/* Education section */
:root {
    --primary-color: #1a237e;
    /* --secondary-color: #3949ab; */
    --accent-color: #00acc1;
    --light-color: #f5f7fa;
    --dark-color: #263238;
    --success-color: #00c853;
    --text-color: #455a64;
    --sidebar-bg: #171b26;
    --sidebar-border: #232537;
    --sidebar-text: #ccd6f6;
    --card-shadow: 0 4px 12px rgba(2, 2, 2, 0.08);
    --hover-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
    --gradient-primary: linear-gradient(135deg, #1a237e 0%, #3949ab 100%);
    --gradient-accent: linear-gradient(135deg, #00acc1 0%, #0097a7 100%);
    --gradient-success: linear-gradient(135deg, #00c853 0%, #00a040 100%);
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #e67e22;
    --accent-light: #f39c12;
    --text-color: #2c3e50;
    --text-light: #7f8c8d;
    --bg-color: #fdfaf6;
    --card-bg: #ffffff;
    --card-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
    --hover-shadow: 0 12px 24px rgba(0, 0, 0, 0.12);
    --border-radius: 12px;
    --tag-bg: #fff3e0;
    --tag-color: #e67e22;
    --header-gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

body {
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f8f9fa;
    overflow-x: hidden;
}

/* Main Content Styles */
.main-content {
    flex: 1;
    padding: 30px;
    margin-left: 280px;
    overflow-y: auto;
    transition: margin-left 0.3s ease;
}

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

header {
    text-align: center;
    margin-bottom: 35px;
    padding: 14px 16px;
    background: #2d3748;
    border-radius: 12px;
    color: white;
    box-shadow: var(--card-shadow);
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
}

header::after {
    content: '';
    position: absolute;
    bottom: -50%;
    left: -10%;
    width: 250px;
    height: 250px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
}

h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.5rem;
    margin-bottom: 10px;
    position: relative;
    z-index: 1;
}

.subtitle {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.1rem;
    font-weight: 300;
    position: relative;
    z-index: 1;
}

.section {
    margin-bottom: 60px;
}

.section-title {
    font-family: 'Montserrat', sans-serif;
    color: #2d3748;
    font-size: 1.8rem;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--accent-color);
    display: flex;
    align-items: center;
    position: relative;
}

.section-title i {
    margin-right: 15px;
    color: var(--accent-color);
    font-size: 1.5rem;
}

.timeline {
    position: relative;
    padding-left: 30px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 0;
    width: 3px;
    height: 100%;
    background:#e67e22;
    border-radius: 3px;
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
    background: white;
    border-radius: 12px;
    padding: 25px 30px 25px 40px;
    box-shadow: var(--card-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.timeline-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -46px;
    top: 25px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: white;
    border: 4px solid var(--accent-color);
    z-index: 2;
}

.research-timeline .timeline-item::before {
    border-color: #e67e22;
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.timeline-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.3rem;
    color: #2d3748;
    font-weight: 600;
}

.timeline-subtitle {
    color: #2d3748;
    font-size: 1rem;
    margin-top: 5px;
}

.timeline-date {
    background: var(--gradient-accent);
    color: white;
    padding: 6px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    white-space: nowrap;
    margin-left: 10px;
}

.research-timeline .timeline-date {
    background: var(--gradient-success);
}

.timeline-content {
    margin-top: 15px;
}

.detail-item {
    margin-bottom: 12px;
    display: flex;
}

.detail-label {
    font-weight: 600;
    min-width: 110px;
    color: var(--dark-color);
}

.detail-value {
    flex: 1;
}

.research-description {
    font-size: 0.95rem;
    margin-bottom: 15px;
    line-height: 1.6;
    color: var(--text-color);
}

.research-list {
    margin-top: 15px;
}

.research-list li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 20px;
    font-size: 0.95rem;
    line-height: 1.5;
}

.research-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

.research-certificate-btn {
    display: inline-flex;
    align-items: center;
    background: var(--gradient-success);
    color: white;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 20px;
    transition: all 0.3s ease;
    margin-top: 15px;
    box-shadow: 0 2px 4px rgba(0, 200, 83, 0.2);
}

.research-certificate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
    background: #2d3748;
}

.research-certificate-btn i {
    margin-left: 8px;
}

/* Certificate and card */

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* certificate section */
/* Category Filter */

/* Category Filter */
.category-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-bottom: 2.5rem;
    justify-content: center;
}

.category-btn {
    height: 40px;
    border-radius: 20px;
    background-color: var(--card-bg);
    color: var(--text-color);
    border: 1px solid #e0e0e0;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0 1.2rem;
    box-shadow: 0 3px 5px rgba(0, 0, 0, 0.05);
}

.category-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.08);
    border-color: var(--accent-light);
}

.category-btn.active {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    box-shadow: 0 5px 10px rgba(230, 126, 34, 0.3);
}

/* Certificate Cards */
.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.certificate-card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--card-shadow);
    overflow: hidden;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    border: 1px solid #f0f0f0;
    height: auto;
}

.certificate-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
}

.certificate-card.hidden {
    display: none;
}

.cert-header {
    padding: 1.2rem;
    background: var(--header-gradient);
    color: white;
    position: relative;
    overflow: hidden;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.cert-header::before {
    content: '';
    position: absolute;
    top: -20px;
    right: -20px;
    width: 80px;
    height: 80px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
}

.cert-header h3 {
    font-size: 1.1rem;
    margin-bottom: 0.3rem;
    font-weight: 600;
    position: relative;
    z-index: 1;
    line-height: 1.3;
}

.cert-header .provider {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.8);
    position: relative;
    z-index: 1;
}

.cert-body {
    padding: 1.2rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--card-bg);
}

.cert-info {
    margin-bottom: 1rem;
    color: var(--text-color);
}

.cert-info-row {
    display: flex;
    align-items: flex-start;
    margin-bottom: 0.6rem;
    font-size: 0.85rem;
}

.cert-info-row:last-child {
    margin-bottom: 0;
}

.cert-info-icon {
    margin-right: 0.6rem;
    color: var(--accent-color);
    width: 16px;
    text-align: center;
    font-size: 0.9rem;
    flex-shrink: 0;
    margin-top: 2px;
}

.cert-info-label {
    color: var(--primary-color);
    margin-right: 0.5rem;
    font-weight: 500;
    width: 80px;
    flex-shrink: 0;
}

.cert-info-value {
    flex: 1;
    font-size: 0.85rem;
    word-wrap: break-word;
    overflow-wrap: break-word;
    max-width: 100%;
}

.cert-tags {
    margin-bottom: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    display: inline-flex;
    align-items: center;
    padding: 0.3rem 0.7rem;
    background-color: var(--tag-bg);
    border-radius: 16px;
    font-size: 0.75rem;
    color: var(--tag-color);
    font-weight: 500;
    box-shadow: 0 2px 4px rgba(230, 126, 34, 0.1);
    white-space: nowrap;
}

.tag i {
    margin-right: 0.4rem;
    color: var(--tag-color);
    font-size: 0.7rem;
}

.cert-footer {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px dashed #f0f0f0;
    display: flex;
    justify-content: center;
    background-color: var(--card-bg);
}

.cert-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1.2rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-light));
    box-shadow: 0 3px 8px rgba(230, 126, 34, 0.3);
    font-size: 0.85rem;
    white-space: nowrap;
}

.cert-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 12px rgba(230, 126, 34, 0.4);
}

.cert-link i {
    margin-left: 0.5rem;
    font-size: 0.8rem;
}



/* Responsive Styles */
@media (max-width: 955px) {

    .main-content {
        margin-left: 0;
    }

    .container {
        padding: 15px;
    }

    h1 {
        font-size: 2.2rem;
    }

    .section-title {
        font-size: 1.7rem;
    }

    .timeline {
        padding-left: 20px;
    }

    .timeline-item {
        padding: 20px 25px 20px 30px;
    }

    .timeline-item::before {
        left: -36px;
        width: 16px;
        height: 16px;
    }

    .timeline-header {
        flex-direction: column;
    }

    .timeline-date {
        margin-left: 0;
        margin-top: 10px;
        align-self: flex-start;
    }

    .courses-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }

}

@media (max-width: 768px) {

    .container {
        padding: 10px;
    }

    header {
        padding: 30px 15px;
    }

    h1 {
        font-size: 1.9rem;
    }

    .timeline {
        padding-left: 15px;
    }

    .timeline-item {
        padding: 15px 20px 15px 25px;
    }

    .timeline-item::before {
        left: -31px;
        width: 14px;
        height: 14px;
    }

    .detail-item {
        flex-direction: column;
    }

    .detail-label {
        margin-bottom: 5px;
    }

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

    .category-btn {
        height: 36px;
        font-size: 0.85rem;
        padding: 0 1rem;
    }

    .cert-info-label {
        width: 70px;
        font-size: 0.8rem;
    }

    .cert-info-value {
        font-size: 0.8rem;
    }

    .certificate-card {
        max-height: 360px;
    }
}

@media (max-width: 600px) {
    .main-content {
        padding: 15px;
    }

    header {
        padding: 20px 0;
        margin-bottom: 30px;
    }

    .filter-section {
        gap: 10px;
        margin-bottom: 20px;
    }

    .filter-btn {
        font-size: 0.9rem;
        padding: 6px 15px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }
}

/* Responsive Styles */
@media (max-width: 1200px) {
    .certificates-grid {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (max-width: 992px) {
    .certificates-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }

    .cert-info-label {
        width: 70px;
        font-size: 0.8rem;
    }

    .cert-info-value {
        font-size: 0.8rem;
    }
}

@media (max-width: 768px) {
    .certificates-grid {
        grid-template-columns: 1fr;
        gap: 1.2rem;
    }

    .category-btn {
        height: 36px;
        font-size: 0.85rem;
        padding: 0 1rem;
    }

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

    .cert-info-icon {
        margin-bottom: 0.3rem;
    }

    .cert-info-label {
        width: 100%;
        margin-bottom: 0.2rem;
        font-size: 0.8rem;
    }

    .cert-info-value {
        font-size: 0.8rem;
        margin-left: 1.2rem;
    }

    .cert-header h3 {
        font-size: 1rem;
    }

    .cert-header .provider {
        font-size: 0.75rem;
    }

    .cert-body {
        padding: 1rem;
    }

    .cert-tags {
        margin-bottom: 0.8rem;
    }

    .cert-footer {
        padding-top: 0.8rem;
    }
}

@media (max-width: 480px) {
    .certificates-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .cert-header {
        padding: 1rem;
        min-height: 70px;
    }

    .cert-header h3 {
        font-size: 0.95rem;
    }

    .cert-header .provider {
        font-size: 0.7rem;
    }

    .cert-body {
        padding: 0.8rem;
    }

    .cert-info-row {
        margin-bottom: 0.5rem;
    }

    .cert-info-value {
        margin-left: 1rem;
        font-size: 0.75rem;
    }

    .tag {
        padding: 0.25rem 0.6rem;
        font-size: 0.7rem;
    }

    .cert-link {
        padding: 0.4rem 1rem;
        font-size: 0.8rem;
    }
}