/* 基础样式 */
:root {
    --primary-color: #4a6cf7;
    --secondary-color: #6c757d;
    --dark-color: #212529;
    --light-color: #f8f9fa;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #fff;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
}

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

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 50px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--primary-color);
}

section {
    padding: 100px 0;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    text-align: center;
}

.primary-btn {
    background-color: var(--primary-color);
    color: #fff;
}

.primary-btn:hover {
    background-color: #3a5bd9;
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

.secondary-btn {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.secondary-btn:hover {
    background-color: var(--primary-color);
    color: #fff;
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

/* 导航栏 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: #fff;
    box-shadow: var(--box-shadow);
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
}

.nav-links li {
    margin-left: 30px;
}

.nav-links a {
    font-weight: 600;
    transition: var(--transition);
}

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

.burger {
    display: none;
    cursor: pointer;
}

.burger div {
    width: 25px;
    height: 3px;
    background-color: var(--dark-color);
    margin: 5px;
    transition: var(--transition);
}

/* 首页英雄区 */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    background-color: #f9f9f9;
    margin-top: 80px;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
}

.highlight {
    color: var(--primary-color);
}

.subtitle {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-bottom: 40px;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

/* 关于我 */
.about {
    background-color: #fff;
}

.about-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.about-image {
    flex: 1;
}

.about-text {
    flex: 2;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.personal-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.info-item {
    display: flex;
}

.info-label {
    font-weight: 600;
    margin-right: 10px;
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: #f0f0f0;
    color: var(--dark-color);
    transition: var(--transition);
}

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

/* 图片占位符 */
.image-placeholder {
    width: 100%;
    height: 300px;
    background-color: #f0f0f0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    overflow: hidden;
}

.image-placeholder i {
    font-size: 3rem;
    color: #ccc;
    margin-bottom: 10px;
}

.image-placeholder p {
    color: #999;
}

/* 项目 */
.projects {
    background-color: #f9f9f9;
}

.filter-buttons {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-btn {
    padding: 8px 20px;
    background-color: transparent;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.filter-btn:hover, .filter-btn.active {
    background-color: var(--primary-color);
    color: #fff;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.project-card {
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-10px);
}

.project-image {
    height: 200px;
    overflow: hidden;
}

.project-info {
    padding: 20px;
}

.project-title {
    font-size: 1.5rem;
    margin-bottom: 5px;
}

.project-category {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 10px;
}

.project-description {
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 15px;
}

.tag {
    padding: 5px 10px;
    background-color: #f0f0f0;
    border-radius: 50px;
    font-size: 0.8rem;
}

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

.project-link {
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
}

.project-link:hover {
    color: #3a5bd9;
}

/* 技能 */
.skills-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.category-title {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.skill-item {
    margin-bottom: 20px;
}

.skill-name {
    font-weight: 600;
    margin-bottom: 5px;
}

.skill-bar {
    height: 10px;
    background-color: #f0f0f0;
    border-radius: 10px;
    overflow: hidden;
}

.skill-level {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 10px;
}

/* 联系 */
.contact {
    background-color: #f9f9f9;
}

.contact-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
}

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-right: 20px;
    width: 50px;
    height: 50px;
    background-color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--box-shadow);
}

.contact-details h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
}

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

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 600;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: inherit;
    font-size: 1rem;
}

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

/* 页脚 */
footer {
    background-color: var(--dark-color);
    color: #fff;
    padding: 30px 0;
    text-align: center;
}

/* 响应式设计 */
@media screen and (max-width: 768px) {
    .nav-links {
        position: absolute;
        right: 0;
        top: 80px;
        background-color: #fff;
        width: 100%;
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        transform: translateY(-150%);
        transition: var(--transition);
        box-shadow: var(--box-shadow);
    }

    .nav-links.active {
        transform: translateY(0);
    }

    .nav-links li {
        margin: 15px 0;
    }

    .burger {
        display: block;
    }

    .about-content {
        flex-direction: column;
    }

    .personal-info {
        grid-template-columns: 1fr;
    }

    .cta-buttons {
        flex-direction: column;
        gap: 10px;
    }

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

    .subtitle {
        font-size: 1.2rem;
    }

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

@media screen and (max-width: 480px) {
    .projects-grid {
        grid-template-columns: 1fr;
    }

    .skills-content {
        grid-template-columns: 1fr;
    }

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