@media (max-width: 900px) {
    .mobile-menu-btn {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 40px;
        height: 40px;
        background: rgba(37, 99, 235, 0.2);
        border: 1px solid rgba(37, 99, 235, 0.4);
        border-radius: 10px;
        cursor: pointer;
        margin-right: 10px;
    }

    .mobile-menu-btn span {
        display: block;
        width: 20px;
        height: 2px;
        background: var(--text);
        position: relative;
        transition: all 0.3s;
    }

    .mobile-menu-btn span::before,
    .mobile-menu-btn span::after {
        content: '';
        position: absolute;
        width: 20px;
        height: 2px;
        background: var(--text);
        left: 0;
        transition: all 0.3s;
    }

    .mobile-menu-btn span::before {
        top: -6px;
    }

    .mobile-menu-btn span::after {
        top: 6px;
    }

    .mobile-menu-btn.active span {
        background: transparent;
    }

    .mobile-menu-btn.active span::before {
        top: 0;
        transform: rotate(45deg);
    }

    .mobile-menu-btn.active span::after {
        top: 0;
        transform: rotate(-45deg);
    }

    .app-header {
        padding: 10px 12px;
    }

    .app-logo span {
        display: none;
    }

    .app-logo img {
        width: 36px;
        height: 36px;
    }

    .nav-user {
        display: none;
    }

    .header-link {
        display: none;
    }

    .sidebar {
        display: none;
        position: fixed;
        top: 57px;
        left: 0;
        right: 0;
        bottom: 0;
        width: 100%;
        z-index: 100;
        background: rgba(2, 6, 23, 0.98);
        backdrop-filter: blur(10px);
        padding: 20px;
        overflow-y: auto;
        animation: slideDown 0.3s ease-out;
    }

    @keyframes slideDown {
        from {
            opacity: 0;
            transform: translateY(-10px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    .sidebar.mobile-open {
        display: flex;
    }

    .sidebar-user {
        padding: 16px;
        text-align: center;
        background: radial-gradient(circle at center,
                                     rgba(37,99,235,0.3),
                                     rgba(15,23,42,1));
    }

    .sidebar-user-name {
        font-size: 18px;
    }

    .sidebar-role {
        font-size: 14px;
    }

    .sidebar-nav {
        gap: 8px;
        margin-top: 10px;
    }

    .sidebar-nav a {
        padding: 14px 16px;
        font-size: 16px;
        border-radius: 12px;
        display: flex;
        align-items: center;
        justify-content: space-between;
        background: rgba(15, 23, 42, 0.5);
        border: 1px solid rgba(31, 41, 55, 0.5);
    }

    .sidebar-nav a:active {
        background: rgba(37, 99, 235, 0.3);
        transform: scale(0.98);
    }

    .sidebar-logout {
        margin-top: 20px;
        padding-top: 20px;
        border-top: 1px solid var(--border);
    }

    .logout-btn {
        padding: 14px 18px;
        font-size: 16px;
    }

    .app-body {
        min-height: calc(100vh - 57px);
    }

    .app-main {
        padding: 16px 12px;
        max-width: 100%;
    }

    .auth-wrapper {
        grid-template-columns: 1fr;
        gap: 20px;
        margin-top: 20px;
    }

    .auth-info {
        padding: 20px;
        text-align: center;
    }

    .auth-info h1 {
        font-size: 22px;
    }

    .big-logo {
        width: 60px;
        height: 60px;
    }

    .info-links {
        flex-direction: row;
        justify-content: center;
        flex-wrap: wrap;
    }

    .auth-form {
        padding: 16px;
    }

    .tabs a {
        padding: 10px 0;
    }

    .grid-3 {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }
    
    .grid-3 > .card:first-child {
        grid-column: 1 / -1;
        text-align: center;
    }
    
    .grid-3 > .card:first-child h2 {
        justify-content: center;
    }

    .card {
        padding: 14px 16px;
        margin-bottom: 0;
        border-radius: 12px;
        text-align: center;
    }
    
    .card h2 {
        font-size: 0.95rem;
        margin-bottom: 10px;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 6px;
    }
    
    .card h2::before {
        font-size: 1rem;
    }
    
    .card.neon-blue h2::before { content: '👋'; }
    .card.neon-purple h2::before { content: '🏆'; }
    .card.neon-green h2::before { content: '📊'; }
    
    .card .big-text {
        font-size: 1.3rem;
        margin-bottom: 6px;
    }
    
    .card p {
        font-size: 13px;
        margin-bottom: 6px;
        line-height: 1.4;
    }
    
    .card .btn-secondary.small {
        margin-top: 8px;
        display: inline-block;
        padding: 8px 14px;
        font-size: 12px;
    }
    
    .upcoming-grid {
        gap: 12px;
    }
    
    .upcoming-card {
        padding: 14px 16px;
    }
    
    .upcoming-header h3 {
        font-size: 1rem;
    }
    
    .upcoming-row {
        padding: 6px 0;
    }
    
    .upcoming-btn {
        margin-top: 12px;
        width: 100%;
        justify-content: center;
        padding: 12px;
    }
    
    .card.full-width h2 {
        font-size: 1.15rem;
        margin-bottom: 16px;
    }
    
    .card.full-width h2::before {
        content: '🎮';
    }
    
    .empty-state {
        padding: 20px;
        text-align: center;
        font-size: 14px;
    }

    .tournament-card {
        padding: 12px 14px;
    }

    .tournament-card header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .tournament-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .tournament-actions .btn-primary,
    .tournament-actions .btn-secondary,
    .tournament-actions .btn-danger {
        width: 100%;
        justify-content: center;
    }

    .table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }

    .filter-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-bar label {
        width: 100%;
    }

    .filter-bar select,
    .filter-bar input {
        width: 100%;
    }

    .rank-group {
        flex-direction: column;
    }

    .rank-card {
        min-width: 100%;
    }

    .ticket-messages {
        max-height: 400px;
    }

    .message-bubble {
        max-width: 90%;
    }

    .message-form {
        flex-direction: column;
    }

    .message-form textarea {
        width: 100%;
    }

    .message-form button {
        width: 100%;
    }

    .close-ticket-form {
        flex-direction: column;
    }

    .close-ticket-form label,
    .close-ticket-form select,
    .close-ticket-form button {
        width: 100%;
    }

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

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

    .paypal-row {
        flex-direction: column;
        align-items: flex-start;
    }

    .modal-content {
        width: 95%;
        margin: 10px;
    }

    .inline-form {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    .inline-form input,
    .inline-form select,
    .inline-form button {
        width: 100%;
    }

    .info-box {
        padding: 12px 14px;
        font-size: 13px;
    }

    .request-card {
        padding: 12px;
    }

    .request-card header {
        flex-direction: column;
        gap: 8px;
    }

    input, select, textarea {
        font-size: 16px;
        padding: 12px;
    }

    .btn-primary, .btn-secondary, .btn-danger, .btn-warning, .btn-success {
        padding: 12px 20px;
        font-size: 15px;
    }

    .lang-switcher {
        margin-right: 0;
    }

    .lang-btn {
        width: 32px;
        height: 32px;
    }

    .lang-flag {
        width: 22px;
        height: 22px;
    }

    .mobile-overlay {
        display: none;
        position: fixed;
        top: 57px;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 99;
    }

    .mobile-overlay.active {
        display: block;
    }
}

@media (min-width: 901px) {
    .mobile-menu-btn {
        display: none;
    }

    .mobile-overlay {
        display: none !important;
    }
}