html, body {
    overflow-x: hidden;
    max-width: 100%;
}

* {
    box-sizing: border-box;
}

img, video, iframe {
    max-width: 100%;
    height: auto;
}

button, a, input, select, textarea {
    min-height: 44px;
}

.mobile-menu-toggle {
    display: block;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1040;
    background: rgba(102, 126, 234, 0.9);
    color: white;
    border: none;
    border-radius: 0.5rem;
    padding: 0.75rem;
    cursor: pointer;
}

@media (min-width: 1024px) {
    .mobile-menu-toggle {
        display: none;
    }
}

.table-mobile-stack {
    display: block;
}

@media (max-width: 768px) {
    .table-mobile-stack thead {
        display: none;
    }

    .table-mobile-stack tbody,
    .table-mobile-stack tr,
    .table-mobile-stack td {
        display: block;
        width: 100%;
    }

    .table-mobile-stack tr {
        margin-bottom: 1rem;
        border: 1px solid #e5e7eb;
        border-radius: 0.5rem;
        padding: 1rem;
    }

    .table-mobile-stack td {
        border: none;
        padding: 0.25rem 0;
    }

    .table-mobile-stack td::before {
        content: attr(data-label) ": ";
        font-weight: 600;
        color: #374151;
    }
}

.event-card {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.dashboard-stats {
    display: grid;
    gap: 1rem;
}

@media (max-width: 480px) {
    .dashboard-stats {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 481px) and (max-width: 768px) {
    .dashboard-stats {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 769px) {
    .dashboard-stats {
        grid-template-columns: repeat(4, 1fr);
    }
}

.registration-details {
    padding: 1rem;
}

@media (max-width: 768px) {
    .registration-details {
        padding: 0.75rem;
    }

    .registration-details .student-info {
        flex-direction: column;
        gap: 0.5rem;
    }

    .registration-details .actions {
        flex-direction: column;
        gap: 0.5rem;
    }

    .registration-details .actions .btn {
        width: 100%;
    }
}

.search-bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex: 1;
    max-width: 400px;
}

.search-bar input {
    flex: 1;
    min-width: 0;
}

.search-bar button {
    flex-shrink: 0;
    white-space: nowrap;
}

@media (max-width: 768px) {
    .search-bar {
        flex-direction: column;
        max-width: 100%;
        gap: 0.75rem;
    }

    .search-bar input,
    .search-bar button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .search-bar {
        margin: 1rem 0;
    }

    .search-bar input,
    .search-bar button {
        font-size: 0.875rem;
        padding: 0.75rem;
    }
}

@media (max-width: 768px) {
    .dashboard-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .dashboard-header h1 {
        font-size: 1.5rem;
    }

    .dashboard-header p {
        font-size: 0.875rem;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }

    .stat-card {
        padding: 0.75rem;
    }

    .stat-card .text-2xl {
        font-size: 1.5rem;
    }
}

@media (max-width: 640px) {
    .btn-group {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
    }

    .btn-group .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .table-responsive {
        font-size: 0.875rem;
    }

    .table th,
    .table td {
        padding: 0.5rem;
        white-space: nowrap;
    }

    .table .btn {
        padding: 0.25rem 0.5rem;
        font-size: 0.75rem;
    }
}

@media (max-width: 640px) {
    .modal-content {
        margin: 1rem;
        max-width: calc(100% - 2rem);
    }

    .modal-header {
        padding: 1rem;
    }

    .modal-body {
        padding: 1rem;
    }

    .modal-footer {
        padding: 1rem;
        flex-direction: column;
        gap: 0.5rem;
    }

    .modal-footer .btn {
        width: 100%;
    }
}

@media (max-width: 640px) {
    .event-card {
        margin-bottom: 1rem;
    }

    .event-content {
        padding: 1rem;
    }

    .event-title {
        font-size: 1rem;
        line-height: 1.4;
    }

    .category-badge {
        font-size: 0.75rem;
        padding: 0.25rem 0.5rem;
    }
}

@media (max-width: 640px) {
    .form-container {
        padding: 1rem;
    }

    .form-container .grid {
        gap: 1rem;
    }

    .form-container input,
    .form-container select,
    .form-container textarea {
        font-size: 1rem;
        padding: 0.75rem;
    }

    .form-container label {
        font-size: 0.875rem;
        margin-bottom: 0.5rem;
    }
}

@media print {
    .sidebar,
    .mobile-menu-toggle,
    .navbar {
        display: none;
    }

    main, .main-content {
        margin: 0;
        padding: 1rem;
    }

    .card, .event-card {
        break-inside: avoid;
        border: 1px solid #ccc;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms;
        animation-iteration-count: 1;
        transition-duration: 0.01ms;
    }
}

.responsive-container {
    width: 100%;
    max-width: 100%;
    padding-left: 1rem;
    padding-right: 1rem;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .responsive-container {
        padding-left: 2rem;
        padding-right: 2rem;
    }
}

@media (min-width: 1024px) {
    .responsive-container {
        max-width: 1024px;
    }
}

@media (min-width: 1280px) {
    .responsive-container {
        max-width: 1280px;
    }
}

.responsive-text {
    font-size: 0.875rem;
    line-height: 1.5;
}

@media (min-width: 768px) {
    .responsive-text {
        font-size: 1rem;
    }
}

@media (min-width: 1024px) {
    .responsive-text {
        font-size: 1.125rem;
    }
}

.touch-target {
    min-height: 44px;
    min-width: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.text-truncate-responsive {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

.grid-responsive {
    display: grid;
    gap: 1rem;
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .grid-responsive {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid-responsive {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1280px) {
    .grid-responsive {
        grid-template-columns: repeat(4, 1fr);
    }
}

.desktop-only { display: none; }
.tablet-only { display: none; }

@media (min-width: 481px) and (max-width: 768px) {
    .tablet-only { display: block; }
    .mobile-only { display: none; }
}

@media (min-width: 769px) {
    .desktop-only { display: block; }
    .mobile-only { display: none; }
    .tablet-only { display: none; }
}