:root {
    --bg-color: transparent;
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;
    --link-color: #0066cc;
    --link-hover: #004499;
    --border-color: #d2d2d7;
    --section-spacing: 120px;
    --container-width: 980px;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    width: 80%;
    margin-left: 20%;
    padding: 0 4%;
}

/* Typography */
h1, h2, h3 {
    font-weight: 600;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 56px;
    line-height: 1.07143;
    margin-bottom: 20px;
}

h2.section-title {
    font-size: 40px;
    line-height: 1.1;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

h3 {
    font-size: 24px;
    line-height: 1.16667;
    margin-bottom: 8px;
}

p {
    font-size: 19px; /* slightly larger for readability */
    color: var(--text-secondary);
    margin-bottom: 1.5em;
    font-weight: 400;
}

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

a:hover {
    color: var(--link-hover);
    text-decoration: underline;
}

/* Header */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    z-index: 1000;
    padding: 20px 0;
    transition: background 0.3s ease;
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 600;
    font-size: 21px;
    color: var(--text-primary);
}

.logo:hover {
    text-decoration: none;
    opacity: 0.8;
}

.site-nav ul {
    list-style: none;
    display: flex;
    gap: 24px;
}

.site-nav a {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 400;
}

.site-nav a:hover {
    color: var(--text-primary);
    text-decoration: none;
}

/* Main Content */
main {
    padding-top: 120px; /* offset for fixed header */
}

.section {
    padding-bottom: var(--section-spacing);
}

/* Intro Section */
.intro {
    padding-top: 60px;
    padding-bottom: 160px;
}

.profile-photo {
    width: 20vw;
    height: 20vw;
    border-radius: 2%;
    object-fit: cover;
    margin-bottom: 24px;
    /* box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1); */
}

.eyebrow {
    font-size: 21px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.intro-text {
    font-size: 28px;
    line-height: 1.2;
    color: var(--text-secondary);
    max-width: 800px;
}

.apple-text {
    /* Optionally style "Apple" differently, but keeping it simple is better */
}

/* Publication List */
.publication-item {
    display: flex;
    gap: 32px;
    margin-bottom: 48px;
}

.pub-year {
    font-size: 17px;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
    width: 60px;
    flex-shrink: 0;
    padding-top: 4px;
}

.pub-content {
    flex-grow: 1;
}

.pub-title a {
    color: var(--text-primary);
}

.pub-title a:hover {
    color: var(--link-color);
}

.pub-authors {
    font-size: 17px;
    margin-bottom: 4px;
}

.pub-venue {
    font-size: 17px;
    font-style: italic;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.pub-links a {
    font-size: 14px;
    margin-right: 16px;
    display: inline-block;
}

/* News List */
.news-list {
    list-style: none;
}

.news-list li {
    display: flex;
    margin-bottom: 24px;
    font-size: 17px;
}

.news-list .date {
    width: 120px;
    flex-shrink: 0;
    color: var(--text-secondary);
    font-variant-numeric: tabular-nums;
}

.news-list .news-content {
    color: var(--text-primary);
}

/* Contact */
.button {
    display: inline-block;
    background-color: var(--text-primary);
    color: #fff;
    padding: 12px 24px;
    border-radius: 980px; /* Pill shape */
    font-size: 17px;
    font-weight: 500;
    margin-top: 20px;
    margin-bottom: 30px;
}

.button:hover {
    background-color: #333;
    color: #fff;
    text-decoration: none;
}

.social-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.social-links a {
    font-size: 17px;
    color: var(--text-secondary);
}

.social-links a:hover {
    color: var(--text-primary);
    text-decoration: none;
}

/* Footer */
.site-footer {
    padding: 40px 0;
    /* border-top: 1px solid var(--border-color); */
    font-size: 12px;
    color: var(--text-secondary);
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* Scroll Reveal */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    h1 {
        font-size: 40px;
    }
    
    .intro-text {
        font-size: 24px;
    }

    .profile-photo {
        width: 180px;
        height: 180px;
    }
    
    .publication-item {
        flex-direction: column;
        gap: 8px;
    }
    
    .pub-year {
        width: auto;
    }
    
    .news-list li {
        flex-direction: column;
    }
    
    .news-list .date {
        margin-bottom: 4px;
    }
}