:root {
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --dark: #1e293b;
  --gray: #64748b;
  --light: #f8fafc;
  --white: #ffffff;
  --accent: #06b6d4;
  --border: #e2e8f0;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; color: var(--dark); line-height: 1.6; background: var(--white); padding-top: 64px; }

/* Nav */
nav { position: fixed; top: 0; left: 0; right: 0; background: rgba(255,255,255,0.98); backdrop-filter: blur(20px); z-index: 100; box-shadow: 0 1px 12px rgba(0,0,0,0.06); }
.nav-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; justify-content: space-between; align-items: center; height: 60px; }
.nav-logo { font-size: 20px; font-weight: 800; text-decoration: none; background: linear-gradient(135deg, #4f46e5, #7c3aed); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; letter-spacing: 0.5px; }
.nav-links { display: flex; gap: 4px; align-items: center; }
.nav-links a { color: var(--gray); text-decoration: none; font-size: 14px; font-weight: 500; transition: all 0.25s; padding: 8px 14px; border-radius: 8px; }
.nav-links a:hover { color: var(--primary); background: rgba(79,70,229,0.08); }
.nav-links a.active { color: white; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); }
@media (max-width: 768px) { .nav-links { display: none; } }

/* Page header */
.page-header { background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #06b6d4 100%); color: white; padding: 60px 24px 48px; text-align: center; }
.page-header h1 { font-size: 32px; margin-bottom: 8px; }
.page-header p { font-size: 16px; opacity: 0.8; }

/* Content */
.page-content { max-width: 1200px; margin: 0 auto; padding: 48px 24px 80px; }

/* Cards */
.card { background: var(--white); border: 1px solid var(--border); border-radius: 16px; padding: 32px; transition: all 0.3s; }
.card:hover { box-shadow: 0 12px 40px rgba(79,70,229,0.12); transform: translateY(-4px); border-color: var(--primary-light); }
.card h3 { font-size: 18px; margin-bottom: 12px; }
.card p { color: var(--gray); font-size: 14px; line-height: 1.7; }

/* Grid */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }
.grid-projects { display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); gap: 24px; }
@media (max-width: 768px) { .grid-2 { grid-template-columns: 1fr; } }

/* Section */
.section-divider { width: 60px; height: 4px; background: var(--primary); margin: 0 auto 48px; border-radius: 2px; }

/* Tags */
.tag { background: var(--light); border: 1px solid var(--border); padding: 8px 18px; border-radius: 20px; font-size: 14px; color: var(--dark); transition: all 0.3s; display: inline-block; }
.tag:hover { border-color: var(--primary); color: var(--primary); }
.tag.highlight { background: var(--primary); color: white; border-color: var(--primary); }
.tags-wrap { display: flex; flex-wrap: wrap; gap: 10px; }

/* Icon */
.icon-box { width: 48px; height: 48px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 16px; }

/* Timeline */
.timeline { position: relative; max-width: 900px; margin: 0 auto; }
.timeline::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 2px; background: var(--border); }
.timeline-item { position: relative; padding-left: 32px; padding-bottom: 40px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot { position: absolute; left: -6px; top: 4px; width: 14px; height: 14px; border-radius: 50%; background: var(--primary); border: 3px solid var(--white); box-shadow: 0 0 0 2px var(--primary); }
.timeline-date { font-size: 14px; color: var(--primary); font-weight: 600; margin-bottom: 4px; }
.timeline-title { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
.timeline-company { color: var(--gray); font-size: 15px; margin-bottom: 8px; }
.timeline-desc { color: var(--gray); font-size: 14px; line-height: 1.7; }

/* Project cards */
.project-card { background: var(--white); border: 1px solid var(--border); border-radius: 16px; overflow: hidden; transition: all 0.3s; }
.project-card:hover { box-shadow: 0 12px 40px rgba(79,70,229,0.12); transform: translateY(-4px); }
.project-header { padding: 24px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: white; }
.project-header h3 { font-size: 18px; margin-bottom: 6px; }
.project-meta { display: flex; gap: 12px; font-size: 13px; opacity: 0.85; flex-wrap: wrap; }
.project-budget { background: rgba(255,255,255,0.2); padding: 2px 10px; border-radius: 12px; }
.project-body { padding: 24px; }
.project-tech { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.tech-tag { background: var(--light); color: var(--gray); padding: 4px 12px; border-radius: 12px; font-size: 12px; }
.tech-tag.xinchuang { background: #fef3c7; color: #92400e; }
.project-body p { color: var(--gray); font-size: 14px; line-height: 1.7; }
.project-result { margin-top: 12px; padding: 12px; background: #ecfdf5; border-radius: 10px; font-size: 14px; color: #065f46; }

/* Case cards */
.case-card { border: 2px dashed var(--border); border-radius: 16px; padding: 48px 32px; text-align: center; transition: all 0.3s; background: var(--light); }
.case-card:hover { border-color: var(--primary-light); background: var(--white); }
.case-icon { font-size: 48px; margin-bottom: 16px; opacity: 0.4; }
.case-badge { display: inline-block; background: var(--light); color: var(--gray); padding: 4px 14px; border-radius: 12px; font-size: 12px; }

/* Contact */
.contact-section { background: linear-gradient(135deg, var(--dark), #0f172a); color: white; padding: 80px 24px; text-align: center; }
.contact-inner { max-width: 600px; margin: 0 auto; }
.contact-items { display: flex; flex-direction: column; gap: 16px; align-items: center; }
.contact-item { display: flex; align-items: center; gap: 12px; background: rgba(255,255,255,0.08); padding: 16px 32px; border-radius: 30px; text-decoration: none; color: white; font-size: 16px; transition: all 0.3s; }
.contact-item:hover { background: rgba(255,255,255,0.15); transform: translateY(-2px); }

/* Footer */
footer { background: var(--dark); color: rgba(255,255,255,0.5); text-align: center; padding: 24px; font-size: 13px; }
footer a { color: rgba(255,255,255,0.6); text-decoration: none; }
footer a:hover { color: white; }

/* Info table */
.info-table { background: white; border: 1px solid var(--border); border-radius: 16px; padding: 0; overflow: hidden; }
.info-table-title { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: white; padding: 20px 28px; font-size: 16px; font-weight: 700; display: flex; align-items: center; gap: 8px; }
.info-row { display: flex; align-items: center; padding: 16px 28px; transition: background 0.2s; }
.info-row:hover { background: var(--light); }
.info-row:not(:last-child) { border-bottom: 1px solid var(--border); }
.info-label { width: 80px; color: var(--gray); font-size: 13px; flex-shrink: 0; }
.info-value { font-weight: 600; color: var(--dark); font-size: 15px; }

/* Skills */
.skills-container { background: var(--light); border-radius: 20px; padding: 48px; }
.skills-category { margin-bottom: 32px; }
.skills-category:last-child { margin-bottom: 0; }
.skills-category-title { font-size: 16px; font-weight: 700; margin-bottom: 16px; color: var(--primary); }

/* Hero (index only) */
.hero { background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #06b6d4 100%); color: white; padding: 120px 24px 100px; text-align: center; position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -50%; left: -20%; width: 60%; height: 200%; background: radial-gradient(ellipse, rgba(255,255,255,0.08), transparent 60%); pointer-events: none; }
.hero::after { content: ''; position: absolute; bottom: -50%; right: -20%; width: 60%; height: 200%; background: radial-gradient(ellipse, rgba(6,182,212,0.15), transparent 60%); pointer-events: none; }
.hero h1 { font-size: 36px; margin-bottom: 12px; }
.hero-subtitle { font-size: 28px; font-weight: 700; margin-bottom: 20px; letter-spacing: 2px; position: relative; }
.hero-subtitle::after { content: ''; display: block; width: 50px; height: 3px; background: rgba(255,255,255,0.6); margin: 16px auto 0; border-radius: 2px; }
.hero-tagline { font-size: 15px; opacity: 0.85; max-width: 900px; margin: 0 auto 32px; white-space: nowrap; letter-spacing: 0.5px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin-bottom: 32px; }
.hero-tag { background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3); padding: 8px 20px; border-radius: 25px; font-size: 14px; }
.hero-contact { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-contact a { background: rgba(255,255,255,0.15); border: 2px solid rgba(255,255,255,0.4); color: white; text-decoration: none; padding: 12px 28px; border-radius: 30px; font-size: 15px; transition: all 0.3s; }
.hero-contact a:hover { background: white; color: var(--primary); }

/* Home cards */
.home-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; max-width: 1200px; margin: 0 auto; padding: 0 24px 80px; }
.home-card { background: var(--white); border: 1px solid var(--border); border-radius: 16px; padding: 32px; text-decoration: none; color: var(--dark); transition: all 0.3s; display: block; }
.home-card:hover { box-shadow: 0 12px 40px rgba(79,70,229,0.12); transform: translateY(-4px); border-color: var(--primary-light); }
.home-card-icon { width: 48px; height: 48px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 16px; }
.home-card h3 { font-size: 18px; margin-bottom: 8px; }
.home-card p { color: var(--gray); font-size: 14px; line-height: 1.7; }
.home-card-arrow { margin-top: 16px; color: var(--primary); font-size: 14px; font-weight: 600; }