:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --text: #1a1d21;
  --text-muted: #5b6470;
  --accent: #4f6ef2;
  --accent-dark: #3a54c9;
  --border: #e6e8ec;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(26, 29, 33, 0.06);
  --container: 1080px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* 导航 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.4rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo .dot {
  color: var(--accent);
}

.nav-links {
  display: flex;
  gap: 28px;
}

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

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

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

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

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

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

/* Hero */
.hero {
  padding: 120px 0 100px;
  text-align: center;
}

.hero-eyebrow {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.hero-desc {
  max-width: 560px;
  margin: 0 auto 36px;
  color: var(--text-muted);
  font-size: 1.02rem;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

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

.btn-primary:hover {
  background: var(--accent-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(79, 110, 242, 0.3);
}

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

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

/* 通用区块 */
.section {
  padding: 90px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 40px;
  position: relative;
  padding-bottom: 12px;
}

.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 40px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* 关于 */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 48px;
  align-items: start;
}

.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.about-facts {
  list-style: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.about-facts li {
  display: flex;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  font-size: 0.95rem;
}

.about-facts li:last-child {
  border-bottom: none;
}

.about-facts strong {
  color: var(--text-muted);
  font-weight: 500;
}

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

.skill-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.skill-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.skill-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.skill-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* 作品 */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.project-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
  transition: transform 0.2s, box-shadow 0.2s;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.project-cover {
  height: 160px;
}

.cover-a {
  background: linear-gradient(135deg, #4f6ef2, #8aa2ff);
}

.cover-b {
  background: linear-gradient(135deg, #14b8a6, #5eead4);
}

.cover-c {
  background: linear-gradient(135deg, #f59e0b, #fcd34d);
}

.project-card h3 {
  font-size: 1.15rem;
  padding: 20px 20px 0;
}

.project-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
  padding: 10px 20px;
}

.project-tag {
  display: inline-block;
  margin: 0 20px 20px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--bg-alt);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 500;
}

/* 联系 */
.contact-lead {
  color: var(--text-muted);
  margin-bottom: 32px;
  max-width: 520px;
}

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

/* 页脚 */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* 响应式 */
@media (max-width: 768px) {
  .hero {
    padding: 80px 0 70px;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .section {
    padding: 64px 0;
  }

  .nav-links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px 20px;
    gap: 14px;
    display: none;
  }

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

  .nav-toggle {
    display: flex;
  }

  .hero-actions,
  .contact-actions {
    flex-direction: column;
    align-items: stretch;
  }
}