/* 全局重置与变量 */
:root {
  --bg: #f8f9fa;
  --text: #1a1a2e;
  --primary: #1a1a2e;
  --accent: #f5c518;
  --card: #fff;
  --border: #e0e0e0;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --radius: 12px;
  --max-w: 1200px;
  --glass-bg: rgba(255,255,255,0.15);
  --glass-border: rgba(255,255,255,0.3);
  --glass-shadow: 0 8px 32px rgba(0,0,0,0.1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d1a;
    --text: #eaeaea;
    --primary: #0d0d1a;
    --card: #1a1a2e;
    --border: #2a2a3e;
    --shadow: 0 2px 8px rgba(0,0,0,0.5);
    --glass-bg: rgba(26,26,46,0.6);
    --glass-border: rgba(255,255,255,0.1);
    --glass-shadow: 0 8px 32px rgba(0,0,0,0.3);
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* 滚动动画基础 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

section {
  padding: 60px 20px;
  animation: fadeInUp 0.6s ease-out;
}

/* 头部导航 */
header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  max-width: var(--max-w);
  margin: 0 auto;
}

.logo {
  font-weight: 700;
  font-size: 1.4rem;
  color: var(--accent);
  letter-spacing: 1px;
  transition: transform 0.3s;
}

.logo:hover {
  transform: scale(1.05);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  padding: 6px 0;
  font-size: 0.95rem;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s, color 0.2s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s;
}

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

.nav-links a:hover {
  border-bottom-color: transparent;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
  transition: transform 0.2s;
}

.menu-toggle:hover {
  transform: rotate(90deg);
}

/* Hero 区域 - 渐变Banner */
.hero {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  color: #fff;
  padding: 100px 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(245,197,24,0.1) 0%, transparent 60%);
  animation: heroGlow 8s ease-in-out infinite;
}

@keyframes heroGlow {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(30px, -30px); }
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 0.5rem;
  position: relative;
  z-index: 1;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto 1.5rem;
  opacity: 0.95;
  position: relative;
  z-index: 1;
}

.hero .btn {
  display: inline-block;
  background: var(--accent);
  color: #1a1a2e;
  padding: 14px 36px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 1rem;
  transition: transform 0.3s, box-shadow 0.3s;
  border: none;
  cursor: pointer;
  position: relative;
  z-index: 1;
  box-shadow: 0 4px 15px rgba(245,197,24,0.3);
}

.hero .btn:hover {
  transform: scale(1.08) translateY(-2px);
  box-shadow: 0 8px 25px rgba(245,197,24,0.5);
}

/* 标题样式 */
.section-title {
  font-size: 1.8rem;
  margin-bottom: 1rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 50px;
  height: 3px;
  background: var(--accent);
  margin-top: 6px;
  transition: width 0.3s;
}

.section-title:hover::after {
  width: 80px;
}

/* 网格布局 */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
  align-items: start;
}

.grid-3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 24px;
}

/* 卡片 - 圆角 + 毛玻璃效果 */
.card {
  background: var(--card);
  padding: 28px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.3s, box-shadow 0.3s, background 0.3s;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(245,197,24,0.05), transparent);
  transition: left 0.5s;
}

.card:hover::before {
  left: 100%;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.12);
}

/* 毛玻璃卡片变体 */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
}

.card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
  color: var(--accent);
}

.card p {
  font-size: 0.95rem;
  opacity: 0.85;
  line-height: 1.7;
}

/* FAQ 样式 */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
  cursor: pointer;
  transition: background 0.2s;
  border-radius: 8px;
  padding-left: 12px;
  padding-right: 12px;
}

.faq-item:hover {
  background: rgba(245,197,24,0.05);
}

.faq-question {
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1.05rem;
}

.faq-question span {
  font-size: 1.4rem;
  transition: transform 0.3s;
  color: var(--accent);
}

.faq-item.open .faq-question span {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease, opacity 0.3s ease;
  padding-top: 0;
  opacity: 0;
  color: var(--text);
  opacity: 0.8;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding-top: 14px;
  opacity: 1;
}

/* 使用指南步骤 */
.howto-step {
  display: flex;
  gap: 18px;
  margin-bottom: 22px;
  align-items: flex-start;
  transition: transform 0.2s;
}

.howto-step:hover {
  transform: translateX(6px);
}

.howto-step .num {
  background: var(--accent);
  color: #1a1a2e;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
  font-size: 1.1rem;
  box-shadow: 0 4px 12px rgba(245,197,24,0.3);
  transition: transform 0.3s;
}

.howto-step:hover .num {
  transform: scale(1.1);
}

/* 联系信息 */
.contact-info p {
  margin-bottom: 10px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--border);
}

.contact-info p:last-child {
  border-bottom: none;
}

/* 页脚 */
.footer {
  background: var(--card);
  border-top: 1px solid var(--border);
  padding: 40px 20px;
  font-size: 0.9rem;
  text-align: center;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.footer .legal-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  margin-top: 14px;
}

.footer a {
  color: var(--text);
  text-decoration: underline;
  transition: color 0.2s;
}

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

/* 回到顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--accent);
  color: #1a1a2e;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 4px 20px rgba(245,197,24,0.4);
  cursor: pointer;
  border: none;
  z-index: 99;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s, visibility 0.4s, transform 0.3s;
  transform: scale(0.8);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: scale(1);
}

.back-to-top:hover {
  transform: scale(1.15) translateY(-3px);
  box-shadow: 0 6px 25px rgba(245,197,24,0.6);
}

/* 特殊背景区域 */
#company,
#services,
#industries,
#workflow,
#testimonials,
#howto {
  background: var(--card);
  position: relative;
}

#company::before,
#services::before,
#industries::before,
#workflow::before,
#testimonials::before,
#howto::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(245,197,24,0.03) 0%, transparent 50%);
  pointer-events: none;
}

/* 知识中心文章卡片 */
#knowledge .card {
  border-left: 3px solid var(--accent);
}

/* 响应式设计 */
@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero {
    padding: 70px 20px;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    background: var(--card);
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }

  .nav-links.open {
    display: flex;
    animation: slideDown 0.3s ease-out;
  }

  @keyframes slideDown {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .nav-links li {
    padding: 8px 0;
  }

  .nav-links a {
    font-size: 1.1rem;
  }

  .menu-toggle {
    display: block;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .card {
    padding: 20px;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
    font-size: 1.3rem;
  }

  .footer .legal-links {
    gap: 16px;
  }

  .howto-step {
    gap: 14px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.6rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .hero .btn {
    padding: 12px 28px;
    font-size: 0.95rem;
  }

  section {
    padding: 40px 16px;
  }

  .container {
    padding: 0 14px;
  }
}

/* 暗色模式增强适配 */
@media (prefers-color-scheme: dark) {
  .card {
    border-color: var(--border);
  }

  .hero {
    background: linear-gradient(135deg, #0a0a1a 0%, #12122a 50%, #1a1a3e 100%);
  }

  .hero::before {
    background: radial-gradient(circle, rgba(245,197,24,0.08) 0%, transparent 60%);
  }

  .glass-card {
    background: rgba(26,26,46,0.7);
  }

  .faq-item:hover {
    background: rgba(245,197,24,0.08);
  }

  .back-to-top {
    box-shadow: 0 4px 20px rgba(245,197,24,0.3);
  }
}

/* 打印样式 */
@media print {
  .back-to-top,
  .menu-toggle {
    display: none !important;
  }

  .hero {
    background: #1a1a2e !important;
    color: #fff !important;
  }

  .card {
    break-inside: avoid;
    box-shadow: none;
  }
}