/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #1a1a1a;
    background-color: #ffffff;
    padding-top: 60px;
}

/* Navigation Bar */
.top-nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: #ffffff;
    border-bottom: 1px solid #e0e0e0;
    z-index: 1000;
    padding: 0;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 15px 20px;
    color: #1a1a1a;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.main-navigation {
    display: flex;
    justify-content: center;
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 0;
}

.nav-list li {
    margin: 0;
}

.nav-link {
    display: block;
    padding: 18px 30px;
    color: #666666;
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    transition: color 0.2s ease, background-color 0.2s ease;
    border-bottom: 2px solid transparent;
}

.nav-link:hover {
    color: #1a1a1a;
    background-color: #f8f8f8;
}

.nav-link.active {
    color: #1a1a1a;
    border-bottom: 2px solid #1a1a1a;
}

/* Main Container */
.main-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* Content Sections */
.content-section {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Home Section */
.home-header {
    display: flex;
    gap: 60px;
    margin-bottom: 50px;
    align-items: flex-start;
}

.left-column {
    flex: 1;
}

.right-column {
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.fun-fact {
    margin-top: 20px;
    text-align: center;
    max-width: 240px;
}

.fun-fact p {
    font-size: 14px;
    line-height: 1.6;
    color: #666666;
    margin: 0;
}

.fun-fact strong {
    color: #333333;
    font-weight: 600;
}

.personal-info {
    margin-bottom: 30px;
}

.name {
    font-size: 36px;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.title {
    font-size: 18px;
    color: #555555;
    margin-bottom: 4px;
    font-weight: 500;
}

.affiliation {
    font-size: 16px;
    color: #666666;
    margin-bottom: 2px;
}

.location {
    font-size: 15px;
    color: #888888;
}

.contact-info {
    margin-top: 20px;
}

.contact-info p {
    margin-bottom: 8px;
    font-size: 15px;
    color: #444444;
}

.contact-info a {
    color: #1a1a1a;
    text-decoration: none;
    border-bottom: 1px solid #d0d0d0;
    transition: border-color 0.2s ease;
}

.contact-info a:hover {
    border-bottom-color: #1a1a1a;
}

.profile-photo {
    width: 240px;
    height: 240px;
    object-fit: cover;
    border: 1px solid #e0e0e0;
}

/* Section Blocks */
.section-block {
    margin-bottom: 50px;
}

.section-block h2 {
    font-size: 28px;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid #1a1a1a;
    letter-spacing: -0.3px;
}

.section-block h3 {
    font-size: 20px;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 8px;
}

.section-block h4 {
    font-size: 17px;
    font-weight: 600;
    color: #1a1a1a;
    margin-top: 20px;
    margin-bottom: 10px;
}

.section-block p {
    color: #333333;
    font-size: 15px;
    line-height: 1.7;
    margin-bottom: 15px;
}

.section-block a {
    color: #1a1a1a;
    text-decoration: none;
    border-bottom: 1px solid #d0d0d0;
    transition: border-color 0.2s ease;
}

.section-block a:hover {
    border-bottom-color: #1a1a1a;
}

/* Education Items */
.education-item {
    margin-bottom: 30px;
}

.education-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

.institution {
    color: #555555;
    font-size: 15px;
    margin-bottom: 5px;
}

.gpa, .minor {
    color: #666666;
    font-size: 14px;
    margin-bottom: 3px;
}

.date {
    font-size: 14px;
    color: #888888;
    white-space: nowrap;
}

/* Research Items */
.research-item {
    margin-bottom: 40px;
}

.research-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

.supervisor {
    color: #555555;
    font-size: 14px;
    margin-bottom: 12px;
    font-style: italic;
}

.details-list {
    list-style-position: outside;
    padding-left: 20px;
    margin-top: 10px;
}

.details-list li {
    color: #444444;
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 8px;
}

.note {
    margin-top: 15px;
    padding: 15px;
    background-color: #f8f8f8;
    border-left: 3px solid #1a1a1a;
    font-size: 14px;
    line-height: 1.6;
    color: #555555;
    font-style: italic;
}

/* Experience Items */
.experience-item {
    margin-bottom: 40px;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

/* Project Items */
.project-item {
    margin-bottom: 35px;
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 8px;
}

.project-tech, .project-description {
    color: #666666;
    font-size: 14px;
    margin-bottom: 10px;
}

.project-link {
    color: #555555;
    font-size: 14px;
    margin-top: 10px;
}

/* Skills Section */
.skills-section {
    display: grid;
    gap: 25px;
}

.skill-category h4 {
    font-size: 16px;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 8px;
}

.skill-category p {
    color: #555555;
    font-size: 15px;
    line-height: 1.6;
}

/* Awards */
.award-item {
    margin-bottom: 20px;
}

.award-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
}

.award-level {
    font-size: 14px;
    color: #666666;
}

/* Activities */
.activity-item {
    margin-bottom: 25px;
}

.activity-item h3 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 5px;
}

.activity-item p {
    color: #666666;
    font-size: 14px;
    margin-bottom: 10px;
}
/* Friends Section */
.friends-title {
    text-align: center;
    margin-bottom: 15px;
}

.friends-logo {
    height: 60px;
    width: auto;
}

.friends-note {
    text-align: center;
    color: #888888;
    font-size: 14px;
    margin-bottom: 35px;
    font-style: italic;
}

.friend-item {
    margin-bottom: 35px;
    padding-bottom: 30px;
    border-bottom: 1px solid #e0e0e0;
}

.friend-item:last-child {
    border-bottom: none;
}

.friend-item h3 {
    font-size: 20px;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 8px;
}

.friend-link {
    font-size: 14px;
    margin-bottom: 12px;
}

.friend-link a {
    color: #1a1a1a;
    text-decoration: none;
    border-bottom: 1px solid #d0d0d0;
}

.friend-link a:hover {
    border-bottom-color: #1a1a1a;
}

.friend-item p {
    color: #444444;
    font-size: 15px;
    line-height: 1.7;
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        padding-top: 60px;
    }
    
    .top-nav-header {
        height: 60px;
    }
    
    .mobile-menu-toggle {
        display: block;
        padding: 18px 20px;
    }
    
    .nav-container {
        position: relative;
        justify-content: flex-start;
        padding: 0;
        height: 100%;
    }
    
    .main-navigation {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        width: 100%;
        background-color: #ffffff;
        border-bottom: 1px solid #e0e0e0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }
    
    .main-navigation.active {
        max-height: 300px;
    }
    
    .nav-list {
        flex-direction: column;
        padding: 0;
        width: 100%;
        margin: 0;
    }
    
    .nav-list li {
        width: 100%;
        border-bottom: 1px solid #f0f0f0;
        margin: 0;
    }
    
    .nav-list li:last-child {
        border-bottom: none;
    }
    
    .nav-link {
        display: block;
        padding: 10px 15px;
        font-size: 15px;
        width: 100%;
        text-align: left;
        border-bottom: none;
        box-sizing: border-box;
    }
    
    .nav-link.active {
        background-color: #f8f8f8;
        color: #1a1a1a;
        border-bottom: none;
    }
    
    .home-header {
        flex-direction: column;
        gap: 30px;
    }
    
    .right-column {
        width: 100%;
        display: flex;
        justify-content: center;
    }
    
    .profile-photo {
        width: 200px;
        height: 200px;
    }
    
    .name {
        font-size: 30px;
    }
    
    .section-block h2 {
        font-size: 24px;
    }
    
    .education-header,
    .research-header,
    .experience-header,
    .project-header,
    .award-header {
        flex-direction: column;
        gap: 5px;
    }
    
    .date {
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .main-container {
        padding: 20px 30px;
    }
}

.site-footer {
    text-align: center;
    padding: 20px;
    border-top: 1px solid #e0e0e0;
    margin: 40px auto 0 auto;  /* 改这里：加上 auto */
    background-color: #fafafa;
    width: 100%;
    max-width: 100%;  /* 加这行 */
    clear: both;
}

.footer-content {
    width: 100%;  /* 改这里 */
    max-width: 1000px;  /* 加这行，跟 main-container 一样 */
    margin: 0 auto;
    padding: 0;
    text-align: center;  /* 加这行 */
}

.footer-content a {
    display: inline-block;
}

.footer-content img {
    display: block;
    margin: 0 auto;
}

.footer-text {
    margin: 10px auto 0;
    color: #999;
    font-size: 0.85em;
}