/* ===== 变量 ===== */
:root {
  --bg: #fafafa;
  --bg-alt: #f3f4f6;
  --text: #171717;
  --text-muted: #737373;
  --text-light: #a3a3a3;
  --primary: #171717;
  --primary-hover: #404040;
  --card: #ffffff;
  --border: #e5e5e5;
  --radius: 12px;
  --radius-lg: 20px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ===== 导航 ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav__inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--text);
  letter-spacing: -0.02em;
}

.nav__links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.nav__links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

/* ===== 首屏 ===== */
.hero {
  max-width: 600px;
  margin: 0 auto;
  padding: 100px 24px 80px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero__avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: linear-gradient(135deg, #d4d4d4, #a3a3a3);
  margin-bottom: 28px;
}

.hero__name {
  font-size: 2.6rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 6px;
}

.hero__role {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.hero__bio {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 420px;
  line-height: 1.8;
  margin-bottom: 32px;
}

.hero__actions {
  display: flex;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 24px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
}

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

.btn--primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

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

.btn--ghost:hover {
  background: var(--bg-alt);
  border-color: var(--text-muted);
}

/* 滚动指示器 */
.hero__scroll {
  margin-top: 60px;
  width: 24px;
  height: 40px;
  border: 2px solid var(--border);
  border-radius: 12px;
  position: relative;
}

.hero__scroll span {
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: var(--text-muted);
  border-radius: 2px;
  animation: scrollBounce 2s ease-in-out infinite;
}

@keyframes scrollBounce {
  0%, 100% { top: 8px; opacity: 1; }
  50% { top: 20px; opacity: 0.3; }
}

/* ===== 通用区块 ===== */
.section {
  padding: 80px 24px;
}

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

.section__inner {
  max-width: 800px;
  margin: 0 auto;
}

.section__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.section__title {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 40px;
}

/* ===== 关于 ===== */
.about__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 48px;
  align-items: start;
}

.about__text p {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 0.95rem;
}

.about__info {
  list-style: none;
  border-left: 1px solid var(--border);
  padding-left: 24px;
}

.about__info li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-bottom: 20px;
}

.about__key {
  font-size: 0.75rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 500;
}

.about__info li span:last-child {
  font-size: 0.95rem;
  color: var(--text);
}

/* ===== 时间线 ===== */
.timeline {
  position: relative;
  padding-left: 24px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--border);
}

.timeline__item {
  position: relative;
  margin-bottom: 32px;
}

.timeline__item:last-child {
  margin-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: -24px;
  top: 8px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--primary);
  border: 2px solid var(--bg-alt);
}

.timeline__card {
  padding: 20px 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.timeline__date {
  font-size: 0.8rem;
  color: var(--text-light);
  font-weight: 500;
}

.timeline__card h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 6px 0 4px;
}

.timeline__card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0;
}

/* ===== 技能卡片 ===== */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.skill-card {
  padding: 28px 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
  transition: all 0.25s ease;
}

.skill-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
  border-color: transparent;
}

.skill-card__icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.skill-card h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.skill-card p {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin: 0;
}

/* ===== 联系 ===== */
.contact__desc {
  color: var(--text-muted);
  margin-bottom: 32px;
  font-size: 0.95rem;
}

.contact__list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.contact__item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: all 0.2s ease;
}

.contact__item:hover {
  background: var(--bg-alt);
  border-color: var(--text-muted);
}

.contact__icon {
  font-size: 1.2rem;
}

.contact__text {
  font-size: 0.95rem;
}

/* ===== 页脚 ===== */
.footer {
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid var(--border);
}

.footer p {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .hero {
    padding: 60px 24px 60px;
  }

  .hero__name {
    font-size: 2rem;
  }

  .section {
    padding: 60px 20px;
  }

  .section__title {
    font-size: 1.6rem;
    margin-bottom: 32px;
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .about__info {
    border-left: none;
    border-top: 1px solid var(--border);
    padding-left: 0;
    padding-top: 20px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .about__info li {
    margin-bottom: 0;
  }

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

  .nav__inner {
    padding: 12px 20px;
  }

  .nav__links {
    gap: 16px;
  }
}

@media (max-width: 480px) {
  .hero__actions {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    justify-content: center;
  }

  .skills__grid {
    grid-template-columns: 1fr;
  }

  .about__info {
    grid-template-columns: 1fr;
  }
}