/* ========================================
   基础变量与重置
   ======================================== */
:root {
    /* 主色调 - 深色科技风 */
    --color-bg: #0a0a0f;
    --color-bg-secondary: #12121a;
    --color-bg-card: #1a1a25;
    --color-bg-hover: #252535;
    
    /* 强调色 - 蓝紫渐变 */
    --color-primary: #6366f1;
    --color-primary-light: #818cf8;
    --color-secondary: #a855f7;
    --color-accent: #22d3ee;
    
    /* 文字颜色 */
    --color-text: #f8fafc;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    
    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    --gradient-accent: linear-gradient(135deg, var(--color-accent) 0%, var(--color-primary) 100%);
    --gradient-text: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-accent) 100%);
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -4px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);
    
    /* 字体 */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    /* 间距 */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* 重置 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

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

/* 粒子背景画布 */
#particle-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--space-md) 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    padding: var(--space-sm) 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
}

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

.nav-menu {
    display: flex;
    gap: var(--space-xl);
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    position: relative;
    transition: color var(--transition-fast);
    padding: var(--space-xs) 0;
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--color-text);
}

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

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

.bar {
    width: 25px;
    height: 2px;
    background: var(--color-text);
    transition: all var(--transition-base);
    border-radius: 2px;
}

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

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

.hamburger.active .bar:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: var(--space-3xl) var(--space-lg);
    text-align: center;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
}

.hero-greeting {
    margin-bottom: var(--space-md);
}

.greeting-text {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--color-primary-light);
    letter-spacing: 0.1em;
}

.hero-title {
    margin-bottom: var(--space-lg);
}

.title-line {
    display: block;
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    line-height: 1.1;
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.title-line.secondary {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    font-weight: 400;
    color: var(--color-text-secondary);
    -webkit-text-fill-color: var(--color-text-secondary);
    margin-top: var(--space-sm);
}

.hero-typing {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    margin-bottom: var(--space-xl);
    min-height: 2rem;
}

.typing-prefix {
    color: var(--color-text-secondary);
}

.typing-text {
    color: var(--color-accent);
}

.typing-cursor {
    color: var(--color-primary);
    animation: blink 1s infinite;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

.hero-description {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--space-xl);
    line-height: 1.8;
}

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

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

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

.btn-secondary:hover {
    border-color: var(--color-primary);
    background: rgba(99, 102, 241, 0.1);
}

.btn-icon {
    width: 18px;
    height: 18px;
    transition: transform var(--transition-base);
}

.btn:hover .btn-icon {
    transform: translateX(4px);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* 滚动指示器 */
.hero-scroll {
    position: absolute;
    bottom: var(--space-xl);
    left: 50%;
    transform: translateX(-50%);
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    opacity: 0.6;
    animation: bounce 2s infinite;
}

.scroll-text {
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-muted);
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--color-primary);
    border-bottom: 2px solid var(--color-primary);
    transform: rotate(45deg);
}

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

/* ========================================
   通用区块样式
   ======================================== */
.section {
    padding: var(--space-3xl) 0;
    position: relative;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-number {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.section-subtitle {
    font-size: 1rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

/* ========================================
   关于我
   ======================================== */
.about-content {
    display: grid;
    gap: var(--space-3xl);
}

.about-text {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.about-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.about-card:hover {
    transform: translateY(-5px);
    border-color: rgba(99, 102, 241, 0.3);
    box-shadow: var(--shadow-lg);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
}

.card-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.about-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.about-card p {
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* 统计数据 */
.about-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--space-lg);
    text-align: center;
}

.stat-item {
    padding: var(--space-lg);
}

.stat-number {
    display: block;
    font-size: 3rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: var(--space-xs);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

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

.timeline-line {
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--color-primary), var(--color-secondary));
}

.timeline-item {
    position: relative;
    padding-left: 60px;
    padding-bottom: var(--space-2xl);
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: 11px;
    top: 5px;
    width: 20px;
    height: 20px;
    background: var(--color-bg);
    border: 3px solid var(--color-primary);
    border-radius: 50%;
    transition: all var(--transition-base);
}

.timeline-item:hover .timeline-dot {
    background: var(--color-primary);
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.5);
}

.timeline-content {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.timeline-content:hover {
    border-color: rgba(99, 102, 241, 0.2);
}

.timeline-period {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary-light);
    margin-bottom: var(--space-xs);
}

.timeline-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.timeline-company {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    margin-bottom: var(--space-md);
}

.timeline-desc {
    margin-bottom: var(--space-md);
}

.timeline-desc li {
    color: var(--color-text-secondary);
    padding-left: var(--space-md);
    position: relative;
    margin-bottom: var(--space-xs);
}

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

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
}

.tag {
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.15);
    color: var(--color-primary-light);
    border-radius: var(--radius-full);
    border: 1px solid rgba(99, 102, 241, 0.3);
}

/* ========================================
   技能
   ======================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.skill-category {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.skill-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.skill-icon {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.skill-icon svg {
    width: 24px;
    height: 24px;
    color: white;
}

.skill-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.skill-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.skill-name {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.skill-bar {
    height: 6px;
    background: var(--color-bg-hover);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    width: 0;
    transition: width 1s ease-out;
}

/* ========================================
   联系
   ======================================== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: start;
}

.contact-info h3 {
    font-size: 1.75rem;
    margin-bottom: var(--space-md);
}

.contact-info > p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.contact-link {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.contact-link:hover {
    border-color: var(--color-primary);
    background: var(--color-bg-hover);
    transform: translateX(5px);
}

.link-icon {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.link-icon svg {
    width: 22px;
    height: 22px;
    color: white;
}

.link-text {
    display: flex;
    flex-direction: column;
}

.link-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.link-value {
    font-size: 0.95rem;
    color: var(--color-text);
    font-weight: 500;
}

/* 联系表单 */
.contact-form {
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.form-group {
    position: relative;
    margin-bottom: var(--space-lg);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--space-md) 0;
    font-size: 1rem;
    color: var(--color-text);
    background: transparent;
    border: none;
    border-bottom: 2px solid var(--color-bg-hover);
    outline: none;
    transition: border-color var(--transition-base);
    font-family: inherit;
}

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

.form-group label {
    position: absolute;
    left: 0;
    top: var(--space-md);
    font-size: 1rem;
    color: var(--color-text-muted);
    pointer-events: none;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group input:not(:placeholder-shown),
.form-group textarea:not(:placeholder-shown) {
    border-color: var(--color-primary);
}

.form-group input:focus ~ label,
.form-group textarea:focus ~ label,
.form-group input:not(:placeholder-shown) ~ label,
.form-group textarea:not(:placeholder-shown) ~ label {
    top: -10px;
    font-size: 0.75rem;
    color: var(--color-primary-light);
}

.form-line {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-base);
}

.form-group input:focus ~ .form-line,
.form-group textarea:focus ~ .form-line {
    width: 100%;
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-content {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.footer-logo {
    font-family: var(--font-mono);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
}

.footer-text {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.footer-social {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

.social-link {
    width: 44px;
    height: 44px;
    background: var(--color-bg-card);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

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

.social-link svg {
    width: 20px;
    height: 20px;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-tech {
    margin-top: var(--space-xs);
    font-family: var(--font-mono);
    font-size: 0.75rem !important;
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--color-bg);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: var(--space-xl) 0;
        gap: var(--space-md);
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        padding-top: 100px;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
    
    .about-text {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .timeline-line {
        left: 15px;
    }
    
    .timeline-item {
        padding-left: 45px;
    }
    
    .timeline-dot {
        left: 6px;
        width: 18px;
        height: 18px;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --space-lg: 1.5rem;
        --space-xl: 2rem;
        --space-2xl: 3rem;
        --space-3xl: 4rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .about-stats {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-md);
    }
}

/* ========================================
   动画类（用于JS触发）
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* 技能条动画 */
.skill-item.animate .skill-progress {
    width: var(--skill-level);
}