/* --- CSS Variables & Reset --- */
:root {
    --primary-blue: #00A8E8; /* Vibrant Sky Blue */
    --secondary-blue: #007EA7; /* Deep Sky Blue */
    --dark-blue: #003459; /* Text/Heading Blue */
    --light-bg: #F0F8FF; /* Alice Blue - very light background */
    --white: #FFFFFF;
    --text-gray: #555555;
    --shadow: 0 10px 30px rgba(0, 168, 232, 0.15);
    --gradient: linear-gradient(135deg, rgba(0, 168, 232, 0.85), rgba(0, 126, 167, 0.85));
    --timeline-color: #e0e0e0;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-gray);
    background-color: var(--light-bg);
}

/* --- Typography & Utilities --- */
h1, h2, h3 {
    color: var(--dark-blue);
    font-weight: 700;
}

h1 { font-size: 2.5rem; margin-bottom: 1rem; }
h2 { font-size: 2rem; margin-bottom: 2rem; text-align: center; }
h3 { font-size: 1.3rem; margin-bottom: 0.5rem; }
p { margin-bottom: 1rem; }

.container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.primary-btn {
    background: var(--white);
    color: var(--primary-blue);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.primary-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

/* --- Navigation --- */
.navbar {
    background: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

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

.logo {
    font-weight: 700;
    color: var(--primary-blue);
    text-decoration: none;
    font-size: 1.2rem;
}

.nav-links {
    list-style: none;
    display: flex;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark-blue);
    font-weight: 600;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary-blue);
}

/* --- Hero Section --- */
.hero {
    color: var(--white);
    padding: 10rem 0 8rem;
    text-align: center;
    position: relative;
    /* REPLACE THE URL BELOW WITH YOUR ACTUAL IMAGE PATH */
    background-image:
        var(--gradient),
        url('images/header-bg.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    border-bottom-left-radius: 50% 5%;
    border-bottom-right-radius: 50% 5%;
}

.hero h1 {
    color: var(--white);
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.conference-details {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

/* --- Main Content & Sections --- */
.main-wrapper {
    padding: 4rem 0;
}

.section {
    margin-bottom: 5rem;
}

.section-title {
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient);
    border-radius: 3px;
}

/* --- Cards & Grids --- */
.card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 768px) {
    .grid-2 { grid-template-columns: 1fr 1fr; }
}

/* --- Learning Objectives (Highlighted Style) --- */
.objectives-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .objectives-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 992px) {
    .objectives-grid { grid-template-columns: repeat(3, 1fr); }
}

.objective-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 168, 232, 0.1);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-bottom: 3px solid transparent;
}

.objective-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 168, 232, 0.2);
    border-bottom-color: var(--primary-blue);
}

.objective-icon {
    font-size: 2.5rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
    display: inline-block;
    background: rgba(0, 168, 232, 0.05);
    padding: 1rem;
    border-radius: 50%;
}

.objective-card p {
    margin-bottom: 0;
    font-weight: 500;
}

/* --- Timeline Section --- */
.timeline {
    position: relative;
    padding-left: 2rem;
    border-left: 3px solid var(--timeline-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.6rem;
    top: 0.3rem;
    width: 1.2rem;
    height: 1.2rem;
    background: var(--white);
    border: 3px solid var(--primary-blue);
    border-radius: 50%;
    z-index: 1;
}

.timeline-time {
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 0.5rem;
    display: inline-block;
    background: rgba(0, 168, 232, 0.1);
    padding: 0.2rem 0.8rem;
    border-radius: 20px;
    font-size: 0.9rem;
}

.timeline-content h3 {
    margin-top: 0;
    color: var(--dark-blue);
}

.timeline-content p {
    margin-bottom: 0;
}

/* --- Bios Section Specifics (Links) --- */
.bio-card {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
}

.bio-img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--primary-blue);
    flex-shrink: 0;
}

.bio-card h3 { color: var(--primary-blue); margin-top: 0; }
.affiliation {
    font-style: italic;
    font-size: 0.9rem;
    color: var(--secondary-blue);
    margin-bottom: 1rem;
}

.bio-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.bio-links a {
    color: var(--secondary-blue);
    font-size: 1.2rem;
    transition: color 0.3s ease, transform 0.3s ease;
}

.bio-links a:hover {
    color: var(--primary-blue);
    transform: translateY(-2px);
}

/* --- Research Section Specifics (Image Fit) --- */
.research-item {
    margin-bottom: 3rem;
}

.research-content h3 {
    color: var(--primary-blue);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.research-img-big {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    margin: 1.5rem 0;
    display: block;
}

.publication-ref {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #eee;
    font-size: 0.95rem;
    color: var(--secondary-blue);
    background: rgba(0, 126, 167, 0.05);
    padding: 1rem;
    border-radius: 8px;
}

/* --- Footer (Copyright) --- */
.footer {
    background: var(--dark-blue);
    color: var(--white);
    text-align: center;
    padding: 3rem 0;
    margin-top: 0rem;
}

.footer p { margin-bottom: 0.5rem; opacity: 0.8; }
.tiny-text { font-size: 0.8rem; opacity: 0.6; }
.copyright-text {
    margin-top: 1.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary-blue);
    opacity: 1;
}

/* --- Animations --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Mobile Responsiveness Tweaks --- */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero h1 { font-size: 2rem; }
    .hero { padding: 6rem 0 4rem; }
    .card { padding: 1.5rem; }

    .bio-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    .bio-img { margin-bottom: 1rem; }
    .bio-links { justify-content: center; }

    .timeline { padding-left: 1.5rem; }
    .timeline-item::before { left: -2.1rem; }
    
    .objectives-grid { grid-template-columns: 1fr; }
}