/* ===== 全局重置与变量 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --brand: #0b1a2e;
  --brand-light: #1a3050;
  --accent: #f0b429;
  --accent2: #d99f1c;
  --glass: rgba(255, 255, 255, 0.15);
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
  --radius: 24px;
  --radius-sm: 12px;
  --transition: 0.25s ease;
  --font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  --bg: #f5f7fc;
  --text: #1a2332;
  --card-bg: rgba(255, 255, 255, 0.7);
  --card-border: rgba(255, 255, 255, 0.2);
  --header-bg: rgba(255, 255, 255, 0.7);
  --header-border: rgba(0, 0, 0, 0.02);
  --nav-bg: rgba(255, 255, 255, 0.95);
  --brand-story-bg: rgba(255, 255, 255, 0.3);
  --faq-answer-color: #5a6a7a;
  --footer-border: rgba(255, 255, 255, 0.05);
  --input-bg: var(--glass);
  --input-border: rgba(255, 255, 255, 0.2);
}

body.dark {
  --bg: #0b111e;
  --text: #e3e8f0;
  --glass: rgba(0, 0, 0, 0.4);
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.5);
  --card-bg: rgba(20, 28, 48, 0.7);
  --card-border: rgba(255, 255, 255, 0.05);
  --header-bg: rgba(10, 16, 30, 0.8);
  --header-border: rgba(255, 255, 255, 0.05);
  --nav-bg: rgba(8, 14, 28, 0.96);
  --brand-story-bg: rgba(0, 0, 0, 0.2);
  --faq-answer-color: #a0b0c0;
  --footer-border: rgba(255, 255, 255, 0.05);
  --input-bg: rgba(0, 0, 0, 0.4);
  --input-border: rgba(255, 255, 255, 0.1);
}

body {
  font-family: var(--font-family);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 通用组件 ===== */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 24px;
  transition: transform 0.2s, background 0.3s;
  border: 1px solid var(--card-border);
}

.card:hover {
  transform: translateY(-4px);
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #0b1a2e;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: 40px;
  text-decoration: none;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background: var(--accent2);
  transform: scale(1.02);
  box-shadow: 0 6px 16px rgba(240, 180, 41, 0.3);
}

.gradient-bg {
  background: linear-gradient(145deg, #0b1a2e 0%, #1f3a5f 100%);
}

body.dark .gradient-bg {
  background: linear-gradient(145deg, #030712 0%, #162040 100%);
}

.glass-effect {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius);
}

/* ===== 头部 ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--header-border);
  transition: background 0.3s;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
}

.logo svg {
  height: 44px;
  width: auto;
  display: block;
}

.nav {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav a {
  text-decoration: none;
  color: inherit;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
  position: relative;
}

.nav a:hover,
.nav a.active {
  color: var(--accent);
}

.nav a.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent);
  border-radius: 4px;
}

.dark-toggle {
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 30px;
  padding: 6px 14px;
  font-size: 0.9rem;
  cursor: pointer;
  color: inherit;
  transition: 0.2s;
}

.dark-toggle:hover {
  background: var(--glass);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: inherit;
}

@media (max-width: 768px) {
  .nav {
    display: none;
    flex-direction: column;
    background: var(--nav-bg);
    position: absolute;
    top: 68px;
    left: 0;
    width: 100%;
    padding: 20px 24px;
    gap: 16px;
    backdrop-filter: blur(20px);
  }

  .nav.open {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }
}

/* ===== Hero ===== */
.hero {
  padding: 80px 0 100px;
  position: relative;
  overflow: hidden;
  color: white;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(240, 180, 41, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-grid {
  display: flex;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
}

.hero-text {
  flex: 1 1 380px;
}

.hero-text h1 {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.hero-text .accent {
  color: var(--accent);
}

.hero-text p {
  font-size: 1.2rem;
  margin: 24px 0 32px;
  opacity: 0.85;
  max-width: 520px;
}

.hero-visual {
  flex: 1 1 340px;
  display: flex;
  justify-content: center;
}

.hero-visual svg {
  width: 100%;
  max-width: 460px;
  height: auto;
  filter: drop-shadow(0 12px 30px rgba(0, 0, 0, 0.1));
}

/* ===== 通用section ===== */
section {
  padding: 72px 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 40px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--accent);
  border-radius: 8px;
  margin-top: 8px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

/* ===== 品牌介绍+故事+历程+文化 ===== */
.brand-story {
  background: var(--brand-story-bg);
  backdrop-filter: blur(4px);
  border-radius: var(--radius);
  padding: 28px;
}

.timeline {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 20px;
}

.timeline-item {
  background: var(--glass);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  flex: 1 1 140px;
  border-left: 4px solid var(--accent);
}

/* ===== 产品卡片 ===== */
.product-icon {
  margin-bottom: 12px;
}

.product-icon svg {
  width: 48px;
  height: 48px;
}

/* ===== 案例轮播 ===== */
.carousel-wrap {
  overflow: hidden;
  position: relative;
}

.carousel-track {
  display: flex;
  transition: transform 0.4s ease;
  gap: 24px;
}

.carousel-item {
  min-width: 280px;
  flex: 1;
  background: var(--glass);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-sm);
  padding: 24px;
}

/* ===== FAQ ===== */
.faq-item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding: 16px 0;
  cursor: pointer;
}

.faq-question {
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.2s;
  padding-top: 0;
  color: var(--faq-answer-color);
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-top: 12px;
}

/* ===== 联系区域 ===== */
.contact-block {
  background: var(--brand);
  color: white;
  border-radius: var(--radius);
  padding: 40px;
}

body.dark .contact-block {
  background: #0a1428;
}

.contact-block a {
  color: var(--accent);
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--footer-border);
  padding: 40px 0 20px;
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 32px;
  margin-bottom: 20px;
}

.footer-links a {
  color: inherit;
  opacity: 0.7;
  text-decoration: none;
}

.footer-links a:hover {
  opacity: 1;
}

/* ===== 动画辅助 ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.count-up {
  font-weight: 700;
}

/* ===== 搜索模拟 ===== */
.search-sim {
  display: flex;
  gap: 8px;
  max-width: 400px;
  margin: 20px 0;
}

.search-sim input {
  flex: 1;
  padding: 12px 18px;
  border-radius: 40px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  backdrop-filter: blur(4px);
  color: inherit;
}

.search-sim button {
  background: var(--accent);
  border: none;
  border-radius: 40px;
  padding: 0 22px;
  font-weight: 600;
  color: #0b1a2e;
  cursor: pointer;
}

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed;
  bottom: 40px;
  right: 30px;
  background: var(--accent);
  color: #0b1a2e;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.3s;
  border: none;
}

.back-top.show {
  opacity: 1;
}

/* ===== 响应式调整 ===== */
@media (max-width: 640px) {
  .hero-text h1 {
    font-size: 2.2rem;
  }

  .section-title {
    font-size: 1.6rem;
  }
}