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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.education-container {
    max-width: 1200px;
    margin: 30px auto;
    padding: 0 20px;
}

.education-header {
    background: linear-gradient(135deg, #e8f5e9 0%, #f1f8e9 100%);
    border-radius: 12px;
    padding: 60px 40px;
    text-align: center;
    margin-bottom: 60px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.education-header h1 {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    font-size: 2.5em;
    font-weight: 700;
    color: #2e7d32;
    margin-bottom: 15px;
}

.education-header img {
    width: 60px;
    height: 60px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.education-header p {
    font-size: 1.1em;
    color: #666;
    max-width: 700px;
    margin: 0 auto;
}

.papers-section,
.videos-section,
.links-section {
    margin-bottom: 80px;
}

.section-title {
    font-size: 1.8em;
    font-weight: 600;
    color: #333;
    margin-bottom: 30px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.carousel-container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    background-color: white;
    border: 1px solid #e0e0e0;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    z-index: 10;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    background-repeat: no-repeat;
    background-position: center;
    background-size: 40%;
}

.carousel-btn:hover {
    background-color: #f0f8f5;
    transform: translateY(-50%) scale(1.05);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.carousel-btn.prev {
    left: -22px;
    background-image: url('/static/img/arrow1.png');
}

.carousel-btn.next {
    right: -22px;
    background-image: url('/static/img/arrow.png');
}

.papers-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    width: 100%;
    max-width: 1050px;
}

.paper-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.paper-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.paper-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: #f0f0f0;
}

.paper-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.paper-content {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.paper-title {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
    line-height: 1.4;
}

.paper-author {
    font-size: 0.9em;
    color: #4caf50;
    margin-bottom: 12px;
    font-weight: 500;
}

.paper-description {
    font-size: 0.9em;
    color: #666;
    line-height: 1.5;
    margin-bottom: 15px;
    flex-grow: 1;
}

.btn-read {
    display: inline-block;
    padding: 10px 20px;
    background: #4caf50;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
}

.btn-read:hover {
    background: #45a049;
    transform: scale(1.02);
}

.videos-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
    width: 100%;
    max-width: 1050px;
}

.video-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.video-info {
    padding: 20px;
    order: 1;
}

.video-info h3 {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
}

.video-info p {
    font-size: 0.9em;
    color: #666;
    line-height: 1.5;
}

.video-thumbnail {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    background: #000;
    cursor: pointer;
    overflow: hidden;
    order: 2;
}

.video-thumbnail img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.video-thumbnail:hover img {
    transform: scale(1.05);
}

.play-button {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 68px;
    height: 48px;
    transition: transform 0.3s ease;
    pointer-events: none;
}

.video-thumbnail:hover .play-button {
    transform: translate(-50%, -50%) scale(1.1);
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    order: 2;
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    width: 100%;
    max-width: 1050px;
}

.link-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    border-left: 4px solid #4caf50;
}

.link-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
    border-left-color: #2e7d32;
}

.link-icon {
    font-size: 3em;
    margin-bottom: 15px;
}

.link-title {
    font-size: 1.1em;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    line-height: 1.4;
}

.link-description {
    font-size: 0.9em;
    color: #666;
    line-height: 1.6;
    margin-bottom: 15px;
    flex-grow: 1;
}

.link-url {
    font-size: 0.85em;
    color: #4caf50;
    font-weight: 500;
}

@media (max-width: 1100px) {
    .papers-grid,
    .links-grid {
        grid-template-columns: repeat(2, 1fr);
        max-width: 700px;
    }
    
    .videos-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
    }
}

@media (max-width: 768px) {
    .education-header {
        padding: 40px 20px;
    }
    
    .education-header h1 {
        font-size: 2em;
        flex-direction: column;
    }
    
    .section-title {
        font-size: 1.5em;
    }
    
    .papers-grid,
    .videos-grid,
    .links-grid {
        grid-template-columns: 1fr;
        max-width: 350px;
    }
    
    .carousel-btn {
        display: none !important;
    }
}

.header {
    background-color: #ffffff;
    padding: 15px 0;
    border-bottom: 1px solid #e5e7eb;
    width: 100%;
}

.header .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-img {
    height: 40px;
}

.nav {
    display: flex;
    gap: 25px;
}

.nav a {
    color: #4b5563;
    text-decoration: none;
    font-weight: 400;
    font-size: 16px;
    transition: color 0.3s ease;
}

.nav a:hover {
    color: #059669;
}

.auth-buttons {
    display: flex;
    gap: 12px;
    align-items: center;
}

.user-greeting {
    color: #4b5563;
    font-size: 14px;
    font-weight: 500;
    margin-right: 5px;
}

.btn {
    padding: 8px 18px;
    border-radius: 20px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
    border: 1px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background-color: #059669;
    color: white;
    border-color: #059669;
}

.btn-primary:hover {
    background-color: #047857;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(5, 150, 105, 0.3);
}

.btn-secondary {
    background-color: #0f172a;
    color: #ffffff;
    border: none;
}

.btn-secondary:hover {
    background-color: #1e293b;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.2);
}

.breadcrumb-nav {
    background-color: #f9fafb;
    border-bottom: 1px solid #e5e7eb;
    padding: 12px 0;
}

.breadcrumb-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.breadcrumb-list {
    display: flex;
    align-items: center;
    list-style: none;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
}

.breadcrumb-item {
    font-size: 14px;
    color: #6b7280;
}

.breadcrumb-item a {
    color: #059669;
    text-decoration: none;
    transition: color 0.2s;
}

.breadcrumb-item a:hover {
    color: #047857;
    text-decoration: underline;
}

.breadcrumb-item.active {
    color: #1f2937;
    font-weight: 600;
}

.breadcrumb-separator {
    margin: 0 8px;
    color: #9ca3af;
    font-size: 14px;
}