```css
/* =========================================================
   PARVIZ TAVAKOLI-KOLOUR
   CORAL REEF ECOLOGY WEBSITE
   ========================================================= */


/* =========================================================
   RESET
   ========================================================= */

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

html {
    scroll-behavior: smooth;
}

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

    color: #18343b;
    background: #ffffff;
    line-height: 1.7;
}

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

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

button {
    font: inherit;
}

section[id] {
    scroll-margin-top: 100px;
}


/* =========================================================
   VARIABLES
   ========================================================= */

:root {

    --navy: #12363d;
    --deep: #09282f;
    --teal: #0f6670;
    --aqua: #3b9ca0;

    --sand: #f4efe6;
    --off-white: #f8faf9;
    --white: #ffffff;

    --text: #18343b;
    --muted: #63777b;
    --line: #dce6e4;

    --max-width: 1180px;

    --shadow:
        0 15px 45px rgba(9, 40, 47, 0.08);

    --transition:
        0.25s ease;
}


/* =========================================================
   GLOBAL LAYOUT
   ========================================================= */

.section {
    padding: 100px max(6vw, 24px);
}

.section-light {
    background: var(--off-white);
}

.section-heading {
    max-width: 760px;
    margin-bottom: 55px;
}

.section-heading > p:last-child {
    margin-top: 18px;
    color: var(--muted);
    max-width: 680px;
}

.section-label {
    color: var(--teal);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 15px;
}

h1,
h2,
h3 {
    color: var(--navy);
    line-height: 1.15;
    font-weight: 650;
}

h1 {
    font-size: clamp(3rem, 7vw, 6.8rem);
}

h2 {
    font-size: clamp(2rem, 4vw, 3.6rem);
}

h3 {
    font-size: 1.35rem;
}

p {
    color: var(--text);
    font-size: 1rem;
}

.text-link {
    display: inline-block;
    margin-top: 20px;

    color: var(--teal);

    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 0.08em;

    transition: var(--transition);
}

.text-link:hover {
    transform: translateX(5px);
}


/* =========================================================
   HEADER
   ========================================================= */

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

    background: rgba(255, 255, 255, 0.96);

    border-bottom: 1px solid rgba(18, 54, 61, 0.08);

    backdrop-filter: blur(14px);
}

.nav-container {
    width: min(var(--max-width), 92%);
    margin: auto;

    min-height: 78px;

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

    gap: 30px;
}

.site-name {
    flex-shrink: 0;

    color: var(--navy);

    font-size: 0.82rem;
    font-weight: 850;
    letter-spacing: 0.08em;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 26px;
}

.main-nav > a,
.dropdown > a {
    position: relative;

    color: var(--navy);

    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.1em;
}

.main-nav > a::after,
.dropdown > a::after {
    content: "";

    position: absolute;
    left: 0;
    bottom: -8px;

    width: 0;
    height: 2px;

    background: var(--teal);

    transition: var(--transition);
}

.main-nav > a:hover::after,
.dropdown > a:hover::after {
    width: 100%;
}

.dropdown {
    position: relative;
}

.arrow {
    margin-left: 4px;
    font-size: 0.8rem;
}

.dropdown-menu {
    position: absolute;

    top: calc(100% + 18px);
    left: -18px;

    min-width: 245px;

    padding: 12px;

    background: white;

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

    box-shadow: var(--shadow);

    opacity: 0;
    visibility: hidden;

    transform: translateY(8px);

    transition: var(--transition);
}

.dropdown:hover .dropdown-menu,
.dropdown:focus-within .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu a {
    display: block;

    padding: 11px 13px;

    color: var(--text);

    font-size: 0.78rem;

    border-radius: 3px;

    transition: var(--transition);
}

.dropdown-menu a:hover {
    color: var(--teal);
    background: var(--off-white);
}

.menu-toggle {
    display: none;

    width: 42px;
    height: 42px;

    background: none;
    border: 0;

    cursor: pointer;
}

.menu-toggle span {
    display: block;

    width: 25px;
    height: 2px;

    margin: 5px auto;

    background: var(--navy);

    transition: var(--transition);
}


/* =========================================================
   HERO
   ========================================================= */

.hero {
    position: relative;

    min-height: calc(100vh - 78px);

    display: flex;
    align-items: center;

    background-image:
        linear-gradient(
            90deg,
            rgba(6, 34, 40, 0.82),
            rgba(6, 34, 40, 0.35)
        ),
        url("../image/hero.jpg");

    background-size: cover;
    background-position: center;
}

.hero-overlay {
    position: absolute;
    inset: 0;
}

.hero-content {
    position: relative;
    z-index: 2;

    width: min(var(--max-width), 92%);

    margin: auto;

    padding: 100px 0;

    color: white;
}

.hero-kicker {
    color: rgba(255,255,255,0.85);

    font-size: 0.74rem;
    font-weight: 800;
    letter-spacing: 0.2em;

    margin-bottom: 22px;
}

.hero h1 {
    color: white;

    font-size: clamp(3.3rem, 8vw, 7.8rem);

    letter-spacing: -0.04em;
}

.hero-position {
    margin-top: 28px;

    color: white;

    font-size: 1.3rem;
    font-weight: 500;
}

.hero-affiliation {
    margin-top: 5px;

    color: rgba(255,255,255,0.8);
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;

    margin-top: 35px;
}


/* =========================================================
   BUTTONS
   ========================================================= */

.button {
    display: inline-flex;

    align-items: center;
    justify-content: center;

    min-height: 48px;

    padding: 0 24px;

    border: 1px solid transparent;

    font-size: 0.73rem;
    font-weight: 800;
    letter-spacing: 0.1em;

    transition: var(--transition);
}

.button-light {
    color: var(--navy);
    background: white;
}

.button-light:hover {
    background: var(--sand);
    transform: translateY(-2px);
}

.button-outline {
    color: white;
    border-color: rgba(255,255,255,0.7);
}

.button-outline:hover {
    color: var(--navy);
    background: white;
}

.button-dark {
    color: white;
    background: var(--navy);
}

.button-dark:hover {
    background: var(--teal);
    transform: translateY(-2px);
}

.button-small {
    display: inline-flex;

    padding: 8px 14px;

    color: var(--teal);

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

    font-size: 0.68rem;
    font-weight: 800;
    letter-spacing: 0.08em;

    transition: var(--transition);
}

.button-small:hover {
    color: white;
    background: var(--teal);
}


/* =========================================================
   INTRO
   ========================================================= */

.intro-section {
    width: min(var(--max-width), 92%);
    margin: auto;

    padding-top: 110px;
    padding-bottom: 110px;

    display: grid;

    grid-template-columns:
        minmax(300px, 0.85fr)
        minmax(320px, 1fr);

    gap: clamp(50px, 8vw, 110px);

    align-items: center;
}

.intro-image {
    overflow: hidden;
}

.image-frame {
    position: relative;
}

.image-frame::after {
    content: "";

    position: absolute;

    left: 20px;
    bottom: 20px;

    width: 100%;
    height: 100%;

    border: 1px solid rgba(15,102,112,0.3);

    z-index: -1;
}

.intro-image img {
    aspect-ratio: 4 / 5;
    object-fit: cover;
}

.intro-text h2 {
    margin-bottom: 24px;
}

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

    margin-bottom: 15px;
}


/* =========================================================
   RESEARCH CARDS
   ========================================================= */

.research-home {
    padding-top: 100px;
    padding-bottom: 110px;
}

.research-home .section-heading,
.research-grid {
    width: min(var(--max-width), 92%);
    margin-left: auto;
    margin-right: auto;
}

.research-grid {
    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 16px;
}

.research-card {
    position: relative;

    min-height: 280px;

    padding: 30px;

    background: white;

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

    transition: var(--transition);
}

.research-card:hover {
    transform: translateY(-7px);
    border-color: var(--aqua);
    box-shadow: var(--shadow);
}

.card-number {
    display: block;

    margin-bottom: 65px;

    color: var(--aqua);

    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.1em;
}

.research-card h3 {
    margin-bottom: 12px;
}

.research-card p {
    color: var(--muted);
    font-size: 0.92rem;
}


/* =========================================================
   FIELDWORK
   ========================================================= */

.field-section {
    display: grid;

    grid-template-columns: 1fr 1fr;

    min-height: 600px;
}

.field-image {
    overflow: hidden;
}

.field-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;

    min-height: 500px;
}

.field-content {
    display: flex;
    flex-direction: column;
    justify-content: center;

    padding: 80px clamp(30px, 7vw, 100px);

    background: var(--sand);
}

.field-content h2 {
    margin-bottom: 25px;
}

.field-content p {
    max-width: 550px;

    color: var(--muted);

    margin-bottom: 20px;
}


/* =========================================================
   PUBLICATION HOME
   ========================================================= */

.publication-home {
    width: min(850px, 92%);
    margin: auto;

    text-align: center;
}

.publication-home p:not(.section-label) {
    color: var(--muted);

    margin-top: 20px;
}


/* =========================================================
   PAGE HERO
   ========================================================= */

.page-hero {
    min-height: 390px;

    display: flex;
    align-items: flex-end;

    padding: 80px max(6vw, 24px);

    background:
        linear-gradient(
            120deg,
            var(--deep),
            var(--teal)
        );
}

.page-hero-content {
    width: min(var(--max-width), 100%);
    margin: auto;
}

.page-hero .section-label {
    color: #8ed4d5;
}

.page-hero h1 {
    max-width: 850px;

    color: white;

    font-size: clamp(2.8rem, 6vw, 5.8rem);
}

.page-hero p:last-child {
    max-width: 650px;

    margin-top: 20px;

    color: rgba(255,255,255,0.78);
}


/* =========================================================
   ABOUT
   ========================================================= */

.content-section {
    max-width: 1250px;
    margin: auto;
}

.two-column {
    display: grid;

    grid-template-columns:
        minmax(300px, 0.8fr)
        minmax(320px, 1.2fr);

    gap: 90px;

    align-items: center;
}

.content-image img {
    aspect-ratio: 4 / 5;
    object-fit: cover;
}

.two-column h2 {
    margin-bottom: 25px;
}

.two-column p {
    color: var(--muted);
    margin-bottom: 16px;
}

.timeline {
    max-width: 900px;
}

.timeline-item {
    display: grid;

    grid-template-columns: 130px 1fr;

    gap: 40px;

    padding: 30px 0;

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

.timeline-year {
    color: var(--teal);

    font-weight: 800;
}

.timeline-item p {
    color: var(--muted);
}

.experience-grid {
    display: grid;

    grid-template-columns: repeat(2, 1fr);

    gap: 20px;
}

.experience-card {
    padding: 35px;

    border: 1px solid var(--line);
}

.experience-date {
    display: block;

    margin-bottom: 20px;

    color: var(--teal);

    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.1em;
}

.experience-card h3 {
    margin-bottom: 12px;
}

.institution {
    color: var(--navy) !important;
    font-weight: 600;
}

.experience-card p:last-child {
    color: var(--muted);
}

.quote-section {
    padding: 100px 24px;

    background: var(--navy);
}

.quote-section > div {
    width: min(850px, 92%);
    margin: auto;
}

.quote-section p {
    color: white;

    font-size: clamp(1.7rem, 3vw, 2.7rem);
    line-height: 1.35;
}


/* =========================================================
   RESEARCH PAGE
   ========================================================= */

.research-intro {
    width: min(1000px, 92%);
    margin: auto;
}

.research-detail {
    display: grid;

    grid-template-columns: 120px 1fr;

    gap: 50px;

    max-width: 1100px;
    margin: auto;
}

.research-number {
    color: var(--aqua);

    font-size: 1rem;
    font-weight: 850;
    letter-spacing: 0.1em;
}

.research-detail-content {
    max-width: 850px;
}

.research-detail-content h2 {
    margin-bottom: 25px;
}

.research-detail-content > p:not(.section-label) {
    color: var(--muted);
    margin-bottom: 18px;
}

.method-grid {
    display: grid;

    grid-template-columns: repeat(2, 1fr);

    gap: 15px;

    margin-top: 35px;
}

.method-grid > div {
    padding: 25px;

    background: white;

    border: 1px solid var(--line);
}

.method-grid h3 {
    margin-bottom: 8px;
}

.method-grid p {
    color: var(--muted);
    font-size: 0.9rem;
}


/* =========================================================
   PUBLICATIONS
   ========================================================= */

.publications-section,
.full-publications,
.assessment-section {
    max-width: 1250px;
    margin: auto;
}

.publication-list {
    display: flex;
    flex-direction: column;

    gap: 24px;
}

.publication-card {
    display: grid;

    grid-template-columns: 310px 1fr;

    min-height: 280px;

    background: white;

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

    overflow: hidden;

    transition: var(--transition);
}

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

.publication-image {
    min-height: 280px;

    overflow: hidden;
}

.publication-image img {
    width: 100%;
    height: 100%;

    object-fit: cover;

    transition: transform 0.5s ease;
}

.publication-card:hover .publication-image img {
    transform: scale(1.04);
}

.publication-content {
    padding: 35px 40px;
}

.publication-year {
    display: inline-block;

    margin-bottom: 12px;

    color: var(--teal);

    font-size: 0.72rem;
    font-weight: 850;
    letter-spacing: 0.1em;
}

.publication-content h3 {
    margin-bottom: 12px;

    font-size: 1.55rem;
    line-height: 1.3;
}

.publication-authors {
    margin-bottom: 3px;

    color: var(--text);
    font-size: 0.88rem;
}

.publication-journal {
    margin-bottom: 15px;

    color: var(--teal);
    font-size: 0.88rem;
    font-weight: 700;
}

.publication-content > p:not(.publication-authors):not(.publication-journal) {
    color: var(--muted);
    font-size: 0.92rem;
}

.publication-links {
    display: flex;
    gap: 10px;

    margin-top: 22px;
}

.publication-filters {
    display: flex;
    flex-wrap: wrap;

    gap: 8px;

    margin-bottom: 35px;
}

.filter-button {
    padding: 9px 16px;

    background: white;

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

    color: var(--text);

    font-size: 0.72rem;
    font-weight: 800;

    cursor: pointer;

    transition: var(--transition);
}

.filter-button:hover,
.filter-button.active {
    color: white;
    background: var(--teal);
    border-color: var(--teal);
}

.full-list {
    display: flex;
    flex-direction: column;
}

.full-publication {
    display: grid;

    grid-template-columns: 70px 1fr;

    gap: 25px;

    padding: 22px 0;

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

.full-publication span {
    color: var(--teal);
    font-weight: 800;
}

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

.full-publication.hidden {
    display: none;
}

.assessment-box {
    padding: 55px;

    background: var(--sand);
}

.assessment-box h2 {
    margin-bottom: 20px;
}

.assessment-box p:not(.section-label) {
    max-width: 760px;

    color: var(--muted);

    margin-bottom: 15px;
}


/* =========================================================
   GALLERY
   ========================================================= */

.gallery-section {
    max-width: 1250px;
    margin: auto;
}

.gallery-grid {
    display: grid;

    grid-template-columns: repeat(3, 1fr);

    gap: 15px;
}

.gallery-item {
    margin: 0;

    aspect-ratio: 4 / 3;

    overflow: hidden;

    background: #e8eeee;
}

.gallery-item img {
    width: 100%;
    height: 100%;

    object-fit: cover;

    transition: transform 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}


/* =========================================================
   CONTACT
   ========================================================= */

.contact-section {
    max-width: 1150px;
    margin: auto;
}

.contact-grid {
    display: grid;

    grid-template-columns: 1.2fr 0.8fr;

    gap: 90px;
}

.contact-main h2 {
    margin-bottom: 20px;
}

.contact-main > p {
    color: var(--muted);
}

.contact-item {
    padding: 22px 0;

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

    margin-top: 25px;
}

.contact-label {
    display: block;

    margin-bottom: 8px;

    color: var(--teal);

    font-size: 0.72rem;
    font-weight: 850;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.contact-item a {
    color: var(--navy);
    font-weight: 650;
}

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

.contact-links {
    padding: 35px;

    background: var(--off-white);

    border: 1px solid var(--line);
}

.profile-link {
    display: flex;

    justify-content: space-between;

    padding: 18px 0;

    border-bottom: 1px solid var(--line);

    color: var(--navy);

    font-weight: 650;

    transition: var(--transition);
}

.profile-link:hover {
    color: var(--teal);
    padding-left: 6px;
}

.contact-bottom {
    max-width: none;
}

.contact-message {
    width: min(800px, 100%);
    margin: auto;
    text-align: center;
}

.contact-message h2 {
    margin-bottom: 20px;
}

.contact-message p:not(.section-label) {
    color: var(--muted);

    margin-bottom: 25px;
}


/* =========================================================
   FOOTER
   ========================================================= */

footer {
    background: var(--deep);

    padding: 55px max(6vw, 24px) 25px;
}

.footer-content {
    width: min(var(--max-width), 100%);
    margin: auto;

    display: flex;
    justify-content: space-between;
    gap: 40px;
}

.footer-content h3 {
    color: white;

    font-size: 0.85rem;
    letter-spacing: 0.08em;
}

.footer-content p {
    color: rgba(255,255,255,0.62);

    font-size: 0.86rem;
}

.footer-social {
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.footer-social a {
    display: flex;

    width: 38px;
    height: 38px;

    align-items: center;
    justify-content: center;

    color: rgba(255,255,255,0.8);

    border: 1px solid rgba(255,255,255,0.2);

    font-size: 0.7rem;
    font-weight: 800;

    transition: var(--transition);
}

.footer-social a:hover {
    color: white;
    border-color: white;
    transform: translateY(-3px);
}

.copyright {
    width: min(var(--max-width), 100%);
    margin: 40px auto 0;
    padding-top: 20px;

    border-top: 1px solid rgba(255,255,255,0.12);

    color: rgba(255,255,255,0.4);

    font-size: 0.72rem;
}


/* =========================================================
   RESPONSIVE — TABLET
   ========================================================= */

@media (max-width: 1050px) {

    .main-nav {
        gap: 17px;
    }

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

    .publication-card {
        grid-template-columns: 260px 1fr;
    }

}


/* =========================================================
   RESPONSIVE — MOBILE
   ========================================================= */

@media (max-width: 800px) {

    .nav-container {
        min-height: 70px;
    }

    .menu-toggle {
        display: block;
    }

    .main-nav {
        position: absolute;

        top: 70px;
        left: 0;
        right: 0;

        display: none;

        flex-direction: column;
        align-items: stretch;

        gap: 0;

        padding: 12px 6vw 25px;

        background: white;

        border-bottom: 1px solid var(--line);

        box-shadow: var(--shadow);
    }

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

    .main-nav > a,
    .dropdown > a {
        display: block;

        padding: 14px 0;

        font-size: 0.75rem;
    }

    .main-nav > a::after,
    .dropdown > a::after {
        display: none;
    }

    .dropdown-menu {
        position: static;

        display: none;

        opacity: 1;
        visibility: visible;

        transform: none;

        min-width: 0;

        padding: 0 0 8px;

        border: 0;
        box-shadow: none;
    }

    .dropdown.open .dropdown-menu {
        display: block;
    }

    .dropdown-menu a {
        padding: 10px 15px;
    }

    .hero {
        min-height: 650px;
    }

    .hero-content {
        padding: 70px 0;
    }

    .hero h1 {
        font-size: clamp(3rem, 15vw, 5rem);
    }

    .intro-section,
    .two-column,
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .intro-section {
        width: 100%;
        padding-left: 6vw;
        padding-right: 6vw;
    }

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

    .field-section {
        grid-template-columns: 1fr;
    }

    .field-image {
        min-height: 400px;
    }

    .field-image img {
        min-height: 400px;
    }

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

    .publication-image {
        min-height: 240px;
        height: 240px;
    }

    .research-detail {
        grid-template-columns: 1fr;
        gap: 15px;
    }

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

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

    .contact-grid {
        gap: 40px;
    }

    .footer-content {
        flex-direction: column;
    }

}


/* =========================================================
   RESPONSIVE — SMALL MOBILE
   ========================================================= */

@media (max-width: 520px) {

    .site-name {
        font-size: 0.68rem;
    }

    .section {
        padding-top: 70px;
        padding-bottom: 70px;
    }

    .page-hero {
        min-height: 330px;
    }

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

    .button {
        width: 100%;
    }

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

    .full-publication {
        grid-template-columns: 55px 1fr;
        gap: 15px;
    }

    .publication-content {
        padding: 25px;
    }

    .assessment-box {
        padding: 30px;
    }

    .footer-social {
        flex-wrap: wrap;
    }

}
```