/* ==========================================
   Purdue Link Hub - Main Stylesheet
   Colors: Purdue Black, Gold, and White
   ========================================== */

/* CSS Variables - Purdue Branding */
:root {
    --purdue-gold: #CEB888;
    --purdue-old-gold: #B1810B;
    --purdue-black: #000000;
    --purdue-white: #FFFFFF;
    --purdue-gray: #E8E8E8;
    --purdue-dark-gray: #3C3C3C;

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);

    --border-radius: 12px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
    color: var(--purdue-black);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

/* ==========================================
   Toggle-Theme
   ========================================== */


.theme-toggle {
    position: relative;
    left: 0;
    transform: none;
}

.theme-switch-input {
    display: none;
}


.theme-switch-label {
    width: 90px;
    height: 42px;
    background: #dcdcdc;
    border-radius: 50px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 10px;
    position: relative;
    cursor: pointer;
}

.sun-icon,
.moon-icon {
    font-size: 22px;
    opacity: 0.6;
}

.toggle-ball {
    position: absolute;
    top: 4px;
    left: 4px;
    width: 34px;
    height: 34px;
    background: white;
    border-radius: 50%;
    transition: .25s ease;
    box-shadow: 0 2px 6px rgba(0,0,0,0.25);
}

.theme-switch-input:checked + .theme-switch-label {
    background: #444;
}

.theme-switch-input:checked + .theme-switch-label .toggle-ball {
    transform: translateX(46px);
}

.theme-switch-input:checked + .theme-switch-label .sun-icon {
    opacity: .3;
}

.theme-switch-input:checked + .theme-switch-label .moon-icon {
    opacity: 1;
}


/* ==========================================
   Header
   ========================================== */
.header {
    background: var(--purdue-black);
    color: var(--purdue-white);
    padding: 20px 0;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: stretch;
    position: relative;
}


.logo-section {
    display: flex;
    justify-content: center;
    pointer-events: none;
    order: 2;
}


.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--purdue-gold);
    margin: 0;
}

.search-section {
    display: flex;
    justify-content: flex-end;
    order: 3;
}

.search-input {
    width: 100%;
    padding: 12px 20px;
    border: 2px solid var(--purdue-gold);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--purdue-white);
}

.search-input:focus {
    outline: none;
    border-color: var(--purdue-old-gold);
    box-shadow: 0 0 0 3px rgba(206, 184, 136, 0.2);
}

.search-input::placeholder {
    color: #999;
}

/* ==========================================
   Banner
   ========================================== */
.banner {
    background: linear-gradient(135deg, var(--purdue-old-gold), var(--purdue-gold));
    color: var(--purdue-black);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
    position: relative;
    box-shadow: var(--shadow-sm);
    font-weight: 500;
}

.banner p {
    margin: 0;
    padding-right: 30px;
}

.banner-close {
    position: absolute;
    top: 50%;
    right: 15px;
    transform: translateY(-50%);
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--purdue-black);
    font-weight: bold;
    padding: 0;
    width: 25px;
    height: 25px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-close:hover {
    opacity: 0.7;
}

/* ==========================================
   Main Content
   ========================================== */
.main-content {
    flex: 1;
    padding: 30px 0;
}

/* Category Tabs */
.category-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    overflow-x: auto;
    padding-bottom: 10px;
    scrollbar-width: thin;
    scrollbar-color: var(--purdue-gold) var(--purdue-gray);
}

.category-tabs::-webkit-scrollbar {
    height: 6px;
}

.category-tabs::-webkit-scrollbar-track {
    background: var(--purdue-gray);
    border-radius: 3px;
}

.category-tabs::-webkit-scrollbar-thumb {
    background: var(--purdue-gold);
    border-radius: 3px;
}

.tab-button {
    padding: 10px 20px;
    border: 2px solid var(--purdue-black);
    background: var(--purdue-white);
    color: var(--purdue-black);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 600;
    white-space: nowrap;
    transition: var(--transition);
}

.tab-button:hover {
    background: var(--purdue-gray);
    transform: translateY(-2px);
}

.tab-button.active {
    background: var(--purdue-black);
    color: var(--purdue-gold);
    border-color: var(--purdue-black);
}

/* Links Grid */
.links-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin-bottom: 30px;
}

/* Link Card */
.link-card {
    background: var(--purdue-white);
    border: 2px solid var(--purdue-gray);
    border-radius: var(--border-radius);
    padding: 20px;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.link-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--purdue-gold);
}

.link-card:active {
    transform: translateY(-2px);
}

.link-card.pinned {
    border-color: var(--purdue-old-gold);
    background: linear-gradient(135deg, #ffffff 0%, #fffef8 100%);
    box-shadow: 0 2px 8px rgba(206, 184, 136, 0.2);
}

.link-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.link-title-section {
    flex: 1;
}

.link-icon {
    font-size: 2rem;
    margin-bottom: 5px;
    display: block;
}

.link-name {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--purdue-black);
    margin: 0 0 5px 0;
}

.link-description {
    font-size: 0.9rem;
    color: var(--purdue-dark-gray);
    margin: 0;
    line-height: 1.5;
}

.link-category {
    display: inline-block;
    padding: 4px 12px;
    background: var(--purdue-gray);
    color: var(--purdue-black);
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-top: 10px;
}

.pin-button {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
    transition: var(--transition);
    filter: grayscale(100%);
}

.pin-button:hover {
    transform: scale(1.2);
}

.pin-button.pinned {
    filter: grayscale(0%);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--purdue-dark-gray);
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--purdue-black);
}

.empty-state p {
    font-size: 1rem;
    color: var(--purdue-dark-gray);
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--purdue-black);
    color: var(--purdue-white);
    padding: 30px 0;
    text-align: center;
    margin-top: auto;
}

.footer p {
    margin: 5px 0;
}

.footer-note {
    font-size: 0.85rem;
    color: var(--purdue-gold);
    opacity: 0.8;
}

/* ==========================================
   Responsive Design - Tablet
   ========================================== */
@media (min-width: 768px) {
    .header-content {
        display: grid;
        grid-template-columns: 90px 1fr 400px;
        gap: 20px;
        align-items: center;
    }

    .theme-toggle {
        order: 0;
    }

    .logo-section {
        text-align: center;
        order: 0;
    }

    .logo {
        font-size: 1.75rem;
    }

    .search-section {
        max-width: 400px;
        order: 0;
    }

    .links-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }

    .category-tabs {
        justify-content: center;
    }
}

/* ==========================================
   Responsive Design - Desktop
   ========================================== */
@media (min-width: 1024px) {
    .logo {
        font-size: 2rem;
    }

    .search-section {
        max-width: 500px;
    }

    .links-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 30px;
    }

    .main-content {
        padding: 40px 0;
    }
}

/* ==========================================
   Animations
   ========================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.link-card {
    animation: fadeIn 0.3s ease;
}

.empty-state {
    animation: fadeInUp 0.4s ease;
}

.banner {
    animation: fadeInUp 0.4s ease;
}

/* ==========================================
   Accessibility
   ========================================== */
.tab-button:focus,
.search-input:focus,
.pin-button:focus {
    outline: 3px solid var(--purdue-gold);
    outline-offset: 2px;
}

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



/* ==========================================
   Dark mode
   ========================================== */

body.dark-theme {
    background: linear-gradient(135deg, #424242 0%, #181818 100%);
    color: var(--purdue-gray);
}

body.dark-theme .search-input {
    background: #1f1f1f;
    color: var(--purdue-white);
    border-color: var(--purdue-gold);
}

body.dark-theme .search-input::placeholder {
    color: #bbbbbb;
}

body.dark-theme .link-card {
    background: #181818;
    border-color: #333333;
}

body.dark-theme .link-name {
    color: var(--purdue-white);
}

body.dark-theme .link-description {
    color: var(--purdue-gray);
}

body.dark-theme .link-category {
    background: #2a2a2a;
    color: var(--purdue-gray);
}

body.dark-theme .tab-button {
    background: #181818;
    color: var(--purdue-gray);
    border-color: #333333;
}

body.dark-theme .tab-button.active {
    background: var(--purdue-gold);
    color: var(--purdue-black);
    border-color: var(--purdue-gold);
}

body.dark-theme .footer {
    background: #050505;
}

/* ==========================================
   Course Search Pagination
   ========================================== */
.result-info {
    padding: 15px 0;
    text-align: center;
    color: var(--purdue-dark-gray);
    font-weight: 500;
    border-bottom: 2px solid var(--purdue-gray);
    margin-bottom: 20px;
}

.pagination-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    padding: 30px 0;
    margin-top: 20px;
    border-top: 2px solid var(--purdue-gray);
}

.pagination-btn {
    padding: 12px 24px;
    border: 2px solid var(--purdue-black);
    background: var(--purdue-white);
    color: var(--purdue-black);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
}

.pagination-btn:hover:not(:disabled) {
    background: var(--purdue-gold);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.pagination-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    border-color: var(--purdue-gray);
}

.page-info {
    font-size: 1rem;
    font-weight: 600;
    color: var(--purdue-black);
    min-width: 120px;
    text-align: center;
}

body.dark-theme .result-info {
    color: var(--purdue-gray);
    border-bottom-color: #333333;
}

body.dark-theme .pagination-controls {
    border-top-color: #333333;
}

body.dark-theme .pagination-btn {
    background: #181818;
    color: var(--purdue-gray);
    border-color: #333333;
}

body.dark-theme .pagination-btn:hover:not(:disabled) {
    background: var(--purdue-gold);
    color: var(--purdue-black);
    border-color: var(--purdue-gold);
}

body.dark-theme .page-info {
    color: var(--purdue-gray);
}

/* ==========================================
   Section Pagination
   ========================================== */
.section-info-header {
    padding: 10px 0;
    text-align: center;
    font-size: 0.9rem;
    color: var(--purdue-dark-gray);
    font-weight: 500;
    border-bottom: 1px solid var(--purdue-gray);
    margin-bottom: 15px;
}

.section-pagination-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    padding: 20px 0 10px 0;
    margin-top: 15px;
    border-top: 1px solid var(--purdue-gray);
}

.section-pagination-btn {
    padding: 8px 16px;
    border: 2px solid var(--purdue-black);
    background: var(--purdue-white);
    color: var(--purdue-black);
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: var(--transition);
}

.section-pagination-btn:hover:not(:disabled) {
    background: var(--purdue-gold);
    transform: translateY(-1px);
}

.section-pagination-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.section-page-info {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--purdue-black);
    min-width: 100px;
    text-align: center;
}

body.dark-theme .section-info-header {
    color: var(--purdue-gray);
    border-bottom-color: #333333;
}

body.dark-theme .section-pagination-controls {
    border-top-color: #333333;
}

body.dark-theme .section-pagination-btn {
    background: #181818;
    color: var(--purdue-gray);
    border-color: #333333;
}

body.dark-theme .section-pagination-btn:hover:not(:disabled) {
    background: var(--purdue-gold);
    color: var(--purdue-black);
}

body.dark-theme .section-page-info {
    color: var(--purdue-gray);
}

/* ==========================================
   Search Help Button & Modal
   ========================================== */
.search-section {
    position: relative;
    display: flex;
    gap: 8px;
    align-items: center;
}

.search-help-btn {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 2px solid var(--purdue-gold);
    background: var(--purdue-white);
    color: var(--purdue-old-gold);
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.search-help-btn:hover {
    background: var(--purdue-gold);
    color: var(--purdue-black);
    transform: scale(1.05);
}

.search-help-btn .help-icon {
    font-size: 1.3rem;
    line-height: 1;
}

/* Modal Overlay */
.search-tips-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
    animation: fadeIn 0.2s ease;
}

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

/* Modal Content */
.search-tips-modal {
    background: var(--purdue-white);
    border-radius: var(--border-radius);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        transform: translateY(20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.search-tips-header {
    background: linear-gradient(135deg, var(--purdue-old-gold), var(--purdue-gold));
    padding: 20px 25px;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.search-tips-header h3 {
    margin: 0;
    font-size: 1.5rem;
    color: var(--purdue-black);
}

.close-tips-btn {
    background: transparent;
    border: none;
    font-size: 2rem;
    color: var(--purdue-black);
    cursor: pointer;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--transition);
}

.close-tips-btn:hover {
    background: rgba(0, 0, 0, 0.1);
}

.search-tips-content {
    padding: 25px;
}

.tip-section {
    margin-bottom: 25px;
}

.tip-section:last-child {
    margin-bottom: 0;
}

.tip-section h4 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--purdue-black);
}

.tip-section ul {
    list-style: none;
    padding: 0;
}

.tip-section li {
    padding: 8px 0;
    color: #333;
    line-height: 1.6;
}

.tip-section kbd {
    background: var(--purdue-black);
    color: var(--purdue-white);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9rem;
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.tip-section code {
    background: var(--purdue-gold);
    color: var(--purdue-black);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.9rem;
    font-weight: bold;
}

.shortcut-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 10px;
    margin-top: 12px;
}

.shortcut-item {
    background: var(--purdue-gray);
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 0.95rem;
    text-align: center;
    transition: var(--transition);
}

.shortcut-item:hover {
    background: var(--purdue-gold);
    transform: translateY(-2px);
}

/* Dark Theme Support */
body.dark-theme .search-help-btn {
    background: #181818;
    border-color: var(--purdue-gold);
    color: var(--purdue-gold);
}

body.dark-theme .search-help-btn:hover {
    background: var(--purdue-gold);
    color: var(--purdue-black);
}

body.dark-theme .search-tips-modal {
    background: #181818;
}

body.dark-theme .search-tips-header h3 {
    color: var(--purdue-black);
}

body.dark-theme .search-tips-content {
    color: var(--purdue-gray);
}

body.dark-theme .tip-section h4 {
    color: var(--purdue-gold);
}

body.dark-theme .tip-section li {
    color: var(--purdue-gray);
}

body.dark-theme .shortcut-item {
    background: #282828;
    color: var(--purdue-gray);
}

body.dark-theme .shortcut-item:hover {
    background: var(--purdue-gold);
    color: var(--purdue-black);
}

/* Responsive Design */
@media (max-width: 768px) {
    .search-tips-modal {
        max-width: 100%;
        margin: 10px;
    }

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

    .search-help-btn {
        width: 38px;
        height: 38px;
        font-size: 1rem;
    }
}