/* ===== 全局重置 & CSS变量 ===== */
:root {
  --bg: #f8faff;
  --bg-card: rgba(255,255,255,0.75);
  --bg-glass: rgba(255,255,255,0.2);
  --text: #0b1a2e;
  --text-secondary: #1f3a5f;
  --border: #d0d9e8;
  --accent: #f0c27f;
  --accent2: #fc5c7d;
  --shadow: 0 8px 32px rgba(0,0,0,0.06);
  --shadow-hover: 0 16px 48px rgba(0,0,0,0.12);
  --radius: 24px;
  --radius-sm: 16px;
  --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  --gradient-main: linear-gradient(135deg, var(--accent), var(--accent2));
  --gradient-bg: linear-gradient(135deg, #0b1a2e 0%, #1f3a5f 100%);
}

[data-theme="dark"] {
  --bg: #0b1a2e;
  --bg-card: rgba(21,42,68,0.85);
  --bg-glass: rgba(255,255,255,0.08);
  --text: #eef3fc;
  --text-secondary: #b0c8e0;
  --border: #2a4160;
  --shadow: 0 8px 32px rgba(0,0,0,0.3);
  --shadow-hover: 0 16px 48px rgba(0,0,0,0.5);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

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

a {
  color: var(--accent2);
  text-decoration: none;
  transition: color var(--transition);
}

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

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

ul, ol {
  list-style: none;
}

/* ===== 布局容器 ===== */
header, main, footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== 导航栏 ===== */
.nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  flex-wrap: wrap;
  gap: 0.5rem;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius-sm);
  padding-left: 1.5rem;
  padding-right: 1.5rem;
  margin-top: 0.5rem;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0.5rem;
  z-index: 100;
}

.logo-area {
  display: flex;
  align-items: center;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.25rem;
}

.brand-text {
  font-size: 1.5rem;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 1.8rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.3rem 0;
  position: relative;
  transition: color var(--transition);
}

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

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

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

.nav-actions {
  display: flex;
  gap: 0.6rem;
  align-items: center;
}

.icon-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 40px;
  padding: 0.45rem 0.9rem;
  cursor: pointer;
  font-size: 1.2rem;
  transition: background var(--transition), transform var(--transition);
  backdrop-filter: blur(4px);
}

.icon-btn:hover {
  background: var(--accent);
  transform: scale(1.05);
}

.mobile-only {
  display: none;
}

/* ===== Hero 区块 ===== */
#hero {
  display: flex;
  gap: 2.5rem;
  align-items: center;
  padding: 4rem 0;
  flex-wrap: wrap;
  min-height: 70vh;
  position: relative;
}

#hero::before {
  content: '';
  position: absolute;
  top: -20%;
  left: -10%;
  width: 60%;
  height: 80%;
  background: radial-gradient(circle at 30% 50%, rgba(240,194,127,0.15), transparent 60%);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  flex: 1 1 400px;
  position: relative;
  z-index: 1;
}

#hero-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.gradient-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 500px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.btn-primary, .btn-outline, .btn-small {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 2rem;
  border-radius: 60px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-main);
  color: #0b1a2e;
  box-shadow: 0 4px 20px rgba(252,92,125,0.3);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(252,92,125,0.4);
}

.btn-outline {
  border: 2px solid var(--accent2);
  color: var(--accent2);
  background: transparent;
}

.btn-outline:hover {
  background: var(--accent2);
  color: white;
  transform: translateY(-3px);
}

.btn-small {
  padding: 0.5rem 1.2rem;
  font-size: 0.9rem;
  background: var(--gradient-main);
  color: #0b1a2e;
}

.btn-small:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(252,92,125,0.3);
}

.hero-visual {
  flex: 0 0 320px;
  position: relative;
  z-index: 1;
}

.hero-visual svg {
  border-radius: var(--radius);
  box-shadow: var(--shadow-hover);
  transition: transform var(--transition);
}

.hero-visual:hover svg {
  transform: scale(1.03) rotate(1deg);
}

/* ===== 产品卡片网格 ===== */
#products {
  padding: 4rem 0;
}

#products-title {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
}

.badge {
  background: var(--gradient-main);
  color: #0b1a2e;
  border-radius: 60px;
  padding: 0.25rem 1.2rem;
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.8rem;
}

.card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 2rem 1.8rem;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  border: 1px solid rgba(255,255,255,0.1);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 20%, rgba(240,194,127,0.05), transparent 50%);
  opacity: 0;
  transition: opacity var(--transition);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

.card:hover::before {
  opacity: 1;
}

.card svg {
  margin-bottom: 1.2rem;
  transition: transform var(--transition);
}

.card:hover svg {
  transform: scale(1.1) rotate(-5deg);
}

.card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.6rem;
  font-weight: 700;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ===== 优势区块 ===== */
#advantages {
  padding: 4rem 0;
}

#advantages-title {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  margin-bottom: 2rem;
  text-align: center;
}

.advantage-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.2rem;
}

.advantage-item {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-sm);
  padding: 1.5rem 1.2rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  border: 1px solid transparent;
}

.advantage-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

.adv-icon {
  font-size: 2rem;
  flex-shrink: 0;
  line-height: 1;
}

.advantage-item strong {
  font-size: 1.05rem;
  display: block;
  margin-bottom: 0.2rem;
}

/* ===== HowTo 区块 ===== */
#howto-section {
  padding: 4rem 0;
  text-align: center;
}

#howto-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 2rem;
}

.howto-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.step {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  border-radius: 60px;
  padding: 0.7rem 1.6rem 0.7rem 0.8rem;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition);
  box-shadow: var(--shadow);
}

.step:hover {
  transform: translateY(-3px) scale(1.02);
  border-color: var(--accent);
}

.step-num {
  background: var(--gradient-main);
  color: #0b1a2e;
  border-radius: 50%;
  width: 30px;
  height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.howto-cta {
  font-size: 1.05rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  flex-wrap: wrap;
}

/* ===== 知识库 ===== */
#knowledge {
  padding: 4rem 0;
}

#knowledge-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 2rem;
}

.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.2rem;
}

.knowledge-card {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  border: 1px solid transparent;
  display: flex;
  flex-direction: column;
}

.knowledge-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

.knowledge-card h4 {
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.knowledge-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  flex: 1;
}

.read-more {
  font-weight: 600;
  color: var(--accent2);
  transition: color var(--transition);
  align-self: flex-start;
}

.read-more:hover {
  color: var(--accent);
}

/* ===== FAQ 区块 ===== */
#faq-section {
  padding: 4rem 0;
}

#faq-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 2rem;
}

.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-sm);
  margin-bottom: 0.8rem;
  padding: 0.8rem 1.2rem;
  box-shadow: var(--shadow);
  border: 1px solid transparent;
  transition: all var(--transition);
  overflow: hidden;
}

.faq-item:hover {
  border-color: var(--accent);
}

.faq-item summary {
  font-weight: 600;
  cursor: pointer;
  padding: 0.4rem 0;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: color var(--transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 300;
  transition: transform var(--transition);
  color: var(--accent2);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item p {
  padding: 0.8rem 0 0.4rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== 联系区块 ===== */
#contact {
  padding: 4rem 0;
}

#contact-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 2rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.2rem;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255,255,255,0.1);
}

.contact-grid div {
  padding: 0.5rem;
}

.contact-grid strong {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 1rem;
}

.legal-links {
  margin-top: 2.5rem;
  padding: 1.2rem 0;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.8rem;
}

.legal-links a {
  color: var(--text-secondary);
  transition: color var(--transition);
}

.legal-links a:hover {
  color: var(--accent2);
}

/* ===== 回到顶部按钮 ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--gradient-main);
  color: #0b1a2e;
  border: none;
  border-radius: 50%;
  width: 52px;
  height: 52px;
  font-size: 1.5rem;
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
  transition: all var(--transition);
  pointer-events: none;
  box-shadow: 0 4px 20px rgba(252,92,125,0.3);
  z-index: 999;
  display: flex;
  align-items: center;
  justify-content: center;
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 30px rgba(252,92,125,0.4);
}

/* ===== 滚动动画 (Intersection Observer 配合) ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== 暗黑模式微调 ===== */
[data-theme="dark"] .card,
[data-theme="dark"] .advantage-item,
[data-theme="dark"] .knowledge-card,
[data-theme="dark"] .faq-item,
[data-theme="dark"] .step,
[data-theme="dark"] .contact-grid {
  border-color: rgba(255,255,255,0.05);
}

[data-theme="dark"] .btn-primary {
  color: #0b1a2e;
}

[data-theme="dark"] .hero-visual svg {
  box-shadow: 0 8px 32px rgba(0,0,0,0.5);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  #hero {
    padding: 3rem 0;
  }
  
  .hero-visual {
    flex-basis: 280px;
  }
}

@media (max-width: 768px) {
  header, main, footer {
    padding: 0 1rem;
  }

  .nav-bar {
    padding: 0.8rem 1rem;
    border-radius: var(--radius-sm);
  }

  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 0.6rem;
    padding: 1rem 0 0.5rem;
    border-top: 1px solid var(--border);
    margin-top: 0.5rem;
  }

  .nav-links.open {
    display: flex;
  }

  .mobile-only {
    display: inline-flex;
  }

  #hero {
    flex-direction: column;
    text-align: center;
    padding: 2.5rem 0;
    min-height: auto;
  }

  .hero-sub {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta-group {
    justify-content: center;
  }

  .hero-visual {
    flex-basis: auto;
    width: 100%;
    max-width: 320px;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .advantage-list {
    grid-template-columns: 1fr;
  }

  .knowledge-grid {
    grid-template-columns: 1fr 1fr;
  }

  .howto-steps {
    flex-direction: column;
    align-items: center;
  }

  .step {
    width: 100%;
    max-width: 400px;
    justify-content: center;
  }

  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }

  .back-to-top {
    bottom: 1.2rem;
    right: 1.2rem;
    width: 44px;
    height: 44px;
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .knowledge-grid {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  #products-title,
  #advantages-title,
  #howto-title,
  #knowledge-title,
  #faq-title,
  #contact-title {
    font-size: 1.4rem;
  }

  .brand-text {
    font-size: 1.2rem;
  }

  .hero-cta-group {
    flex-direction: column;
    align-items: center;
  }

  .btn-primary, .btn-outline {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
}

/* ===== 打印样式 ===== */
@media print {
  .back-to-top,
  .nav-actions,
  .icon-btn {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .card, .advantage-item, .knowledge-card, .faq-item {
    box-shadow: none;
    border: 1px solid #ddd;
    background: white;
  }
}