/* style.css (Maroon & Gold Palette) */

/* --- 1. Google Fonts Import --- */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@600;700&family=Source+Serif+Pro:wght@400;600&display=swap');

/* --- 2. CSS Variables (New Palette & Fonts) --- */
:root {
    --primary-color: #570036; /* User's Requested Maroon */
    --primary-darker: #3d0026; /* Darker Maroon */
    --secondary-color: #fbf9fa; /* Warmer, light gray */
    --accent-color: #c78c36; /* Muted Gold/Ochre */
    --text-color: #212529; /* Near black for better contrast */
    --light-text-color: #FFFFFF;
    
    --font-heading: 'Poppins', sans-serif; /* Modern, clean heading */
    --font-body: 'Source Serif Pro', serif; /* Elegant, readable body */
    --shadow-light: 0 5px 15px rgba(0, 0, 0, 0.07);
    --shadow-hover: 0 8px 25px rgba(0, 0, 0, 0.1);
}

/* --- 3. General Body & Layout Styling --- */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 120px; 
}
body {
    font-family: var(--font-body);
    color: var(--text-color);
    line-height: 1.8;
    margin: 0;
    background-color: #FFFFFF;
    font-size: 18px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='40' height='40' viewBox='0 0 40 40'%3E%3Cg fill-rule='evenodd'%3E%3Cg fill='%23e9ecef' fill-opacity='0.4'%3E%3Cpath d='M0 38.59l2.83-2.83 1.41 1.41L1.41 40H0v-1.41zM0 1.4l2.83 2.83 1.41-1.41L1.41 0H0v1.41zM38.59 40l-2.83-2.83 1.41-1.41L40 38.59V40h-1.41zM40 1.41l-2.83 2.83-1.41-1.41L38.59 0H40v1.41zM20 18.6l2.83-2.83 1.41 1.41L21.41 20l2.83 2.83-1.41 1.41L20 21.41l-2.83 2.83-1.41-1.41L18.59 20l-2.83-2.83 1.41-1.41L20 18.59z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}
section {
    padding: 80px 0;
}
main > section:nth-of-type(even) {
    background-color: var(--secondary-color);
}
hr.separator { 
    border: 0; 
    height: 1px; 
    background: #dee2e6; 
    margin: 60px 0; 
}

/* --- 4. Typography --- */
h1, h2, h3 { font-family: var(--font-heading); color: var(--primary-color); margin-top: 0; font-weight: 700; }
h1 { font-size: 3.2rem; line-height: 1.2; }
h2 { font-size: 2.5rem; text-align: center; margin-bottom: 50px;}
h2 small {
  font-size: medium;
  font-weight: normal;
  color: #666; /* A lighter gray color */
  margin-left: 8px; /* Adds a little space after the main title */
}
h3 { font-size: 1.6rem; font-weight: 600; }
a { color: var(--accent-color); text-decoration: none; transition: all 0.3s ease; }
a:hover { color: var(--primary-color); }
strong { font-weight: 600; }

/* --- 5. Header & Navigation Bar (CORRECTED) --- */
/* --- NEW: Dropdown Menu Styles --- */
/* --- Dropdown Menu Styles (Corrected & Complete) --- */
.main-nav li.dropdown {
    position: relative; /* Essential for positioning the submenu */
}

.main-nav li.dropdown > a {
    display: inline-flex; /* Treat link as flex container */
    align-items: center;  /* Vertically align text and arrow */
    gap: 8px;           /* Space between text and arrow */
    position: relative;   /* Keep for dropdown positioning if needed */
    padding-right: 0;     /* Reset padding */
}

.main-nav li.dropdown > a .arrow {
    font-size: 0.7em;       /* Adjust arrow size */
    line-height: 1;      /* Prevent extra line height issues */
    /* No absolute positioning needed */
}

.dropdown-menu {
    display: none;/* Hides the menu by default */
    position: absolute;
    top: 100%; /* Positions below the parent link */
    left: 0; /* Aligns with the left edge of the parent */
    background-color: #ffffff;
    border: 1px solid #e9ecef;
    border-top: none; /* Remove top border for seamless look */
    border-radius: 0 0 8px 8px; 
    box-shadow: var(--shadow-light);
    min-width: 200px; 
    z-index: 1001; 
    padding: 10px 0;
    list-style: none;
    margin: 0; 
    overflow: hidden;
}

/* This rule makes the menu visible ONLY when hovering the parent LI */
.main-nav li.dropdown:hover > .dropdown-menu {
    display: block; 
}

.dropdown-menu li {
    margin: 0; 
    width: 100%;
}

.dropdown-menu li a {
    display: block;
    padding: 10px 20px;
    font-weight: 600;
    color: var(--text-color);
    text-transform: none; 
    font-size: 0.9rem;
    letter-spacing: 0;
    white-space: nowrap;
    border-bottom: none; 
}
/* Ensure the main nav underline effect doesn't apply here */
.dropdown-menu li a::after {
   display: none;
}

.dropdown-menu li a:hover {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}
.main-header {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 1rem 0;
    border-bottom: 1px solid #e9ecef;
    position: sticky;
    top: 0;
    z-index: 1000;
}
.main-header .container { display: flex; justify-content: space-between; align-items: center; }
.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    white-space: nowrap; /* Keeps name on one line */
    flex-shrink: 0; /* Prevents shrinking */
    text-decoration: none; /* Ensure no underline on the link */
}.main-nav { flex-grow: 1; display: flex; justify-content: flex-end; }
.main-nav > ul { list-style: none; display: flex; margin: 0; padding: 0; }
.main-nav li { margin-left: 20px; } /* Reduced margin */
.main-nav a { font-weight: 600; text-transform: uppercase; font-size: .8rem; letter-spacing: 0.5px; text-decoration: none; color: var(--text-color); padding-bottom: 8px; position: relative; } /* Reduced font size */
.main-nav a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 3px; background-color: var(--primary-color); transition: width 0.3s ease; }
.main-nav a:hover::after, .main-nav a.active::after { width: 100%; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; font-size: 1.8rem; color: var(--primary-color); }

/* --- 6. Homepage & Page Header Styles --- */
.hero { position: relative; padding: 120px 0; background-image: url('https://source.unsplash.com/random/1600x900/?molecule,network'); background-size: cover; background-position: center; color: var(--light-text-color); }
.hero::before { content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: linear-gradient(60deg, rgba(87, 0, 54, 0.9), rgba(61, 0, 38, 0.9)); z-index: 1; } /* Updated gradient to match maroon */
.hero .container { position: relative; z-index: 2; display: flex; align-items: center; gap: 50px; }
.hero h1, .hero p { color: var(--light-text-color); text-shadow: 1px 1px 3px rgba(0,0,0,0.2); }
.hero-image { flex: 1; max-width: 280px; }
.hero-image img { width: 100%; border-radius: 50%; border: 6px solid hsla(0,0%,100%,.7); box-shadow: 0 10px 30px rgba(0,0,0,.2); }
.hero-text { flex: 2; }
.hero-text h1 { margin-bottom: 15px; }
.hero-text .professional-title { display: inline-block; background-color: rgba(255, 255, 255, 0.15); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); padding: 8px 18px; border-radius: 30px; border: 1px solid rgba(255, 255, 255, 0.2); font-family: var(--font-heading); font-size: 1rem; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; margin: 0 0 20px 0; color: var(--light-text-color); }
.hero-text .research-statement { font-family: var(--font-body); font-size: 1.5rem; font-style: italic; color: hsla(0,0%,100%,.95); border-left: 4px solid var(--accent-color); padding-left: 25px; margin: 25px 0 0 0; }
.page-header { background: linear-gradient(60deg, var(--primary-color), var(--primary-darker)); padding: 70px 0; text-align: center; }
.page-header h1 { font-size: 3rem; margin: 0; color: var(--light-text-color); }
.welcome-message { font-family: var(--font-heading); font-size: 2rem; font-weight: 700; color: var(--primary-color); margin-bottom: 25px; }

/* --- 7. Generic Card & Component Styles --- */
.btn { display: inline-block; background: linear-gradient(60deg, var(--accent-color), #a0702b); color: var(--light-text-color); padding: 14px 28px; border-radius: 30px; font-weight: 700; text-transform: uppercase; font-size: .9rem; border: none; transition: transform .3s ease, box-shadow .3s ease; box-shadow: var(--shadow-light); }
.btn:hover { transform: translateY(-3px) scale(1.05); box-shadow: 0 8px 25px rgba(199, 140, 54, 0.3); } /* Updated shadow color */
.pillar-card, .project-card, .course-card, .service-item, .impact-item { background-color: #FFFFFF; border: 1px solid #e9ecef; border-radius: 12px; padding: 35px; box-shadow: var(--shadow-light); transition: transform 0.3s ease, box-shadow 0.3s ease; }
.pillar-card:hover, .project-card:hover, .course-card:hover, .service-item:hover, .impact-item:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }
.impact-grid, .pillars-grid, .projects-grid, .courses-grid, .contact-grid, .cv-columns, .collaborator-columns { display: grid; gap: 30px; }
.impact-grid { grid-template-columns: repeat(4, 1fr); }
.pillars-grid { grid-template-columns: repeat(3, 1fr); }
.projects-grid, .courses-grid { grid-template-columns: repeat(2, 1fr); }
.contact-grid { grid-template-columns: 1fr 1fr; }
.cv-columns { grid-template-columns: repeat(3, 1fr); }
.impact-item { text-align: center; }
.impact-item:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }
.course-card .program {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--primary-color);
    color: var(--light-text-color);
    border-radius: 20px;
    font-family: var(--font-heading);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: -15px; /* Pulls it up slightly */
    margin-bottom: 15px;
}

.course-card .key-topics {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid #e9ecef;
}

.course-card .key-topics strong {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    color: var(--primary-color);
    display: block;
    margin-bottom: 8px;
}

.course-card .key-topics span {
    font-size: 0.9rem;
    color: #6c757d;
}
/* --- 8. Page Specific Styles --- */
.intro-section, .narrative-section, .philosophy-section, .research-overview, .mentorship-section .container, .collaboration-section .container {max-width: 1100px; margin: 0 auto;}
.overview-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 50px; align-items: start; }
.overview-interests { padding-left: 30px; border-left: 2px solid var(--primary-color); }
.interests-list { list-style: none; padding: 0; margin: 0; }
.interests-list li { margin-bottom: 12px; padding-left: 25px; position: relative; font-weight: 600; }
.interests-list li::before { content: "→"; position: absolute; left: 0; color: var(--primary-color); font-weight: 700; }
.project-card .status, .course-card .level { font-size: 0.9rem; font-weight: 600; color: #6c757d; margin-top: -15px; margin-bottom: 15px; }
.project-card .status { display: inline-block; padding: 4px 12px; border-radius: 20px; align-self: flex-start; }
.project-card .status.ongoing { background-color: #d1e7dd; color: #0f5132; }
.project-card .status.completed { background-color: #e2e3e5; color: #41464b; }
.project-card .funding { font-size: 0.9rem; font-weight: 600; color: #495057; margin-top: auto; padding-top: 15px; border-top: 1px solid #dee2e6; }
.impact-item .number { font-family: var(--font-heading); font-size: 3.5rem; font-weight: 700; color: var(--accent-color); line-height: 1; margin-bottom: 10px; }
.impact-item .label { display: inline-block; padding: 4px 12px; background-color: #e9ecef; border-radius: 20px; font-family: var(--font-heading); text-transform: uppercase; font-size: 0.8rem; letter-spacing: 0.5px; color: #495057; font-weight: 700; }
.impact-item .description { display: none; }
.publication-list { list-style: none; padding-left: 0; counter-reset: pub-counter; }
.publication-list li { padding-left: 50px; position: relative; padding-bottom: 60px; margin-bottom: 25px; border-bottom: 1px solid #e9ecef; }
.publication-list li::before { counter-increment: pub-counter; content: counter(pub-counter); position: absolute; left: 0; top: 0; font-family: var(--font-heading); font-size: 2rem; font-weight: 700; color: var(--primary-color); opacity: 0.2; }
.publication-list .citation { display: block; }
/* Find and replace this rule */
.publication-list li::after {
    content: 'Published: ' attr(data-year); /* Adds text before the year */
    position: absolute;
    bottom: 25px;            /* Positions it 25px from the very bottom */
    left: 50px;             /* Aligns it with the citation text (respecting the number) */
    
    /* Subtle styling */
    font-family: var(--font-body);
    font-style: italic;
    font-size: 0.9rem;
    font-weight: 400;       /* Normal font weight */
    color: #6c757d;         /* A muted gray color */
    
    /* Resetting badge styles */
    background: none;
    border: none;
    padding: 0;
    line-height: 1;
}
.publication-list .journal { font-style: italic; }
.doi-link { display: inline-block; margin-left: 15px; font-size: 0.9rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; background-color: #e9ecef; padding: 6px 14px; border-radius: 20px; color: var(--primary-color); }
.doi-link:hover { background-color: var(--primary-color); color: var(--light-text-color); }
.pub-filters { background-color: #fff; border: 1px solid #dee2e6; border-radius: 8px; padding: 20px; display: flex; gap: 20px; align-items: center; margin-bottom: 40px; }
.pub-filters input, .pub-filters select { padding: 12px; border: 1px solid #ced4da; border-radius: 5px; font-size: 1rem; font-family: var(--font-body); }
.pub-filters input { flex-grow: 1; }
.page-nav { border-top: 1px solid #dee2e6; border-bottom: 1px solid #dee2e6; padding: 10px 0; margin-bottom: 50px; }
.page-nav ul { list-style: none; padding: 0; margin: 0; display: flex; justify-content: center; gap: 15px; }
.page-nav li{ background-color: #e9ecef; padding: 0; border-radius: 20px; color: var(--primary-color);}
.page-nav a { display: block; padding: 8px 20px; font-weight: 600; color: var(--text-color); border-radius: 20px; transition: all 0.3s ease; }
.page-nav a:hover { background-color: var(--primary-color); color: var(--light-text-color); }
.tab-nav { display: flex; border-bottom: 2px solid #dee2e6; margin-bottom: 30px; }
.tab-btn { padding: 15px 25px; cursor: pointer; border: none; background-color: transparent; font-size: 1.1rem; font-weight: 600; color: #6c757d; border-bottom: 3px solid transparent; transition: all 0.3s ease; }
.tab-btn.active, .tab-btn:hover { color: var(--primary-color); }
.tab-btn.active { border-bottom: 3px solid var(--primary-color); }
.tab-pane { display: none; } .tab-pane.active { display: block; }
.service-list, .project-list { list-style: none; padding: 0; margin: 0; }
.service-item, .project-list-item { background-color: #FFFFFF; border: 1px solid #e9ecef; border-radius: 12px; padding: 35px; box-shadow: var(--shadow-light); transition: transform 0.3s ease, box-shadow 0.3s ease; margin-bottom: 20px; }
.service-item:hover, .project-list-item:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }
.service-item .title, .project-title { font-weight: 700; font-size: 1.2rem; display: block; color: var(--primary-color); font-family: var(--font-heading); }
.service-item .details, .project-meta { font-size: 1rem; color: #495057; margin-top: 5px; }
.project-list-item .project-title { text-align: justify; }
/* Add this to style.css for the status badge */
.project-list-item .status {
    display: inline-block;
    padding: 4px 12px;
    font-size: 0.8rem;
    font-weight: 700;
    border-radius: 20px;
    margin-bottom: 10px; /* Space below the badge */
}

.project-list-item .status.ongoing {
    background-color: #d4edda; /* Light Green */
    color: #155724; /* Dark Green */
}
.project-meta .year { font-weight: 600; }
.contact-info-item { margin-bottom: 25px; }
.contact-info-item strong { display: block; color: var(--text-color); font-family: var(--font-heading); margin-bottom: 5px; }
.map-container { border-radius: 12px; overflow: hidden; margin-top: 30px; box-shadow: var(--shadow-light); }
.map-container iframe { width: 100%; height: 350px; border: 0; }
.contact-form .form-group { margin-bottom: 20px; }
.contact-form label { display: block; margin-bottom: 8px; font-weight: 600; }
.contact-form input, .contact-form textarea { width: 100%; padding: 14px; border: 1px solid #ced4da; border-radius: 8px; font-size: 1rem; font-family: var(--font-body); box-sizing: border-box; }
.contact-form textarea { resize: vertical; min-height: 150px; }
.social-card { 
    background: linear-gradient(135deg, #fdf4f8 0%, #ffffff 100%); /* Updated gradient for social card */
    border: 1px solid #dee2e6; 
    border-radius: 12px; 
    padding: 35px; 
    text-align: center; 
    box-shadow: var(--shadow-light); 
}
.social-links { list-style: none; padding: 0; margin: 0; display: flex; gap: 25px; justify-content: center; }
.social-links a { font-size: 2.5rem; color: var(--primary-color); transition: transform 0.3s ease, color 0.3s ease; }
.social-links a:hover { transform: scale(1.15) translateY(-5px); }
/* Brand colors on hover */
.social-links a[title="LinkedIn"]:hover { color: #0077B5; }
.social-links a[title="Google Scholar"]:hover { color: #4285F4; }
.social-links a[title="ResearchGate"]:hover { color: #00CCBB; }
.social-links a[title="ORCID"]:hover { color: #A6CE39; }
.cv-timeline-section .container { position: relative; }
.cv-timeline-section .container::before { content: ''; position: absolute; width: 4px; background-color: var(--primary-color); opacity: 0.1; top: 120px; bottom: 0; left: 50%; margin-left: -2px; z-index: 0; }
.cv-column { background-color: #ffffff; border: 1px solid #e9ecef; border-radius: 12px; padding: 35px; box-shadow: var(--shadow-light); transition: transform 0.3s ease, box-shadow 0.3s ease; position: relative; }
.cv-column:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }
.cv-column::after { content: ''; position: absolute; width: 20px; height: 20px; top: 45px; left: 50%; transform: translateX(-50%); background-color: white; border: 5px solid var(--primary-color); border-radius: 50%; z-index: 2; }
.cv-column h3 { display: flex; align-items: center; gap: 10px; border-bottom: 2px solid var(--primary-color); padding-bottom: 10px; margin-bottom: 20px; }
.cv-column h3 .icon { font-size: 1.5rem; }
.cv-column ul { list-style: none; padding: 0; margin: 0; }
.cv-column li { padding-bottom: 20px; margin-bottom: 20px; border-bottom: 1px solid #e9ecef; }
.cv-column li:last-child { border-bottom: none; }
.cv-column strong { display: block; font-size: 1.1rem; font-family: var(--font-heading); color: var(--text-color); font-weight: 600; }
.cv-column span { font-size: 1rem; color: #6c757d; }
.collaborator-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; position: relative; padding: 0 20px; }
.collaborator-columns::before { content: ''; position: absolute; left: 50%; top: 0; bottom: 0; width: 1px; background-color: #dee2e6; }
.collaborators-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.collaborator-card { background-color: #FFFFFF; border: 1px solid #e9ecef; border-radius: 12px; padding: 25px; box-shadow: var(--shadow-light); transition: transform 0.3s ease, box-shadow 0.3s ease; text-align: center; }
.collaborator-card:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }
.collaborator-photo img { width: 100px; height: 100px; border-radius: 50%; object-fit: cover; margin-bottom: 15px; border: 4px solid #fff; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
.collaborator-name { font-family: var(--font-heading); font-size: 1.2rem; font-weight: 700; margin: 0; color: var(--primary-color); }
.collaborator-affiliation { font-size: 0.9rem; color: #6c757d; margin: 5px 0 15px 0; }
.collaborator-link a { display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 0.9rem; }

/* --- 9. Footer --- */
footer { background: linear-gradient(60deg, var(--primary-darker), #29001a); color: rgba(255, 255, 255, 0.85); padding: 50px 0; text-align: center; } /* Updated gradient */
footer a { color: #fcedc2   ; font-weight: 400; text-decoration: underline; text-decoration-color: rgba(255,255,255,0.3); } /* This yellow works well with maroon */
footer a:hover {color: #f6edd2 ; font-weight: 600;text-decoration-color: var(--accent-color); }

/* --- 10. Animation on Scroll --- */
.fade-in-section, .fade-in-item { opacity: 0; transform: translateY(30px); transition: opacity 0.8s ease-out, transform 0.8s ease-out; }
.fade-in-section.visible, .fade-in-item.visible { opacity: 1; transform: translateY(0); }

/* --- NEW: Login Page Styles --- */
.login-container {
    max-width: 450px;
    margin: 100px auto;
    padding: 40px;
    background-color: #fff;
    border-radius: 12px;
    box-shadow: var(--shadow-hover);
    text-align: center;
}
.login-form h1 {
    margin-bottom: 30px;
}
.login-form .form-group {
    text-align: left;
}
.login-form .btn {
    width: 100%;
    margin-top: 10px;
}
#login-error {
    color: #dc3545; /* Red */
    font-weight: 600;
    margin-top: 15px;
    display: none; /* Hidden by default */
}

/* --- 11. Mobile Styles --- */
@media (max-width: 992px) {
    /* Activate Hamburger Menu & Adjust Header */
    .main-header .container {
        flex-wrap: wrap; /* Allows nav to wrap below */
    }
    .logo {
        font-size: 1.3rem; /* Slightly smaller logo on tablets */
    }
    .menu-toggle { 
        display: block; /* Show hamburger */
    }
    .main-nav { 
        flex-basis: 100%; /* Nav takes full width on its own line */
        order: 3; /* Position nav below logo/button */
        justify-content: center; /* Center the nav items container */
    }
    .main-nav ul { 
        display: none; /* Hide nav links by default */
        flex-direction: column; 
        width: 100%; 
        text-align: center; 
        margin-top: 15px; 
    }
    .main-nav ul.active { 
        display: flex; /* Show nav links when toggled */
    }
    .main-nav li { 
        margin: 10px 0; /* Stack items vertically */
        width: 100%; 
    }

    /* Stack Grids */
    .impact-grid, .pillars-grid, .projects-grid, .courses-grid, .cv-columns, .collaborator-columns, .overview-grid, .contact-grid { 
        grid-template-columns: 1fr; 
    }
    
    /* Adjustments for specific layouts */
    .collaborator-columns::before { display: none; } /* Hide vertical line */
    .overview-interests { padding-left: 0; border-left: none; margin-top: 30px; }
     .cv-timeline-section .container::before { display: none; } /* Hide timeline line */
    .cv-column { margin-left: 0; }
    .cv-column::after { display: none; } /* Hide timeline dots */
    .collaborators-grid { grid-template-columns: repeat(2, 1fr); } /* Keep 2 columns for collaborators if possible */

}
@media (max-width: 768px) {
    body { font-size: 16px; }
    h1 { font-size: 2.5rem; } h2 { font-size: 2rem; }
    .page-header h1 { font-size: 2.2rem; }
    .hero .container { flex-direction: column; text-align: center; }
    .logo { font-size: 1.2rem; }
    .main-header .container { flex-wrap: wrap; }
    .menu-toggle { display: block; }
    .main-nav { flex-basis: 100%; order: 3; }
    .main-nav ul { display: none; flex-direction: column; width: 100%; text-align: center; margin-top: 15px; }
    .main-nav ul.active { display: flex; }
    .main-nav li { margin: 10px 0; width: 100%; }
    .overview-grid, .contact-grid, .impact-grid { grid-template-columns: 1fr; }
    .overview-interests { padding-left: 0; border-left: none; margin-top: 30px; }
    .pub-filters { flex-direction: column; align-items: stretch; }
    .tab-nav { flex-direction: column; border-bottom: none; }
    .tab-btn { text-align: left; border-bottom: 1px solid #dee2e6; }
    .tab-btn.active { border-bottom: 3px solid var(--primary-color); }
    .page-nav { overflow-x: auto; -webkit-overflow-scrolling: touch; }
    .page-nav ul { justify-content: flex-start; flex-wrap: nowrap; }
    .cv-timeline-section .container::before { left: 31px; }
    .cv-column { margin-left: 40px; }
    .cv-column::after { left: -25px; top: 48px; transform: translateX(0); }
    .collaborators-grid { grid-template-columns: 1fr; }
}