/* CSS Reset & Variables */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #7f8c8d;
    --accent-color: #2980b9;
    --background-light: #ffffff;
    --background-off-white: #f8f9fa;
    --background-dark: #34495e;
    --text-color: #333333;
    --text-light: #ecf0f1;

    --font-heading: 'Inter', sans-serif;
    --font-body: 'Lora', serif;

    --nav-height: 70px;
    --container-width: 1000px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--background-light);
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    margin-bottom: 1rem;
    color: var(--primary-color);
}

a {
    text-decoration: none;
    color: var(--accent-color);
    transition: color 0.3s ease;
}

a:hover {
    color: var(--primary-color);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
}

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

.bg-dark {
    background-color: var(--background-dark);
}

.text-white {
    color: var(--text-light);
}

.link-white {
    color: var(--text-light);
    text-decoration: underline;
}

.link-white:hover {
    color: #bdc3c7;
}

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

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    font-weight: 700;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(5px);
}

.nav-container {
    width: 100%;
    max-width: var(--container-width);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.nav-logo {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    font-family: var(--font-heading);
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.95rem;
}

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

.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    transition: all 0.3s ease-in-out;
    background-color: var(--primary-color);
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding-top: var(--nav-height);
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.subtitle {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--secondary-color);
    font-weight: 300;
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* About Section */
.about-container {
    display: flex;
    align-items: center;
    gap: 4rem;
}

.about-text {
    flex: 1;
}

.about-image {
    flex: 0 0 300px;
}

.about-image img {
    width: 100%;
    border-radius: 4px;
    /* Minimalist rounded corner */
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    object-fit: cover;
}

/* Publications Scroll */
.publications-scroll-container {
    max-height: 600px;
    overflow-y: auto;
    padding-right: 1rem;
    border-left: 1px solid #ddd;
    padding-left: 2rem;
}

/* Custom Scrollbar for Publications */
.publications-scroll-container::-webkit-scrollbar {
    width: 6px;
}

.publications-scroll-container::-webkit-scrollbar-track {
    background: #f1f1f1;
}

.publications-scroll-container::-webkit-scrollbar-thumb {
    background: #bdc3c7;
    border-radius: 3px;
}

.publications-scroll-container::-webkit-scrollbar-thumb:hover {
    background: #95a5a6;
}

.publication-item {
    margin-bottom: 2.5rem;
}

.pub-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.pub-meta {
    font-style: italic;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.pub-abstract {
    font-size: 0.95rem;
    color: #555;
    text-align: justify;
}

/* Work in Progress */
.wip-item {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid #eee;
}

.wip-item:last-child {
    border-bottom: none;
}

/* CV Button */
.cv-summary {
    max-width: 600px;
    margin: 0 auto 2rem;
    font-size: 1.1rem;
}

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-transform: uppercase;
    font-family: var(--font-heading);
    font-weight: 600;
    letter-spacing: 1px;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #34495e;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(44, 62, 80, 0.3);
    color: white;
}

/* Contact */
.contact-links p {
    margin: 0.5rem 0;
    font-size: 1.1rem;
}

.social-icons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.social-icon-link img {
    width: 50px;
    height: 50px;
    object-fit: cover;
    /* Ensures images fill the square without distortion if aspect ratio differs, crops if necessary. Safe for profile pics/icons. */
    border-radius: 8px;
    /* Soft rounding */
    transition: transform 0.3s ease;
    background-color: white;
    /* background for transparent images if any, ensures visibility on dark bg */
}

.social-icon-link img:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

/* Footer */
.footer {
    padding: 2rem 0;
    background-color: #f1f1f1;
    color: #7f8c8d;
    font-family: var(--font-heading);
    font-size: 0.9rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .hamburger {
        display: block;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: var(--nav-height);
        flex-direction: column;
        background-color: white;
        width: 100%;
        height: calc(100vh - var(--nav-height));
        /* Full height minus navbar */
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 10px rgba(0, 0, 0, 0.05);
        padding-top: 2rem;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-item {
        margin: 1.5rem 0;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .about-container {
        flex-direction: column;
        text-align: center;
    }

    .about-image {
        width: 100%;
        max-width: 300px;
    }

    .publications-scroll-container {
        padding-right: 0;
        padding-left: 0;
        border-left: none;
        max-height: none;
        /* Let it expand on mobile for better UX? Or keep scroll. Requirements said "sticky while rest of page remains". Keeping height. */
        /* Actually on mobile fixed height areas can be annoying. 
           But to follow "specific section... designated area", I'll keep it but maybe increase height or adjust padding. */
    }
}