/* vietnamese */
@font-face {
    font-family: 'Alata';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url(https://fonts.gstatic.com/s/alata/v12/PbytFmztEwbIoceyzqYhQA.woff2) format('woff2');
    unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* latin-ext */
@font-face {
    font-family: 'Alata';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url(https://fonts.gstatic.com/s/alata/v12/PbytFmztEwbIocezzqYhQA.woff2) format('woff2');
    unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
    font-family: 'Alata';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url(https://fonts.gstatic.com/s/alata/v12/PbytFmztEwbIoce9zqY.woff2) format('woff2');
    unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* CSS Variables & Reset */
:root {
    --primary-color: #003366; /* Deep Blue */
    --accent-color: #00A19D; /* Teal/Green */
    --text-color: #16324f; /* Dark Blue */
    --light-gray: #f4f6f8;
    --white: #ffffff;
    --dark-bg: #0a1f33;
    --font-heading: 'Alata', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-body: 'Alata', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --transition: all 0.3s ease;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 10px 15px rgba(0, 0, 0, 0.15);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--white);
    overflow-x: hidden;
    -webkit-text-size-adjust: 100%;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 700;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

.icon {
    width: 1em;
    height: 1em;
    display: inline-block;
    vertical-align: middle;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    flex-shrink: 0;
}

.icon-inline {
    margin-left: 6px;
}

section {
    position: relative;
    overflow: hidden;
    scroll-margin-top: 88px;
}

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

.section-padding {
    padding: 80px 0;
}

.bg-light {
    background-color: var(--light-gray);
}

.bg-dark {
    background-color: var(--dark-bg);
}

.text-white {
    color: var(--white);
}

.text-center {
    text-align: center;
}

.divider {
    height: 4px;
    width: 60px;
    background-color: var(--accent-color);
    margin: 10px auto 30px;
    border-radius: 2px;
}

.divider-light {
    background-color: var(--white);
}

.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 50px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
    min-height: 44px;
    line-height: 1.2;
    text-align: center;
    white-space: normal;
}

.btn-sm {
    padding: 8px 20px;
    font-size: 0.8rem;
    min-height: 36px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: #002a54;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: var(--white);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
}

.btn-outline-light {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: var(--white);
}

.btn-outline-light:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

.btn-outline-dark {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: var(--white);
}

.btn-outline-dark:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

.btn-text {
    background: none;
    border: none;
    color: var(--accent-color);
    font-weight: 600;
    cursor: pointer;
    padding: 5px 0;
    font-size: 1rem;
}

.btn-text:hover {
    text-decoration: underline;
}

/* Header */
.site-header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow);
    padding: 15px 0;
    transition: var(--transition);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo img {
    height: 40px;
    width: auto;
}

.logo-text {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.main-nav ul {
    display: flex;
    gap: 25px;
    align-items: center;
}

.main-nav a {
    font-weight: 500;
    font-size: 0.95rem;
    color: var(--primary-color);
}

.main-nav a:not(.btn):hover {
    color: var(--accent-color);
}

.mobile-menu-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
}

/* Hero Section */
.hero-section {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #003366 0%, #001a33 100%); /* Fallback */
    background-image: url('assets/hero1.webp?v=20260213');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color: var(--white);
    padding-top: 80px;
    text-align: center;
}

.hero-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: url('assets/hero2.webp?v=20260213');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    animation: heroCrossfade 5s ease-in-out infinite;
    z-index: 0;
    pointer-events: none;
}

.hero-bg-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(rgba(0, 51, 102, 0.8), rgba(0, 161, 157, 0.4));
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
}

.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--white);
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.tagline {
    font-size: 1.2rem;
    font-weight: 300;
    margin-bottom: 40px;
    opacity: 0.9;
}

.conference-banner {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 40px;
}

.badge {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    text-transform: uppercase;
    font-weight: 700;
    margin-bottom: 15px;
    display: inline-block;
}

.conference-banner h2 {
    color: var(--white);
    font-size: 2rem;
    margin-bottom: 15px;
}

.event-details {
    display: flex;
    justify-content: center;
    gap: 30px;
    font-size: 1.1rem;
    flex-wrap: wrap;
}

.event-details span {
    overflow-wrap: anywhere;
}

.event-details i {
    margin-right: 8px;
    color: var(--white);
}

.event-details .icon {
    margin-right: 8px;
    color: var(--white);
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

/* Animations */
.animate-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

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

@keyframes heroCrossfade {
    0%, 35% {
        opacity: 0;
    }
    50%, 85% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 50px;
    align-items: center;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.more-content {
    display: none;
}

.more-content.show {
    display: block;
    animation: fadeIn 0.5s;
}

/* Leadership Section */
.leadership-card-wrapper {
    display: flex;
    justify-content: center;
}

.profile-card {
    background: var(--white);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    display: flex;
    max-width: 800px;
    transition: var(--transition);
}

.profile-card:hover {
    box-shadow: var(--shadow-hover);
}

.profile-img-container {
    flex: 1;
    min-width: 300px;
}

.profile-img-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-content {
    flex: 1.5;
    padding: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.profile-content h3 {
    font-size: 1.8rem;
    margin-bottom: 5px;
}

.profile-content .role {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 20px;
    display: block;
}

.btn-link {
    color: var(--primary-color);
    font-weight: 600;
    margin-top: 20px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-link:hover {
    color: var(--accent-color);
}

/* Conferences Section */
.conferences-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.conf-card {
    background: var(--white);
    border-radius: 10px;
    padding: 30px;
    border: 1px solid #eee;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.conf-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
    border-color: var(--accent-color);
}

.conf-card.featured {
    border: 2px solid var(--primary-color);
    background: #f0f8ff;
}

.conf-date {
    display: flex;
    align-items: baseline;
    gap: 5px;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.conf-date .day { font-size: 2rem; font-weight: 700; }
.conf-date .month { font-size: 1.2rem; font-weight: 600; text-transform: uppercase; }
.conf-date .year { color: #5b7591; }

.conf-info h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.location {
    color: #476482;
    margin-bottom: 15px;
    font-size: 0.9rem;
    overflow-wrap: anywhere;
}

.themes {
    margin-bottom: 20px;
    flex-grow: 1;
}

.themes li {
    font-size: 0.9rem;
    color: #3f5b78;
    margin-bottom: 5px;
    padding-left: 15px;
    position: relative;
}

.themes li::before {
    content: "•";
    color: var(--accent-color);
    position: absolute;
    left: 0;
}

/* Awards Section */
.awards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    text-align: center;
}

.award-item {
    background: rgba(255, 255, 255, 0.05);
    padding: 40px 20px;
    border-radius: 10px;
    transition: var(--transition);
}

.award-item:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-5px);
}

.award-icon {
    font-size: 3rem;
    color: var(--accent-color);
    margin-bottom: 20px;
}

.award-icon .icon {
    width: 1em;
    height: 1em;
}

.award-item h3 {
    color: var(--white);
    font-size: 1.3rem;
}

.award-item p {
    color: #ccc;
    font-size: 0.95rem;
}

.awards-cta {
    display: flex;
    justify-content: center;
    gap: 14px;
    flex-wrap: wrap;
}

/* Publications Section */
.publication-showcase {
    display: flex;
    align-items: center;
    gap: 50px;
    max-width: 1000px;
    margin: 0 auto;
    background: var(--light-gray);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow);
}

.journal-cover {
    flex: 0 0 250px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transform: rotate(-2deg);
    transition: var(--transition);
}

.journal-cover:hover {
    transform: rotate(0) scale(1.05);
}

.journal-cover img {
    border-radius: 5px;
}

.journal-info {
    flex: 1;
}

.journal-meta {
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 15px;
}

.journal-actions {
    margin-top: 30px;
    display: flex;
    gap: 15px;
}

/* News Section */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.news-card {
    background: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.news-image {
    height: 200px;
    overflow: hidden;
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.news-card:hover .news-image img {
    transform: scale(1.1);
}

.news-content {
    padding: 25px;
}

.news-date {
    font-size: 0.8rem;
    color: #5b7591;
    margin-bottom: 10px;
    display: block;
}

.news-content h3 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    line-height: 1.4;
}

.read-more {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: 10px;
    display: inline-block;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 50px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-logo img {
    height: 30px;
    width: auto;
}

.social-links {
    margin-top: 20px;
    display: flex;
    gap: 15px;
}

.social-links a {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-links .icon {
    width: 18px;
    height: 18px;
}

.social-links a:hover {
    background: var(--accent-color);
    transform: translateY(-3px);
}

.footer-col h4 {
    color: var(--white);
    margin-bottom: 25px;
    font-size: 1.1rem;
}

.footer-col ul li {
    margin-bottom: 12px;
}

.footer-col ul li a {
    color: #ccc;
    font-size: 0.95rem;
}

.footer-col ul li a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer-col p {
    color: #ccc;
    margin-bottom: 15px;
    font-size: 0.95rem;
    overflow-wrap: anywhere;
}

.footer-col p .icon {
    width: 20px;
    height: 20px;
    color: var(--accent-color);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    color: #9bb2c8;
}

/* Responsive */
@media (max-width: 992px) {
    .section-padding { padding: 60px 0; }
    
    .hero-content h1 { font-size: 2.5rem; }
    .tagline { font-size: 1.1rem; }
    .conference-banner h2 { font-size: 1.6rem; }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .publication-showcase {
        flex-direction: column;
        gap: 30px;
        text-align: center;
    }
    
    .about-image { order: -1; }
    
    .profile-card { 
        flex-direction: column;
        max-width: 100%;
    }
    .profile-img-container { min-width: auto; height: 300px; }
    .profile-content { padding: 30px; }
    
    .awards-grid { 
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-content { 
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    html { font-size: 15px; }
    
    .container { padding: 0 15px; }
    .section-padding { padding: 50px 0; }
    
    /* Header */
    .site-header {
        padding: 12px 0;
        backdrop-filter: none;
    }
    .logo img { height: 35px; }
    .logo-text { font-size: 1.3rem; }
    
    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--white);
        box-shadow: var(--shadow);
        padding: 20px;
        max-height: calc(100vh - 68px);
        overflow-y: auto;
    }
    
    .main-nav.active { display: block; }
    .main-nav ul { 
        flex-direction: column;
        align-items: stretch;
        gap: 15px;
    }
    .main-nav li { width: 100%; }
    .main-nav a {
        display: flex;
        align-items: center;
        min-height: 44px;
        padding: 10px;
    }
    .main-nav .btn {
        width: 100%;
        text-align: center;
    }
    
    .mobile-menu-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        width: 44px;
        height: 44px;
    }
    
    /* Hero */
    .hero-section { 
        height: auto;
        min-height: 100svh;
        padding: 100px 0 60px;
        background-image: url('assets/hero1.webp?v=20260213');
    }

    .hero-section::before {
        display: block;
        background-image: url('assets/hero2.webp?v=20260213');
        animation: heroCrossfade 5s ease-in-out infinite;
    }
    .hero-content h1 { font-size: 1.8rem; line-height: 1.3; }
    .tagline { font-size: 1rem; margin-bottom: 30px; }
    .conference-banner { padding: 20px; }
    .conference-banner {
        backdrop-filter: blur(8px);
        -webkit-backdrop-filter: blur(8px);
    }
    .conference-banner h2 { font-size: 1.3rem; }
    .event-details { 
        flex-direction: column;
        gap: 8px;
        font-size: 0.95rem;
    }
    .hero-buttons { 
        flex-direction: column;
        gap: 15px;
    }
    .hero-buttons .btn { width: 100%; }

    .btn-sm {
        min-height: 44px;
    }

    .awards-cta {
        flex-direction: column;
        align-items: center;
    }

    .awards-cta .btn {
        width: min(100%, 340px);
    }

    .profile-content {
        padding: 24px 20px;
    }
    
    /* About */
    .about-text p { font-size: 1rem; }
    
    /* Conferences */
    .conferences-grid { grid-template-columns: 1fr; }
    .conf-card { padding: 25px; }
    
    /* Publications */
    .publication-showcase { 
        padding: 30px 20px;
        gap: 30px;
    }
    .journal-cover { 
        flex: 0 0 200px;
        margin: 0 auto;
        transform: none;
    }
    .journal-actions { 
        flex-direction: column;
        gap: 10px;
    }
    .journal-actions .btn { width: 100%; }
    
    /* News */
    .news-grid { grid-template-columns: 1fr; }

    .news-content {
        padding: 20px;
    }
    
    /* Footer */
    .footer-logo img { height: 25px; }
}

@media (max-width: 480px) {
    .section-padding { padding: 42px 0; }

    .site-header {
        padding: 10px 0;
    }

    .hero-content h1 { font-size: 1.5rem; }
    .conference-banner h2 { font-size: 1.1rem; }
    .btn { padding: 10px 20px; font-size: 0.85rem; }
    .btn-sm { padding: 10px 16px; }
    .conf-date .day { font-size: 1.5rem; }
    .conf-date .month { font-size: 1rem; }

    .news-image {
        height: 180px;
    }

    .conference-banner,
    .publication-showcase,
    .conf-card,
    .news-content {
        padding-left: 16px;
        padding-right: 16px;
    }

    .profile-img-container {
        height: 240px;
    }

    .footer-content {
        gap: 28px;
    }

    .footer-col p,
    .footer-col ul li a {
        font-size: 0.92rem;
    }
}

@media (max-width: 360px) {
    html { font-size: 14px; }

    .container {
        padding: 0 12px;
    }

    .hero-section {
        padding: 92px 0 44px;
    }

    .hero-content {
        max-width: 100%;
    }

    .hero-content h1 {
        font-size: 1.35rem;
    }

    .tagline {
        font-size: 0.95rem;
    }

    .conference-banner {
        padding: 14px;
    }

    .event-details {
        font-size: 0.88rem;
    }

    .btn {
        width: 100%;
        padding: 10px 16px;
    }

    .awards-cta .btn {
        width: 100%;
    }

    .section-header h2 {
        font-size: 1.35rem;
    }

    .news-image {
        height: 160px;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .animate-up,
    .hero-section::before,
    .btn,
    .news-image img,
    .conf-card,
    .news-card,
    .award-item,
    .social-links a,
    .journal-cover {
        animation: none !important;
        transition: none !important;
        transform: none !important;
    }
}

@media (hover: none) {
    .btn-primary:hover,
    .btn-secondary:hover,
    .conf-card:hover,
    .news-card:hover,
    .award-item:hover,
    .social-links a:hover,
    .journal-cover:hover {
        transform: none;
    }
}