:root {
    --primary: #2c3e50;
    --accent: #3498db;
    --text: #333;
    --text-light: #555;
    --bg: #fff;
    --bg-light: #f8f9fa;
    --border: #e0e0e0;
    --max-width: 860px;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text);
    line-height: 1.6;
    background: var(--bg);
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Header / Navigation */
header {
    background: var(--primary);
    color: #fff;
    padding: 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    padding: 0 1.5rem;
}

nav .site-title {
    font-size: 1.1rem;
    font-weight: 600;
    padding: 0.9rem 0;
    margin-right: 2rem;
    white-space: nowrap;
}

nav .site-title a {
    color: #fff;
    text-decoration: none;
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
}

nav ul li a {
    color: rgba(255,255,255,0.85);
    padding: 0.9rem 1rem;
    display: block;
    font-size: 0.9rem;
    transition: color 0.2s;
}

nav ul li a:hover,
nav ul li a.active {
    color: #fff;
    text-decoration: none;
}

nav ul li a.active {
    border-bottom: 2px solid #fff;
}

/* Hamburger */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    margin-left: auto;
}

/* Main content */
main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem 1.5rem 3rem;
}

h1 {
    font-size: 1.8rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 1.3rem;
    color: var(--primary);
    margin-top: 2rem;
    margin-bottom: 0.8rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.3rem;
}

h3 {
    font-size: 1.1rem;
    color: var(--primary);
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
}

p {
    margin-bottom: 1rem;
}

/* Home page hero */
.hero {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    margin-bottom: 2rem;
}

.hero-photo {
    width: 200px;
    min-width: 200px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.12);
}

.hero-text h1 {
    margin-bottom: 0.5rem;
}

.hero-text .subtitle {
    color: var(--text-light);
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.profiles {
    font-size: 0.9rem;
    margin-top: 0.5rem;
    line-height: 1.8;
}

.contact {
    margin-top: 1rem;
    font-size: 0.95rem;
    color: var(--text-light);
}

/* Publication / Talk list */
.pub-year {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary);
    margin-top: 2rem;
    margin-bottom: 0.6rem;
    border-bottom: 2px solid var(--accent);
    padding-bottom: 0.2rem;
}

.pub-list {
    list-style: none;
    padding: 0;
}

.pub-list li {
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 3px solid var(--bg-light);
    line-height: 1.5;
}

.pub-list li:hover {
    border-left-color: var(--accent);
}

.pub-title {
    font-weight: 500;
}

.pub-venue {
    font-style: italic;
    color: var(--text-light);
}

.pub-details {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Teaching */
.course-list {
    list-style: none;
    padding: 0;
}

.course-list li {
    padding: 0.6rem 0 0.6rem 1rem;
    border-left: 3px solid var(--bg-light);
    margin-bottom: 0.5rem;
}

.course-list li:hover {
    border-left-color: var(--accent);
}

.course-name {
    font-weight: 500;
}

.course-years {
    color: var(--text-light);
    font-size: 0.9rem;
}

.course-type {
    color: var(--text-light);
    font-size: 0.85rem;
}

/* CV page */
.cv-download {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--accent);
    color: #fff;
    padding: 0.7rem 1.5rem;
    border-radius: 6px;
    font-size: 1rem;
    transition: background 0.2s;
    margin-top: 1rem;
}

.cv-download:hover {
    background: #2980b9;
    text-decoration: none;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-light);
    font-size: 0.85rem;
    border-top: 1px solid var(--border);
    margin-top: 3rem;
}

/* Responsive */
@media (max-width: 600px) {
    .hero {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .hero-photo {
        width: 160px;
        min-width: 160px;
    }

    .nav-toggle {
        display: block;
    }

    nav ul {
        display: none;
        width: 100%;
        flex-direction: column;
    }

    nav ul.open {
        display: flex;
    }

    nav ul li a {
        padding: 0.7rem 0;
    }
}