/* Styling for About, Library, and Sitemap Pages */

/* ==========================================
   ABOUT STICKY TABS
   ========================================== */
.about-sticky-tabs {
    position: sticky;
    top: 5rem;
    z-index: 40;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-slate-100);
    box-shadow: var(--shadow-sm);
}

.about-tabs-wrap {
    display: flex;
    gap: 0.25rem;
    overflow-x: auto;
    padding: 0.75rem 0;
    scrollbar-width: none;
}
.about-tabs-wrap::-webkit-scrollbar {
    display: none;
}

@media (min-width: 640px) {
    .about-tabs-wrap { gap: 1rem; }
}

.about-tab-link {
    flex-shrink: 0;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-slate-600);
    background: none;
    border: none;
    cursor: pointer;
    transition: var(--transition-all-300);
}

@media (min-width: 640px) {
    .about-tab-link { font-size: 0.875rem; }
}

.about-tab-link:hover {
    color: var(--color-brand-teal);
    background-color: var(--color-brand-bg);
}

.about-tab-link.active {
    background-color: var(--color-brand-navy);
    color: var(--color-white);
    box-shadow: var(--shadow-sm);
}

/* ==========================================
   DEVELOPMENT TIMELINE LIST
   ========================================== */
.timeline-centered-wrap {
    max-width: 56rem;
    margin: 0 auto;
    position: relative;
    padding-left: 0.5rem;
}
@media (min-width: 640px) {
    .timeline-centered-wrap { padding-left: 0; }
}

.timeline-track-line {
    position: absolute;
    left: 4.5rem;
    top: 1rem;
    bottom: 1rem;
    width: 2px;
    background-color: var(--color-brand-teal-light);
}

@media (min-width: 640px) {
    .timeline-track-line { left: 7rem; }
}

.timeline-event-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.timeline-node-item {
    display: flex;
    align-items: start;
    position: relative;
}

.timeline-event-year {
    width: 3.75rem;
    text-align: right;
    font-weight: 600;
    color: var(--color-slate-800);
    font-size: 0.875rem;
    padding-top: 1rem;
    flex-shrink: 0;
    line-height: 1.2;
}

@media (min-width: 640px) {
    .timeline-event-year { width: 6.25rem; font-size: 1rem; }
}

.timeline-dot-container {
    width: 1.5rem;
    display: flex;
    justify-content: center;
    padding-top: 1.125rem;
    flex-shrink: 0;
    z-index: 10;
    margin: 0 0.25rem;
}

@media (min-width: 640px) {
    .timeline-dot-container { width: 2.5rem; margin: 0 0.5rem; }
}

.timeline-dot-outer {
    width: 1rem;
    height: 1rem;
    border-radius: var(--radius-full);
    background-color: var(--color-white);
    border: 2px solid var(--color-brand-teal);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-sm);
}

.timeline-dot-inner {
    width: 0.375rem;
    height: 0.375rem;
    border-radius: var(--radius-full);
    background-color: var(--color-brand-teal);
}

.timeline-card-content {
    flex-grow: 1;
    position: relative;
    background-color: var(--color-white);
    border-radius: var(--radius-xl);
    padding: 1.25rem;
    border: 1px solid var(--color-slate-200);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-fast);
}

@media (min-width: 640px) {
    .timeline-card-content { padding: 1.5rem; }
}

.timeline-card-content:hover {
    box-shadow: var(--shadow-md);
}

.timeline-card-arrow {
    display: none;
}

@media (min-width: 640px) {
    .timeline-card-arrow {
        display: block;
        position: absolute;
        left: -6px;
        top: 1.25rem;
        width: 12px;
        height: 12px;
        background-color: var(--color-white);
        border-left: 1px solid var(--color-slate-200);
        border-bottom: 1px solid var(--color-slate-200);
        transform: rotate(45deg);
    }
}

.timeline-card-content h4 {
    font-weight: 700;
    font-size: 0.875rem;
    color: var(--color-slate-900);
    line-height: 1.4;
}

@media (min-width: 640px) {
    .timeline-card-content h4 { font-size: 1rem; }
}

.timeline-bullets-list {
    margin-top: 0.875rem;
    border-top: 1px solid var(--color-slate-100);
    padding-top: 0.75rem;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.timeline-bullets-list li {
    display: flex;
    align-items: start;
    gap: 0.625rem;
    font-size: 0.75rem;
    color: var(--color-slate-600);
}

@media (min-width: 640px) {
    .timeline-bullets-list li { font-size: 0.875rem; }
}

.timeline-bullets-list li .bullet-dot-about {
    width: 6px;
    height: 6px;
    border-radius: var(--radius-full);
    background-color: var(--color-brand-teal);
    margin-top: 6px;
    flex-shrink: 0;
}

/* ==========================================
   ABOUT CERTIFICATIONS GRID
   ========================================== */
.about-certs-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

@media (min-width: 1024px) {
    .about-certs-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
        gap: 1.5rem;
    }
}

.about-cert-box {
    background-color: var(--color-white);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    border: 1px solid var(--color-slate-200);
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: var(--transition-all-300);
}

.about-cert-box:hover {
    border-color: rgba(0, 155, 163, 0.4);
    box-shadow: var(--shadow-md);
}

.about-cert-circle {
    width: 4rem;
    height: 4rem;
    border-radius: var(--radius-full);
    background-color: var(--color-slate-50);
    border: 1px solid var(--color-slate-200);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-brand-navy);
    font-family: var(--font-display);
    font-weight: 900;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.about-cert-box h3 {
    font-weight: 700;
    font-size: 1rem;
    color: var(--color-slate-900);
    margin-bottom: 4px;
}

.about-cert-box p {
    color: var(--color-slate-500);
    font-size: 0.75rem;
    line-height: 1.4;
}

@media (min-width: 640px) {
    .about-cert-box p { font-size: 0.875rem; }
}

/* ==========================================
   VIETNAM OFFICES LOCATIONS
   ========================================== */
.vietnam-locations-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .vietnam-locations-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.location-box-card {
    background-color: rgba(248, 250, 252, 0.6);
    padding: 1.25rem;
    border-radius: var(--radius-xl);
    border: 1px solid rgba(241, 245, 249, 0.8);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 1.5rem;
}

.location-title-wrap {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    font-weight: 900;
    color: var(--color-brand-navy);
    text-transform: uppercase;
}

.location-title-wrap svg {
    width: 0.875rem;
    height: 0.875rem;
    color: var(--color-brand-teal);
}

.location-address-txt {
    color: var(--color-slate-600);
    font-size: 0.75rem;
    line-height: 1.6;
    margin-top: 0.5rem;
}

@media (min-width: 640px) {
    .location-address-txt { font-size: 0.875rem; }
}

.location-meta-footer {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    padding-top: 0.75rem;
    border-top: 1px solid rgba(226, 232, 240, 0.5);
}

.location-meta-footer a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: var(--color-slate-500);
}

.location-meta-footer a:hover {
    color: var(--color-brand-navy);
}

.location-meta-footer svg {
    width: 0.75rem;
    height: 0.75rem;
    color: var(--color-slate-400);
}

/* ==========================================
   LIBRARY PAGE SPECIFIC STYLING
   ========================================== */
.library-page-wrapper {
    background-color: var(--color-slate-50);
    min-height: 100vh;
    color: var(--color-slate-800);
}

.library-hero-cta {
    display: inline-block;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-lg);
    font-size: 0.8125rem;
    font-weight: bold;
    color: var(--color-white);
    background-image: linear-gradient(to right, var(--color-brand-teal), var(--color-brand-teal-dark));
    transition: var(--transition-all-300);
    text-decoration: none;
}
.library-hero-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 155, 163, 0.3);
}

.archive-card-container {
    display: flex;
    justify-content: flex-end;
}

.digital-archive-card {
    width: 100%;
    max-width: 22rem;
    background-color: rgba(16, 42, 67, 0.9);
    border: 1px solid rgba(0, 155, 163, 0.3);
    border-radius: var(--radius-xl);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(4px);
    color: var(--color-white);
}

.archive-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding-bottom: 0.75rem;
}

.archive-card-tag {
    font-size: 10px;
    font-family: var(--font-mono);
    color: var(--color-brand-teal);
    font-weight: 700;
    letter-spacing: 0.05em;
}

.archive-card-icon {
    font-size: 14px;
}

.archive-card-bg-icon {
    height: 6rem;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.25;
    font-size: 4rem;
}

.archive-card-meta {
    display: flex;
    flex-direction: column;
    gap: 4px;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--color-slate-400);
}

.archive-card-meta .highlight-white {
    color: var(--color-white);
    font-weight: bold;
}

.archive-card-meta .highlight-cyan {
    color: var(--color-brand-teal);
    font-weight: bold;
}

.library-content-section {
    padding: 4rem 0;
}

.center-heading {
    text-align: center;
    margin-bottom: 3rem;
}

.gallery-item-title {
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--color-slate-900);
    font-size: 0.875rem;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    height: 2.5rem;
}

.library-videos-section {
    background-color: var(--color-white);
    border-top: 1px solid var(--color-slate-200);
    padding: 4rem 0;
}

.library-video-section-header {
    border-left: 4px solid var(--color-brand-teal);
    padding-left: 1rem;
    margin-bottom: 2.5rem;
}

.video-section-tag {
    font-size: 11px;
    font-weight: 700;
    color: var(--color-brand-teal);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    font-family: var(--font-mono);
}

.video-section-title {
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--color-slate-900);
    font-size: 1.5rem;
    margin-top: 2px;
}

.library-videos-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}
@media (min-width: 640px) {
    .library-videos-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}
@media (min-width: 1024px) {
    .library-videos-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.library-video-card {
    background-color: rgba(248, 250, 252, 0.6);
    border-radius: var(--radius-xl);
    border: 1px solid rgba(241, 245, 249, 0.8);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.video-thumbnail-wrapper {
    aspect-ratio: 16 / 9;
    background-color: var(--color-slate-950);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-thumbnail {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.75;
    transition: var(--transition-all-300);
}

.library-video-card:hover .video-thumbnail {
    transform: scale(1.05);
    opacity: 0.85;
}

.video-play-btn {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 50%;
    background-color: var(--color-brand-teal);
    color: var(--color-brand-navy);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 4px 10px rgba(0, 155, 163, 0.3);
    transition: var(--transition-all-300);
    position: relative;
    z-index: 10;
}

.library-video-card:hover .video-play-btn {
    transform: scale(1.1);
    background-color: var(--color-white);
}

.video-duration-tag {
    position: absolute;
    bottom: 0.75rem;
    right: 0.75rem;
    background-color: rgba(15, 23, 42, 0.85);
    color: var(--color-white);
    font-family: var(--font-mono);
    font-size: 9px;
    padding: 2px 6px;
    border-radius: 2px;
}

.video-card-body {
    padding: 1rem;
}

.video-card-title {
    font-family: var(--font-sans);
    font-weight: 700;
    color: var(--color-slate-900);
    font-size: 0.875rem;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    height: 2.5rem;
}

/* ==========================================
   SITEMAP PAGE INTERACTIVE GRID
   ========================================== */
.sitemap-page-wrapper {
    background-color: var(--color-slate-50);
    min-height: 100vh;
    color: var(--color-slate-800);
}

.sitemap-diagram-section {
    padding: 4rem 0;
}

.sitemap-interactive-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    align-items: stretch;
}

@media (min-width: 640px) {
    .sitemap-interactive-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}
@media (min-width: 1024px) {
    .sitemap-interactive-grid {
        grid-template-columns: repeat(5, minmax(0, 1fr));
    }
}