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

:root {
    --bg: #ffffff;
    --bg-grey: #f7f7f7;
    --text: #1a1a1a;
    --text-sub: #666;
    --text-light: #999;
    --border: #e8e8e8;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
    --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
    --shadow-3d: 0 20px 60px rgba(0,0,0,0.15), 0 4px 12px rgba(0,0,0,0.08);
    --radius: 16px;
    --radius-sm: 10px;
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
.hidden { display: none !important; }

.container { max-width: 960px; margin: 0 auto; padding: 0 2rem; }

/* ===== 导航栏 ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 100;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.nav-inner {
    max-width: 960px; margin: 0 auto;
    padding: 0 2rem;
    display: flex; align-items: center; justify-content: space-between;
    height: 56px;
}

.logo { font-size: 1.2rem; font-weight: 700; letter-spacing: -0.02em; }
.dot { color: #e74c3c; }

.nav-links { display: flex; gap: 2rem; }
.nav-links a {
    font-size: 0.85rem; font-weight: 500;
    color: var(--text-sub);
    transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

.menu-btn {
    display: none; background: none; border: none;
    cursor: pointer; flex-direction: column; gap: 5px; padding: 4px;
}
.menu-btn span {
    width: 20px; height: 2px; background: var(--text);
    display: block; transition: 0.3s;
}

.mobile-menu {
    position: fixed; top: 56px; left: 0; right: 0;
    background: white; padding: 1rem 2rem;
    display: flex; flex-direction: column; gap: 0.8rem;
    border-bottom: 1px solid var(--border);
    z-index: 99;
    box-shadow: var(--shadow-md);
}

/* ===== Hero ===== */
.hero {
    padding: 120px 0 60px;
    min-height: 80vh;
    display: flex; align-items: center;
}

.hero-grid {
    display: grid; grid-template-columns: 1fr 280px;
    gap: 3rem; align-items: center;
}

.hero-sub {
    font-size: 1rem; color: var(--text-light);
    margin-bottom: 0.3rem;
}

.hero-name {
    font-size: 3.5rem; font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: 0.5rem;
}

.hero-title {
    font-size: 1.2rem; color: var(--text-sub);
    font-weight: 500;
    margin-bottom: 0.3rem;
}

.hero-desc {
    font-size: 0.95rem; color: var(--text-light);
    margin-bottom: 2rem;
}

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

.btn {
    display: inline-flex; align-items: center; gap: 0.4rem;
    padding: 0.7rem 1.4rem;
    border-radius: 10px;
    font-weight: 600; font-size: 0.9rem;
    transition: all 0.25s;
    cursor: pointer;
}

.btn-dark {
    background: #1a1a1a; color: white;
}
.btn-dark:hover { background: #333; transform: translateY(-2px); box-shadow: var(--shadow-md); }

.btn-outline {
    background: transparent; border: 1.5px solid var(--border);
    color: var(--text);
}
.btn-outline:hover { border-color: #1a1a1a; transform: translateY(-2px); }

/* ===== 3D 头像 ===== */
.hero-avatar-wrap {
    perspective: 800px;
    display: flex; justify-content: center;
}

.hero-avatar-3d {
    width: 240px; height: 300px;
    border-radius: 20px;
    overflow: hidden;
    background: linear-gradient(135deg, #f5f5f5, #e8e8e8);
    box-shadow: var(--shadow-3d);
    transform: rotateY(-5deg) rotateX(3deg);
    transition: transform 0.4s cubic-bezier(0.03, 0.98, 0.52, 0.99);
}

.hero-avatar-3d:hover {
    transform: rotateY(0deg) rotateX(0deg) scale(1.02);
}

.hero-avatar-3d img {
    width: 100%; height: 100%; object-fit: cover;
}

.hero-avatar-3d.fallback {
    display: flex; align-items: center; justify-content: center;
    font-size: 80px;
}
.hero-avatar-3d.fallback::after {
    content: '‍💻';
}

/* ===== Section ===== */
.section { padding: 5rem 0; }
.section-grey { background: var(--bg-grey); }

.section-heading {
    font-size: 1.8rem; font-weight: 700;
    margin-bottom: 2.5rem;
    letter-spacing: -0.02em;
}

/* ===== 关于我 ===== */
.about-grid {
    display: grid; grid-template-columns: 200px 1fr;
    gap: 3rem; align-items: start;
}

.about-photo-3d { perspective: 600px; }

.card-3d {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-3d);
    transform: rotateY(-3deg) rotateX(2deg);
    transition: transform 0.4s;
}

.card-3d:hover {
    transform: rotateY(0) rotateX(0) scale(1.02);
}

.card-3d img { width: 100%; aspect-ratio: 3/4; object-fit: cover; }

.about-social-row {
    display: flex; gap: 0.6rem;
    margin-top: 1rem; justify-content: center;
}

.social-btn {
    width: 36px; height: 36px;
    border-radius: 50%;
    background: #f0f0f0;
    display: flex; align-items: center; justify-content: center;
    color: var(--text);
    transition: all 0.2s;
}
.social-btn:hover { background: #1a1a1a; color: white; transform: translateY(-3px); box-shadow: var(--shadow-sm); }

.about-content p {
    font-size: 0.95rem; color: var(--text-sub);
    margin-bottom: 0.6rem;
    line-height: 1.8;
}

.stats-row {
    display: flex; gap: 1rem;
    margin-top: 1.5rem;
}

.stat-card-3d {
    flex: 1;
    padding: 1rem;
    background: white;
    border-radius: var(--radius-sm);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transform: translateY(0);
    transition: transform 0.3s, box-shadow 0.3s;
}

.stat-card-3d:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.stat-num {
    display: block; font-size: 1.5rem; font-weight: 800;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label { font-size: 0.75rem; color: var(--text-light); }

/* ===== 项目 ===== */
.project-grid {
    display: grid; grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.project-card-3d {
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transform: perspective(800px) rotateX(0) rotateY(0) translateY(0);
    transition: all 0.4s cubic-bezier(0.03, 0.98, 0.52, 0.99);
    cursor: pointer;
}

.project-card-3d:hover {
    transform: perspective(800px) rotateX(-2deg) rotateY(2deg) translateY(-8px);
    box-shadow: var(--shadow-3d);
}

.project-thumb {
    height: 140px;
    display: flex; align-items: center; justify-content: center;
}

.project-icon { font-size: 3rem; }

.project-body { padding: 1.2rem; }

.project-body h3 {
    font-size: 1.05rem; font-weight: 700;
    margin-bottom: 0.3rem;
}

.project-body > p {
    font-size: 0.85rem; color: var(--text-sub);
    margin-bottom: 0.6rem;
    line-height: 1.5;
}

.project-tags {
    display: flex; flex-wrap: wrap; gap: 0.3rem;
    margin-bottom: 0.6rem;
}

.project-tags span {
    font-size: 0.7rem;
    padding: 0.15rem 0.5rem;
    border-radius: 20px;
    background: #f5f0ff;
    color: #764ba2;
    font-weight: 500;
}

.project-meta {
    display: flex; gap: 1rem;
    font-size: 0.75rem; color: var(--text-light);
}

/* ===== GitHub ===== */
.github-card-3d {
    background: white;
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    max-width: 700px; margin: 0 auto;
    transform: translateY(0);
    transition: transform 0.3s, box-shadow 0.3s;
}

.github-card-3d:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.github-header {
    display: flex; align-items: center; gap: 1rem;
    margin-bottom: 1rem;
}

.github-avatar { width: 44px; height: 44px; border-radius: 50%; }
.github-header h3 { font-size: 1rem; }
.github-link { font-size: 0.8rem; color: var(--text-light); }

.github-chart { width: 100%; border-radius: 8px; }

/* ===== 教育 ===== */
.edu-card-3d {
    background: white;
    border-radius: var(--radius);
    padding: 1.5rem 1.5rem 1.5rem 2rem;
    box-shadow: var(--shadow-md);
    position: relative;
    max-width: 500px;
    transform: translateY(0);
    transition: transform 0.3s, box-shadow 0.3s;
}

.edu-card-3d:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.edu-timeline-bar {
    position: absolute; left: 0; top: 0; bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, #667eea, #764ba2);
    border-radius: 4px 0 0 4px;
}

.edu-year {
    font-size: 0.8rem; color: var(--text-light);
    display: block; margin-bottom: 0.2rem;
}

.edu-info h3 { font-size: 1.2rem; margin-bottom: 0.1rem; }
.edu-info p { font-size: 0.9rem; color: var(--text-sub); }
.edu-detail { font-size: 0.8rem !important; color: var(--text-light) !important; margin-top: 0.2rem; }

/* ===== 技能 ===== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    max-width: 600px; margin: 0 auto;
}

.skill-card-3d {
    background: white;
    border-radius: var(--radius-sm);
    padding: 1.2rem 0.8rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transform: perspective(500px) rotateX(0);
    transition: all 0.3s cubic-bezier(0.03, 0.98, 0.52, 0.99);
    cursor: default;
}

.skill-card-3d:hover {
    transform: perspective(500px) rotateX(-5deg) translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.skill-icon { font-size: 1.8rem; margin-bottom: 0.4rem; }

.skill-card-3d span {
    font-size: 0.8rem; font-weight: 600;
    display: block;
}

/* ===== 联系 ===== */
.contact-grid {
    display: flex; justify-content: center; gap: 1.2rem;
    flex-wrap: wrap;
}

.contact-card-3d {
    display: flex; align-items: center; gap: 0.6rem;
    padding: 1rem 1.5rem;
    background: white;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
    font-weight: 600; font-size: 0.9rem;
    transition: all 0.3s cubic-bezier(0.03, 0.98, 0.52, 0.99);
}

.contact-card-3d:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.contact-card-3d svg { color: var(--text-sub); }

/* ===== 底部 ===== */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-light);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
}

/* ===== 滚动动画 ===== */
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s, transform 0.6s;
}

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

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .menu-btn { display: flex; }

    .hero-grid { grid-template-columns: 1fr; text-align: center; }
    .hero-name { font-size: 2.5rem; }
    .hero-actions { justify-content: center; }
    .hero-avatar-wrap { order: -1; }
    .hero-avatar-3d { width: 180px; height: 220px; }

    .about-grid { grid-template-columns: 1fr; }
    .about-photo-3d { max-width: 180px; margin: 0 auto; }

    .project-grid { grid-template-columns: 1fr; }
    .skills-grid { grid-template-columns: repeat(2, 1fr); }
}