/* ====================================
   NEXUS - RESPONSIVE STYLES
   Clean and organized breakpoints
   ==================================== */

/* ============ LARGE DESKTOP (min-width: 1800px) ============ */
@media (min-width: 1800px) {
    :root {
        --max-width: 1800px;
    }
    .researchers-grid {
        grid-template-columns: repeat(5, 1fr);
    }
}

/* ============ LARGE DESKTOP (min-width: 1400px) ============ */
@media (min-width: 1400px) {
    :root {
        --max-width: 1600px;
        --sidebar-width: 300px;
    }
    .researchers-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: var(--spacing-xl);
    }
}

/* ============ TABLET (max-width: 1199px) ============ */
@media (max-width: 1199px) {
    :root {
        --sidebar-width: 260px;
        --spacing-xl: 2.5rem;
        --spacing-xxl: 3rem;
    }
    .header-container {
        padding: var(--spacing-md);
    }
    .nav-list {
        gap: var(--spacing-md);
    }
    .nav-link {
        font-size: 0.8125rem;
    }
    .researchers-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--spacing-md);
    }
    .footer-content,
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-lg);
    }
}

/* ============ TABLET (max-width: 991px) ============ */
@media (max-width: 991px) {
    .social-links {
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

/* ============ MOBILE (max-width: 767px) ============ */
@media (max-width: 767px) {
    /* Variables */
    :root {
        --font-size-3xl: 1.75rem;
        --font-size-2xl: 1.375rem;
        --spacing-lg: 1.25rem;
        --spacing-xl: 1.5rem;
        --spacing-xxl: 2rem;
    }

    /* Header */
    .header {
        position: relative;
    }
    .header-container {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 1rem;
        flex-wrap: wrap;
    }
    .logo-text {
        font-size: var(--font-size-lg);
    }
    .header-actions {
        gap: var(--spacing-sm);
    }
    .language-selector {
        display: none;
    }
    .social-links {
        display: none;
    }

    /* Mobile Menu Toggle */
    .mobile-menu-toggle {
        display: flex !important;
        flex-direction: column;
        gap: 5px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 10px;
        z-index: 1001;
    }
    .mobile-menu-toggle span {
        display: block;
        width: 28px;
        height: 3px;
        background-color: #1a1a1a;
        border-radius: 2px;
        transition: all 0.3s ease;
    }

    /* Hide Desktop Navigation */
    .main-nav {
        display: none !important;
    }

    /* Mobile Navigation Active */
    .main-nav.active {
        display: flex !important;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: #ffffff;
        border-top: 1px solid #e0e0e0;
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        padding: 0;
        z-index: 1000;
    }
    .main-nav.active .nav-list {
        flex-direction: column;
        gap: 0;
        padding: 0;
        margin: 0;
        list-style: none;
        width: 100%;
    }
    .main-nav.active .nav-item {
        width: 100%;
    }
    .main-nav.active .nav-link {
        display: block;
        padding: 16px 20px;
        color: #1a1a1a;
        border-bottom: 1px solid #f0f0f0;
        font-size: 16px;
        text-decoration: none;
    }
    .main-nav.active .nav-link:hover {
        background-color: #f5f5f5;
        color: #00d573;
    }

    /* Main Content */
    .main-content {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    .content-wrapper {
        grid-template-columns: 1fr !important;
    }

    /* Sidebar */
    .sidebar {
        display: none;
    }

    /* Section Header */
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-lg);
    }
    .section-title {
        font-size: var(--font-size-2xl);
    }

    /* Researchers Grid */
    .researchers-section {
        width: 100%;
        padding: 1rem;
    }
    .researchers-grid {
        grid-template-columns: 1fr !important;
        gap: var(--spacing-lg);
    }
    .researcher-card {
        width: 100%;
    }

    /* Cards */
    .card-image {
        padding-top: 56.25%;
    }
    .card-content {
        padding: var(--spacing-md);
    }
    .card-title {
        font-size: var(--font-size-base);
        -webkit-line-clamp: 3;
    }

    /* Pagination */
    .pagination {
        flex-wrap: wrap;
        gap: 8px;
    }
    .pagination-btn {
        min-width: 36px;
        height: 36px;
        padding: 0 10px;
        font-size: var(--font-size-xs);
    }

    /* Footer */
    .footer {
        padding: var(--spacing-xl) var(--spacing-md) var(--spacing-md);
    }
    .footer-container {
        padding: 0 var(--spacing-md);
    }
    .footer-content,
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    .footer-section {
        padding-bottom: var(--spacing-lg);
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .footer-section:last-child {
        border-bottom: none;
        padding-bottom: 0;
    }
    .footer-bottom {
        margin-top: var(--spacing-lg);
        padding-top: var(--spacing-md);
        border-top: 1px solid rgba(255,255,255,0.1);
    }

    /* Empty State */
    .empty-state {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    .empty-state-icon {
        width: 60px;
        height: 60px;
    }
    .empty-state-title {
        font-size: var(--font-size-xl);
    }
    .empty-state-text {
        font-size: var(--font-size-sm);
    }

    /* AI Research Page */
    .research-container {
        padding: 1rem;
    }
    .research-hero {
        padding: 2rem 1rem;
    }
    .research-hero-title {
        font-size: 1.75rem;
    }
    .search-input-wrapper {
        flex-direction: column;
        gap: 0.5rem;
    }
    .example-queries {
        grid-template-columns: 1fr;
    }
    .results-container {
        padding: 1rem;
    }
    .answer-card {
        padding: 1rem;
    }
    .sources-grid {
        grid-template-columns: 1fr;
    }

    /* Opportunities Page */
    .opportunities-grid,
    .three-column-layout {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }
    .opportunity-card {
        padding: 1rem;
    }

    /* Projects Page */
    .projects-layout {
        flex-direction: column;
    }
    .projects-sidebar {
        width: 100%;
        max-height: none;
    }
    .map-container {
        width: 100%;
        height: 300px !important;
    }
    #projectsMap {
        height: 250px !important;
    }

    /* Profile Page */
    .profile-header-content {
        flex-direction: column;
        text-align: center;
    }
    .profile-photo {
        margin-bottom: 1rem;
    }
    .profile-grid {
        grid-template-columns: 1fr !important;
    }

    /* Dashboard */
    .dashboard-container {
        grid-template-columns: 1fr;
    }
    .dashboard-sidebar {
        display: none;
    }
    .dashboard-grid {
        grid-template-columns: 1fr !important;
    }
}

/* ============ SMALL MOBILE (max-width: 480px) ============ */
@media (max-width: 480px) {
    :root {
        --font-size-3xl: 1.5rem;
        --font-size-2xl: 1.25rem;
        --spacing-md: 0.875rem;
        --spacing-lg: 1rem;
    }
    .header-container {
        padding: var(--spacing-sm);
    }
    .main-content {
        padding: var(--spacing-md);
    }
    .btn {
        padding: 8px 16px;
        font-size: var(--font-size-xs);
    }
    .researchers-grid {
        gap: var(--spacing-md);
    }
    .card-content {
        padding: var(--spacing-sm);
    }
    .card-footer {
        padding: var(--spacing-sm);
        padding-top: 0;
    }
    .search-input {
        padding: 10px 36px 10px 12px;
        font-size: var(--font-size-sm);
    }
}

/* ============ LANDSCAPE MOBILE ============ */
@media (max-height: 600px) and (orientation: landscape) {
    .header {
        position: relative;
    }
    .sidebar {
        position: static;
    }
    .main-content {
        padding-top: var(--spacing-md);
    }
}

/* ============ PRINT STYLES ============ */
@media print {
    .header,
    .sidebar,
    .pagination,
    .footer,
    .mobile-menu-toggle,
    .search-box,
    .btn {
        display: none !important;
    }
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    .researchers-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
    .researcher-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid var(--border-color);
    }
    body {
        font-size: 12pt;
    }
}

/* ============ ACCESSIBILITY ============ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --gray-200: #cccccc;
    }
    .btn-primary {
        border: 2px solid var(--black);
    }
    .researcher-card {
        border-width: 2px;
    }
}