/* ==================== 
   基础样式与变量
   ==================== */
:root {
    /* 蓝绿色系配色 */
    --primary-color: #2E8B8B;      /* 深青色 */
    --primary-light: #3AAFA9;      /* 浅青色 */
    --primary-dark: #1A5F5F;       /* 深色青 */
    --accent-color: #5BB5B5;       /* 强调色 */
    --secondary-color: #4ECDC4;    /* 辅助色 */
    
    /* 背景色 */
    --bg-light: #F0F9F9;           /* 浅青背景 */
    --bg-white: #FFFFFF;
    --bg-card: #FAFCFC;
    
    /* 文字色 */
    --text-primary: #2C3E50;
    --text-secondary: #5A6C7D;
    --text-light: #8A9BA8;
    
    /* 其他 */
    --border-color: #D1E8E8;
    --shadow: 0 4px 20px rgba(46, 139, 139, 0.1);
    --shadow-hover: 0 8px 30px rgba(46, 139, 139, 0.15);
    --radius: 12px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-light);
}

.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);
    z-index: 1000;
    transition: var(--transition);
    border-bottom: 1px solid transparent;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    border-bottom-color: var(--border-color);
    box-shadow: var(--shadow);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

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

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

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

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: var(--transition);
}

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

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

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

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 3px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* ==================== 
   个人简介区 (Hero)
   ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    background: linear-gradient(135deg, var(--bg-light) 0%, #E8F5F5 50%, #D9F0F0 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(78, 205, 196, 0.15) 0%, transparent 70%);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(46, 139, 139, 0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 4rem;
    position: relative;
    z-index: 1;
}

.avatar {
    flex-shrink: 0;
}

.avatar-placeholder {
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
    font-weight: 700;
    box-shadow: 0 10px 40px rgba(46, 139, 139, 0.3);
    border: 5px solid white;
}

.hero-text h1 {
    font-size: 3rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.hero-text .subtitle {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.hero-text .school-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.school-icon {
    font-size: 1.2rem;
}

.hero-text .intro {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 500px;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 2rem;
    border-radius: 50px;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: 0 4px 15px rgba(46, 139, 139, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(46, 139, 139, 0.4);
}

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

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

/* ==================== 
   技能展示区
   ==================== */
.skills-section {
    padding: 100px 0;
    background: var(--bg-white);
}

.section-title {
    text-align: center;
    font-size: 2.25rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: 1rem auto 0;
    border-radius: 2px;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.skill-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-light);
}

.skill-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.skill-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.skill-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.skill-level {
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.skill-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 4px;
    width: var(--level);
    transition: width 1s ease;
}

/* ==================== 
   课程列表区
   ==================== */
.courses-section {
    padding: 100px 0;
    background: var(--bg-light);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.course-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius);
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-light);
}

.course-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: var(--transition);
}

.course-card:hover::before {
    transform: scaleX(1);
}

.course-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.course-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.course-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    flex-grow: 1;
    line-height: 1.6;
}

.course-status {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.375rem 1rem;
    background: var(--bg-light);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    align-self: flex-start;
}

.course-card-placeholder {
    background: linear-gradient(135deg, var(--bg-light), #E8F5F5);
    border-style: dashed;
    cursor: default;
}

.course-card-placeholder:hover {
    transform: none;
    box-shadow: none;
}

.course-card-placeholder .course-status {
    background: var(--border-color);
    color: var(--text-secondary);
}

/* ==================== 
   联系方式区
   ==================== */
.contact-section {
    padding: 100px 0;
    background: var(--bg-white);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-card);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.contact-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow);
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

.social-links {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    padding: 2rem;
    background: linear-gradient(135deg, var(--bg-light), #E8F5F5);
    border-radius: var(--radius);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background: var(--bg-white);
    border-radius: 50%;
    color: var(--primary-color);
    transition: var(--transition);
    box-shadow: var(--shadow);
}

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

/* ==================== 
   页脚
   ==================== */
.footer {
    background: var(--primary-dark);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
}

.footer-note {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* ==================== 
   响应式设计
   ==================== */
@media (max-width: 992px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }

    .hero-text .intro {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-buttons {
        justify-content: center;
    }

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

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        align-items: center;
        padding: 2rem;
        gap: 1.5rem;
        transform: translateY(-150%);
        transition: var(--transition);
        box-shadow: var(--shadow);
    }

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

    .hero-text h1 {
        font-size: 2.25rem;
    }

    .avatar-placeholder {
        width: 150px;
        height: 150px;
        font-size: 3rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

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

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

    .btn {
        width: 100%;
        max-width: 250px;
    }
}

@media (max-width: 480px) {
    .navbar .container {
        height: 60px;
    }

    .hero {
        padding-top: 60px;
    }

    .hero-text h1 {
        font-size: 1.75rem;
    }

    .hero-text .subtitle {
        font-size: 1rem;
    }

    .avatar-placeholder {
        width: 120px;
        height: 120px;
        font-size: 2.5rem;
    }

    .skills-section,
    .courses-section,
    .contact-section {
        padding: 60px 0;
    }

    .skill-card,
    .course-card {
        padding: 1.5rem;
    }
}

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

.hero-content,
.skill-card,
.course-card,
.contact-item {
    animation: fadeInUp 0.6s ease forwards;
}

.skill-card:nth-child(1) { animation-delay: 0.1s; }
.skill-card:nth-child(2) { animation-delay: 0.2s; }
.skill-card:nth-child(3) { animation-delay: 0.3s; }
.skill-card:nth-child(4) { animation-delay: 0.4s; }

.course-card:nth-child(1) { animation-delay: 0.1s; }
.course-card:nth-child(2) { animation-delay: 0.15s; }
.course-card:nth-child(3) { animation-delay: 0.2s; }
.course-card:nth-child(4) { animation-delay: 0.25s; }
.course-card:nth-child(5) { animation-delay: 0.3s; }
.course-card:nth-child(6) { animation-delay: 0.35s; }