/* ===== 全局样式 ===== */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #7c3aed;
    --accent-color: #06b6d4;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-alt: #f9fafb;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --radius: 12px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--bg-color);
}

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

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.nav-logo:hover {
    color: var(--primary-dark);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: var(--transition);
}

/* ===== Hero部分 ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 100px 20px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="50" cy="10" r="0.5" fill="rgba(255,255,255,0.05)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.5;
}

.hero-content {
    text-align: center;
    color: white;
    position: relative;
    z-index: 1;
}

.hero-content h1 {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease;
}

.hero-content .subtitle {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-content .tagline {
    font-size: 1.1rem;
    opacity: 0.8;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease 0.6s both;
}

.cta-button {
    display: inline-block;
    padding: 15px 40px;
    background: white;
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.cta-button-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.cta-button-secondary:hover {
    background: white;
    color: var(--primary-color);
}

.hero-image {
    position: absolute;
    right: 10%;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1;
}

.avatar-placeholder {
    width: 200px;
    height: 200px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 80px;
    color: white;
    border: 4px solid rgba(255, 255, 255, 0.3);
    animation: fadeIn 1s ease 0.8s both;
}

/* ===== 通用部分样式 ===== */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--bg-alt);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-color);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

/* ===== 关于我 ===== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    color: var(--text-light);
    line-height: 1.8;
}

.about-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.info-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 1.5rem;
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.info-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.info-item i {
    font-size: 2rem;
    color: var(--primary-color);
    min-width: 50px;
}

.info-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.info-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ===== 工作经历时间线 ===== */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 50px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
    border-radius: 3px;
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    animation: fadeInLeft 0.5s ease;
}

.timeline-dot {
    position: absolute;
    left: -38px;
    top: 20px;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 4px solid white;
    box-shadow: 0 0 0 3px var(--primary-color);
}

.timeline-content {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
}

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

.timeline-header h3 {
    font-size: 1.2rem;
    color: var(--text-color);
}

.timeline-date {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.25rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.timeline-position {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.timeline-description {
    list-style: none;
    padding: 0;
}

.timeline-description li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-light);
    line-height: 1.6;
}

.timeline-description li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* ===== 项目经历 ===== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border-top: 4px solid var(--primary-color);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.project-header h3 {
    font-size: 1.3rem;
    color: var(--text-color);
}

.project-date {
    background: var(--bg-alt);
    padding: 0.25rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text-light);
}

.project-tech {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.project-description {
    list-style: none;
    padding: 0;
}

.project-description li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-light);
    line-height: 1.6;
    font-size: 0.95rem;
}

.project-description li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ===== 技能证书 ===== */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.skill-category h3 {
    font-size: 1.2rem;
    color: var(--text-color);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.skill-category h3 i {
    color: var(--primary-color);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

.skill-tag:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
}

/* ===== 个人项目展示 ===== */
.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-top: -2rem;
    margin-bottom: 3rem;
}

.projects-showcase {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    max-width: 800px;
    margin: 0 auto;
}

.project-link-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem 2rem;
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
    text-decoration: none;
    color: var(--text-color);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

.project-link-card:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
    border-left-color: var(--secondary-color);
}

.project-link-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.project-link-icon i {
    font-size: 1.5rem;
    color: white;
}

.project-link-info {
    flex: 1;
}

.project-link-info h3 {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
    color: var(--text-color);
}

.project-link-info p {
    font-size: 0.9rem;
    color: var(--text-light);
}

.project-link-arrow {
    color: var(--text-light);
    transition: var(--transition);
}

.project-link-card:hover .project-link-arrow {
    color: var(--primary-color);
    transform: translateX(5px);
}

/* ===== 联系方式 ===== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-alt);
    border-radius: var(--radius);
    transition: var(--transition);
}

.contact-item:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.contact-item i {
    font-size: 2rem;
    color: var(--primary-color);
    min-width: 50px;
}

.contact-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.contact-item p {
    color: var(--text-light);
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-md);
}

.contact-form h3 {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.submit-btn {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.4);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-links a {
    color: white;
    font-size: 1.5rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--accent-color);
    transform: translateY(-3px);
}

/* ===== 动画 ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 2rem;
        transition: var(--transition);
    }

    .nav-menu.active {
        left: 0;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-content .subtitle {
        font-size: 1.2rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .cta-button {
        width: 100%;
        max-width: 250px;
        text-align: center;
    }

    .hero-image {
        display: none;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .timeline {
        padding-left: 40px;
    }

    .timeline-dot {
        left: -28px;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .projects-showcase {
        grid-template-columns: 1fr;
    }

    .project-link-card {
        padding: 1rem 1.5rem;
    }

    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 2rem;
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .project-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* ===== 平滑滚动到锚点时的偏移 ===== */
section[id] {
    scroll-margin-top: 70px;
}