/* --- 基础变量与重置 --- */
:root {
    --bg-color: #0a0a0c;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --accent-color: #3b82f6;
    --accent-glow: rgba(59, 130, 246, 0.5);
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-hover-bg: rgba(255, 255, 255, 0.06);
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* --- 导航栏 --- */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 10, 12, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

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

/* --- Hero 首屏 --- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 0 2rem;
    text-align: center;
    overflow: hidden;
}

.hero-glow {
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59,130,246,0.15) 0%, rgba(10,10,12,0) 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: -1;
    pointer-events: none;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 800;
    letter-spacing: -1px;
    background: linear-gradient(to right, #fff, #9ca3af);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.hero-subtitle {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.hero-desc {
    max-width: 600px;
    margin: 0 auto 2.5rem auto;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* --- 按钮组件 --- */
.btn {
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--text-primary);
    color: var(--bg-color);
}

.btn-primary:hover {
    background: #e5e7eb;
    box-shadow: 0 0 15px rgba(255,255,255,0.2);
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-primary);
    border-color: var(--glass-border);
}

.btn-secondary:hover {
    background: var(--card-hover-bg);
    border-color: rgba(255,255,255,0.2);
}

/* --- 通用区块与卡片 --- */
.section {
    padding: 6rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.glass-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2rem;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-5px);
    background: var(--card-hover-bg);
    border-color: rgba(255, 255, 255, 0.15);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(59, 130, 246, 0.1);
}

/* --- About & Tech Stack --- */
.about-grid {
    display: grid;
    grid-template-columns: 3fr 2fr;
    gap: 2rem;
}

.about-text h3, .tech-tags h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
    color: var(--text-primary);
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.tags-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
}

.tag {
    background: rgba(59, 130, 246, 0.1);
    color: #60a5fa;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid rgba(59, 130, 246, 0.2);
}

/* --- Grid 布局 (Projects & Blog) --- */
.card-grid {
    display: grid;
    gap: 2rem;
}

.projects-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.blog-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.card-icon {
    width: 40px;
    height: 40px;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    line-height: 1.4;
}

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

.card-link {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 600;
    display: inline-block;
}

.card-link:hover {
    color: #60a5fa;
}

.blog-date {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.8rem;
    font-family: monospace;
}

/* --- 页脚 --- */
.footer {
    border-top: 1px solid var(--glass-border);
    padding: 4rem 0 2rem 0;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-brand h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: 1rem;
}

.footer-bottom {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* --- 动画 --- */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* --- 响应式 --- */
@media (max-width: 768px) {
    .nav-links {
        display: none; /* 移动端极简处理，隐藏导航链接 */
    }
    
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}