/* ===== 全局重置 & CSS变量 ===== */
:root {
  --bg-primary: #0a0a1a;
  --bg-secondary: #12122a;
  --bg-card: rgba(18, 18, 42, 0.7);
  --bg-glass: rgba(255, 255, 255, 0.08);
  --text-primary: #f0f0ff;
  --text-secondary: #b0b0d0;
  --text-muted: #7a7a9a;
  --accent-gold: #f7c948;
  --accent-rose: #e94560;
  --accent-blue: #4a6cf7;
  --accent-cyan: #00d4ff;
  --gradient-hero: linear-gradient(135deg, #0a0a1a 0%, #1a1a3e 40%, #2a1a4e 100%);
  --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.05), rgba(255,255,255,0.02));
  --shadow-card: 0 8px 32px rgba(0,0,0,0.4), 0 2px 8px rgba(0,0,0,0.2);
  --shadow-glow: 0 0 20px rgba(247, 201, 72, 0.15);
  --border-glass: 1px solid rgba(255,255,255,0.08);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-med: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* 暗色模式默认已启用（深色主题） */
body.dark-mode {
  --bg-primary: #0a0a1a;
  --bg-secondary: #12122a;
  --bg-card: rgba(18, 18, 42, 0.7);
  --text-primary: #f0f0ff;
  --text-secondary: #b0b0d0;
  --text-muted: #7a7a9a;
}

/* ===== 基础样式 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  transition: background var(--transition-med), color var(--transition-med);
  overflow-x: hidden;
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--accent-gold);
  text-decoration: none;
}

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

ul, ol {
  list-style: none;
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: var(--accent-gold);
  border-radius: 3px;
}

/* ===== 导航栏 ===== */
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 2rem;
  background: rgba(10, 10, 26, 0.85);
  backdrop-filter: blur(20px) saturate(1.2);
  -webkit-backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: var(--border-glass);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: background var(--transition-med);
}

nav > a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}
nav > a svg {
  filter: drop-shadow(0 0 8px rgba(247, 201, 72, 0.3));
}
nav > a span {
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-rose));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

nav ul {
  display: flex;
  gap: 0.25rem;
  align-items: center;
}

nav ul li a {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  transition: all var(--transition-fast);
}
nav ul li a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 60%;
  height: 2px;
  background: var(--accent-gold);
  border-radius: 1px;
  transition: transform var(--transition-med);
}
nav ul li a:hover {
  color: var(--text-primary);
  background: var(--bg-glass);
}
nav ul li a.active {
  color: var(--accent-gold);
}
nav ul li a.active::after {
  transform: translateX(-50%) scaleX(1);
}

#darkModeToggle {
  background: var(--bg-glass);
  border: var(--border-glass);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  transition: all var(--transition-fast);
  color: var(--text-primary);
  backdrop-filter: blur(4px);
}
#darkModeToggle:hover {
  background: rgba(255,255,255,0.15);
  transform: scale(1.05);
  box-shadow: var(--shadow-glow);
}

#mobileMenuBtn {
  display: none;
  background: var(--bg-glass);
  border: var(--border-glass);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
  transition: all var(--transition-fast);
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}
#mobileMenuBtn:hover {
  background: rgba(255,255,255,0.15);
}

/* ===== 主内容区 ===== */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* ===== 通用Section样式（毛玻璃卡片） ===== */
section {
  margin-bottom: 2.5rem;
  padding: 2.5rem 2rem;
  background: var(--bg-card);
  backdrop-filter: blur(12px) saturate(1.1);
  -webkit-backdrop-filter: blur(12px) saturate(1.1);
  border: var(--border-glass);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  transition: transform var(--transition-med), box-shadow var(--transition-med);
  position: relative;
  overflow: hidden;
}
section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-card);
  pointer-events: none;
  border-radius: inherit;
}
section:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.5), 0 0 30px rgba(247, 201, 72, 0.05);
}

section > * {
  position: relative;
  z-index: 1;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-rose), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.5px;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--text-primary);
  position: relative;
  padding-bottom: 0.6rem;
  letter-spacing: -0.3px;
}
h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-rose));
  border-radius: 2px;
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
  color: var(--accent-gold);
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ===== Hero区域（渐变Banner） ===== */
#hero {
  text-align: center;
  padding: 5rem 2rem 4rem;
  background: var(--gradient-hero);
  border: none;
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
}
#hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(247, 201, 72, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(233, 69, 96, 0.06) 0%, transparent 50%);
  animation: heroGlow 8s ease-in-out infinite alternate;
  pointer-events: none;
}
@keyframes heroGlow {
  0% { transform: translate(0, 0) rotate(0deg); }
  100% { transform: translate(2%, -2%) rotate(3deg); }
}

#hero h1 {
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  margin-bottom: 1.2rem;
  -webkit-text-fill-color: transparent;
  animation: heroTitleFade 1s ease-out;
}
@keyframes heroTitleFade {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

#hero p {
  font-size: 1.15rem;
  color: rgba(255,255,255,0.8);
  max-width: 650px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

#hero a[role="button"] {
  display: inline-block;
  margin: 0.4rem 0.6rem;
  padding: 0.85rem 2.5rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-med);
  position: relative;
  overflow: hidden;
  letter-spacing: 0.3px;
}
#hero a[role="button"]:first-of-type {
  background: linear-gradient(135deg, var(--accent-gold), #e6b422);
  color: #0a0a1a;
  box-shadow: 0 4px 20px rgba(247, 201, 72, 0.3);
}
#hero a[role="button"]:first-of-type:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(247, 201, 72, 0.4);
}
#hero a[role="button"]:last-of-type {
  background: var(--bg-glass);
  color: var(--text-primary);
  border: 1px solid rgba(255,255,255,0.15);
  backdrop-filter: blur(8px);
}
#hero a[role="button"]:last-of-type:hover {
  background: rgba(255,255,255,0.12);
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.3);
}

/* ===== 关于我们 ===== */
#about p:last-of-type {
  margin-bottom: 0;
}

/* ===== 服务列表 ===== */
#services ul li {
  padding: 0.8rem 1rem 0.8rem 2rem;
  position: relative;
  margin-bottom: 0.5rem;
  background: var(--bg-glass);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}
#services ul li::before {
  content: '✦';
  position: absolute;
  left: 0.8rem;
  color: var(--accent-gold);
  font-size: 0.8rem;
}
#services ul li:hover {
  background: rgba(255,255,255,0.06);
  transform: translateX(4px);
}
#services ul li strong {
  color: var(--accent-cyan);
  margin-right: 0.5rem;
}

/* ===== 特色列表 ===== */
#features ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}
#features ul li {
  padding: 1.2rem;
  background: var(--bg-glass);
  border-radius: var(--radius-md);
  border: var(--border-glass);
  transition: all var(--transition-med);
  text-align: center;
}
#features ul li:hover {
  transform: translateY(-4px);
  background: rgba(255,255,255,0.06);
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
  border-color: rgba(247, 201, 72, 0.2);
}
#features ul li strong {
  display: block;
  font-size: 1.1rem;
  color: var(--accent-gold);
  margin-bottom: 0.4rem;
}

/* ===== FAQ（手风琴） ===== */
#faq dl {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
#faq dt {
  font-weight: 600;
  cursor: pointer;
  padding: 0.9rem 1rem;
  background: var(--bg-glass);
  border-radius: var(--radius-sm);
  border: var(--border-glass);
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-primary);
  user-select: none;
}
#faq dt::after {
  content: '+';
  font-size: 1.2rem;
  color: var(--accent-gold);
  transition: transform var(--transition-fast);
}
#faq dt.active::after {
  transform: rotate(45deg);
}
#faq dt:hover {
  background: rgba(255,255,255,0.06);
  border-color: rgba(247, 201, 72, 0.2);
}
#faq dd {
  padding: 0.8rem 1.2rem;
  display: none;
  color: var(--text-secondary);
  line-height: 1.7;
  border-left: 2px solid var(--accent-gold);
  margin-left: 1rem;
  animation: faqSlide 0.3s ease-out;
}
@keyframes faqSlide {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}
#faq dd.active {
  display: block;
}

/* ===== HowTo步骤 ===== */
#howto ol {
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}
#howto ol li {
  counter-increment: step;
  padding: 1rem 1rem 1rem 3rem;
  background: var(--bg-glass);
  border-radius: var(--radius-sm);
  position: relative;
  transition: all var(--transition-fast);
}
#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-rose));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: #0a0a1a;
}
#howto ol li:hover {
  background: rgba(255,255,255,0.06);
  transform: translateX(4px);
}
#howto ol li strong {
  color: var(--accent-cyan);
  margin-right: 0.4rem;
}

/* ===== 知识中心 ===== */
#knowledge-hub {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}
#knowledge-hub h2 {
  grid-column: 1 / -1;
}
#knowledge-hub article {
  padding: 1.5rem;
  background: var(--bg-glass);
  border-radius: var(--radius-md);
  border: var(--border-glass);
  transition: all var(--transition-med);
  display: flex;
  flex-direction: column;
}
#knowledge-hub article:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
  border-color: rgba(74, 108, 247, 0.2);
}
#knowledge-hub article h3 {
  font-size: 1.1rem;
  margin-bottom: 0.6rem;
}
#knowledge-hub article p {
  font-size: 0.9rem;
  flex: 1;
  margin-bottom: 1rem;
}
#knowledge-hub article a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--accent-cyan);
  transition: all var(--transition-fast);
}
#knowledge-hub article a::after {
  content: '→';
  transition: transform var(--transition-fast);
}
#knowledge-hub article a:hover {
  color: var(--accent-gold);
}
#knowledge-hub article a:hover::after {
  transform: translateX(4px);
}

/* ===== 联系我们 ===== */
#contact address {
  font-style: normal;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}
#contact address p {
  padding: 0.8rem 1rem;
  background: var(--bg-glass);
  border-radius: var(--radius-sm);
  border: var(--border-glass);
  margin-bottom: 0;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transition: all var(--transition-fast);
}
#contact address p:hover {
  background: rgba(255,255,255,0.06);
}
#contact address a {
  color: var(--accent-gold);
  font-weight: 500;
}

/* ===== 页脚 ===== */
footer {
  background: var(--bg-secondary);
  padding: 2.5rem 2rem 1.5rem;
  text-align: center;
  border-top: var(--border-glass);
  margin-top: 3rem;
}
footer nav ul {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.2rem;
  flex-wrap: wrap;
}
footer nav ul li a {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
  position: relative;
}
footer nav ul li a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent-gold);
  transition: width var(--transition-med);
}
footer nav ul li a:hover {
  color: var(--accent-gold);
}
footer nav ul li a:hover::after {
  width: 100%;
}
footer p {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 0;
}

/* ===== 返回顶部按钮 ===== */
#backToTop {
  display: none;
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--accent-gold), #e6b422);
  color: #0a0a1a;
  border: none;
  border-radius: 50%;
  font-size: 1.4rem;
  cursor: pointer;
  z-index: 999;
  box-shadow: 0 4px 20px rgba(247, 201, 72, 0.3);
  transition: all var(--transition-med);
  display: flex;
  align-items: center;
  justify-content: center;
}
#backToTop:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 30px rgba(247, 201, 72, 0.4);
}
#backToTop:active {
  transform: scale(0.95);
}

/* ===== 响应式布局 ===== */
@media (max-width: 968px) {
  main {
    padding: 1.5rem 1rem;
  }
  section {
    padding: 1.8rem 1.2rem;
  }
  #features ul {
    grid-template-columns: repeat(2, 1fr);
  }
  #knowledge-hub {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  nav {
    padding: 0.6rem 1rem;
  }
  nav ul {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(10, 10, 26, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: var(--border-glass);
    padding: 0.8rem;
    gap: 0.3rem;
    animation: mobileMenuSlide 0.3s ease-out;
  }
  @keyframes mobileMenuSlide {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
  }
  nav ul.active {
    display: flex;
  }
  nav ul li a {
    padding: 0.6rem 1rem;
    border-radius: var(--radius-sm);
  }
  #mobileMenuBtn {
    display: flex;
  }
  #darkModeToggle {
    width: 36px;
    height: 36px;
    font-size: 1rem;
  }
  #hero {
    padding: 3rem 1.2rem 2.5rem;
  }
  #hero a[role="button"] {
    padding: 0.7rem 1.8rem;
    font-size: 0.9rem;
  }
  #features ul {
    grid-template-columns: 1fr;
  }
  #knowledge-hub {
    grid-template-columns: 1fr;
  }
  #contact address {
    grid-template-columns: 1fr;
  }
  h1 {
    font-size: 1.8rem;
  }
  h2 {
    font-size: 1.4rem;
  }
  footer {
    padding: 2rem 1rem 1rem;
  }
  footer nav ul {
    gap: 1rem;
  }
  #backToTop {
    width: 42px;
    height: 42px;
    font-size: 1.2rem;
    bottom: 1.5rem;
    right: 1.5rem;
  }
}

@media (max-width: 480px) {
  section {
    padding: 1.2rem 0.8rem;
    border-radius: var(--radius-md);
  }
  #hero {
    padding: 2.5rem 1rem 2rem;
    border-radius: var(--radius-lg);
  }
  #hero a[role="button"] {
    display: block;
    margin: 0.5rem auto;
    max-width: 220px;
  }
  #services ul li {
    padding: 0.6rem 0.8rem 0.6rem 1.6rem;
  }
  #faq dt {
    padding: 0.7rem 0.8rem;
    font-size: 0.9rem;
  }
  #faq dd {
    padding: 0.6rem 0.8rem;
    font-size: 0.9rem;
  }
  #howto ol li {
    padding: 0.8rem 0.8rem 0.8rem 2.5rem;
  }
  #howto ol li::before {
    width: 22px;
    height: 22px;
    font-size: 0.75rem;
  }
  #knowledge-hub article {
    padding: 1rem;
  }
}

/* ===== 滚动动画（通用入场） ===== */
section {
  opacity: 0;
  transform: translateY(30px);
  animation: sectionFadeIn 0.6s ease-out forwards;
}
@keyframes sectionFadeIn {
  to { opacity: 1; transform: translateY(0); }
}
/* 延迟各个section入场（可选） */
#hero { animation-delay: 0.05s; }
#about { animation-delay: 0.1s; }
#services { animation-delay: 0.15s; }
#features { animation-delay: 0.2s; }
#faq { animation-delay: 0.25s; }
#howto { animation-delay: 0.3s; }
#knowledge-hub { animation-delay: 0.35s; }
#contact { animation-delay: 0.4s; }

/* ===== 暗色模式切换辅助 ===== */
body:not(.dark-mode) {
  /* 默认即为暗色，此规则保留兼容 */
}

/* ===== 选中文本颜色 ===== */
::selection {
  background: var(--accent-gold);
  color: #0a0a1a;
}

/* ===== 焦点样式（无障碍） ===== */
:focus-visible {
  outline: 2px solid var(--accent-gold);
  outline-offset: 2px;
}