/* ===== CSS Variables ===== */
:root {
    --color-primary: #1a365d;
    --color-primary-light: #2c5282;
    --color-accent: #c53030;
    --color-text: #2d3748;
    --color-text-light: #4a5568;
    --color-bg: #ffffff;
    --color-bg-alt: #f7fafc;
    --color-border: #e2e8f0;
    --font-serif: 'Crimson Pro', Georgia, serif;
    --font-sans: 'Source Sans 3', -apple-system, BlinkMacSystemFont, sans-serif;
    --max-width: 900px;
    --nav-height: 70px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-sans);
    font-size: 17px;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
}

/* ===== Typography ===== */
h1, h2, h3, h4 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-primary);
}

h1 {
    font-size: 2.75rem;
    margin-bottom: 0.5rem;
}

h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    padding-bottom: 0.75rem;
    border-bottom: 3px solid var(--color-primary);
    display: inline-block;
}

h3 {
    font-size: 1.35rem;
    margin-bottom: 1rem;
    color: var(--color-primary-light);
}

h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
}

p {
    margin-bottom: 1rem;
}

a {
    color: var(--color-primary-light);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

strong {
    font-weight: 600;
}

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

.section {
    padding: 5rem 0;
}

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

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: box-shadow 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

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

.nav-name {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 0.5rem 0;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* ===== Hero Section ===== */
.hero {
    padding-top: calc(var(--nav-height) + 4rem);
    padding-bottom: 4rem;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 4rem;
    align-items: start;
}

.hero-image {
    position: sticky;
    top: calc(var(--nav-height) + 2rem);
}

.image-placeholder {
    width: 250px;
    height: 300px;
    background: linear-gradient(135deg, var(--color-bg-alt) 0%, var(--color-border) 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-light);
    font-size: 1.25rem;
    border: 2px dashed var(--color-border);
}

.image-placeholder img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 8px;
}

.hero-content .title {
    font-size: 1.35rem;
    color: var(--color-primary-light);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.hero-content .affiliation {
    font-size: 1.1rem;
    color: var(--color-text-light);
    margin-bottom: 0.5rem;
}

.hero-content .status {
    display: inline-block;
    background-color: var(--color-accent);
    color: white;
    padding: 0.35rem 1rem;
    border-radius: 4px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.contact-info {
    margin-bottom: 2rem;
    padding: 1.25rem;
    background-color: var(--color-bg-alt);
    border-radius: 8px;
    border-left: 4px solid var(--color-primary);
}

.contact-info p {
    margin-bottom: 0.5rem;
}

.contact-info p:last-child {
    margin-bottom: 0;
    font-size: 0.95rem;
    color: var(--color-text-light);
}

.hero-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--color-primary);
    color: white;
    font-weight: 600;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.btn:hover {
    background-color: var(--color-primary-light);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(26, 54, 93, 0.3);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

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

/* ===== About Section ===== */
.about-content {
    max-width: 750px;
}

.research-interests, .committee {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: var(--color-bg-alt);
    border-radius: 8px;
}

.research-interests h3, .committee h3 {
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
}

.research-interests p, .committee p {
    margin-bottom: 0.5rem;
}

.research-interests p:last-child, .committee p:last-child {
    margin-bottom: 0;
}

/* ===== Research Section ===== */
.research-category {
    margin-bottom: 3rem;
}

.research-category:last-child {
    margin-bottom: 0;
}

.category-title {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--color-border);
}

.paper {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: var(--color-bg);
    border-radius: 8px;
    border-left: 4px solid var(--color-primary-light);
}

.paper:last-child {
    margin-bottom: 0;
}

.paper-title {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.paper-authors {
    font-style: italic;
    color: var(--color-text-light);
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
}

.paper-journal {
    color: var(--color-text-light);
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
}

.paper-abstract {
    font-size: 0.95rem;
    color: var(--color-text-light);
    line-height: 1.6;
    margin-bottom: 1rem;
    text-align: justify;
}

.paper-links {
    display: flex;
    gap: 1rem;
}

.paper-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-primary-light);
    padding: 0.25rem 0.75rem;
    background-color: var(--color-bg-alt);
    border-radius: 4px;
    transition: all 0.2s ease;
}

.paper-link:hover {
    background-color: var(--color-primary);
    color: white;
}

/* ===== Teaching Section ===== */
.award-highlight {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    padding: 1.25rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 2.5rem;
    border-left: 4px solid #d97706;
}

.award-highlight p {
    margin-bottom: 0;
    font-size: 1.05rem;
}

.teaching-category {
    margin-bottom: 2.5rem;
}

.teaching-category h3 {
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.institution {
    color: var(--color-text-light);
    font-style: italic;
    margin-bottom: 1rem;
}

.course {
    margin-bottom: 1.25rem;
    padding-left: 1.5rem;
    border-left: 3px solid var(--color-border);
}

.course h4 {
    font-family: var(--font-sans);
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.course p {
    font-size: 0.95rem;
    color: var(--color-text-light);
    margin-bottom: 0;
}

/* ===== Footer ===== */
.footer {
    background-color: var(--color-primary);
    color: rgba(255, 255, 255, 0.9);
    padding: 3rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
}

.footer a {
    color: rgba(255, 255, 255, 0.9);
}

.footer a:hover {
    color: white;
}

.footer-update {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 1rem;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    :root {
        --nav-height: 60px;
    }

    body {
        font-size: 16px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .nav-links a {
        font-size: 0.85rem;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .hero-image {
        position: static;
        display: flex;
        justify-content: center;
    }

    .image-placeholder {
        width: 200px;
        height: 240px;
    }

    .contact-info {
        text-align: left;
    }

    .hero-links {
        justify-content: center;
    }

    .section {
        padding: 3rem 0;
    }

    .container {
        padding: 0 1.5rem;
    }

    .paper {
        padding: 1.25rem;
    }

    .paper-abstract {
        text-align: left;
    }
}

@media (max-width: 480px) {
    .nav-container {
        flex-direction: column;
        padding: 0.5rem 1rem;
        height: auto;
    }

    .navbar {
        height: auto;
        padding: 0.5rem 0;
    }

    .nav-links {
        gap: 0.75rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    h1 {
        font-size: 1.75rem;
    }

    .hero {
        padding-top: 8rem;
    }

    .btn {
        padding: 0.6rem 1.25rem;
        font-size: 0.95rem;
    }
}

/* ===== Print Styles ===== */
@media print {
    .navbar, .hero-links, .paper-links {
        display: none;
    }

    .section {
        padding: 2rem 0;
    }

    .hero {
        padding-top: 0;
        min-height: auto;
    }
}