    min-width: 200px;
    transition: all 0.3s ease;
}

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

.quiz-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 2rem;
    animation: fadeIn 0.3s ease;
}

.quiz-modal-content {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    max-width: 500px;
    width: 100%;
    text-align: center;
    animation: slideUp 0.3s ease;
}

.user-profile-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 2rem;
    animation: fadeIn 0.3s ease;
}

.user-profile-modal-content {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    max-width: 700px;
    width: 100%;
    max-height: 80vh;
    overflow: auto;
    animation: slideUp 0.3s ease;
}

.user-quiz-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    max-height: 300px;
    overflow: auto;
}

.user-quiz-card {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all 0.3s ease;
}

.user-quiz-card:hover {
    border-color: #667eea;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.privacy-selector {
    padding: 0.25rem 0.5rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 0.9rem;
    background: white;
    cursor: pointer;
}

.badge-list {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.custom-badge {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 600;
    display: inline-block;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.score-display {
    text-align: center;
    background: white;
    border-radius: 20px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.score-number {
    font-size: 4rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.score-text {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 1rem;
}

.loading {
    text-align: center;
    padding: 3rem;
    color: #666;
}

.loading i {
    font-size: 3rem;
    margin-bottom: 1rem;
    animation: spin 2s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.multiplayer-section {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.players-list {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.player-card {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: white;
    padding: 0.75rem 1rem;
    border-radius: 25px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.player-name {
    font-weight: 600;
    color: #333;
}

.player-score {
    background: #667eea;
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 600;
}

.admin-panel {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

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

.admin-card {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.admin-card h3 {
    margin-bottom: 1rem;
    color: #333;
}

.announcement-banner {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 1rem 2rem;
    border-radius: 15px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    animation: slideDown 0.5s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(-100%);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.shutdown-screen {
    min-height: 100vh;
    background: linear-gradient(135deg, #1f2937, #374151);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
}

.shutdown-content {
    max-width: 800px;
    margin: 0 auto;
}

.admin-ai-popup {
    position: fixed;
    top: 80px;
    right: 20px;
    width: 400px;
    height: 500px;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.chat-messages {
    flex: 1;
    overflow: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.chat-message {
    padding: 0.75rem;
    border-radius: 10px;
    max-width: 80%;
}

.chat-message.user {
    background: #667eea;
    color: white;
    align-self: flex-end;
}

.chat-message.assistant {
    background: #f0f0f0;
    color: black;
    align-self: flex-start;
}

.chat-container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    height: 80vh;
    display: flex;
    flex-direction: column;
}

.chat-channels {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.channel-button {
    padding: 0.5rem 1rem;
    border: 2px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.channel-button.active {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border-color: transparent;
}

.channel-button:hover:not(.active) {
    background: rgba(102, 126, 234, 0.1);
}

.chat-info {
    margin-bottom: 1rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    font-size: 0.9rem;
    border-left: 4px solid #667eea;
}

.chat-messages-container {
    flex: 1;
    overflow: auto;
    border: 1px solid #e1e5e9;
    border-radius: 10px;
    padding: 1rem;
    margin-bottom: 1rem;
    background: white;
}

.chat-message-item {
    margin-bottom: 1rem;
    padding: 0.75rem;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid transparent;
}

.chat-message-item.system {
    background: #f0f8ff;
    border-left-color: #667eea;
}

.chat-message-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.chat-avatar {
    width: 24px;
    height: 24px;
    border-radius: 50%;
}

.chat-username {
    font-weight: 600;
    color: #333;
}

.chat-timestamp {
    font-size: 0.8rem;
    color: #666;
}

.chat-content {
    white-space: pre-wrap;
    line-height: 1.4;
}

.chat-input-area {
    display: flex;
    gap: 0.5rem;
}

.chat-input-field {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

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

.chat-send-button {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    padding: 0.75rem 1rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.chat-send-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.profile-container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.profile-header {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.profile-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
}

.profile-info h2 {
    margin-bottom: 0.5rem;
    color: #333;
}

.profile-bio {
    color: #666;
    margin-bottom: 1rem;
}

.profile-stats-quick {
    display: flex;
    gap: 1rem;
}

.profile-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.profile-stat-card {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
}

.profile-stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: #667eea;
}

.profile-stat-label {
    color: #666;
    font-size: 0.9rem;
}

.badges-section {
    margin-bottom: 2rem;
}

.badges-grid {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.badge-card {
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s ease;
}

.badge-card.earned {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.badge-card.not-earned {
    background: #f0f0f0;
    color: #666;
    opacity: 0.5;
}

.badge-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.badge-name {
    font-weight: bold;
    margin-bottom: 0.25rem;
}

.badge-requirement {
    font-size: 0.8rem;
}

.bio-edit-section {
    margin-top: 2rem;
}

.bio-textarea {
    width: 100%;
    min-height: 100px;
    padding: 0.75rem;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 1rem;
    resize: vertical;
    font-family: inherit;
}

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

.save-bio-btn {
    margin-top: 1rem;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.save-bio-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.rainbow-mode {
    animation: rainbow 3s linear infinite;
}

@keyframes rainbow {
    0% { filter: hue-rotate(0deg); }
    100% { filter: hue-rotate(360deg); }
}

.edit-quiz-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 2rem;
}

.edit-quiz-content {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    max-width: 600px;
    width: 100%;
    max-height: 80vh;
    overflow: auto;
}

.edit-quiz-field {
    width: 100%;
    padding: 0.5rem;
    margin: 0.5rem 0;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.edit-quiz-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.edit-quiz-save {
    background: #10b981;
    color: white;
    border: none;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: pointer;
}

.edit-quiz-cancel {
    background: #6b7280;
    color: white;
    border: none;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    cursor: pointer;
}

.admin-feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.admin-feature-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: center;
}

.admin-feature-btn.primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.admin-feature-btn.secondary {
    background: white;
    color: #667eea;
    border: 2px solid #667eea;
}

.admin-feature-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.admin-info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.admin-info-card {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 10px;
}

.admin-info-card h3 {
    margin-bottom: 1rem;
    color: #333;
}

.admin-info-card p {
    margin-bottom: 0.5rem;
}

.user-activity-monitor {
    max-height: 200px;
    overflow: auto;
}

.activity-item {
    margin-bottom: 0.5rem;
    padding: 0.5rem;
    background: white;
    border-radius: 5px;
    border-left: 3px solid #667eea;
}

.activity-user {
    font-weight: 600;
    color: #333;
}

.activity-details {
    font-size: 0.8rem;
    color: #666;
    margin-top: 0.25rem;
}

.announcements-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-top: 2rem;
}

.announcement-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #f8f9fa;
    padding: 0.75rem;
    border-radius: 8px;
}

.remove-announcement-btn {
    background: #ef4444;
    color: white;
    border: none;
    padding: 0.25rem 0.5rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.8rem;
}

@media (max-width: 768px) {
    .header {
        padding: 1rem;
        flex-direction: column;
        gap: 1rem;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .quiz-grid {
        grid-template-columns: 1fr;
    }
    
    .difficulty-buttons {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .quiz-actions {
        flex-direction: column;
    }
    
    .profile-header {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }
    
    .profile-stats-quick {
        justify-content: center;
    }
    
    .badges-grid {
        justify-content: center;
    }
    
    .chat-channels {
        justify-content: center;
    }
    
    .admin-feature-grid {
        grid-template-columns: 1fr;
    }
    
    .admin-info-grid {
        grid-template-columns: 1fr;
    }
}