:root {
    --background: #f8fafc;
    --surface: #ffffff;
    --alternate-surface: #eef2f7;
    --text-primary: #172033;
    --text-secondary: #5d6678;
    --border: #dce2ea;
    --accent: #1f4f78;
    --accent-dark: #173c5b;
    --maximum-width: 1180px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 90px;
}

body {
    font-family:
        Inter,
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;

    line-height: 1.7;
    color: var(--text-primary);
    background: var(--background);
}

a {
    color: inherit;
}

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

/* Navigation */

.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;

    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid var(--border);

    backdrop-filter: blur(12px);
}

.navbar {
    max-width: var(--maximum-width);
    min-height: 74px;
    margin: 0 auto;
    padding: 0 24px;

    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 1.1rem;
    font-weight: 750;
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 22px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.93rem;
    font-weight: 600;
    text-decoration: none;
}

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

.menu-button {
    display: none;

    border: 0;
    background: transparent;

    font-size: 1.6rem;
    cursor: pointer;
}

/* Hero section */

.hero {
    max-width: var(--maximum-width);
    min-height: 76vh;
    margin: 0 auto;
    padding: 90px 24px;

    display: grid;
    grid-template-columns: 1.5fr 0.8fr;
    align-items: center;
    gap: 70px;
}

.eyebrow,
.section-label {
    margin-bottom: 12px;

    color: var(--accent);

    font-size: 0.82rem;
    font-weight: 750;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.hero h1 {
    max-width: 850px;
    margin-bottom: 22px;

    font-size: clamp(2rem, 4vw, 3.5rem);
    line-height: 1.1;
    letter-spacing: -0.035em;
}

.hero-description {
    max-width: 700px;

    color: var(--text-secondary);

    font-size: 1.28rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;

    margin-top: 34px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;

    min-height: 48px;
    padding: 11px 21px;

    border: 1px solid transparent;
    border-radius: 8px;

    font-weight: 700;
    text-decoration: none;
}

.primary-button {
    color: #ffffff;
    background: var(--accent);
}

.primary-button:hover {
    background: var(--accent-dark);
}

.secondary-button {
    color: var(--text-primary);
    background: var(--surface);
    border-color: var(--border);
}

.secondary-button:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.hero-image-wrapper {
    display: flex;
    justify-content: center;
}

.profile-image {
    width: 310px;
    height: 380px;

    object-fit: cover;

    border-radius: 22px;

    box-shadow:
        0 22px 55px rgba(23, 32, 51, 0.17);
}

/* General sections */

.section {
    padding:
        90px max(24px, calc((100% - var(--maximum-width)) / 2));
}

.alternate-section {
    background: var(--alternate-surface);
}

.section-heading {
    max-width: 760px;
    margin-bottom: 44px;
}

.section-heading h2,
.cv-section h2 {
    margin-bottom: 16px;

    font-size: clamp(2rem, 4vw, 3.3rem);
    line-height: 1.15;
    letter-spacing: -0.035em;
}

.section-heading p:not(.section-label),
.cv-section p {
    color: var(--text-secondary);
}

/* Research section */

.research-interests-block>h3 {
    margin-bottom: 22px;
    font-size: 1.5rem;
}

.research-interests {
    padding: 26px;

    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 14px;
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag-list span {
    padding: 6px 11px;

    color: var(--accent);
    background: #eaf1f7;

    border-radius: 999px;

    font-size: 0.82rem;
    font-weight: 650;
}

.publications-block {
    margin-top: 45px;
}

.publications-block>h3 {
    margin-bottom: 22px;
    font-size: 1.5rem;
}

.publication-item {
    padding: 26px;

    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 14px;
}

.publication-item+.publication-item {
    margin-top: 18px;
}

.publication-title {
    margin-bottom: 7px;

    font-size: 1.1rem;
    font-weight: 750;
}

.publication-authors,
.publication-status {
    color: var(--text-secondary);
}

.publication-status {
    margin-top: 4px;
    font-size: 0.92rem;
}

.publication-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;

    margin-top: 14px;
}

.publication-links a {
    color: var(--accent);

    font-weight: 700;
    text-decoration: none;
}

.publication-links a:hover {
    text-decoration: underline;
}

/* Cards */

.card-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
}

.card {
    padding: 28px;

    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 14px;
}

.card h3 {
    margin-bottom: 12px;
    font-size: 1.25rem;
}

.card p {
    color: var(--text-secondary);
}

.card-meta {
    margin-bottom: 8px;

    color: var(--accent) !important;

    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
}

.text-link {
    display: inline-block;
    margin-top: 18px;

    color: var(--accent);

    font-weight: 700;
    text-decoration: none;
}

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

/* Experience timeline */

.timeline {
    display: grid;
    gap: 20px;
}

.timeline-item {
    display: grid;
    grid-template-columns: 190px 1fr;
    gap: 28px;

    padding: 26px;

    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 14px;
}

.timeline-date {
    color: var(--accent);
    font-size: 0.82rem;
    font-weight: 750;
    white-space: nowrap;
}

.timeline-content h3 {
    margin-bottom: 8px;
}

.timeline-content p {
    color: var(--text-secondary);
}

.experience-location {
    margin-bottom: 10px;

    color: var(--accent) !important;

    font-size: 0.9rem;
    font-weight: 650;
}

.experience-list {
    margin-top: 8px;
    padding-left: 20px;

    color: var(--text-secondary);
}

.experience-list li {
    margin-bottom: 10px;
}

.experience-list li:last-child {
    margin-bottom: 0;
}

/* Skills */

.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.skill-group {
    padding: 24px;

    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 12px;
}

.skill-group h3 {
    margin-bottom: 8px;
}

.skill-group p {
    color: var(--text-secondary);
}

/* CV section */

.cv-section {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
}

.cv-section>div {
    max-width: 760px;
}

/* Contact section */

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

.contact-section .section-heading {
    margin-right: auto;
    margin-left: auto;
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 14px;
}

.contact-links a {
    padding: 10px 18px;

    color: var(--accent);
    background: var(--surface);

    border: 1px solid var(--border);
    border-radius: 8px;

    font-weight: 700;
    text-decoration: none;
}

.contact-links a:hover {
    border-color: var(--accent);
}

/* Footer */

.site-footer {
    padding: 28px 24px;

    color: var(--text-secondary);
    background: var(--surface);

    border-top: 1px solid var(--border);

    text-align: center;
}

/* Tablet layout */

@media (max-width: 900px) {
    .hero {
        grid-template-columns: 1fr;
        min-height: auto;
    }

    .hero-image-wrapper {
        justify-content: flex-start;
    }

    .profile-image {
        width: 260px;
        height: 320px;
    }

    .card-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

}

/* Mobile layout */

@media (max-width: 760px) {
    .menu-button {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 74px;
        right: 0;
        left: 0;

        display: none;
        flex-direction: column;
        align-items: flex-start;
        gap: 0;

        padding: 12px 24px 22px;

        background: var(--surface);
        border-bottom: 1px solid var(--border);
    }

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

    .nav-links a {
        width: 100%;
        padding: 10px 0;
    }

    .hero {
        padding-top: 65px;
        padding-bottom: 65px;
        gap: 45px;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .hero-description {
        font-size: 1.15rem;
    }

    .card-grid,
    .skills-grid {
        grid-template-columns: 1fr;
    }

    .timeline-item {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .timeline-date {
        white-space: normal;
    }

    .cv-section {
        align-items: flex-start;
        flex-direction: column;
    }
}

/* Small mobile screens */

@media (max-width: 480px) {
    .navbar {
        padding: 0 18px;
    }

    .hero {
        padding-right: 18px;
        padding-left: 18px;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-description {
        font-size: 1.08rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .button {
        width: 100%;
    }

    .profile-image {
        width: 100%;
        height: auto;

        aspect-ratio: 4 / 5;
    }

    .section {
        padding-right: 18px;
        padding-left: 18px;
    }
}