:root {
  --bg: #ffffff;
  --bg-alt: #f6f8fa;
  --text: #1f2328;
  --text-muted: #59636e;
  --border: #e3e6e9;
  --primary: #2563eb;
  --primary-soft: rgba(37, 99, 235, 0.1);
  --radius: 12px;
  --shadow: 0 4px 24px rgba(31, 35, 40, 0.06);
  --font: "Inter", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --container: 1024px;
  --nav-h: 64px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-h);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

/* ---------- Hero ---------- */
.hero {
  padding: 96px 0 72px;
  background:
    radial-gradient(60% 50% at 80% 0%, var(--primary-soft), transparent 70%),
    var(--bg);
}

.hero-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 48px;
}

.hero-text {
  flex: 1;
  max-width: 560px;
}

.hero-eyebrow {
  color: var(--primary);
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.hero-desc {
  color: var(--text-muted);
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.3);
}

.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.hero-avatar {
  flex-shrink: 0;
}

.avatar-inner {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  font-weight: 600;
  color: var(--primary);
  background: linear-gradient(135deg, var(--primary-soft), transparent);
  border: 2px solid var(--border);
  user-select: none;
}

/* ---------- Sections ---------- */
.section {
  padding: 88px 0;
}

.section-alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-title {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 32px;
}

.about-content {
  max-width: 640px;
  color: var(--text-muted);
  display: grid;
  gap: 16px;
}

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.contact-card {
  display: grid;
  gap: 6px;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  text-decoration: none;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.contact-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.contact-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.contact-value {
  font-weight: 500;
  color: var(--primary);
  word-break: break-all;
}

/* ---------- Footer ---------- */
.site-footer {
  padding: 40px 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-year {
  margin-bottom: 4px;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .hero {
    padding: 64px 0 48px;
  }

  .hero-inner {
    flex-direction: column-reverse;
    text-align: center;
  }

  .hero-text {
    max-width: 100%;
  }

  .hero-actions {
    justify-content: center;
  }

  .avatar-inner {
    width: 120px;
    height: 120px;
    font-size: 3rem;
  }

  .section {
    padding: 64px 0;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 8px 0;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li {
    width: 100%;
  }

  .nav-links a {
    display: block;
    padding: 12px 24px;
  }

  .nav-toggle.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle.open span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}