/* CSS Variables */
:root {
    --color-text: #333;
    --color-text-light: #666;
    --color-link: #1772d0;
    --color-link-hover: #f09228;
    --color-bg: #fff;
    --color-border: #ddd;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-size-base: 15px;
    --font-size-small: 13px;
    --font-size-large: 18px;
    --max-width: 950px;
    --sidebar-width: 250px;
}

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

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
}

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

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

h1, h2, h3, h4, h5, h6 {
    margin: 0;
    font-weight: 600;
}

p {
    margin: 0 0 0.8rem 0;
}

ul {
    margin: 0;
    padding-left: 1.2rem;
}

img {
    max-width: 100%;
    height: auto;
}

/* Layout */
.container {
    display: flex;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem 1.5rem;
    gap: 3rem;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    position: sticky;
    top: 2rem;
    height: fit-content;
}

.profile {
    text-align: center;
    margin-bottom: 1.5rem;
}

.profile-photo {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1rem;
    border: 3px solid var(--color-border);
}

.name {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.3rem;
    color: var(--color-text);
}

.title {
    font-size: var(--font-size-base);
    color: var(--color-text-light);
    margin-bottom: 0.2rem;
}

.affiliation {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin-bottom: 0.2rem;
}

.contact {
    text-align: center;
    margin-bottom: 1rem;
}

.contact p {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin: 0;
}

.email {
    font-size: var(--font-size-small);
}

.copy-btn {
    background: none;
    border: none;
    padding: 0.2rem;
    cursor: pointer;
    color: var(--color-text-light);
    transition: color 0.2s ease;
    display: inline-flex;
    align-items: center;
}

.copy-btn:hover {
    color: var(--color-link);
}

.links {
    text-align: center;
    font-size: var(--font-size-small);
    margin-bottom: 1.5rem;
}

.links a {
    font-weight: 500;
}

.separator {
    color: var(--color-text-light);
    margin: 0 0.3rem;
}

.nav-links {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
}

.nav-links a {
    font-weight: 500;
    font-size: var(--font-size-base);
}

/* Main Content */
.content {
    flex: 1;
    min-width: 0;
}

.section {
    margin-bottom: 2.5rem;
}

.section h2 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--color-text);
}

.interests {
    color: var(--color-text-light);
    font-size: var(--font-size-small);
}

/* Research Items */
.research-item {
    margin-bottom: 1.5rem;
}

.research-header {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.5rem;
    margin-bottom: 0.3rem;
}

.research-title {
    font-weight: 600;
    color: var(--color-text);
}

.research-role {
    color: var(--color-text-light);
    font-size: var(--font-size-small);
}

.research-role::before {
    content: "| ";
}

.research-date {
    color: var(--color-text-light);
    font-size: var(--font-size-small);
    margin-left: auto;
}

.research-desc {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin: 0;
}

/* Publications */
.publication {
    margin-bottom: 1.5rem;
}

.pub-title {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 0.2rem;
}

.pub-authors {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin-bottom: 0.2rem;
}

.pub-venue {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin-bottom: 0.3rem;
}

.pub-links {
    font-size: var(--font-size-small);
    margin: 0;
}

.pub-links a {
    margin-right: 0.8rem;
}

/* Experience */
.experience-item {
    margin-bottom: 1.5rem;
}

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

.exp-company {
    font-weight: 600;
    color: var(--color-text);
}

.exp-date {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

.exp-role {
    font-size: var(--font-size-small);
    color: var(--color-link);
    margin-bottom: 0.3rem;
}

.exp-desc {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin: 0;
}

/* Teaching */
.teaching-item {
    margin-bottom: 1.5rem;
}

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

.teaching-course {
    font-weight: 600;
    color: var(--color-text);
}

.teaching-date {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

.teaching-details {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin: 0.3rem 0 0 0;
}

/* Awards */
.awards-list {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

.awards-list li {
    margin-bottom: 0.3rem;
}

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

.news-list li {
    display: flex;
    gap: 1rem;
    margin-bottom: 0.8rem;
    font-size: var(--font-size-small);
}

.news-date {
    font-weight: 600;
    color: var(--color-link);
    min-width: 80px;
    flex-shrink: 0;
}

.news-text {
    color: var(--color-text-light);
}

/* Projects */
.project-item {
    margin-bottom: 1.5rem;
}

.project-header {
    display: flex;
    align-items: baseline;
    gap: 0.8rem;
    margin-bottom: 0.3rem;
}

.project-title {
    font-weight: 600;
    color: var(--color-text);
}

.project-link {
    font-size: var(--font-size-small);
}

.project-desc {
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    margin: 0;
}

/* Footer */
footer {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1.5rem;
    text-align: center;
    border-top: 1px solid var(--color-border);
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

footer p {
    margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        flex-direction: column;
        padding: 1.5rem 1rem;
        gap: 2rem;
    }

    .sidebar {
        width: 100%;
        position: static;
        border-bottom: 1px solid var(--color-border);
        padding-bottom: 1.5rem;
    }

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

    .research-header,
    .exp-header,
    .teaching-header {
        flex-direction: column;
        gap: 0.2rem;
    }

    .research-date,
    .exp-date,
    .teaching-date {
        margin-left: 0;
    }

    .research-role::before {
        content: "";
    }

    .news-list li {
        flex-direction: column;
        gap: 0.2rem;
    }

    .news-date {
        min-width: auto;
    }

    .project-header {
        flex-direction: column;
        gap: 0.3rem;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }

    .profile-photo {
        width: 120px;
        height: 120px;
    }

    .name {
        font-size: 1.3rem;
    }
}

/* Print Styles */
@media print {
    .sidebar {
        position: static;
    }

    .container {
        max-width: 100%;
    }

    a {
        color: var(--color-text);
    }

    .copy-btn {
        display: none;
    }
}