:root {
    --primary-color: #5e2a8e;      /* Tsinghua purple, matches the CV section headings */
    --text-color: #1a1a1a;
    --muted-color: #666;
    --bg-color: #f7f7f8;
    --sidebar-bg: #fff;
    --link-color: #0b5cad;
    --border-color: #e7e7ea;
    --heading-font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    --body-font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
    font-family: var(--body-font);
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 0;
    line-height: 1.65;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

.container {
    display: flex;
    max-width: 1100px;
    margin: 40px auto;
    background: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.04);
    border: 1px solid var(--border-color);
    min-height: 90vh;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--sidebar-bg);
    padding: 44px 24px;
    text-align: center;
    border-right: 1px solid var(--border-color);
    flex-shrink: 0;
}

.profile-photo {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 18px;
    border: 1px solid var(--border-color);
}

.name {
    font-family: var(--heading-font);
    font-size: 1.5em;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-bottom: 6px;
    color: #111;
}

.affiliation {
    font-size: 0.88em;
    color: var(--muted-color);
    line-height: 1.5;
}

/* Quick links row: Email / CV / GitHub */
.quick-links {
    margin-top: 22px;
    padding-top: 18px;
    border-top: 1px solid var(--border-color);
    font-size: 0.9em;
}

.quick-links a {
    color: var(--link-color);
    text-decoration: none;
    white-space: nowrap;
}

.quick-links a:hover { text-decoration: underline; }

.quick-links .sep {
    color: #c8c8cc;
    margin: 0 6px;
}

.contact-info {
    font-size: 0.85em;
    text-align: left;
    margin-top: 20px;
    color: var(--muted-color);
}

.contact-item {
    margin-bottom: 8px;
    display: flex;
    align-items: baseline;
    word-break: break-word;
}

.contact-item i {
    margin-right: 9px;
    color: var(--primary-color);
    width: 14px;
    flex-shrink: 0;
    text-align: center;
}

/* Main Content */
.main-content {
    flex-grow: 1;
    padding: 44px 52px;
    min-width: 0;
}

section { margin-bottom: 34px; }
section:last-child { margin-bottom: 0; }

h2 {
    font-family: var(--heading-font);
    color: var(--primary-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 7px;
    margin-bottom: 16px;
    font-size: 1.08em;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

h3 {
    font-family: var(--heading-font);
    font-size: 1.02em;
    font-weight: 600;
    margin: 0 0 3px;
    color: #111;
}

p { margin: 0 0 12px; max-width: 68ch; }

.subtitle {
    font-size: 0.92em;
    color: var(--muted-color);
    margin-bottom: 8px;
    display: block;
}

.date-location {
    float: right;
    font-size: 0.86em;
    color: #8a8a90;
    font-weight: 400;
    font-variant-numeric: tabular-nums;
}

ul { padding-left: 20px; margin: 0; }
li { margin-bottom: 6px; max-width: 68ch; }

a { color: var(--link-color); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    border-radius: 2px;
}

/* News */
.news-list { list-style: none; padding-left: 0; }

.news-list li {
    display: flex;
    gap: 12px;
    margin-bottom: 7px;
}

.news-date {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.86em;
    white-space: nowrap;
    flex-shrink: 0;
    width: 82px;
    padding-top: 2px;
    font-variant-numeric: tabular-nums;
}

/* Manuscripts */
.pub-list { list-style: none; padding-left: 0; }

.pub-list li {
    margin-bottom: 14px;
    padding-left: 14px;
    border-left: 2px solid var(--border-color);
}

.pub-title { font-weight: 600; color: #111; }
.pub-authors { font-size: 0.94em; }
.pub-venue { font-size: 0.9em; color: var(--muted-color); font-style: italic; }

/* Research items */
.research-item + .research-item { margin-top: 20px; }

/* Skills Table */
.skills-table { width: 100%; border-collapse: collapse; font-size: 0.94em; }
.skills-table td { padding: 5px 0; vertical-align: top; }
.skill-category { font-weight: 600; width: 180px; color: #333; padding-right: 16px; }

/* Responsive */
@media (max-width: 820px) {
    .container {
        flex-direction: column;
        margin: 0;
        border: none;
        box-shadow: none;
    }

    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 32px 20px;
    }

    .main-content { padding: 28px 20px; }

    .date-location {
        float: none;
        display: block;
        margin-bottom: 4px;
    }

    .skill-category { width: 140px; }
}

@media (prefers-reduced-motion: reduce) {
    * { transition: none !important; animation: none !important; }
}