:root {
    --color-primary: #123c73;
    --color-primary-dark: #0d2b52;
    --color-accent: #2a7abf;
    --color-accent-light: #eaf3fb;
    --color-bg: #f5f7fb;
    --color-surface: #ffffff;
    --color-text: #1f2937;
    --color-text-light: #5b6472;
    --color-border: #dbe4ee;
    --shadow-soft: 0 10px 30px rgba(15, 23, 42, 0.06);
    --shadow-card: 0 8px 24px rgba(15, 23, 42, 0.08);
    --radius-lg: 20px;
    --radius-md: 14px;
    --radius-sm: 10px;
    --container-width: 1180px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Noto Sans SC', sans-serif;
    font-size: 16px;
    line-height: 1.75;
    color: var(--color-text);
    background: linear-gradient(to bottom, #f7f9fc 0%, #eef3f8 100%);
}

img {
    max-width: 100%;
    display: block;
    border-radius: 12px;
}

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

a:hover {
    text-decoration: underline;
}

ul {
    padding-left: 1.2rem;
}

.container {
    width: min(var(--container-width), calc(100% - 32px));
    margin: 0 auto;
}

/* Navigation */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(18, 60, 115, 0.92);
    backdrop-filter: blur(10px);
    box-shadow: 0 6px 20px rgba(13, 43, 82, 0.18);
}

.navbar {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    color: #fff;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.brand-title {
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: 0.2px;
}

.brand-subtitle {
    font-size: 0.82rem;
    opacity: 0.85;
}

.nav-toggle {
    display: none;
    border: none;
    background: transparent;
    color: #fff;
    font-size: 1.4rem;
    cursor: pointer;
}

.nav-menu {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 10px;
    padding-left: 0;
}

.nav-link {
    color: #fff;
    padding: 10px 14px;
    border-radius: 999px;
    font-size: 0.98rem;
    font-weight: 500;
    transition: background-color 0.25s ease, transform 0.25s ease, opacity 0.25s ease;
    display: inline-flex;
    align-items: center;
    gap: 7px;
}

.nav-link:hover {
    text-decoration: none;
    background: rgba(255, 255, 255, 0.12);
}

.nav-link.active {
    background: #fff;
    color: var(--color-primary);
    font-weight: 700;
}

/* Hero */
.hero {
    padding: 28px 0 28px;
}

.hero-card {
    background: linear-gradient(135deg, rgba(18, 60, 115, 0.96), rgba(42, 122, 191, 0.92));
    color: #fff;
    border-radius: 28px;
    padding: 56px 48px;
    box-shadow: 0 18px 50px rgba(18, 60, 115, 0.22);
    position: relative;
    overflow: hidden;
    margin-top: 24px;
}

.hero-card::before,
.hero-card::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
}

.hero-card::before {
    width: 240px;
    height: 240px;
    top: -80px;
    right: -60px;
}

.hero-card::after {
    width: 180px;
    height: 180px;
    bottom: -70px;
    left: -40px;
}

.hero-eyebrow {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.14);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 18px;
}

.hero h1 {
    font-size: clamp(2rem, 4vw, 3.3rem);
    line-height: 1.2;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
}

.hero p {
    max-width: 760px;
    font-size: 1.06rem;
    opacity: 0.95;
    position: relative;
    z-index: 1;
}

/* Section */
main {
    padding-bottom: 48px;
}

.content-section {
    display: none;
    animation: fadeUp 0.45s ease;
}

.content-section.active {
    display: block;
}

.section-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    padding: 34px;
    margin-bottom: 28px;
}

.section-title {
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: 10px;
    line-height: 1.25;
}

.section-intro {
    color: var(--color-text-light);
    margin-bottom: 24px;
    max-width: 900px;
}

.subheading {
    font-size: 1.2rem;
    color: var(--color-primary-dark);
    margin: 26px 0 12px;
    font-weight: 700;
}

.section-title::after {
    content: "";
    display: block;
    width: 58px;
    height: 4px;
    border-radius: 999px;
    background: var(--color-accent);
    margin-top: 12px;
}

/* Home */
.about-grid {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 28px;
    align-items: center;
}

.about-text p {
    color: var(--color-text-light);
    margin-bottom: 14px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 26px;
}

.stat-card {
    background: var(--color-accent-light);
    border: 1px solid #d7e8f6;
    border-radius: var(--radius-md);
    padding: 18px;
}

.stat-card strong {
    display: block;
    color: var(--color-primary);
    font-size: 1.3rem;
    margin-bottom: 6px;
}

.image-gallery {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.image-gallery img {
    height: 260px;
    object-fit: cover;
    box-shadow: var(--shadow-card);
}

/* Research */
.highlight-list li,
.funding-list li,
.teaching-list li {
    margin-bottom: 10px;
    color: var(--color-text-light);
}

.highlight-box {
    background: #f8fbfe;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-top: 16px;
}

/* People */
.people-group {
    margin-top: 28px;
}

.group-title {
    font-size: 1.45rem;
    color: var(--color-primary-dark);
    margin-bottom: 16px;
}

.people-list {
    display: grid;
    gap: 20px;
}

.person-card {
    border: 1px solid var(--color-border);
    border-radius: 18px;
    padding: 22px;
    background: #fff;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.person-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-card);
}

.person-content {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 22px;
    align-items: start;
}

.person-photo img {
    width: 150px;
    height: 190px;
    object-fit: cover;
    border-radius: 14px;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.1);
}

.person-name {
    font-size: 1.2rem;
    color: var(--color-primary);
    margin-bottom: 8px;
}

.person-role {
    display: inline-block;
    margin-bottom: 12px;
    font-size: 0.92rem;
    color: var(--color-accent);
    font-weight: 600;
    background: var(--color-accent-light);
    border-radius: 999px;
    padding: 4px 12px;
}

.person-info p {
    color: var(--color-text-light);
    margin-bottom: 10px;
}

/* Events */
.event-gallery {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.event-photo {
    background: #fff;
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-soft);
}

.event-photo img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    transition: transform 0.35s ease;
    border-radius: 0;
}

.event-photo:hover img {
    transform: scale(1.04);
}

/* Publications */
.pub-year {
    margin-top: 24px;
    margin-bottom: 12px;
    font-size: 1.2rem;
    color: var(--color-primary-dark);
}

.publication-list {
    display: grid;
    gap: 14px;
}

.publication-item {
    border: 1px solid var(--color-border);
    border-radius: 14px;
    padding: 18px 18px;
    background: #fcfdff;
}

.publication-item p {
    color: var(--color-text-light);
}

/* Teaching */
.teacher-card {
    border: 1px solid var(--color-border);
    border-radius: 16px;
    padding: 20px;
    background: #fff;
    margin-bottom: 18px;
}

.teacher-card h3 {
    color: var(--color-primary);
    margin-bottom: 10px;
    font-size: 1.15rem;
}

/* Contact */
.contact-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 24px;
    align-items: center;
}

.contact-info-box {
    background: #f8fbfe;
    border: 1px solid var(--color-border);
    border-radius: 16px;
    padding: 24px;
}

.contact-info-box p {
    margin-bottom: 10px;
    color: var(--color-text-light);
}

.contact-visual img {
    height: 300px;
    object-fit: cover;
    box-shadow: var(--shadow-card);
}

/* Footer */
footer {
    background: var(--color-primary-dark);
    color: rgba(255, 255, 255, 0.92);
    text-align: center;
    padding: 22px 16px;
    font-size: 0.95rem;
    margin-top: 16px;
}

/* Animation */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 980px) {
    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .event-gallery {
        grid-template-columns: repeat(2, 1fr);
    }

    .person-content {
        grid-template-columns: 130px 1fr;
    }

    .person-photo img {
        width: 130px;
        height: 170px;
    }
}

@media (max-width: 768px) {
    .navbar {
        min-height: 68px;
        align-items: center;
    }

    .nav-toggle {
        display: block;
    }

    .nav-menu {
        position: absolute;
        top: 72px;
        left: 16px;
        right: 16px;
        background: var(--color-primary);
        border-radius: 18px;
        padding: 12px;
        box-shadow: 0 16px 36px rgba(13, 43, 82, 0.2);
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }

    .nav-menu.open {
        display: flex;
    }

    .nav-link {
        width: 100%;
        border-radius: 12px;
        justify-content: flex-start;
    }

    .hero {
        padding-top: 18px;
    }

    .hero-card {
        padding: 36px 24px;
        border-radius: 22px;
        margin-top: 16px;
    }

    .section-card {
        padding: 24px 18px;
    }

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

    .image-gallery,
    .stats-grid,
    .event-gallery {
        grid-template-columns: 1fr;
    }

    .person-content {
        grid-template-columns: 1fr;
    }

    .person-photo img {
        width: 100%;
        max-width: 220px;
        height: auto;
        margin: 0 auto;
    }

    .contact-visual img {
        height: auto;
    }
}
.person-links {
    margin-top: 14px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.profile-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    border-radius: 999px;
    background: var(--color-accent-light);
    color: var(--color-primary);
    border: 1px solid #d7e8f6;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.25s ease;
}

.profile-link:hover {
    text-decoration: none;
    background: var(--color-primary);
    color: #fff;
    transform: translateY(-1px);
}