:root {
  --bg: #f8f9fb;
  --card: #ffffff;
  --primary: #2c3e50;
  --accent: #3b82f6;
  --accent-light: #eff6ff;
  --text: #334155;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --radius: 16px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.06), 0 4px 10px rgba(0,0,0,0.03);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* Navigation */
.nav {
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(12px) saturate(180%);
  background: rgba(255,255,255,0.82);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}
.nav-inner {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; justify-content: center;
  gap: 8px; padding: 12px 0;
  flex-wrap: wrap;
}
.nav a {
  text-decoration: none; color: var(--text-muted);
  font-size: 14px; font-weight: 500;
  padding: 8px 18px; border-radius: 100px;
  transition: all 0.2s;
}
.nav a:hover, .nav a.active { color: var(--accent); background: var(--accent-light); }

/* Hero */
.hero {
  max-width: 1100px; margin: 0 auto; padding: 60px 24px 48px;
  display: flex; align-items: center; gap: 40px;
  flex-wrap: wrap;
}
.hero-avatar {
  width: 130px; height: 130px; border-radius: 50%;
  background: linear-gradient(135deg, #dbeafe, #ede9fe);
  display: flex; align-items: center; justify-content: center;
  font-size: 48px; color: var(--accent);
  flex-shrink: 0;
  box-shadow: 0 0 0 6px rgba(59,130,246,0.08);
}
.hero-info h1 { font-size: 36px; font-weight: 700; color: var(--primary); letter-spacing: -0.5px; }
.hero-info .title { font-size: 17px; color: var(--text-muted); margin: 6px 0 16px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.hero-tags span {
  background: var(--accent-light); color: var(--accent);
  font-size: 13px; font-weight: 500; padding: 5px 14px; border-radius: 100px;
}
.hero-contact { display: flex; flex-wrap: wrap; gap: 20px; margin-top: 18px; }
.hero-contact .item { display: flex; align-items: center; gap: 6px; font-size: 14px; color: var(--text-muted); }
.hero-contact .item svg { width: 16px; height: 16px; opacity: 0.6; }

/* Section */
section { max-width: 1100px; margin: 0 auto; padding: 0 24px 60px; }
.section-title {
  font-size: 22px; font-weight: 700; color: var(--primary);
  margin-bottom: 24px; display: flex; align-items: center; gap: 10px;
}
.section-title::before {
  content: ''; display: inline-block;
  width: 4px; height: 24px; background: var(--accent); border-radius: 2px;
}

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 20px; }
.card {
  background: var(--card); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
  transition: box-shadow 0.25s, transform 0.25s;
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.card h3 { font-size: 17px; font-weight: 600; color: var(--primary); margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--text-muted); }

/* Strengths */
.strength-icon {
  width: 44px; height: 44px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; margin-bottom: 14px;
}
.strength-icon.c1 { background: #eff6ff; color: #3b82f6; }
.strength-icon.c2 { background: #fef3c7; color: #f59e0b; }
.strength-icon.c3 { background: #dcfce7; color: #22c55e; }
.strength-icon.c4 { background: #fce7f3; color: #ec4899; }

/* Timeline */
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: ''; position: absolute; left: 11px; top: 6px; bottom: 6px;
  width: 2px; background: var(--border); border-radius: 1px;
}
.timeline-item { position: relative; margin-bottom: 32px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
  position: absolute; left: -27px; top: 6px;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--accent); border: 3px solid var(--card);
  box-shadow: 0 0 0 3px var(--accent-light);
}
.timeline-header { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; }
.timeline-header h3 { font-size: 17px; font-weight: 600; color: var(--primary); }
.timeline-header .date { font-size: 13px; color: var(--text-muted); white-space: nowrap; }
.timeline-company { font-size: 14px; color: var(--accent); font-weight: 500; margin: 2px 0 8px; }
.timeline-desc { font-size: 14px; color: var(--text-muted); }
.timeline-desc ul { padding-left: 18px; }
.timeline-desc li { margin-bottom: 4px; }

/* Portfolio Categories */
.portfolio-category { margin-bottom: 40px; }
.portfolio-category:last-child { margin-bottom: 0; }
.category-title {
  font-size: 17px; font-weight: 600; color: var(--primary);
  margin-bottom: 16px; padding-left: 4px;
}

/* Video Grid */
.video-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }

/* Video Card */
.video-card {
  background: var(--card); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow);
  transition: box-shadow 0.25s, transform 0.25s;
}
.video-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }

/* Video Player */
.video-player {
  width: 100%; display: block;
  aspect-ratio: 16 / 9;
  background: #0f172a;
  object-fit: contain;
}

/* Placeholder for missing video */
.video-placeholder {
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, #1e293b, #334155);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 12px; cursor: default;
}
.video-placeholder .play-icon {
  width: 56px; height: 56px; border-radius: 50%;
  background: rgba(255,255,255,0.2);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; color: #fff;
}
.video-placeholder .video-label {
  font-size: 13px; color: rgba(255,255,255,0.7);
  font-weight: 500; letter-spacing: 0.5px;
}

.video-desc {
  padding: 14px 18px; font-size: 13px; color: var(--text-muted);
}

/* Footer */
footer {
  text-align: center; padding: 40px 24px;
  font-size: 13px; color: var(--text-muted);
  border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 640px) {
  .hero { flex-direction: column; text-align: center; padding-top: 40px; }
  .hero-avatar { width: 100px; height: 100px; font-size: 36px; }
  .hero-info h1 { font-size: 28px; }
  .hero-contact { justify-content: center; }
  .nav-inner { gap: 4px; }
  .nav a { font-size: 13px; padding: 6px 14px; }
  .card-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: 1fr; }
  .category-title { font-size: 15px; }
}

/* Print */
@media print {
  .nav { display: none; }
  body { background: #fff; }
  .card, .video-card { box-shadow: none; border: 1px solid #e2e8f0; break-inside: avoid; }
  section { padding-bottom: 32px; }
}