/* ===== CSS 变量 ===== */
:root {
  --bg-primary:    #0a0a0f;
  --bg-secondary:  #12121a;
  --bg-elevated:   #1a1a25;
  --border:        #2a2a3a;
  --text-primary:  #e8e8f0;
  --text-secondary:#9090a0;
  --text-muted:    #5a5a6a;
  --accent:        #a855f7;
  --accent-cyan:   #00d4ff;
  --accent-glow:   rgba(168, 85, 247, 0.15);
  --radius-card:   12px;
  --radius-btn:    8px;
  --max-width:     1100px;
  --nav-height:    64px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: 'Inter', -apple-system, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

img { display: block; max-width: 100%; }

/* ===== 容器 ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

/* ===== 通用板块标题 ===== */
.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 3rem;
}

/* ===== 导航 ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.05em;
}

.nav__menu {
  display: flex;
  gap: 2rem;
}

.nav__menu a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

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

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}

.nav__hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__hamburger.open span:nth-child(2) { opacity: 0; }
.nav__hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: var(--nav-height);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
}

.hero__greeting {
  color: var(--text-secondary);
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
  letter-spacing: 0.05em;
}

.hero__name {
  font-size: 4.5rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__title {
  font-family: 'JetBrains Mono', 'Consolas', monospace;
  font-size: 1.25rem;
  color: var(--accent-cyan);
  min-height: 2rem;
  margin-bottom: 1.5rem;
}

.hero__title::after {
  content: '|';
  animation: blink 1s step-end infinite;
  color: var(--accent);
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.hero__tagline {
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 3rem;
}

.hero__scroll {
  display: inline-block;
  color: var(--text-muted);
  font-size: 1.5rem;
  animation: bounce 2s ease-in-out infinite;
  transition: color 0.2s;
}

.hero__scroll:hover { color: var(--accent); }

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

/* ===== About ===== */
.about {
  padding: 6rem 0;
}

.about__content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  margin-top: 3rem;
}

.about__left {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.about__avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 2px solid var(--accent);
  margin-bottom: 1rem;
  background: var(--bg-secondary);
}

.about__name {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.about__headline {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.about__stats {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.stat-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 1.25rem 1.75rem;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  transition: border-color 0.25s, background 0.25s;
}

.stat-card:hover {
  border-color: var(--accent);
  background: var(--bg-elevated);
}

.stat-card__value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-cyan);
  line-height: 1;
}

.stat-card__label {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== Projects ===== */
.projects {
  padding: 6rem 0;
  background: var(--bg-secondary);
}

.projects__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.project-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
}

.project-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.project-card__name {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.project-card__desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}


.projects__more {
  text-align: center;
}

.btn-outline {
  display: inline-block;
  border: 1px solid var(--accent);
  color: var(--accent);
  border-radius: var(--radius-btn);
  padding: 0.6rem 1.75rem;
  font-size: 0.95rem;
  transition: background 0.2s, color 0.2s;
}

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

/* ===== 页脚 ===== */
.footer {
  padding: 3rem 0;
  text-align: center;
  border-top: 1px solid var(--border);
}

.footer__social {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.footer__social a {
  color: var(--text-muted);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--border);
  transition: color 0.2s, border-color 0.2s;
}

.footer__social a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.footer__social svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.footer__copy {
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* ===== 滚动淡入 ===== */
[data-fade] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-fade].visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Focus visible ===== */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ===== prefers-reduced-motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  [data-fade] { opacity: 1; transform: none; }
}

/* ===== 平板 768–1023px ===== */
@media (max-width: 1023px) {
  .projects__grid { grid-template-columns: repeat(2, 1fr); }
}

/* ===== 手机 <768px ===== */
@media (max-width: 767px) {
  .section-title { font-size: 1.75rem; }

  .nav__menu {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0; right: 0;
    flex-direction: column;
    background: rgba(10, 10, 15, 0.97);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem 1.5rem;
    gap: 1.25rem;
  }

  .nav__menu.open { display: flex; }

  .nav__hamburger { display: flex; }

  .hero__name { font-size: 2.5rem; }

  .hero__title { font-size: 1rem; }

  .about { padding: 3rem 0; }

  .about__content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .about__stats { flex-direction: row; flex-wrap: wrap; }

  .stat-card { flex: 1; min-width: 140px; }

  .projects { padding: 3rem 0; }

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