/* ===== 全局重置与基础 ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI',
    'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.7;
  color: #1e293b;
  background-color: #f8fafc;
}

/* ===== 通用工具类 ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

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

/* ===== 链接 ===== */
a {
  color: #2563eb;
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover {
  color: #1d4ed8;
}

/* ===== 面包屑导航 ===== */
.breadcrumb {
  background: #ffffff;
  border-bottom: 1px solid #e2e8f0;
  padding: 12px 0;
  font-size: 13px;
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.breadcrumb li {
  color: #64748b;
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb li:not(:last-child)::after {
  content: '/';
  color: #cbd5e1;
  font-size: 12px;
}

.breadcrumb li a {
  color: #2563eb;
}

.breadcrumb li a:hover {
  color: #1d4ed8;
  text-decoration: underline;
}

.breadcrumb li[aria-current='page'] {
  color: #475569;
  font-weight: 500;
}

/* ===== 头部导航 ===== */
header {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 0;
  gap: 16px;
}

.logo {
  font-size: 22px;
  font-weight: 700;
  color: #1e40af;
  letter-spacing: -0.3px;
  white-space: nowrap;
  transition: opacity 0.2s ease;
}

.logo:hover {
  opacity: 0.85;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 6px;
  list-style: none;
}

.nav-links a {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: #475569;
  padding: 8px 14px;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.nav-links a:hover {
  color: #1e40af;
  background: #eff6ff;
  text-decoration: none;
}

/* ===== Hero区域 ===== */
.hero {
  background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 30%, #2563eb 70%, #3b82f6 100%);
  color: #ffffff;
  padding: 100px 0 90px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(
    ellipse at 40% 30%,
    rgba(255, 255, 255, 0.06) 0%,
    transparent 60%
  );
  pointer-events: none;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 18px;
  line-height: 1.25;
  letter-spacing: -0.5px;
  position: relative;
}

.hero-subtitle {
  font-size: 18px;
  margin-bottom: 36px;
  opacity: 0.9;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.7;
  position: relative;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 14px 36px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  letter-spacing: 0.2px;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(249, 115, 22, 0.35);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #fb923c 0%, #f97316 100%);
  box-shadow: 0 6px 22px rgba(249, 115, 22, 0.45);
  transform: translateY(-2px);
  text-decoration: none;
  color: #ffffff;
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(249, 115, 22, 0.3);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  border: 2px solid rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(4px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.22);
  border-color: #ffffff;
  transform: translateY(-2px);
  text-decoration: none;
  color: #ffffff;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.btn-secondary:active {
  transform: translateY(0);
}

/* ===== 快速导航 ===== */
.quick-nav-section {
  padding: 70px 0;
  background: #ffffff;
}

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

.nav-card {
  background: #f8fafc;
  padding: 36px 28px;
  border-radius: 14px;
  text-align: center;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1.5px solid transparent;
  cursor: default;
}

.nav-card:hover {
  background: #ffffff;
  border-color: #bfdbfe;
  box-shadow: 0 8px 30px rgba(59, 130, 246, 0.1);
  transform: translateY(-5px);
}

.nav-card-icon {
  font-size: 36px;
  display: block;
  margin-bottom: 14px;
}

.nav-card h3 {
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1e40af;
}

.nav-card p {
  font-size: 14px;
  color: #64748b;
  line-height: 1.65;
}

/* ===== 通用 Section 标题 ===== */
.section-subtitle {
  font-size: 13px;
  color: #f97316;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
  text-align: center;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 56px;
  text-align: center;
  color: #0f172a;
  letter-spacing: -0.4px;
  line-height: 1.3;
}

/* ===== 新手指南 ===== */
.guide-section {
  padding: 90px 0;
  background: #f8fafc;
}

.guide-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 28px;
}

.step-card {
  background: #ffffff;
  padding: 34px 28px;
  border-radius: 14px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05), 0 1px 3px rgba(0, 0, 0, 0.04);
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid #f1f5f9;
}

.step-card:hover {
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.09);
  transform: translateY(-5px);
  border-color: #e2e8f0;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 54px;
  height: 54px;
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
  color: #ffffff;
  border-radius: 50%;
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 18px;
  box-shadow: 0 4px 12px rgba(30, 64, 175, 0.25);
}

.step-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1e293b;
}

.step-card p {
  font-size: 14px;
  color: #64748b;
  line-height: 1.7;
}

/* ===== 平台对比 ===== */
.comparison-section {
  padding: 90px 0;
  background: #ffffff;
}

.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: #ffffff;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06), 0 1px 4px rgba(0, 0, 0, 0.04);
  border: 1px solid #e2e8f0;
}

.comparison-table thead th {
  background: linear-gradient(135deg, #1e40af 0%, #1e3a8a 100%);
  color: #ffffff;
  padding: 18px 20px;
  text-align: left;
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.3px;
}

.comparison-table thead th:first-child {
  border-radius: 14px 0 0 0;
}

.comparison-table thead th:last-child {
  border-radius: 0 14px 0 0;
}

.comparison-table td {
  padding: 16px 20px;
  border-bottom: 1px solid #f1f5f9;
  font-size: 14px;
  color: #334155;
  transition: background 0.2s ease;
}

.comparison-table tbody tr {
  transition: background 0.2s ease;
}

.comparison-table tbody tr:hover {
  background: #f8fafc;
}

.comparison-table tbody tr:last-child td {
  border-bottom: none;
}

.comparison-table tbody tr:last-child td:first-child {
  border-radius: 0 0 0 14px;
}

.comparison-table tbody tr:last-child td:last-child {
  border-radius: 0 0 14px 0;
}

.platform-name {
  font-weight: 600;
  color: #1e293b;
}

.platform-name a {
  color: #2563eb;
  font-weight: 600;
}

.platform-name a:hover {
  color: #1d4ed8;
  text-decoration: underline;
}

.badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.badge-safe {
  background: #dcfce7;
  color: #166534;
  border: 1px solid #bbf7d0;
}

/* ===== 安全提示 ===== */
.security-section {
  padding: 90px 0;
  background: #f8fafc;
}

.security-tips {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
}

.tip-card {
  background: #ffffff;
  padding: 32px 28px;
  border-radius: 14px;
  border-left: 4px solid #f97316;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid #f1f5f9;
  border-left-width: 4px;
  border-left-color: #f97316;
}

.tip-card:hover {
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.08);
  transform: translateY(-3px);
}

.tip-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
  color: #1e293b;
}

.tip-card p {
  font-size: 14px;
  color: #64748b;
  line-height: 1.7;
}

.tip-icon {
  font-size: 28px;
  margin-bottom: 12px;
  display: block;
}

/* ===== FAQ 常见问题 ===== */
.faq-section {
  padding: 90px 0;
  background: #ffffff;
}

.faq-container {
  max-width: 820px;
  margin: 0 auto;
}

.faq-item {
  margin-bottom: 16px;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  overflow: hidden;
  background: #ffffff;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: #cbd5e1;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}

.faq-question {
  padding: 20px 24px;
  background: #f8fafc;
  cursor: pointer;
  font-weight: 600;
  font-size: 15px;
  color: #1e293b;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.25s ease;
  user-select: none;
  outline: none;
}

.faq-question:focus-visible {
  box-shadow: inset 0 0 0 2px #2563eb;
}

.faq-question:hover {
  background: #eff6ff;
  color: #1e40af;
}

.faq-toggle {
  font-size: 20px;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  color: #94a3b8;
  flex-shrink: 0;
  margin-left: 16px;
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
  color: #2563eb;
}

.faq-item.active .faq-question {
  background: #eff6ff;
  color: #1e40af;
  border-bottom: 1px solid #e2e8f0;
}

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  color: #475569;
  font-size: 14px;
  line-height: 1.75;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-answer p {
  padding: 20px 0;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

/* ===== 页脚 ===== */
footer {
  background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
  color: #cbd5e1;
  padding: 70px 0 24px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 44px;
  margin-bottom: 48px;
}

.footer-section h4 {
  color: #f1f5f9;
  margin-bottom: 18px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.footer-section p {
  font-size: 14px;
  line-height: 1.7;
  color: #94a3b8;
}

.footer-section ul {
  list-style: none;
}

.footer-section li {
  margin-bottom: 10px;
}

.footer-section a {
  color: #94a3b8;
  font-size: 14px;
  transition: color 0.2s ease;
}

.footer-section a:hover {
  color: #f1f5f9;
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: #64748b;
  line-height: 1.6;
}

/* ===== 滚动动画 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ===== 响应式设计 ===== */

/* 平板 */
@media (max-width: 1024px) {
  .hero h1 {
    font-size: 38px;
  }

  .section-title {
    font-size: 30px;
  }

  .guide-steps {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }
}

/* 手机 */
@media (max-width: 768px) {
  .container {
    padding: 0 18px;
  }

  .breadcrumb {
    padding: 10px 0;
    font-size: 12px;
  }

  header {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
  }

  .logo {
    font-size: 18px;
    width: 100%;
    text-align: center;
  }

  .nav-links {
    gap: 2px;
    flex-wrap: wrap;
    justify-content: center;
  }

  .nav-links a {
    font-size: 13px;
    padding: 6px 10px;
    border-radius: 6px;
  }

  .hero {
    padding: 64px 0 56px;
  }

  .hero h1 {
    font-size: 28px;
    letter-spacing: -0.3px;
  }

  .hero-subtitle {
    font-size: 15px;
    margin-bottom: 28px;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }

  .btn {
    padding: 13px 28px;
    font-size: 15px;
    width: 100%;
    max-width: 300px;
    text-align: center;
  }

  .section-title {
    font-size: 26px;
    margin-bottom: 36px;
  }

  .quick-nav {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

  .guide-steps {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .security-tips {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .comparison-table {
    font-size: 12px;
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .comparison-table thead th,
  .comparison-table td {
    padding: 14px 12px;
    font-size: 12px;
    white-space: nowrap;
  }

  .comparison-table thead th:first-child {
    border-radius: 14px 0 0 0;
    position: sticky;
    left: 0;
    z-index: 2;
  }

  .comparison-table td:first-child {
    position: sticky;
    left: 0;
    background: #ffffff;
    z-index: 1;
    font-weight: 600;
  }

  .comparison-table tbody tr:hover td:first-child {
    background: #f8fafc;
  }

  .faq-question {
    padding: 16px 18px;
    font-size: 14px;
  }

  .faq-answer p {
    font-size: 13px;
  }

  .faq-container {
    max-width: 100%;
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

/* 小屏手机 */
@media (max-width: 480px) {
  .hero h1 {
    font-size: 24px;
  }

  .hero-subtitle {
    font-size: 14px;
  }

  .section-title {
    font-size: 22px;
  }

  .quick-nav {
    grid-template-columns: 1fr;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 28px;
    text-align: center;
  }

  .footer-section ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
  }

  .footer-section li {
    margin-bottom: 0;
  }
}

/* ===== 打印样式 ===== */
@media print {
  header,
  .breadcrumb,
  footer,
  .hero-cta {
    display: none;
  }

  body {
    background: #ffffff;
    color: #000000;
  }

  .hero {
    background: none;
    color: #000000;
    padding: 20px 0;
  }
}