/* === VARIABLES === */
:root {
    --slate-50: #f8fafc;
    --slate-100: #f1f5f9;
    --slate-200: #e2e8f0;
    --slate-300: #cbd5e1;
    --slate-400: #94a3b8;
    --slate-500: #64748b;
    --slate-600: #475569;
    --slate-700: #334155;
    --slate-800: #1e293b;
    --slate-900: #0f172a;
    --gray-50: #f4f5f7;
    --gray-100: #ebedf0;
    --gray-200: #e0e2e6;
    --white: #ffffff;
    --font-serif: 'Playfair Display', Georgia, serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* === RESET === */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--white);
    color: var(--slate-800);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* === NAVIGATION BAR === */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.97);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--slate-200);
    z-index: 1000;
    padding: 0 2rem;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.nav-logo {
    display: flex;
    align-items: center;
}

.nav-logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--slate-600);
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    transition: color 0.2s ease;
    white-space: nowrap;
}

.nav-links a:hover {
    color: var(--slate-900);
}

/* === LANGUAGE TOGGLE === */
.lang-toggle {
    background: var(--slate-800);
    color: var(--white);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    letter-spacing: 0.05em;
    margin-left: 1.5rem;
    flex-shrink: 0;
}

.lang-toggle:hover {
    background: var(--slate-700);
}

/* === MOBILE MENU === */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.25rem;
    color: var(--slate-700);
    cursor: pointer;
    padding: 0.5rem;
    margin-left: 1rem;
}

.mobile-menu {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--slate-200);
    flex-direction: column;
    padding: 1rem 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.mobile-menu.active {
    display: flex;
}

.mobile-menu a {
    padding: 0.875rem 2rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--slate-700);
    text-decoration: none;
    border-bottom: 1px solid var(--slate-100);
}

.mobile-menu a:last-child {
    border-bottom: none;
}

.mobile-menu a:hover {
    background: var(--slate-50);
}

/* === LANDING SECTION (COVER) === */
.landing {
    background: url('assets/landing-bg.png') center center / cover no-repeat;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 2rem 4rem;
    text-align: center;
    position: relative;
}

.landing::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.75);
}

.landing-container {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.landing-subtitle {
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--slate-600);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin-bottom: 1.5rem;
}

.landing-title {
    font-family: var(--font-serif);
    font-size: 4.5rem;
    font-weight: 400;
    color: var(--slate-900);
    line-height: 1.1;
    margin-bottom: 2.5rem;
}

.landing-scroll {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--slate-600);
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 0.8125rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    transition: color 0.3s ease;
}

.landing-scroll:hover {
    color: var(--slate-900);
}

.landing-scroll i {
    font-size: 1.25rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(8px);
    }
    60% {
        transform: translateY(4px);
    }
}

/* === HERO SECTION === */
.hero {
    background: var(--gray-100);
    min-height: 100vh;
    padding: 5rem 0 0 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 2rem;
    align-items: start;
    padding: 2rem;
}

/* Photo */
.hero-photo {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding-top: 3rem;
}

.photo-frame {
    position: relative;
    width: 380px;
    flex-shrink: 0;
}

.photo-bg {
    display: none;
}

.profile-img {
    width: 100%;
    height: auto;
    object-fit: cover;
    object-position: center top;
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

/* Info */
.hero-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 1.5rem;
    padding: 2rem 1rem;
}

.name-block h1 {
    font-family: var(--font-serif);
    font-size: 3.5rem;
    font-weight: 400;
    color: var(--slate-900);
    line-height: 1.15;
    margin-bottom: 0.25rem;
    white-space: nowrap;
}

.credentials {
    font-family: var(--font-sans);
    font-size: 1.125rem;
    color: var(--slate-500);
    font-weight: 400;
    letter-spacing: 0.02em;
}

.position-block {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.role {
    font-family: var(--font-sans);
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--slate-700);
}

.dept {
    font-size: 0.9375rem;
    color: var(--slate-600);
    line-height: 1.5;
}

.university {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--slate-700);
}

.expert-block {
    padding-top: 0.25rem;
}

.expert-title {
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    color: var(--slate-700);
}

.expert-center {
    font-size: 0.875rem;
    color: var(--slate-500);
}

/* Areas */
.areas-block {
    padding-top: 1.25rem;
    border-top: 1px solid var(--gray-200);
}

.section-label {
    font-family: var(--font-sans);
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--slate-500);
    margin-bottom: 0.625rem;
}

.areas-list {
    font-size: 0.9375rem;
    color: var(--slate-600);
    line-height: 1.8;
}

/* Profile Links */
.profiles-block {
    padding-top: 1rem;
}

.profile-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.profile-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    background: var(--slate-800);
    color: var(--white);
    padding: 0.5rem 0.875rem;
    border-radius: 0.375rem;
    font-size: 0.8125rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.profile-btn:hover {
    background: var(--slate-700);
    transform: translateY(-1px);
}

.profile-btn i {
    font-size: 0.6875rem;
    opacity: 0.7;
}

/* === INTERESTS SECTION === */
.interests {
    background: var(--white);
    padding: 4rem 2rem;
    border-bottom: 1px solid var(--slate-200);
}

.interests-container {
    max-width: 850px;
    margin: 0 auto;
    text-align: center;
}

.interests h2 {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    font-weight: 400;
    color: var(--slate-900);
    margin-bottom: 1.5rem;
}

.interests-list {
    font-size: 1rem;
    color: var(--slate-600);
    line-height: 2;
}

/* === BIOGRAPHY SECTION === */
.biography {
    background: var(--white);
    padding: 5rem 2rem;
    border-bottom: 1px solid var(--slate-200);
}

.biography-container {
    max-width: 850px;
    margin: 0 auto;
}

.biography h2 {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    font-weight: 400;
    color: var(--slate-900);
    margin-bottom: 2rem;
}

.bio-content {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.bio-content p {
    font-size: 1rem;
    line-height: 1.85;
    color: var(--slate-600);
    text-align: justify;
}

/* === MEMBERSHIPS SECTION === */
.memberships {
    background: var(--gray-50);
    padding: 5rem 2rem;
}

.memberships-container {
    max-width: 850px;
    margin: 0 auto;
}

.memberships h2 {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    font-weight: 400;
    color: var(--slate-900);
    margin-bottom: 2rem;
}

.membership-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.875rem;
}

.membership-list li {
    position: relative;
    padding-left: 1.75rem;
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--slate-600);
}

.membership-list li::before {
    content: '\f0da';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    left: 0;
    top: 0;
    color: var(--slate-500);
    font-size: 0.875rem;
}

/* === AFFILIATIONS SECTION === */
.affiliations {
    background: var(--white);
    padding: 4rem 2rem;
    border-top: 1px solid var(--slate-200);
    border-bottom: 1px solid var(--slate-200);
}

.affiliations-container {
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.aff-title {
    font-family: var(--font-sans);
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--slate-500);
    margin-bottom: 2rem;
}

.logos-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 3rem;
}

.logo-link {
    display: block;
    transition: all 0.3s ease;
    opacity: 0.65;
}

.logo-link:hover {
    opacity: 1;
}

.logo-link img {
    height: 65px;
    width: auto;
    object-fit: contain;
}

/* === CONTACT SECTION === */
.contact {
    background: var(--gray-50);
    padding: 5rem 2rem;
}

.contact-container {
    max-width: 900px;
    margin: 0 auto;
}

.contact h2 {
    font-family: var(--font-serif);
    font-size: 2.25rem;
    font-weight: 400;
    color: var(--slate-900);
    text-align: center;
    margin-bottom: 3rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.contact-card {
    background: var(--white);
    padding: 1.75rem;
    border-radius: 0.5rem;
    border: 1px solid var(--slate-200);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1rem;
    transition: all 0.3s ease;
}

.contact-card:hover {
    border-color: var(--slate-300);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gray-100);
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-icon i {
    font-size: 1.25rem;
    color: var(--slate-600);
}

.contact-content h4 {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--slate-800);
    margin-bottom: 0.375rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contact-content a {
    color: var(--slate-700);
    font-weight: 500;
    transition: color 0.2s;
}

.contact-content a:hover {
    color: var(--slate-900);
}

.contact-content p {
    font-size: 0.9375rem;
    color: var(--slate-600);
    line-height: 1.5;
}

.contact-content .ext {
    display: block;
    font-size: 0.8125rem;
    color: var(--slate-500);
    margin-top: 0.25rem;
}

/* === FOOTER === */
footer {
    background: var(--white);
    padding: 2rem;
    text-align: center;
    border-top: 1px solid var(--slate-200);
}

footer p {
    font-size: 0.8125rem;
    color: var(--slate-500);
}

/* === RESPONSIVE === */
@media (max-width: 1024px) {
    .landing-title {
        font-size: 3.5rem;
    }

    .landing-tagline {
        font-size: 1.125rem;
    }

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

    .hero-photo {
        justify-content: center;
        order: 1;
        padding-top: 0;
    }

    .hero-info {
        padding: 1rem 2rem 2rem;
        text-align: center;
        align-items: center;
        order: 2;
    }

    .photo-frame {
        width: 320px;
    }

    .profile-links {
        justify-content: center;
    }

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

    .name-block h1 {
        font-size: 2.5rem;
        white-space: normal;
    }
}

@media (max-width: 900px) {
    .nav-links {
        display: none;
    }

    .lang-toggle {
        margin-left: auto;
    }

    .mobile-menu-btn {
        display: block;
    }
}

@media (max-width: 768px) {
    .landing {
        padding: 5rem 1.5rem 3rem;
    }

    .landing-title {
        font-size: 2.75rem;
    }

    .landing-tagline {
        font-size: 1rem;
    }

    .navbar {
        padding: 0 1rem;
    }

    .nav-logo-img {
        height: 32px;
    }

    .hero {
        padding-top: 4rem;
    }

    .hero-info {
        padding: 1rem 1.5rem 2rem;
    }

    .photo-frame {
        width: 280px;
    }

    .name-block h1 {
        font-size: 2rem;
    }

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

    .logos-row {
        gap: 1.5rem;
    }

    .logo-link img {
        height: 50px;
    }

    .biography h2,
    .memberships h2,
    .contact h2,
    .interests h2 {
        font-size: 1.75rem;
    }

    .biography,
    .memberships,
    .interests,
    .contact {
        padding: 3rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .landing-title {
        font-size: 2.25rem;
    }

    .landing-subtitle {
        font-size: 0.75rem;
    }

    .landing-tagline {
        font-size: 0.9375rem;
    }

    .hero-info {
        padding: 0.5rem 1rem 1.5rem;
    }

    .photo-frame {
        width: 240px;
    }

    .name-block h1 {
        font-size: 1.625rem;
    }

    .role {
        font-size: 1rem;
    }

    .profile-btn {
        padding: 0.375rem 0.625rem;
        font-size: 0.6875rem;
    }

    .lang-toggle {
        padding: 0.4rem 0.8rem;
        font-size: 0.6875rem;
    }

    .biography h2,
    .memberships h2,
    .contact h2,
    .interests h2 {
        font-size: 1.5rem;
    }

    .bio-content p,
    .membership-list li,
    .interests-list {
        font-size: 0.875rem;
    }
}