:root {
  --primary: #1d1d1f;
  --accent: #ff6b35;
  --bg: #f2f2f0;
  --ink: #111111;
  --muted: #5c5c58;
  --line: rgba(17, 17, 17, 0.12);
  --max: 1160px;
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 700;
}

p {
  margin: 0;
}

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 页头 ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(242, 242, 240, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: block;
  flex: 0 0 auto;
}

.brand-logo {
  display: block;
  height: 46px;
  width: auto;
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  font-size: 15px;
}

.primary-nav a {
  position: relative;
  padding: 4px 0;
  color: var(--ink);
}

.primary-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.25s ease;
}

.primary-nav a:hover::after {
  width: 100%;
}

.primary-nav .nav-cta {
  background: var(--primary);
  color: #fff;
  padding: 10px 20px;
  font-size: 14px;
}

.primary-nav .nav-cta::after {
  display: none;
}

.primary-nav .nav-cta:hover {
  background: var(--accent);
  color: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: none;
  border: 1px solid var(--line);
  cursor: pointer;
}

.menu-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background: var(--primary);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-bar:first-child {
  transform: translateY(4px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-bar:nth-child(2) {
  transform: translateY(-4px) rotate(-45deg);
}

/* ---------- 区块通用 ---------- */

.section {
  max-width: var(--max);
  margin: 0 auto;
  padding: 92px 24px;
  border-top: 1px solid var(--line);
}

.section-label {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 34px;
}

.section-label::before {
  content: "";
  width: 44px;
  height: 1px;
  background: var(--accent);
}

.section h2 {
  font-size: clamp(1.55rem, 2.6vw, 2.15rem);
  margin-bottom: 24px;
}

/* ---------- 滚动显现 ---------- */

body.reveal-ready .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

body.reveal-ready .reveal.is-visible {
  opacity: 1;
  transform: none;
}

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

  body.reveal-ready .reveal,
  body.reveal-ready .reveal.is-visible {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ---------- 响应式：页头与区块 ---------- */

@media (max-width: 960px) {
  .section {
    padding: 68px 24px;
  }
}

@media (max-width: 768px) {
  .header-inner {
    height: 66px;
  }

  .brand-logo {
    height: 38px;
  }

  .menu-toggle {
    display: flex;
  }

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 8px 24px 20px;
    display: none;
  }

  .primary-nav.is-open {
    display: flex;
  }

  .primary-nav a {
    width: 100%;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
  }

  .primary-nav a::after {
    display: none;
  }

  .primary-nav .nav-cta {
    margin-top: 14px;
    text-align: center;
    border-bottom: 0;
  }
}