:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --dark-color: #1e293b;
    --light-color: #f8fafc;
    --text-color: #334155;
    --text-light: #94a3b8;
    --background-color: #ffffff;
    --card-background: #f1f5f9;
    --border-radius: 10px;
    --transition: all 0.3s ease;
    --box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.1);
    --accent-color: #4f46e5;
    --success-color: #10b981;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
}

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

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
header {
    padding: 50px 0 30px;
    text-align: center;
}

.profile {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.profile-image {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    overflow: hidden;
    border: 5px solid var(--light-color);
    box-shadow: var(--box-shadow);
}

.profile-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    font-size: 60px;
    overflow: hidden;
}

.name {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-top: 15px;
}

.title {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-light);
    margin-bottom: 15px;
}

.social-icons {
    display: flex;
    gap: 15px;
    margin-top: 10px;
}

.social-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--light-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-icon:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

/* Navigation Styles */
nav {
    padding: 20px 0;
    margin-bottom: 40px;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
}

.nav-links a {
    color: var(--text-color);
    font-weight: 500;
    padding: 8px 15px;
    border-radius: 30px;
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    background-color: var(--primary-color);
    color: white;
}

/* Section Styles */
.section {
    padding: 80px 0;
}

.section-inner {
    max-width: 900px;
    margin: 0 auto;
}

.section-title {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 40px;
    color: var(--dark-color);
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 70px;
    height: 4px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.section-content {
    margin-top: 30px;
}

/* About Section */
.about-cta {
    margin-top: 30px;
    text-align: center;
}

.btn {
    display: inline-block;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    color: white;
}

/* Experience Section */
.timeline {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 20px;
    height: 100%;
    width: 2px;
    background-color: var(--text-light);
    opacity: 0.3;
}

.timeline-item {
    position: relative;
    padding-left: 50px;
    margin-bottom: 40px;
}

.timeline-dot {
    position: absolute;
    top: 5px;
    left: 16px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--primary-color);
    z-index: 1;
}

.timeline-date {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 5px;
    font-weight: 500;
}

.timeline-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--dark-color);
}

.timeline-content h4 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-light);
    margin-bottom: 10px;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
}

.project-card {
    border-radius: var(--border-radius);
    overflow: hidden;
    background-color: var(--card-background);
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px -10px rgba(0, 0, 0, 0.15);
}

.project-image {
    height: 180px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    font-size: 40px;
}

.project-info {
    padding: 20px;
}

.project-info h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--dark-color);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 15px 0;
}

.tag {
    font-size: 0.7rem;
    padding: 3px 10px;
    border-radius: 20px;
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
}

.project-links {
    display: flex;
    gap: 15px;
    margin-top: 15px;
}

.project-link {
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Skills Section */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.skill-category h3 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.skill-bars {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.skill-bar {
    width: 100%;
}

.skill-name {
    font-size: 0.9rem;
    margin-bottom: 5px;
    font-weight: 500;
}

.skill-progress {
    height: 8px;
    background-color: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
    overflow: hidden;
}

.skill-level {
    height: 100%;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
    width: 0;
    animation: skill-fill 1.5s ease forwards;
}

@keyframes skill-fill {
    0% {
        width: 0;
    }
    100% {
        width: var(--width);
    }
}

/* Contact Section */
.contact-info {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    margin-bottom: 40px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
}

.contact-item i {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-form {
    max-width: 500px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius);
    font-family: inherit;
    font-size: inherit;
    transition: var(--transition);
}

.form-group textarea {
    height: 150px;
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Footer */
footer {
    text-align: center;
    padding: 30px 0;
    color: var(--text-light);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    margin-top: 50px;
}

/* 添加联系信息简要样式 */
.contact-brief {
    margin: 15px 0;
    text-align: center;
    line-height: 1.8;
}

.contact-brief p {
    margin: 0;
    font-size: 0.95rem;
    color: var(--text-light);
}

.contact-brief a {
    color: var(--primary-color);
    font-weight: 500;
}

.contact-brief a:hover {
    text-decoration: underline;
}

/* 大学 logo 样式 */
#university-logo {
    width: 100%;
    height: 100%;
    object-fit: contain;
    background-color: white;
    border-radius: 50%;
    padding: 10px;
}

/* 项目状态标签 */
.project-status {
    font-size: 0.85rem;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 12px;
    padding: 4px 0;
    border-bottom: 1px dashed rgba(79, 70, 229, 0.3);
}

/* 项目卡片改进 */
.project-card {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.project-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.project-info h3 {
    margin-bottom: 15px;
    color: var(--dark-color);
    line-height: 1.4;
}

.project-info p {
    margin-bottom: 10px;
    font-size: 0.95rem;
}

/* 科研经历部分的图标调整 */
.project-image-placeholder i {
    font-size: 48px;
}

/* 技能部分样式优化 */
.skill-category {
    background-color: var(--card-background);
    padding: 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px -10px rgba(0, 0, 0, 0.15);
}

.skill-category h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.25rem;
    border-bottom: 2px solid rgba(37, 99, 235, 0.2);
    padding-bottom: 8px;
}

.skill-category p {
    line-height: 1.7;
}

/* 时间线项目内容加强 */
.timeline-content h4 {
    margin: 8px 0;
    color: var(--text-light);
}

.timeline-date {
    background-color: rgba(37, 99, 235, 0.1);
    display: inline-block;
    padding: 4px 10px;
    border-radius: 15px;
    font-size: 0.85rem;
    margin-bottom: 10px;
}

/* 暗色模式适配 */
.dark-theme .project-status {
    border-bottom-color: rgba(96, 165, 250, 0.3);
}

.dark-theme .skill-category {
    background-color: var(--card-background);
}

.dark-theme .skill-category h3 {
    border-bottom-color: rgba(59, 130, 246, 0.3);
}

.dark-theme .timeline-date {
    background-color: rgba(59, 130, 246, 0.2);
}

.dark-theme #university-logo {
    background-color: #1e293b;
}

/* Responsive */
@media screen and (max-width: 768px) {
    .name {
        font-size: 2rem;
    }
    
    .title {
        font-size: 1rem;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-item {
        padding-left: 40px;
    }
    
    .contact-info {
        flex-direction: column;
        align-items: center;
    }
    
    .project-card {
        margin-bottom: 25px;
    }
    
    .timeline-content h3 {
        font-size: 1.1rem;
    }
    
    .timeline-content h4 {
        font-size: 0.9rem;
    }
}

@media screen and (max-width: 480px) {
    .nav-links {
        gap: 15px;
    }
    
    .nav-links a {
        padding: 6px 10px;
        font-size: 0.9rem;
    }
}

/* 个人头像样式 */
#profile-avatar {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

/* CSDN图标自定义样式 */
.csdn-icon {
    font-family: "Arial", sans-serif;
    font-weight: bold;
    font-size: 1.3rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--light-color);
    transition: var(--transition);
}

.csdn-icon:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

.dark-theme .csdn-icon {
    color: var(--primary-color);
    background-color: var(--light-color);
}

.dark-theme .csdn-icon:hover {
    background-color: var(--primary-color);
    color: white;
}