/* ==========================================================
   Global
========================================================== */
*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}
html{
    scroll-behavior:smooth;
}
body{
    font-family:"Inter",sans-serif;
    color:#222;
    background:#fff;
    line-height:1.7;
}
img{
    display:block;
    max-width:100%;
    height:auto;
}
a{
    color:inherit;
    text-decoration:none;
}
ul{
    list-style:none;
}
/* ==========================================================
   Layout
========================================================== */
.container{
    width:min(1200px,90%);
    margin:auto;
}
.section{
    padding:90px 0;
}
.section-title{
    margin-bottom:60px;
    text-align:center;
}
.section-title h2{
    font-size:2.4rem;
    font-weight:600;
    color:#12395b;
    margin-bottom:15px;
}
.section-title p{
    max-width:700px;
    margin:auto;
    color:#666;
}
section{
    scroll-margin-top:100px;
}
/* ==========================================================
   Header
========================================================== */
.site-header{
    position:fixed;
    top:0;
    left:0;
    width:100%;
    background:rgba(255,255,255,.95);
    backdrop-filter:blur(10px);
    border-bottom:1px solid #e8e8e8;
    z-index:2000;
}
.site-header .container{
    display:flex;
    justify-content:space-between;
    align-items:center;
    height:80px;
}
.logo a{
    font-size:1.4rem;
    font-weight:600;
    color:#12395b;
}
.main-nav ul{
    display:flex;
    gap:35px;
}
.main-nav a{
    font-size:.95rem;
    transition:.3s;
}
.main-nav a:hover{
    color:#2b6ea6;
}
/* ==========================================================
   Hero
========================================================== */
.hero{
    height:50vh;
    min-height:420px;
    background:url("../images/hero.jpg") center center/cover no-repeat;
    display:flex;
    align-items:center;
    justify-content:center;
    margin-top:80px;
}
.hero-overlay{
    width:100%;
    height:100%;
    display:flex;
    justify-content:center;
    align-items:center;
    background:rgba(10,25,45,.55);
}
.hero-content{
    text-align:center;
    color:#fff;
    max-width:800px;
    padding:20px;
}
.hero-content h1{
    font-size:3.2rem;
    font-weight:600;
    margin-bottom:20px;
    letter-spacing:1px;
}
.hero-content p{
    font-size:1.2rem;
    margin-bottom:35px;
    opacity:.95;
}
.button{
    display:inline-block;
    padding:14px 36px;
    background:#2b6ea6;
    color:#fff;
    border-radius:4px;
    transition:.3s;
}
.button:hover{
    background:#12395b;
    transform:translateY(-2px);
}
/* ==========================================================
   About
========================================================== */
.about-grid{
    display:grid;
    grid-template-columns:2fr 1fr;
    gap:70px;
    align-items:center;
}
.about-text p{
    margin-bottom:22px;
    text-align:justify;
}
.about-image img{
    border-radius:8px;
    box-shadow:0 15px 35px rgba(0,0,0,.18);
}
/* ==========================================================
   Cards
========================================================== */
.cards{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
    gap:35px;
}
.card{
    background:#fff;
    padding:35px;
    border-radius:8px;
    box-shadow:0 8px 24px rgba(0,0,0,.08);
    transition:.35s;
}
.card:hover{
    transform:translateY(-8px);
    box-shadow:0 16px 40px rgba(0,0,0,.15);
}
.card h3{
    color:#12395b;
    margin-bottom:18px;
    font-size:1.35rem;
}
.card p{
    color:#555;
}
/* ==========================================================
   Research
========================================================== */
.research-heading{
    display:flex;
    align-items:center;
    gap:14px;
    margin-bottom:20px;
}
.section-light{
    background:#f8fafc;
}
.section-intro{
    max-width:900px;
    margin:0 auto 50px;
    text-align:center;
    line-height:1.8;
    color:#555;
}
.research-grid{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(280px,1fr));
    gap:35px;
    margin-top:40px;
}
.research-card{
    background:#ffffff;
    padding:35px;
    border-radius:12px;
    box-shadow:0 8px 25px rgba(0,0,0,0.06);
    transition:0.25s;
}
.research-card:hover{
    transform:translateY(-6px);
    box-shadow:0 14px 35px rgba(0,0,0,0.10);
}
.research-card h3{
    color:#1d3557;
    margin-bottom:20px;
}
.research-card h4{
    margin-top:30px;
    margin-bottom:15px;
    color:#1d3557;
}
.research-card p{
    line-height:1.8;
}
.research-list{
    padding-left:20px;
}
.research-list li{
    margin-bottom:18px;
    line-height:1.6;
}
.research-icon{
    width:40px;
    height:40px;
    object-fit:contain;
    flex-shrink:0;
}
.research-link {
    display: inline-block;
    margin-top: 8px;
    color: #1d3557;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
}
.research-link:hover {
    text-decoration: underline;
}
/* ==========================================================
   Publications
========================================================== */
.publication-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
    margin-top: 40px;
}
.publication-card {
    position: relative;
    background: #ffffff;
    padding: 35px 40px;
    border-radius: 12px;
    border-left: 4px solid #1d3557;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 14px 35px rgba(0, 0, 0, 0.10);
}
/* Publication year */
.publication-year {
    font-size: 0.9rem;
    font-weight: 600;
    color: #1d3557;
    margin-bottom: 10px;
    letter-spacing: 0.05em;
}
/* Publication title */
.publication-card h3 {
    margin: 0 0 18px 0;
    color: #1d3557;
    font-size: 1.35rem;
    line-height: 1.4;
}
/* Authors */
.publication-authors {
    margin-bottom: 8px;
    color: #444;
}
/* Journal information */
.publication-journal {
    margin-bottom: 12px;
    color: #555;
    line-height: 1.6;
}
/* DOI */
.publication-doi {
    display: inline-block;
    margin-bottom: 20px;
    color: #1d3557;
    font-size: 0.95rem;
    font-weight: 500;
    text-decoration: none;
}
.publication-doi:hover {
    text-decoration: underline;
}
/* Abstract */
.publication-abstract {
    margin-top: 10px;
    border-top: 1px solid #e5e7eb;
    padding-top: 18px;
}
/* Abstract button */
.publication-abstract summary {
    cursor: pointer;
    color: #1d3557;
    font-weight: 600;
    list-style: none;
}
/* Remove default marker */
.publication-abstract summary::-webkit-details-marker {
    display: none;
}
/* Small arrow */
.publication-abstract summary::after {
    content: "+";
    float: right;
    font-size: 1.1rem;
    font-weight: 400;
}
/* Change symbol when open */
.publication-abstract[open] summary::after {
    content: "-";
}
/* Abstract text */
.publication-abstract p {
    margin-top: 18px;
    color: #555;
    line-height: 1.8;
}
/* ==========================================================
   Software
========================================================== */
.software-card {
    background: #ffffff;
    padding: 40px;
    border-radius: 12px;
    border-left: 4px solid #1d3557;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    max-width: 900px;
    margin: 40px auto 0;
}
.software-content h3 {
    margin: 0 0 6px 0;
    color: #1d3557;
    font-size: 1.6rem;
}
.software-subtitle {
    margin: 0 0 25px 0;
    color: #666;
    font-size: 1rem;
    font-style: italic;
}
.software-content p {
    color: #555;
    line-height: 1.8;
}
.software-button {
    display: inline-block;
    margin-top: 15px;
    text-decoration: none;
}
/* ==========================================================
   Patents
========================================================== */
.patent-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 40px;
}
.patent-card {
    background: #ffffff;
    padding: 32px;
    border-radius: 12px;
    border-left: 4px solid #1d3557;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.patent-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 14px 35px rgba(0, 0, 0, 0.10);
}
.patent-date {
    color: #1d3557;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 10px;
    letter-spacing: 0.03em;
}
.patent-card h3 {
    margin: 0 0 18px 0;
    color: #1d3557;
    font-size: 1.25rem;
    line-height: 1.45;
}
.patent-inventors {
    color: #555;
    line-height: 1.7;
    margin-bottom: 20px;
}
.patent-description {
    border-top: 1px solid #e5e7eb;
    padding-top: 16px;
    margin-top: 10px;
}
.patent-description summary {
    cursor: pointer;
    color: #1d3557;
    font-weight: 600;
    list-style: none;
}
.patent-description summary::-webkit-details-marker {
    display: none;
}
.patent-description summary::after {
    content: "+";
    float: right;
    font-size: 1.1rem;
    font-weight: 400;
}
.patent-description[open] summary::after {
    content: "-";
}
.patent-description p {
    margin-top: 16px;
    color: #555;
    line-height: 1.8;
}
.patent-link {
    display: inline-block;
    margin-top: 20px;
    color: #1d3557;
    font-weight: 500;
    text-decoration: none;
}
.patent-link:hover {
    text-decoration: underline;
}
@media (max-width: 800px) {
    .patent-list {
        grid-template-columns: 1fr;
    }
}
/* ==========================================================
   Astrophotography
========================================================== */
.astrophotography-observatory{
    text-align:center;
    margin:0 auto 25px;
}
.astrophotography-observatory a {
    color: #1d3557;
    text-decoration: none;
    font-weight: 500;
}
.astrophotography-observatory a:hover {
    text-decoration: underline;
}
.astro-category {
    margin-top: 65px;
}
.astro-category h3 {
    color: #1d3557;
    font-size: 1.5rem;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 1px solid #e5e7eb;
}
.astro-gallery {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.astro-card {
    background: #ffffff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.astro-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 14px 35px rgba(0, 0, 0, 0.10);
}
.astro-card > a {
    display: block;
    overflow: hidden;
}
.astro-card img {
    display: block;
    width: 100%;
    height: 240px;
    object-fit: cover;
    transition: transform 0.35s ease;
}
.astro-card:hover img {
    transform: scale(1.03);
}
.astro-info {
    padding: 20px;
}
.astro-info h4 {
    color: #1d3557;
    margin: 0 0 10px 0;
    line-height: 1.4;
}
.astro-info p {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.6;
    margin: 0;
}
.astro-empty {
    color: #777;
    font-style: italic;
    text-align: center;
    padding: 30px;
    border: 1px dashed #d5d9df;
    border-radius: 10px;
}
.astro-lightbox {
    display: none;
    position: fixed;
    z-index: 2000;
    inset: 0;
    background: rgba(0, 0, 0, 0.92);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    padding: 40px;
}
.astro-lightbox.active {
    display: flex;
}
.astro-lightbox img {
    max-width: 92vw;
    max-height: 82vh;
    object-fit: contain;
}
.astro-lightbox p {
    color: #ffffff;
    margin: 18px 0 0 0;
    text-align: center;
}
.lightbox-close {
    position: absolute;
    top: 20px;
    right: 30px;
    background: none;
    border: none;
    color: #ffffff;
    font-size: 2.5rem;
    cursor: pointer;
}
@media (max-width: 1000px) {
    .astro-gallery {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 650px) {
    .astro-gallery {
        grid-template-columns: 1fr;
    }

    .astro-card img {
        height: auto;
    }

    .astro-lightbox {
        padding: 20px;
    }
}
/* ==========================================================
   Observatory
========================================================== */
.observatory {
    margin: 20px auto 60px;
    text-align: center;
}
.observatory h3 {
    color: #1d3557;
    font-size: 1.4rem;
    margin-bottom: 8px;
}
.observatory-gallery {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
    max-width: 900px;
    margin: 0 auto;
}
.observatory-gallery a {
    display: block;
    overflow: hidden;
    border-radius: 12px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
}
.observatory-gallery img {
    display: block;
    width: 100%;
    height: 280px;
    object-fit: cover;
    transition: transform 0.35s ease;
}
.observatory-gallery a:hover img {
    transform: scale(1.03);
}
@media (max-width: 650px) {
    .observatory-gallery {
        grid-template-columns: 1fr;
    }
    .observatory-gallery img {
        height: auto;
    }
}
/* ==========================================================
   Underwater-Exploration
========================================================== */
.dive-intro {
    max-width: 800px;
    margin: 0 auto 45px;
    text-align: center;
}
.dive-location {
    margin-bottom: 60px;
}
.dive-location-header {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-bottom: 28px;
    padding-bottom: 15px;
    border-bottom: 1px solid #e5e7eb;
}
.dive-location-header img {
    width: auto;
    height: 42px;
    border-radius: 3px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}
.dive-location-header h3 {
    margin: 0;
    color: #1d3557;
    font-size: 1.35rem;
}
.dive-entry {
    margin-bottom: 38px;
}
.dive-entry h4 {
    margin: 0 0 5px;
    color: #1d3557;
    font-size: 1.05rem;
}
.dive-entry p {
    margin: 0 0 18px;
    color: #4b5563;
}
.dive-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
    gap: 14px;
}
.dive-gallery a {
    display: block;
    overflow: hidden;
    border-radius: 10px;
    box-shadow: 0 5px 18px rgba(0,0,0,0.08);
}
.dive-gallery img {
    display: block;
    width: 100%;
    aspect-ratio: 4 / 3;
    object-fit: cover;
    transition: transform 0.35s ease;
}
.dive-gallery a:hover img {
    transform: scale(1.04);
}
@media (max-width: 600px) {
    .dive-location-header {
        gap: 12px;
    }
    .dive-location-header img {
        height: 34px;
    }
    .dive-location-header h3 {
        font-size: 1.15rem;
    }
    .dive-gallery {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
}
/* ==========================================================
   Links
========================================================== */
.links-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 45px 30px;
    margin-top: 40px;
}
.link-category h3 {
    color: #1d3557;
    font-size: 1.3rem;
    margin: 0 0 18px 0;
    padding-bottom: 10px;
    border-bottom: 1px solid #e5e7eb;
}
.link-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    background: #ffffff;
    padding: 18px 22px;
    margin-bottom: 12px;
    border-radius: 10px;
    border-left: 3px solid #1d3557;
    box-shadow: 0 5px 18px rgba(0, 0, 0, 0.05);
    color: #333;
    text-decoration: none;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.link-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.09);
}
.link-card strong {
    display: block;
    color: #1d3557;
    font-size: 0.98rem;
    line-height: 1.4;
}
.link-card small {
    display: block;
    margin-top: 4px;
    color: #777;
    font-size: 0.85rem;
    line-height: 1.4;
}
.link-arrow {
    flex-shrink: 0;
    color: #1d3557;
    font-size: 1.2rem;
    transition: transform 0.25s ease;
}
.link-card:hover .link-arrow {
    transform: translateX(4px);
}
@media (max-width: 800px) {
    .links-grid {
        grid-template-columns: 1fr;
        gap: 35px;
    }
}
/* ==========================================================
   Contact
========================================================== */
.contact-content {
    max-width: 750px;
    margin: 0 auto;
}
.contact-content > p {
    text-align: center;
    color: #555;
    line-height: 1.7;
    margin-bottom: 30px;
}
.contact-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    background: #ffffff;
    padding: 20px 24px;
    border-radius: 10px;
    border-left: 3px solid #1d3557;
    box-shadow: 0 5px 18px rgba(0, 0, 0, 0.05);
    color: #333;
    text-decoration: none;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.contact-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.09);
}
.contact-card strong {
    display: block;
    color: #1d3557;
    font-size: 1rem;
}
.contact-card small {
    display: block;
    margin-top: 4px;
    color: #777;
    font-size: 0.85rem;
}
.contact-arrow {
    flex-shrink: 0;
    color: #1d3557;
    font-size: 1.2rem;
    transition: transform 0.25s ease;
}
.contact-card:hover .contact-arrow {
    transform: translateX(4px);
}
/* ==========================================================
   Footer
========================================================== */
.site-footer{
    background:#12395b;
    color:#fff;
    text-align:center;
    padding:35px 0;
    margin-top:80px;
}
.site-footer p{
    font-size:.9rem;
}
/* ==========================================================
   Responsive
========================================================== */
@media(max-width:1000px){
    .about-grid{
        grid-template-columns:1fr;
        gap:50px;
    }
    .about-image{
        max-width:400px;
        margin:auto;
    }
    .hero-content h1{
        font-size:2.5rem;
    }
    .main-nav ul{
        gap:20px;
    }
}
@media(max-width:768px){
    .site-header .container{
        flex-direction:column;
        justify-content:center;
        height:auto;
        padding:18px 0;
    }
    .main-nav{
        margin-top:15px;
    }
    .main-nav ul{
        flex-wrap:wrap;
        justify-content:center;
        gap:12px;
    }
    .hero{
        height:45vh;
        min-height:360px;
        margin-top:120px;
    }
    .hero-content h1{
        font-size:2rem;
    }
    .hero-content p{
        font-size:1rem;
    }
    .section{
        padding:70px 0;
    }
    .section-title h2{
        font-size:2rem;
    }
}
@media(max-width:480px){
    body{
        font-size:.95rem;
    }
    .hero-content h1{
        font-size:1.7rem;
    }
    .button{
        padding:12px 28px;
    }
    .card,
    .publication-card{
        padding:22px;
    }
}
/* ==========================================================
   Fade In Animation
========================================================== */
.card,
.publication-card,
.about-text,
.about-image{
    opacity:0;
    transform:translateY(35px);
    transition:.7s;
}
.visible{
    opacity:1;
    transform:translateY(0);
}