/* ===================================
   主样式表 - 黑白极简风格个人网站
   =================================== */

/* ----------------
   CSS变量定义
   ---------------- */
:root {
    /* 颜色 */
    --color-black: #000000;
    --color-white: #FFFFFF;
    --color-dark-gray: #1a1a1a;
    --color-gray: #666666;
    --color-light-gray: #cccccc;
    --color-bg-light: #f5f5f5;
    --color-border: #e0e0e0;
    
    /* 字体 */
    --font-primary: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-code: 'JetBrains Mono', 'Consolas', monospace;
    
    /* 字号 */
    --font-size-xs: 14px;
    --font-size-sm: 16px;
    --font-size-md: 18px;
    --font-size-lg: 24px;
    --font-size-xl: 32px;
    --font-size-2xl: 48px;
    --font-size-3xl: 64px;
    
    /* 间距 */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 64px;
    --spacing-3xl: 80px;
    --spacing-4xl: 120px;
    
    /* 容器 */
    --container-width: 1200px;
    --container-padding: 24px;
    
    /* 动画 */
    --transition-speed: 0.3s;
    --transition-ease: cubic-bezier(0.4, 0, 0.2, 1);
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
}

/* ----------------
   全局样式
   ---------------- */
body {
    font-family: var(--font-primary);
    font-size: var(--font-size-sm);
    color: var(--color-black);
    background-color: var(--color-white);
    line-height: 1.6;
}

/* 容器 */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* 区块 */
.section {
    padding: var(--spacing-4xl) 0;
}

.section-dark {
    background-color: var(--color-black);
    color: var(--color-white);
}

/* 区块标题 */
.section-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: var(--font-size-md);
    color: var(--color-gray);
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-dark .section-subtitle {
    color: var(--color-light-gray);
}

/* ----------------
   导航栏
   ---------------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    transition: background-color var(--transition-speed) var(--transition-ease);
}

.navbar.scrolled {
    background-color: var(--color-black);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: var(--spacing-sm) var(--container-padding);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo a {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-white);
    transition: opacity var(--transition-speed);
}

.nav-logo a:hover {
    opacity: 0.8;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-white);
    font-size: var(--font-size-sm);
    position: relative;
    transition: opacity var(--transition-speed);
}

.nav-link:hover,
.nav-link.active {
    opacity: 0.7;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-white);
    transition: width var(--transition-speed) var(--transition-ease);
}

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

/* 汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 2px;
    background-color: var(--color-white);
    transition: all var(--transition-speed) var(--transition-ease);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

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

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

/* ----------------
   Hero 区域
   ---------------- */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: var(--color-black);
    color: var(--color-white);
    position: relative;
    padding: var(--spacing-3xl) var(--container-padding);
}

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

.hero-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    line-height: 1.1;
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--color-white) 0%, var(--color-light-gray) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-light-gray);
    margin-bottom: var(--spacing-xl);
    min-height: 40px;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    color: var(--color-white);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ----------------
   按钮样式
   ---------------- */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-align: center;
    border-radius: 4px;
    transition: all var(--transition-speed) var(--transition-ease);
    cursor: pointer;
}

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

.btn-primary:hover {
    background-color: var(--color-light-gray);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-outline:hover {
    background-color: var(--color-white);
    color: var(--color-black);
    transform: translateY(-2px);
}

.btn-small {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-xs);
}

.btn-full {
    width: 100%;
}

/* 黑色背景上的按钮 */
.section-dark .btn-primary {
    background-color: var(--color-black);
    color: var(--color-white);
    border: 2px solid var(--color-white);
}

.section-dark .btn-primary:hover {
    background-color: var(--color-white);
    color: var(--color-black);
}

/* ----------------
   关于我
   ---------------- */
.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-image {
    position: relative;
}

.image-wrapper {
    position: relative;
    width: 100%;
    padding-bottom: 100%;
    border-radius: 8px;
    overflow: hidden;
    background-color: var(--color-bg-light);
}

.avatar {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(100%);
    transition: filter var(--transition-speed);
}

.avatar:hover {
    filter: grayscale(0%);
}

.about-text h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-md);
}

.about-text p {
    color: var(--color-gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.stat-item {
    text-align: center;
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: all var(--transition-speed);
}

.stat-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-sm);
}

.stat-number {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-black);
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
    margin-top: var(--spacing-xs);
}

/* ----------------
   作品集
   ---------------- */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.portfolio-item {
    position: relative;
    cursor: pointer;
    transition: transform var(--transition-speed) var(--transition-ease);
}

.portfolio-item:hover {
    transform: translateY(-8px);
}

.portfolio-image {
    position: relative;
    width: 100%;
    padding-bottom: 75%;
    overflow: hidden;
    border-radius: 8px;
    background-color: var(--color-dark-gray);
}

.portfolio-image img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: grayscale(100%);
    transition: all var(--transition-speed);
}

.portfolio-item:hover .portfolio-image img {
    filter: grayscale(0%);
    transform: scale(1.05);
}

.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-speed);
    padding: var(--spacing-lg);
    border-radius: 8px;
}

.portfolio-item:hover .portfolio-overlay {
    opacity: 1;
}

.portfolio-info {
    text-align: center;
    color: var(--color-white);
}

.portfolio-info h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

.portfolio-info p {
    font-size: var(--font-size-xs);
    color: var(--color-light-gray);
    margin-bottom: var(--spacing-md);
}

.portfolio-tags {
    display: flex;
    gap: var(--spacing-xs);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-md);
}

.tag {
    display: inline-block;
    padding: 4px 12px;
    font-size: 12px;
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 20px;
    color: var(--color-white);
}

.portfolio-content {
    padding: var(--spacing-md) 0;
}

.portfolio-content h3 {
    font-size: var(--font-size-md);
    margin-bottom: var(--spacing-xs);
    color: var(--color-white);
}

.portfolio-content p {
    font-size: var(--font-size-xs);
    color: var(--color-light-gray);
}

/* ----------------
   技能展示
   ---------------- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
}

.skill-category h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-black);
}

.skill-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.skill-item {
    width: 100%;
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.skill-name {
    font-size: var(--font-size-sm);
    font-weight: 600;
}

.skill-percent {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
}

.skill-bar {
    width: 100%;
    height: 8px;
    background-color: var(--color-bg-light);
    border-radius: 4px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background-color: var(--color-black);
    width: 0;
    transition: width 1.5s var(--transition-ease);
}

.skill-progress.animated {
    width: var(--progress-width);
}

/* ----------------
   时间线
   ---------------- */
.timeline-container {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline-container::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-3xl);
    display: flex;
    align-items: center;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
    text-align: right;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
    text-align: left;
}

.timeline-dot {
    width: 16px;
    height: 16px;
    background-color: var(--color-white);
    border: 4px solid var(--color-black);
    border-radius: 50%;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
    transition: all var(--transition-speed);
}

.timeline-item:hover .timeline-dot {
    transform: translateX(-50%) scale(1.3);
    box-shadow: 0 0 0 8px rgba(255, 255, 255, 0.1);
}

.timeline-content {
    width: calc(50% - 40px);
    padding: var(--spacing-lg);
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    transition: all var(--transition-speed);
}

.timeline-item:hover .timeline-content {
    background-color: rgba(255, 255, 255, 0.08);
    transform: translateY(-4px);
}

.timeline-date {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--color-white);
    color: var(--color-black);
    border-radius: 20px;
    font-size: var(--font-size-xs);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.timeline-content h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xs);
}

.timeline-content h4 {
    font-size: var(--font-size-sm);
    color: var(--color-light-gray);
    margin-bottom: var(--spacing-sm);
}

.timeline-content p {
    font-size: var(--font-size-xs);
    color: var(--color-light-gray);
    line-height: 1.6;
}

/* ----------------
   文章精选
   ---------------- */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.blog-card {
    padding: var(--spacing-xl);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: all var(--transition-speed);
    background-color: var(--color-white);
}

.blog-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-black);
}

.blog-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    font-size: var(--font-size-xs);
}

.blog-date {
    color: var(--color-gray);
}

.blog-category {
    padding: 2px 12px;
    background-color: var(--color-black);
    color: var(--color-white);
    border-radius: 12px;
}

.blog-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    line-height: 1.4;
}

.blog-card p {
    color: var(--color-gray);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.blog-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.read-time {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
}

.read-more {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-black);
    transition: opacity var(--transition-speed);
}

.read-more:hover {
    opacity: 0.7;
}

.blog-cta {
    text-align: center;
}

/* ----------------
   联系方式
   ---------------- */
.contact-content {
    max-width: 600px;
    margin: 0 auto;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-3xl);
}

.social-link {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--color-white);
    border-radius: 50%;
    color: var(--color-white);
    transition: all var(--transition-speed);
}

.social-link:hover {
    background-color: var(--color-white);
    color: var(--color-black);
    transform: translateY(-4px) rotate(360deg);
}

/* 联系表单 */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-white);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.form-group input,
.form-group textarea {
    padding: var(--spacing-sm);
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    color: var(--color-white);
    font-size: var(--font-size-sm);
    transition: all var(--transition-speed);
}

.form-group input:focus,
.form-group textarea:focus {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--color-white);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ----------------
   页脚
   ---------------- */
.footer {
    background-color: var(--color-dark-gray);
    color: var(--color-light-gray);
    padding: var(--spacing-xl) 0;
    position: relative;
}

.footer-content {
    text-align: center;
}

.footer-content p {
    font-size: var(--font-size-xs);
    margin-bottom: var(--spacing-xs);
}

.footer-note {
    color: var(--color-gray);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 48px;
    height: 48px;
    background-color: var(--color-white);
    color: var(--color-black);
    border: 2px solid var(--color-black);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-speed);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--color-black);
    color: var(--color-white);
    transform: translateY(-4px);
}

/* ----------------
   响应式设计
   ---------------- */

/* 平板 */
@media (max-width: 1024px) {
    :root {
        --font-size-2xl: 40px;
        --font-size-3xl: 48px;
        --spacing-4xl: 80px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .portfolio-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .blog-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-container::before {
        left: 0;
    }
    
    .timeline-item,
    .timeline-item:nth-child(odd),
    .timeline-item:nth-child(even) {
        flex-direction: row;
        text-align: left;
    }
    
    .timeline-dot {
        left: 0;
        transform: translateX(0);
    }
    
    .timeline-item:hover .timeline-dot {
        transform: translateX(0) scale(1.3);
    }
    
    .timeline-content {
        width: calc(100% - 40px);
        margin-left: 40px;
    }
}

/* 手机 */
@media (max-width: 768px) {
    :root {
        --font-size-xl: 24px;
        --font-size-2xl: 32px;
        --font-size-3xl: 40px;
        --spacing-3xl: 48px;
        --spacing-4xl: 64px;
    }
    
    .navbar {
        position: fixed;
    }
    
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: var(--color-black);
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-speed);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        padding-top: calc(var(--spacing-3xl) + 72px);
    }
    
    .hero-title {
        font-size: var(--font-size-2xl);
    }
    
    .hero-subtitle {
        font-size: var(--font-size-lg);
    }
    
    .hero-cta {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-cta .btn {
        width: 100%;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .portfolio-grid {
        grid-template-columns: 1fr;
    }
    
    .social-links {
        gap: var(--spacing-md);
    }
    
    .back-to-top {
        bottom: 24px;
        right: 24px;
        width: 40px;
        height: 40px;
    }
}

@media (max-width: 480px) {
    :root {
        --container-padding: 16px;
        --font-size-xl: 20px;
        --font-size-2xl: 28px;
        --font-size-3xl: 36px;
    }
}