* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Segoe UI", Arial, sans-serif;
    line-height: 1.7;
    margin: 0;
    padding: 0;
    background: #f7f8fa;
    color: #1d2733;
}

nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: #ffffff;
    padding: 20px 8%;
    border-bottom: 1px solid #e3e7eb;
}

nav a {
    color: #26384a;
    text-decoration: none;
    margin-right: 30px;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.2s ease;
}

nav a:hover {
    color: #1d6078;
}

section {
    padding: 90px 8%;
}

h1 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: clamp(42px, 6vw, 68px);
    line-height: 1.1;
    font-weight: 500;
    color: #172b3a;
    margin: 0 0 18px 0;
}

h2 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 34px;
    font-weight: 500;
    color: #172b3a;
    margin-bottom: 25px;
}

p {
    max-width: 760px;
    font-size: 17px;
    color: #4a5865;
}

#home {
    min-height: 78vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: #eef3f6;
}

#home h2 {
    font-family: "Segoe UI", Arial, sans-serif;
    font-size: 20px;
    font-weight: 500;
    color: #1d6078;
    margin-top: 0;
    margin-bottom: 30px;
}

#home p {
    font-size: 18px;
}

#about,
#experience,
#research,
#education,
#contact {
    background: #ffffff;
    margin-top: 1px;
}

.hero-label {
    font-size: 13px;
    letter-spacing: 3px;
    font-weight: 600;
    color: #1d6078;
    margin-bottom: 18px;
}

.hero-content {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 70px;
}

.hero-text {
    flex: 1;
}

.hero-photo {
    flex: 0 0 380px;
    position: relative;
}

.hero-photo img {
    width: 100%;
    height: 500px;
    object-fit: cover;
    object-position: center;
    border-radius: 3px;
    display: block;
    box-shadow: 0 18px 40px rgba(23, 43, 58, 0.10);
}

.about-grid {
    max-width: 1100px;
    margin-top: 45px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.about-card {
    padding: 30px;
    background: #f7f8fa;
    border: 1px solid #e3e7eb;
}

.about-card h3 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 21px;
    font-weight: 500;
    color: #172b3a;
    margin-top: 0;
}

.about-card p {
    font-size: 15px;
    margin-bottom: 0;
}

.timeline {
    max-width: 950px;
    margin: 50px auto 0;
    position: relative;
}

.timeline::before {
    content: "";
    position: absolute;
    left: 145px;
    top: 0;
    bottom: 0;
    width: 1px;
    background: #d8e0e5;
}

.timeline-item {
    display: grid;
    grid-template-columns: 130px 1fr;
    gap: 45px;
    position: relative;
    margin-bottom: 55px;
}

.timeline-date {
    font-size: 14px;
    font-weight: 600;
    color: #1d6078;
    text-align: right;
    padding-top: 4px;
}

.timeline-content {
    position: relative;
    padding-left: 30px;
}

.timeline-content::before {
    content: "";
    position: absolute;
    left: -51px;
    top: 8px;
    width: 10px;
    height: 10px;
    background: #ffffff;
    border: 2px solid #1d6078;
    border-radius: 50%;
}

.timeline-content h3 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 23px;
    font-weight: 500;
    color: #172b3a;
    margin: 0 0 5px;
}

.timeline-content h4 {
    font-size: 15px;
    font-weight: 500;
    color: #657583;
    margin: 0 0 12px;
}

.timeline-content p {
    font-size: 16px;
    margin: 0;
}

.section-intro {
    max-width: 720px;
    margin-bottom: 45px;
}

.research-grid {
    max-width: 1100px;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.research-card {
    padding: 38px;
    background: #f7f8fa;
    border: 1px solid #e1e6ea;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.research-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(23, 43, 58, 0.08);
}

.research-type {
    font-size: 12px;
    letter-spacing: 2px;
    font-weight: 600;
    color: #1d6078;
    margin-bottom: 18px;
}

.research-card h3 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 23px;
    line-height: 1.35;
    font-weight: 500;
    color: #172b3a;
    margin: 0 0 18px;
}

.research-card p {
    font-size: 15px;
    margin-bottom: 25px;
}

.research-link {
    color: #1d6078;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
}

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

.education-layout {
    max-width: 1100px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 70px;
}

.education-heading {
    font-size: 12px;
    letter-spacing: 2px;
    font-weight: 600;
    color: #1d6078;
    padding-bottom: 18px;
    border-bottom: 1px solid #dfe5e9;
    margin-bottom: 25px;
}

.education-item {
    padding-bottom: 30px;
    margin-bottom: 30px;
    border-bottom: 1px solid #edf0f2;
}

.education-year {
    font-size: 13px;
    font-weight: 600;
    color: #657583;
}

.education-item h3 {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 22px;
    font-weight: 500;
    color: #172b3a;
    margin: 7px 0 8px;
}

.education-item p {
    font-size: 15px;
    margin: 0;
}

.training-item {
    padding: 0 0 22px;
    margin-bottom: 22px;
    border-bottom: 1px solid #edf0f2;
}

.training-item span {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: #657583;
    margin-bottom: 5px;
}

.training-item strong {
    display: block;
    font-size: 16px;
    font-weight: 600;
    color: #26384a;
}

.training-item p {
    font-size: 14px;
    margin: 4px 0 0;
}

.contact-layout {
    max-width: 1100px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: start;
}

.contact-intro h2 {
    font-size: 40px;
    margin-top: 10px;
}

.contact-details {
    border-top: 1px solid #dfe5e9;
}

.contact-item {
    padding: 22px 0;
    border-bottom: 1px solid #dfe5e9;
}

.contact-item span {
    display: block;
    font-size: 12px;
    letter-spacing: 2px;
    text-transform: uppercase;
    font-weight: 600;
    color: #1d6078;
    margin-bottom: 6px;
}

.contact-item a,
.contact-item p {
    font-size: 16px;
    color: #26384a;
    text-decoration: none;
    margin: 0;
}

.contact-item a:hover {
    color: #1d6078;
}

@media (max-width: 800px) {

    nav {
        padding: 16px 20px;
        white-space: nowrap;
        overflow-x: auto;
    }

    nav a {
        margin-right: 20px;
        font-size: 14px;
    }

    section {
        padding: 65px 22px;
    }

    #home {
        min-height: auto;
        padding-top: 75px;
        padding-bottom: 75px;
    }

    .hero-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 45px;
    }

    .hero-photo {
        width: 100%;
        max-width: 360px;
        flex: none;
    }

    .hero-photo img {
        height: auto;
        aspect-ratio: 4 / 5;
    }

    h1 {
        font-size: 44px;
    }

    h2 {
        font-size: 30px;
    }

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

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

    .education-layout {
        grid-template-columns: 1fr;
        gap: 60px;
    }

    .contact-layout {
        grid-template-columns: 1fr;
        gap: 45px;
    }

    .timeline::before {
        left: 0;
    }

    .timeline-item {
        grid-template-columns: 1fr;
        gap: 8px;
        padding-left: 25px;
    }

    .timeline-date {
        text-align: left;
    }

    .timeline-content {
        padding-left: 0;
    }

    .timeline-content::before {
        left: -30px;
    }

}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
}

.nav-brand {
    font-family: Georgia, "Times New Roman", serif;
    font-size: 19px;
    font-weight: 500;
    color: #172b3a;
    text-decoration: none;
    white-space: nowrap;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav-links a {
    margin-right: 0;
}

@media (max-width: 800px) {

    .nav-inner {
        align-items: flex-start;
    }

    .nav-brand {
        font-size: 17px;
    }

    .nav-links {
        gap: 20px;
    }

}

.hero-buttons {
    display: flex;
    gap: 14px;
    margin-top: 35px;
}

.button {
    display: inline-block;
    padding: 12px 22px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.button-primary {
    background: #1d6078;
    color: #ffffff;
}

.button-primary:hover {
    background: #174d61;
}

.button-secondary {
    border: 1px solid #b9c5cc;
    color: #26384a;
    background: transparent;
}

.button-secondary:hover {
    border-color: #1d6078;
    color: #1d6078;
}

@media (max-width: 800px) {

    .hero-buttons {
        flex-wrap: wrap;
    }

}

footer {
    background: #172b3a;
    color: #ffffff;
    padding: 45px 8% 25px;
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 30px;
}

.footer-inner strong {
    display: block;
    font-family: Georgia, "Times New Roman", serif;
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 6px;
}

.footer-inner span {
    display: block;
    font-size: 14px;
    color: #c8d3da;
}

.footer-location {
    font-size: 14px;
    color: #c8d3da;
}

.footer-bottom {
    max-width: 1200px;
    margin: 35px auto 0;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    font-size: 12px;
    color: #aebdc6;
}

@media (max-width: 800px) {

    footer {
        padding: 40px 22px 22px;
    }

    .footer-inner {
        flex-direction: column;
        gap: 20px;
    }

}