/* CSS Styles */
:root {
    --primary-color: #005f73;
    --secondary-color: #94d2bd;
    --text-dark: #333;
    --light-bg: #f4f4f9;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    margin: 0;
    color: var(--text-dark);
    background-color: #fdfdfd; 
}

/* --- NAVIGATION --- */
nav {
    display: flex;
    justify-content: flex-end; 
    align-items: center;
    background: #fff;
    padding: 1rem 5%;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

/* Default Menu Links (Desktop) */
.nav-links {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}
.nav-links li {
    margin-left: 20px;
}
.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: bold;
}

/* Mobile Hamburger Icon */
.hamburger {
    display: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
}
.hamburger .bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-dark);
    transition: all 0.3s ease;
}

/* Mobile Styles */
@media (max-width: 768px) {
    
    /* 1. Make the Top Bar Transparent */
    nav {
        background: transparent; /* Removes white background */
        box-shadow: none;        /* Removes the bar shadow */
    }

    /* 2. Transparent 3-Bar Button */
    .hamburger {
        display: flex;
        opacity: 0.7;       /* Makes the button slightly transparent */
        background: rgba(255, 255, 255, 0.2); /* Optional: tiny background box */
        padding: 5px;       /* Space for the tiny background */
        border-radius: 5px; /* Round corners for the button */
    }
    
    /* Ensure bars are visible (Optional: change to white if background is dark) */
    .hamburger .bar {
        background-color: #333; /* Keep dark, or change to white if needed */
    }

    /* 3. Hero Section Shadows */
    .hero h1, 
    .hero p {
        text-shadow: 0 5px 15px rgba(0, 0, 0, 0.7); /* Strong shadow for text */
    }

    .hero-btn {
        box-shadow: 0 10px 20px rgba(0,0,0,0.4); /* Stronger shadow for button */
    }

    /* 4. Dropdown Menu (Right Aligned & Transparent) */
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        right: 0;
        width: 100%;

        /* Transparent Background */
        background-color: rgba(255, 255, 255, 0.85); 
        backdrop-filter: blur(8px); 

        flex-direction: column;
        align-items: flex-end; /* Right Align */
        padding-right: 30px;
        
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        padding-top: 20px;
        padding-bottom: 20px;
    }

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

    .nav-links li {
        margin: 15px 0; 
        width: 100%; 
        text-align: right; 
    }
}
/* --- HERO SECTION --- */
.hero {
    background: linear-gradient(rgba(0, 95, 115, 0.6), rgba(0, 95, 115, 0.6)), url('cover.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color: white;
    padding: 6rem 5%;
    text-align: center;
}
.hero h1 {
    margin: 0;
    font-size: 2.5rem;
}
.hero p {
    font-size: 1.2rem;
    margin-top: 10px;
}

/* --- GENERAL SECTIONS --- */
.container {
    padding: 2rem 5%;
    max-width: 1000px;
    margin: auto;
}
h2 {
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 10px;
    margin-top: 2rem;
    color: var(--primary-color);
}

/* --- SKILLS --- */
.skills-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.skill-tag {
    background: var(--secondary-color);
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 0.9rem;
}

/* --- PUBLICATIONS (3D Effect + Round Edges) --- */
.publication-item {
    background: white;
    border-left: 5px solid var(--primary-color);
    padding: 25px;
    margin-bottom: 30px;
    
    /* Round Shaped Edges */
    border-radius: 15px; 
    
    /* Layout */
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    gap: 25px;
    
    /* 3D Transition */
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); 
    position: relative;
    top: 0;
    
    /* Default State */
    box-shadow: 0 5px 10px rgba(0,0,0,0.05);
    border: 1px solid #f0f0f0;

    /* Fix for smooth edges during animation */
    backface-visibility: hidden;
    transform: translateZ(0); 
    overflow: hidden; 
}

/* 3D Hover Effect */
.publication-item:hover {
    transform: translateY(-10px); 
    box-shadow: 0 20px 40px rgba(0, 95, 115, 0.2); 
    border-color: var(--secondary-color);
}

.pub-details {
    flex: 1;
}

/* Graphical Abstract Image */
.pub-image {
    width: 200px;
    height: 120px;
    object-fit: cover;      
    border-radius: 10px;    
    border: 1px solid #eee; 
    transition: transform 0.4s ease;
    background-color: #f9f9f9;
}

.publication-item:hover .pub-image {
    transform: scale(1.05); 
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

/* Mobile Publication Layout */
@media (max-width: 600px) {
    .publication-item {
        flex-direction: column; 
        align-items: flex-start;
    }
    .pub-image {
        width: 100%;       
        height: auto;     
        margin-top: 15px;   
    }
}

/* --- CERTIFICATES (Sea Water Effect) --- */
.certificates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
    gap: 20px;
    margin-top: 20px;
}

.certificate-card {
    background: white;
    padding: 25px;
    border-radius: 12px; 
    /* Sea Water Shadow */
    box-shadow: 0 4px 15px rgba(0, 150, 170, 0.15); 
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #e0f7fa; 
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.certificate-card:hover {
    transform: translateY(-5px); 
    box-shadow: 0 10px 25px rgba(0, 150, 170, 0.3);
}

.certificate-card h3 {
    margin: 0 0 10px 0;
    font-size: 1.1rem;
    color: #005f73;
    font-weight: 700;
}

.certificate-card p {
    font-size: 0.9rem;
    color: #555;
    margin: 0 0 20px 0;
    line-height: 1.4;
}

.cert-btn {
    display: inline-flex;
    align-items: center;
    font-size: 0.9rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.2s;
}
.cert-btn::before {
    content: "★ ";
    margin-right: 5px;
}
.cert-btn:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* --- CONTACT SECTION (Clean Split Layout) --- */

/* Main Layout */
.contact-layout {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 40px;
    padding: 30px 0;
    flex-wrap: wrap; /* Stacks on mobile */
}

/* Left Side */
.contact-left {
    flex: 1;
    min-width: 300px;
}
.contact-left h2 {
    font-size: 2rem;
    margin-bottom: 25px;
    border: none;
    padding: 0;
}
.contact-buttons-row {
    display: flex;
    gap: 15px;
}

/* Button Styles (Pill Shape) */
.btn-contact {
    display: inline-flex;
    align-items: center;
    gap: 10px; 
    padding: 12px 35px;
    border-radius: 50px; 
    text-decoration: none;
    font-weight: bold;
    font-size: 1rem;
    transition: all 0.3s ease;
}

/* Email Button */
.btn-email {
    background-color: white;
    color: #005f73 !important; 
    border: 2px solid #005f73;
}
.btn-email:hover {
    background-color: #005f73;
    color: white !important;
    transform: translateY(-3px);
}

/* Right Side: Social Card */
.social-card {
    background: white;
    padding: 25px 40px;
    border-radius: 20px; 
    box-shadow: 0 5px 20px rgba(0,0,0,0.05); 
    flex: 1;
    min-width: 300px;
    border: 1px solid #f0f0f0;
}
.social-card h3 {
    margin: 0 0 15px 0;
    font-size: 1.1rem;
    color: #333;
    font-weight: 800;
}
.social-links-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    align-items: center;
}
.social-links-grid a {
    text-decoration: none;
    color: #444;
    font-weight: 600;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: color 0.2s;
}
.social-links-grid a:hover {
    color: var(--primary-color);
}

/* Contact Mobile Fix */
@media (max-width: 768px) {
    .contact-layout {
        flex-direction: column;
        align-items: flex-start;
    }
    .contact-buttons-row {
        width: 100%;
    }
    .btn-contact {
        flex: 1;
        justify-content: center;
    }
    .social-card {
        width: 100%;
        box-sizing: border-box;
    }
}

/* --- FOOTER --- */
footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 20px;
    margin-top: 40px;
}

/* --- ELEGANT SKILLS SECTION --- */

.skills-wrapper {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); /* Responsive Grid */
    gap: 25px;
    margin-top: 20px;
}

.skill-category {
    background: white;
    padding: 25px;
    border-radius: 15px; /* Soft round corners */
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    border: 1px solid #f4f4f9;
    transition: transform 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px); /* Lifts up slightly on hover */
    box-shadow: 0 10px 25px rgba(0, 95, 115, 0.15); /* Tinted shadow */
    border-color: var(--secondary-color);
}

.skill-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 10px;
}

.skill-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
    background: #e0f7fa;
    padding: 10px;
    border-radius: 10px;
    width: 25px;
    height: 25px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.skill-header h3 {
    margin: 0;
    font-size: 1.2rem;
    color: #333;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap; /* Allows tags to flow to next line */
    gap: 10px;
}

.skill-tags span {
    background-color: #f8f9fa;
    color: #555;
    padding: 8px 15px;
    border-radius: 20px; /* Pill shape tags */
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid #eee;
    transition: all 0.2s ease;
}

/* Hover effect for individual tags */
.skill-tags span:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* --- ELEGANT RESEARCH INTERESTS --- */

.interests-grid {
    display: grid;
    /* This ensures cards are at least 180px wide but stretch to fill space */
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); 
    gap: 25px;
    margin-top: 30px;
}

.interest-card {
    background: white;
    padding: 30px 20px;
    border-radius: 15px;
    text-align: center; /* Centers the icon and text */
    border: 1px solid #f0f0f0;
    box-shadow: 0 5px 15px rgba(0,0,0,0.03);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* Hover Effect: Float up + Shadow + Border Color */
.interest-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 30px rgba(0, 95, 115, 0.1);
    border-color: var(--secondary-color);
}

/* The Circle behind the Icon */
.icon-box {
    width: 60px;
    height: 60px;
    background-color: #e0f7fa; /* Light cyan bg */
    border-radius: 50%; /* Perfect circle */
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
    transition: background-color 0.3s ease;
}

.interest-card:hover .icon-box {
    background-color: var(--primary-color); /* Turns dark blue on hover */
}

/* The Icon Itself */
.icon-box i {
    font-size: 1.5rem;
    color: var(--primary-color);
    transition: color 0.3s ease;
}

.interest-card:hover .icon-box i {
    color: white; /* Turns white on hover */
}

/* The Text */
.interest-card h3 {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
}

/* --- CLICKABLE PUBLICATION TITLES --- */

.pub-title-link {
    text-decoration: none; /* Remove underline */
    color: inherit; /* Keep text dark by default */
    display: block; /* Makes the whole title clickable area larger */
    margin-bottom: 5px;
    transition: color 0.2s ease;
}

.pub-title-link strong {
    font-size: 1.1rem; /* Make title slightly larger */
    line-height: 1.4;
}

/* Hover Effect: Changes color to Primary Blue */
.pub-title-link:hover {
    color: var(--primary-color); 
    text-decoration: underline; /* Adds underline on hover like Google Scholar */
}