/* ============================================
   Tianhui Cai - Academic Personal Website
   ============================================ */

:root {
    --color-text: #2c2c2c;
    --color-muted: #666;
    --color-light: #888;
    --color-accent: #4a6fa5;
    --color-accent-hover: #2c4a7c;
    --color-bg: #ffffff;
    --color-section-bg: #fafafa;
    --color-border: #e5e5e5;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-serif: 'Lora', Georgia, 'Times New Roman', serif;
    --max-width: 1100px;
    --sidebar-width: 280px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.15s ease;
}

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

/* ============================================
   Layout
   ============================================ */

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 3rem 2rem;
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: 3.5rem;
    align-items: start;
}

/* ============================================
   Sidebar
   ============================================ */

.sidebar {
    position: sticky;
    top: 3rem;
    text-align: center;
}

.profile-photo {
    width: 220px;
    height: 220px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1.25rem;
    border: 3px solid var(--color-border);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.name {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 0.4rem;
    color: var(--color-text);
}

.title {
    font-size: 0.95rem;
    color: var(--color-muted);
    margin-bottom: 0.2rem;
    font-weight: 500;
}

.affiliation {
    font-size: 0.9rem;
    color: var(--color-light);
    margin-bottom: 1.2rem;
}

.contact-info {
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    color: var(--color-muted);
}

.social-links {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem 1rem;
    font-size: 0.92rem;
}

.social-links li::after {
    content: '·';
    color: var(--color-light);
    margin-left: 1rem;
}

.social-links li:last-child::after {
    content: '';
    margin: 0;
}

/* ============================================
   Main Content
   ============================================ */

.content {
    min-width: 0; /* prevents grid blowout */
}

section {
    margin-bottom: 3rem;
}

h2 {
    font-family: var(--font-serif);
    font-size: 1.55rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 1.25rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--color-accent);
    display: inline-block;
}

section p {
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--color-text);
}

.note {
    font-size: 0.85rem;
    color: var(--color-muted);
    margin-bottom: 1.25rem;
    font-style: italic;
}

/* ============================================
   Education / Timeline
   ============================================ */

.timeline {
    list-style: none;
}

.timeline li {
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
}

.timeline li:last-child {
    border-bottom: none;
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 0.3rem;
}

.timeline h3 {
    font-size: 1.08rem;
    font-weight: 600;
    color: var(--color-text);
}

.timeline .date {
    font-size: 0.88rem;
    color: var(--color-light);
    font-weight: 500;
    white-space: nowrap;
}

.timeline .degree {
    font-size: 0.98rem;
    color: var(--color-text);
    margin-bottom: 0.2rem;
    font-weight: 400;
}

.timeline .detail {
    font-size: 0.9rem;
    color: var(--color-muted);
    margin-bottom: 0;
}

/* ============================================
   Publications
   ============================================ */

.publications {
    list-style: none;
    counter-reset: pub-counter;
}

.publications li {
    counter-increment: pub-counter;
    padding: 1.1rem 0 1.1rem 2.4rem;
    border-bottom: 1px solid var(--color-border);
    position: relative;
}

.publications li::before {
    content: counter(pub-counter) ".";
    position: absolute;
    left: 0;
    top: 1.1rem;
    font-weight: 600;
    color: var(--color-accent);
    font-family: var(--font-serif);
    font-size: 1rem;
}

.publications li:last-child {
    border-bottom: none;
}

.pub-title {
    font-size: 1rem;
    line-height: 1.45;
    margin-bottom: 0.3rem !important;
    color: var(--color-text);
}

.pub-authors {
    font-size: 0.92rem;
    color: var(--color-muted);
    margin-bottom: 0.25rem !important;
    line-height: 1.5;
}

.pub-venue {
    font-size: 0.92rem;
    color: var(--color-light);
    margin-bottom: 0 !important;
}

.pub-venue em {
    color: var(--color-text);
}

/* ============================================
   Contact
   ============================================ */

.contact-list {
    list-style: none;
    margin-top: 0.75rem;
}

.contact-list li {
    padding: 0.4rem 0;
    font-size: 0.98rem;
}

.contact-list .label {
    display: inline-block;
    width: 80px;
    color: var(--color-muted);
    font-weight: 500;
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
    margin-top: 4rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--color-border);
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-light);
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 820px) {
    .container {
        grid-template-columns: 1fr;
        gap: 2rem;
        padding: 2rem 1.25rem;
    }

    .sidebar {
        position: static;
        text-align: center;
        padding-bottom: 1.5rem;
        border-bottom: 1px solid var(--color-border);
    }

    .profile-photo {
        width: 180px;
        height: 180px;
    }

    h2 {
        font-size: 1.35rem;
    }

    .timeline-header {
        flex-direction: column;
        gap: 0.15rem;
    }

    .publications li {
        padding-left: 1.8rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 1.5rem 1rem;
    }

    .profile-photo {
        width: 150px;
        height: 150px;
    }

    .name {
        font-size: 1.4rem;
    }
}