:root {
    --primary-color: #2f3e9e;
    --secondary-color: #2d7dd2;
    --accent-color: #2ec4b6;
    --text-color: #1f2933;
    --muted-text: #4b5d73;
    --background-color: #f4f6fb;
    --card-background: #ffffff;
    --border-color: #d7deea;
    --pill-background: #d4eef0;
    --pill-text: #1f2933;
    --tag-background: #e6effa;
    --tag-text: #1f2933;
    --chip-active-bg: #2f3e9e;
    --chip-active-text: #ffffff;
    --container-width: 1180px;
    --transition: 0.3s ease;
}

html.theme-dark {
    --primary-color: #7aa2f7;
    --secondary-color: #8f9ff7;
    --accent-color: #4ade80;
    --text-color: #e2e8f0;
    --muted-text: #94a3b8;
    --background-color: #0f172a;
    --card-background: #1e293b;
    --border-color: rgba(148, 163, 184, 0.25);
    --pill-background: #254646;
    --pill-text: #e2e8f0;
    --tag-background: #20334d;
    --tag-text: #e2e8f0;
    --chip-active-bg: #384a9f;
    --chip-active-text: #f8fafc;
}

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

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

body {
    font-family: 'Poppins', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    background-color: var(--background-color);
    line-height: 1.7;
    transition: background-color var(--transition), color var(--transition);
}

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

a:hover,
a:focus {
    color: var(--primary-color);
}

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

.container {
    width: min(100%, var(--container-width));
    margin: 0 auto;
    padding: 0 1.5rem;
}

.hero {
    background: radial-gradient(circle at top left, rgba(46, 196, 182, 0.18), transparent 45%),
                linear-gradient(135deg, var(--primary-color), #3946b8);
    color: #ffffff;
    padding: clamp(3rem, 10vw, 5rem) 0;
    position: relative;
    overflow: hidden;
}

html.theme-dark .hero {
    background: radial-gradient(circle at top left, rgba(148, 163, 184, 0.15), transparent 45%),
                linear-gradient(135deg, #0f172a, #1e293b);
}

.hero::after {
    content: '';
    position: absolute;
    inset: 10% -20% auto auto;
    width: clamp(12rem, 35vw, 18rem);
    aspect-ratio: 1;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.18), transparent 65%);
    filter: blur(0.5px);
    z-index: 0;
}

.hero__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: clamp(2rem, 6vw, 3rem);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero__portrait {
    justify-self: center;
    position: relative;
}

.hero__portrait img {
    width: clamp(180px, 25vw, 220px);
    border-radius: 28px;
    border: 6px solid rgba(255, 255, 255, 0.6);
    box-shadow: 0 24px 50px rgba(18, 34, 78, 0.28);
}

.hero__content h1 {
    font-size: clamp(2.2rem, 4vw, 3.2rem);
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
}

.hero__title {
    font-size: clamp(1.1rem, 2.4vw, 1.5rem);
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin-bottom: 1.25rem;
}

.hero__value {
    font-size: clamp(1rem, 2vw, 1.1rem);
    max-width: 600px;
    margin-bottom: 1.75rem;
    color: rgba(255, 255, 255, 0.88);
}

html.theme-dark .hero__value {
    color: rgba(226, 232, 240, 0.85);
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem 1.5rem;
    margin-bottom: 2rem;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    color: inherit;
}

.contact-link i {
    font-size: 1.1rem;
}

.hero__cta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    padding: 0.85rem 1.8rem;
    border-radius: 999px;
    font-weight: 600;
    font-size: 0.95rem;
    border: 2px solid transparent;
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
}

.btn--primary {
    background: #ffffff;
    color: var(--primary-color);
    box-shadow: 0 12px 30px rgba(17, 30, 87, 0.25);
}

html.theme-dark .btn--primary {
    color: #0f172a;
}

.btn--primary:hover,
.btn--primary:focus {
    transform: translateY(-3px);
    box-shadow: 0 18px 40px rgba(17, 30, 87, 0.25);
}

.btn--ghost {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.6);
    color: #ffffff;
}

.btn--ghost:hover,
.btn--ghost:focus {
    background: rgba(255, 255, 255, 0.15);
}

html.theme-dark .btn--ghost {
    color: var(--text-color);
    border-color: rgba(148, 163, 184, 0.45);
    background: rgba(30, 41, 59, 0.35);
}

html.theme-dark .btn--ghost:hover,
html.theme-dark .btn--ghost:focus {
    background: rgba(148, 163, 184, 0.2);
}

.site-nav {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(21, 37, 81, 0.05);
}

html.theme-dark .site-nav {
    background: rgba(15, 23, 42, 0.92);
    border-bottom-color: rgba(148, 163, 184, 0.25);
    box-shadow: 0 18px 36px rgba(15, 23, 42, 0.5);
}

.nav__inner {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.6rem 0;
    flex-wrap: wrap;
}

.nav__brand {
    font-weight: 700;
    font-size: 1.1rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--primary-color);
}

.nav__toggle {
    display: none;
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    margin-left: auto;
}

.nav__lists {
    display: flex;
    align-items: center;
    gap: 2.5rem;
    width: 100%;
    justify-content: flex-end;
    margin-left: auto;
}

.nav__list {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 1.2rem;
}

.nav__link {
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--muted-text);
    position: relative;
    padding: 0.4rem 0;
}

.nav__link::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -0.2rem;
    width: 100%;
    height: 3px;
    border-radius: 999px;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition);
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.theme-toggle {
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.65);
    color: var(--primary-color);
    border-radius: 999px;
    padding: 0.35rem 0.85rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    margin-left: auto;
    transition: transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition);
}

.theme-toggle:hover,
.theme-toggle:focus {
    transform: translateY(-1px);
    background: rgba(46, 196, 182, 0.12);
    border-color: var(--accent-color);
}

html.theme-dark .theme-toggle {
    background: rgba(30, 41, 59, 0.65);
    color: var(--text-color);
    border-color: rgba(148, 163, 184, 0.35);
}

@media (max-width: 960px) {
    .theme-toggle {
        margin-left: 0;
        order: 2;
    }

    .nav__toggle {
        order: 3;
        margin-left: auto;
    }
}

.nav__link:hover::after,
.nav__link:focus::after,
.nav__link.is-active::after {
    transform: scaleX(1);
}

.nav__more {
    position: relative;
}

.nav__more-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: none;
    border: none;
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--muted-text);
    cursor: pointer;
    padding: 0.4rem 0;
}

.nav__submenu {
    position: absolute;
    top: calc(100% + 0.75rem);
    right: 0;
    min-width: 13rem;
    background: var(--card-background);
    border-radius: 0.75rem;
    padding: 0.75rem;
    box-shadow: 0 18px 38px rgba(32, 48, 96, 0.15);
    border: 1px solid var(--border-color);
    display: grid;
    gap: 0.35rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity var(--transition), transform var(--transition);
}

.nav__more[aria-expanded="true"] .nav__submenu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.section {
    margin: clamp(3rem, 8vw, 5rem) 0;
}

.section__intro {
    max-width: 740px;
    margin-bottom: 2.5rem;
}

.section__intro h2 {
    font-size: clamp(1.8rem, 3vw, 2.4rem);
    color: var(--primary-color);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 0.6rem;
}

.section__intro p {
    color: var(--muted-text);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.75rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 18px 35px rgba(22, 33, 74, 0.06);
    transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover,
.card:focus-within {
    transform: translateY(-4px);
    box-shadow: 0 24px 50px rgba(22, 33, 74, 0.08);
}

.about__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.about__bio {
    display: grid;
    gap: 1.25rem;
}

.about__bio h3 {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.list-check {
    list-style: none;
    display: grid;
    gap: 0.85rem;
}

.list-check li {
    padding-left: 1.8rem;
    position: relative;
    color: var(--muted-text);
}

.list-check li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    top: 0.05rem;
    color: var(--accent-color);
    font-weight: 700;
}

.about__stats {
    display: grid;
    gap: 1rem;
}

.stat-card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 12px 24px rgba(31, 41, 51, 0.08);
    display: grid;
    gap: 0.4rem;
}

.stat-card span {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.timeline {
    position: relative;
    display: grid;
    gap: 2.5rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 14px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--secondary-color), rgba(45, 125, 210, 0.15));
}

.timeline__item {
    padding-left: 3rem;
    position: relative;
}

.timeline__item::before {
    content: '';
    position: absolute;
    left: 5px;
    top: 0.4rem;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    border: 3px solid #ffffff;
    background: var(--accent-color);
    box-shadow: 0 0 0 6px rgba(46, 196, 182, 0.25);
}

.timeline__header h3 {
    font-size: 1.2rem;
    color: var(--primary-color);
}

.timeline__header p {
    color: var(--secondary-color);
    font-weight: 600;
}

.timeline__meta {
    font-size: 0.9rem;
    color: var(--muted-text);
    margin: 0.3rem 0 1rem;
}

.timeline__body {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 12px 28px rgba(22, 33, 74, 0.08);
    display: grid;
    gap: 1rem;
}

.timeline__impact {
    list-style: none;
    display: grid;
    gap: 0.6rem;
    color: var(--muted-text);
}

.timeline__impact li::marker {
    content: '';
}

.timeline__metrics {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.metric-pill {
    background: var(--pill-background);
    color: var(--pill-text);
    padding: 0.45rem 0.9rem;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 600;
}

.timeline__archive {
    border-left: 3px solid rgba(47, 62, 158, 0.15);
    margin-left: 0.5rem;
    padding-left: 1.25rem;
    display: grid;
    gap: 1.5rem;
}

.education__grid {
    display: grid;
    gap: 1.5rem;
}

.education-card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 16px 36px rgba(20, 33, 76, 0.07);
    display: grid;
    gap: 0.6rem;
}

.education-card h3 {
    font-size: 1.1rem;
    color: var(--primary-color);
}

.education-card p {
    color: var(--muted-text);
    font-size: 0.95rem;
}

.skills__wrap {
    display: grid;
    gap: 1.5rem;
}

.skill-cluster {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 14px 32px rgba(20, 33, 76, 0.07);
    display: grid;
    gap: 0.8rem;
}

.skill-cluster h3 {
    font-size: 1.05rem;
    color: var(--secondary-color);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.skill-tag {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.4rem 0.85rem;
    border-radius: 999px;
    background: rgba(47, 62, 158, 0.1);
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.85rem;
}

.publication-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.filter-chip {
    border: 1px solid var(--border-color);
    background: transparent;
    color: var(--muted-text);
    padding: 0.5rem 1.1rem;
    border-radius: 999px;
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition);
}

.filter-chip:hover,
.filter-chip:focus {
    transform: translateY(-2px);
    border-color: var(--chip-active-bg);
    color: var(--chip-active-bg);
}

.filter-chip.is-active {
    background: var(--chip-active-bg);
    border-color: var(--chip-active-bg);
    color: var(--chip-active-text);
    box-shadow: 0 10px 24px rgba(32, 51, 109, 0.25);
}

html.theme-dark .filter-chip {
    background: rgba(15, 23, 42, 0.6);
    color: var(--muted-text);
}

html.theme-dark .filter-chip:hover,
html.theme-dark .filter-chip:focus {
    color: var(--chip-active-text);
}

html.theme-dark .filter-chip.is-active {
    box-shadow: 0 10px 24px rgba(56, 74, 159, 0.32);
}

.publication-category.is-hidden {
    display: none;
}

.publication-category {
    margin-bottom: 2.5rem;
}

.publication-category h3 {
    font-size: 1.15rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.publication-list {
    display: grid;
    gap: 1.25rem;
}

.publication {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 16px 36px rgba(20, 33, 76, 0.07);
    display: grid;
    gap: 0.4rem;
}

.publication strong {
    color: var(--primary-color);
}

.publication span {
    color: var(--muted-text);
    font-size: 0.92rem;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 16px 32px rgba(17, 29, 71, 0.08);
    display: grid;
    gap: 0.6rem;
}

.project-card h3 {
    color: var(--primary-color);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.project-tag {
    background: var(--tag-background);
    color: var(--tag-text);
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.35rem 0.75rem;
}

.awards-list {
    display: grid;
    gap: 1rem;
}

.award-item {
    background: var(--card-background);
    border-radius: 1rem;
    padding: 1.4rem 1.6rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 16px 32px rgba(17, 29, 71, 0.08);
    position: relative;
}

.award-item::before {
    content: '\f559';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    left: 1.2rem;
    top: 1.2rem;
    color: var(--accent-color);
    opacity: 0.7;
}

.award-item p {
    margin-left: 2rem;
    color: var(--muted-text);
}

.contact-section {
    background: linear-gradient(135deg, rgba(47, 62, 158, 0.08), rgba(46, 196, 182, 0.18));
    border-radius: 1.5rem;
    padding: clamp(2.5rem, 6vw, 3.5rem);
    border: 1px solid var(--border-color);
    display: grid;
    gap: 1.75rem;
}

html.theme-dark .contact-section {
    background: linear-gradient(135deg, rgba(122, 162, 247, 0.1), rgba(74, 222, 128, 0.12));
}

.contact-section h2 {
    font-size: clamp(1.8rem, 3vw, 2.3rem);
    color: var(--primary-color);
}

.contact-section p {
    color: var(--muted-text);
}

.contact-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.scroll-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    border: none;
    background: var(--secondary-color);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 16px 32px rgba(45, 125, 210, 0.35);
    cursor: pointer;
    opacity: 0;
    transform: translateY(16px);
    pointer-events: none;
    transition: opacity var(--transition), transform var(--transition), background var(--transition);
    z-index: 11;
}

.scroll-top:hover,
.scroll-top:focus {
    background: var(--primary-color);
}

.scroll-top.is-visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.will-reveal {
    opacity: 0;
    transform: translateY(32px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.is-revealed {
    opacity: 1;
    transform: translateY(0);
}

.footer {
    background: #0f172a;
    color: rgba(255, 255, 255, 0.82);
    padding: 2.5rem 0;
    margin-top: 4rem;
}

.footer__inner {
    display: grid;
    gap: 1rem;
    text-align: center;
}

.footer__links {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.footer__link {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    background: rgba(255, 255, 255, 0.08);
    color: #ffffff;
    transition: background var(--transition), transform var(--transition);
}

.footer__link:hover,
.footer__link:focus {
    background: rgba(46, 196, 182, 0.4);
    transform: translateY(-3px);
}

@media (max-width: 960px) {
    .nav__toggle {
        display: inline-flex;
    }

    .nav__lists {
        position: absolute;
        inset: calc(100% + 0.5rem) 1.5rem auto;
        background: rgba(255, 255, 255, 0.97);
        border-radius: 1rem;
        padding: 1.25rem;
        flex-direction: column;
        align-items: stretch;
        gap: 1.5rem;
        border: 1px solid var(--border-color);
        box-shadow: 0 25px 55px rgba(22, 33, 74, 0.18);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-8px);
        transition: opacity var(--transition), transform var(--transition);
    }

    html.theme-dark .nav__lists {
        background: rgba(15, 23, 42, 0.97);
        box-shadow: 0 30px 60px rgba(8, 13, 25, 0.65);
    }

    .site-nav.is-open .nav__lists {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .nav__list {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.9rem;
    }

    .nav__more {
        width: 100%;
    }

    .nav__submenu {
        position: static;
        background: rgba(47, 62, 158, 0.05);
        border-radius: 0.85rem;
        border: none;
        padding: 0.75rem;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        margin-top: 0.5rem;
    }

    html.theme-dark .nav__submenu {
        background: rgba(15, 23, 42, 0.65);
    }

    .nav__more[aria-expanded="false"] .nav__submenu {
        display: none;
    }

    .hero__grid {
        text-align: center;
    }

    .hero__cta {
        justify-content: center;
    }

    .timeline::before {
        left: 8px;
    }

    .timeline__item {
        padding-left: 2.5rem;
    }
}

@media (max-width: 640px) {
    .contact-links {
        justify-content: center;
    }

    .stat-card span {
        font-size: 1.8rem;
    }

    .timeline__body {
        padding: 1.25rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .will-reveal {
        opacity: 1 !important;
        transform: none !important;
    }
}