/* ========================================
   星屿科技 · 布局系统
   网格 + 板块间距 + 导航布局
   ======================================== */

/* ── 板块通用 ── */
.section {
  position: relative;
  z-index: var(--z-content);
  padding-block: var(--space-32);
}

.section-title {
  margin-bottom: var(--space-16);
}

.section-title h2 {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-3);
}

.section-title p {
  color: var(--color-text-muted);
  font-size: var(--text-lg);
}

/* ── 网格系统 ── */
.grid {
  display: grid;
  gap: var(--space-8);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ── Flex 工具 ── */
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col { display: flex; flex-direction: column; }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* ── 导航 ── */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  padding: var(--space-4) 0;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition:
    padding var(--duration-normal) var(--ease-out),
    background var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out);
}

.nav.scrolled {
  padding-block: var(--space-2);
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.06);
}

.nav-inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding);
}

.brand {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.brand-text {
  font-weight: var(--font-bold);
  font-size: var(--text-lg);
  color: var(--color-text-primary);
}

.brand:hover { color: inherit; }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
}

.nav-links a {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  padding: var(--space-2) var(--space-1);
  position: relative;
  transition: color var(--duration-fast) var(--ease-out);
}

/* 文字翻转动画 */
.nav-links a span {
  display: inline-block;
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease-out;
}

.nav-links a span::before {
  content: attr(data-title);
  position: absolute;
  top: 0;
  left: 0;
  color: var(--color-accent);
  transform: translateY(-110%);
  transition: transform 0.3s ease-out;
}

.nav-links a:hover span {
  transform: translateY(110%);
}

.nav-links a:hover span::before {
  transform: translateY(0);
}

/* 下划线保留给 active */
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--duration-normal) var(--ease-out);
}

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

.nav-links a.active::after {
  width: 100%;
}

/* ── 汉堡菜单 ── */
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-secondary);
  padding: var(--space-2);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* ── Hero ── */
.hero {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  z-index: var(--z-content);
  overflow: hidden;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  padding: var(--space-20) var(--container-padding);
}

.hero-glow {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero-glow);
  pointer-events: none;
  z-index: 0;
}

/* ── Footer ── */
.footer {
  position: relative;
  z-index: var(--z-content);
  padding-block: var(--space-16);
  border-top: none;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-accent-cyan), var(--color-accent));
  opacity: 0.5;
}

/* ── 响应式 ── */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding-block: var(--space-20); }
  .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }

  .nav-links {
    display: none;
    position: fixed;
    inset: 0;
    top: 56px;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    padding: var(--space-10) var(--space-8);
    gap: var(--space-2);
    z-index: 101;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .nav-links.open { display: flex; }
  .nav-links a {
    font-size: var(--text-lg);
    padding: var(--space-4) var(--space-4);
    min-height: 48px;
    display: flex;
    align-items: center;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast) var(--ease-out);
  }
  .nav-links a:hover,
  .nav-links a:active {
    background: rgba(14, 165, 233, 0.06);
  }
  .nav-hamburger { display: flex; }
}

@media (max-width: 480px) {
  .section { padding-block: var(--space-16); }
  .hero-content { padding: var(--space-12) var(--space-4); }
}