:root {
  --primary: #c21a1a;
  --secondary: #2c3e50;
  --accent: #f39c12;
  --bg-light: #f9f9f9;
  --bg-white: #ffffff;
  --text-main: #333333;
  --text-muted: #666666;
  --border: #e1e1e1;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --nav-height: 70px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-main);
  background: var(--bg-light);
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

.wrap {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: bold;
  font-size: 1.5rem;
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 20px;
}

.nav-link {
  font-size: 0.95rem;
  color: var(--secondary);
  font-weight: 500;
  transition: color 0.3s;
  padding: 5px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
}

.nav-burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}

.nav-burger span {
  width: 25px;
  height: 3px;
  background: var(--secondary);
  border-radius: 2px;
}

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 30px;
  border-radius: 50px;
  font-weight: 600;
  transition: all 0.3s;
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--primary);
  color: white;
  box-shadow: 0 4px 15px rgba(194, 26, 26, 0.3);
}

.btn-primary:hover {
  background: #a51616;
  transform: translateY(-2px);
}

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

.btn-outline:hover {
  background: var(--primary);
  color: white;
}

/* Hero 区域 */
.hero {
  padding: 160px 0 80px;
  background: linear-gradient(135deg, #fff 0%, #fef2f2 100%);
  text-align: center;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 20px;
  color: #1a1a1a;
  line-height: 1.2;
}

.hero-sub {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 800px;
  margin: 0 auto 40px;
}

.hero-btns {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 60px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 60px;
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stat-num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* 通用板块样式 */
.sec {
  padding: 100px 0;
}

.sec-white {
  background: var(--bg-white);
}

.sec-head {
  text-align: center;
  margin-bottom: 60px;
}

.sec-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 15px;
  color: #1a1a1a;
}

.sec-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto;
}

/* 特色卡片 */
.feat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-bottom: 80px;
}

.feat-card {
  background: var(--bg-white);
  padding: 40px;
  border-radius: 20px;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  border: 1px solid transparent;
}

.feat-card:hover {
  transform: translateY(-10px);
  border-color: var(--primary);
}

.feat-icon {
  width: 60px;
  height: 60px;
  margin-bottom: 20px;
  color: var(--primary);
}

.feat-name {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 15px;
}

.feat-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* 深入介绍 */
.deep-info {
  margin-top: 80px;
}

.deep-row {
  display: flex;
  align-items: center;
  gap: 60px;
  margin-bottom: 100px;
}

.deep-row:nth-child(even) {
  flex-direction: row-reverse;
}

.deep-text {
  flex: 1;
}

.deep-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.deep-p {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 30px;
}

.deep-img {
  flex: 1;
  background: #f1f1f1;
  height: 350px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* 平台支持 */
.plat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.plat-card {
  background: var(--bg-white);
  padding: 30px;
  border-radius: 15px;
  text-align: center;
  box-shadow: var(--shadow);
}

.plat-icon {
  width: 50px;
  height: 50px;
  margin-bottom: 20px;
  color: var(--secondary);
}

.plat-name {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.plat-req {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

/* 用户评价 */
.rev-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.rev-card {
  background: var(--bg-white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: var(--shadow);
}

.rev-stars {
  color: #ffc107;
  margin-bottom: 15px;
}

.rev-text {
  font-style: italic;
  margin-bottom: 20px;
  color: var(--text-muted);
}

.rev-user {
  display: flex;
  align-items: center;
  gap: 15px;
}

.rev-avatar {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: #eee;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
}

/* 安全保障 */
.sec-items {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 60px;
}

.sec-item {
  text-align: center;
}

.sec-item-icon {
  width: 50px;
  height: 50px;
  margin: 0 auto 15px;
  color: #27ae60;
}

.cmp-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 40px;
  background: var(--bg-white);
  border-radius: 15px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.cmp-table th, .cmp-table td {
  padding: 20px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.cmp-table th {
  background: #f8f9fa;
  font-weight: 700;
}

.cmp-table td:first-child {
  text-align: left;
  font-weight: 500;
}

.cmp-hl {
  color: var(--primary);
  font-weight: bold;
}

/* 版本选择 */
.ver-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.ver-card {
  background: var(--bg-white);
  padding: 50px 40px;
  border-radius: 20px;
  box-shadow: var(--shadow);
  text-align: center;
  position: relative;
  border: 2px solid transparent;
}

.ver-card.featured {
  border-color: var(--primary);
  transform: scale(1.05);
}

.ver-badge {
  position: absolute;
  top: 20px;
  right: 20px;
  background: var(--primary);
  color: white;
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.75rem;
}

.ver-name {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.ver-price {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 30px;
  color: var(--secondary);
}

.ver-list {
  text-align: left;
  margin-bottom: 40px;
}

.ver-list li {
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.95rem;
}

.ver-list svg {
  width: 18px;
  height: 18px;
  color: #27ae60;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-white);
  margin-bottom: 15px;
  border-radius: 10px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
  overflow: hidden;
}

.faq-q {
  padding: 20px 30px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-q:hover {
  background: #fcfcfc;
}

.faq-a {
  padding: 0 30px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease-in-out;
  color: var(--text-muted);
}

.faq-item.open .faq-a {
  padding: 0 30px 20px;
  max-height: 500px;
}

.faq-chevron {
  width: 20px;
  height: 20px;
  transition: transform 0.3s;
}

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

/* 页脚 */
.site-footer {
  background: var(--secondary);
  color: #aaa;
  padding: 60px 0 30px;
  text-align: center;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-copy {
  font-size: 0.9rem;
}

@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

/* 响应式 */
@media (max-width: 1024px) {
  .feat-grid, .plat-grid, .rev-grid, .ver-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: white;
    flex-direction: column;
    padding: 20px;
    gap: 15px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  }
  
  .nav-links.show {
    display: flex;
  }
  
  .nav-burger {
    display: flex;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .deep-row, .deep-row:nth-child(even) {
    flex-direction: column;
  }
  
  .feat-grid, .plat-grid, .rev-grid, .ver-grid, .sec-items {
    grid-template-columns: 1fr;
  }
}