:root {
  --bg: #f8fafc;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
}

.container {
  width: min(1200px, 92vw);
  margin: 0 auto;
}

.hero {
  background: linear-gradient(145deg, #0f172a, #1d1e43);
  color: #fff;
  padding: 32px 0 80px;
}

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

.nav-links {
  display: flex;
  gap: 18px;
  align-items: center;
}

.nav-links a,
.nav-links button {
  color: #e2e8f0;
  text-decoration: none;
  font-size: 14px;
  background: none;
  border: none;
  cursor: pointer;
}

.logo {
  font-weight: 700;
  font-size: 22px;
}

.hero-content {
  margin-top: 60px;
}

.hero h1 {
  font-size: clamp(32px, 6vw, 52px);
  margin-bottom: 16px;
}

.hero p {
  color: rgba(226, 232, 240, 0.9);
  font-size: 18px;
  max-width: 640px;
  line-height: 1.6;
}

.hero-actions {
  margin-top: 24px;
  display: flex;
  gap: 12px;
}

.btn {
  border-radius: 999px;
  padding: 12px 28px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.2s ease;
  text-decoration: none;
  text-align: center;
}

.btn.primary {
  background: var(--primary);
  color: #fff;
  border-color: transparent;
}

.btn.primary:hover {
  background: var(--primary-dark);
}

.btn.secondary {
  background: #fff;
  color: var(--text);
}

.btn.ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.btn.block {
  width: 100%;
}

.btn:hover {
  transform: translateY(-2px);
}

.section {
  padding: 80px 0;
  background: #fff;
}

.section.gray {
  background: #f1f5f9;
}

.section-head {
  text-align: center;
  margin-bottom: 40px;
}

.section-head h2 {
  font-size: 32px;
  margin-bottom: 8px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.grid.apps {
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.card,
.grid > div {
  background: #fff;
  border-radius: 20px;
  padding: 24px;
  border: 1px solid var(--border);
  box-shadow: 0 20px 40px rgba(15, 23, 42, 0.08);
}

.pricing-table {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.card ul {
  padding-left: 18px;
  color: var(--muted);
  line-height: 1.8;
}

.card.featured {
  border: none;
  background: linear-gradient(180deg, #4f46e5, #312e81);
  color: #fff;
}

.card.featured p,
.card.featured li {
  color: #e0e7ff;
}

.testimonials .testimonial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.testimonials .testimonial {
  background: #fff;
  border-radius: 16px;
  padding: 24px;
  border: 1px solid var(--border);
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.testimonial img {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.15);
}

.faq-list details {
  margin-bottom: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 16px 20px;
  background: #fff;
}

.footer {
  background: #0f172a;
  color: rgba(248, 250, 252, 0.7);
  padding: 40px 0;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  color: inherit;
  text-decoration: none;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal.hidden {
  display: none;
}

.modal-body {
  background: #fff;
  padding: 32px;
  border-radius: 16px;
  width: min(380px, 92vw);
  position: relative;
}

.modal-close {
  position: absolute;
  top: 12px;
  right: 12px;
  border: none;
  background: transparent;
  font-size: 24px;
  cursor: pointer;
}

form label {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
}

form input {
  width: 100%;
  margin-top: 6px;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  font-size: 15px;
}

.auth-tab {
  background: none;
  border: none;
  padding: 8px 16px;
  cursor: pointer;
  color: var(--muted);
  font-size: 15px;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

.auth-tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}

.auth-tab:hover {
  color: var(--text);
}

/* ========== 数据展示区块 - 信任元素 ========== */
.stats-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 60px 0;
  margin-top: -40px;
  position: relative;
  z-index: 1;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
}

.stat-item {
  display: flex;
  align-items: center;
  gap: 20px;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  padding: 24px;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.3s ease;
}

.stat-item:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.2);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.stat-icon {
  font-size: 40px;
  line-height: 1;
}

.stat-content {
  flex: 1;
}

.stat-value {
  font-size: 32px;
  font-weight: 700;
  color: #fff;
  line-height: 1.2;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
}

/* ========== 导航栏增强 ========== */
.nav-btn {
  background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
  color: #fff;
  padding: 10px 24px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 14px;
  box-shadow: 0 4px 12px rgba(34, 197, 94, 0.3);
  transition: all 0.3s ease;
}

.nav-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(34, 197, 94, 0.4);
  background: linear-gradient(135deg, #16a34a 0%, #15803d 100%);
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
  z-index: 1001;
}

.mobile-menu-toggle span {
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: all 0.3s ease;
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(8px, 8px);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(8px, -8px);
}

/* ========== 视觉层次优化 ========== */
.section {
  padding: 100px 0;
  background: #fff;
}

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

.section-head h2 {
  font-size: clamp(28px, 4vw, 40px);
  margin-bottom: 12px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.section-head p {
  font-size: 18px;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ========== 卡片交互增强 ========== */
.card,
.grid > div {
  background: #fff;
  border-radius: 20px;
  padding: 32px;
  border: 1px solid var(--border);
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.08);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.card::before,
.grid > div::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), #8b5cf6);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.card:hover::before,
.grid > div:hover::before {
  transform: scaleX(1);
}

.card:hover,
.grid > div:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(15, 23, 42, 0.12);
  border-color: var(--primary);
}

.card h3 {
  font-size: 24px;
  font-weight: 700;
  margin: 0 0 8px 0;
  color: var(--text);
}

.card p {
  color: var(--muted);
  margin: 0 0 20px 0;
  font-size: 15px;
  line-height: 1.6;
}

/* ========== 按钮增强 ========== */
.btn {
  border-radius: 999px;
  padding: 14px 32px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  text-align: center;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 15px;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:active::after {
  width: 300px;
  height: 300px;
}

.btn.primary {
  background: linear-gradient(135deg, var(--primary) 0%, #6366f1 100%);
  color: #fff;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3);
}

.btn.primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(79, 70, 229, 0.4);
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
}

.btn.secondary {
  background: #fff;
  color: var(--text);
  border: 2px solid var(--border);
}

.btn.secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.1);
}

.btn.ghost {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255, 255, 255, 0.4);
}

.btn.ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.6);
  transform: translateY(-3px);
}

/* ========== 骨架屏加载状态 ========== */
.skeleton-card {
  background: #fff;
  border-radius: 20px;
  padding: 24px;
  border: 1px solid var(--border);
  animation: skeleton-loading 1.5s ease-in-out infinite;
  position: relative;
  overflow: hidden;
}

.skeleton-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.6),
    transparent
  );
  animation: skeleton-shimmer 1.5s infinite;
}

.skeleton-app {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

@keyframes skeleton-loading {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.6;
  }
}

@keyframes skeleton-shimmer {
  0% {
    left: -100%;
  }
  100% {
    left: 100%;
  }
}

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

.section > .container > * {
  animation: fadeInUp 0.6s ease-out;
}

/* ========== 响应式优化 ========== */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: flex-start;
    padding: 80px 24px 24px;
    gap: 0;
    transition: right 0.3s ease;
    z-index: 1000;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.3);
  }

  .nav-links.active {
    right: 0;
  }

  .nav-links a,
  .nav-links button {
    width: 100%;
    padding: 16px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 16px;
  }

  .nav-links .btn {
    margin-top: 16px;
    width: 100%;
  }

  .hero {
    padding: 24px 0 60px;
  }

  .hero-content {
    margin-top: 40px;
  }

  .hero h1 {
    font-size: 28px;
    line-height: 1.3;
  }

  .hero p {
    font-size: 16px;
  }

  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .section {
    padding: 60px 0;
  }

  .section-head {
    margin-bottom: 40px;
  }

  .section-head h2 {
    font-size: 24px;
  }

  .stats-section {
    padding: 40px 0;
    margin-top: -20px;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .stat-item {
    flex-direction: column;
    text-align: center;
    padding: 20px;
  }

  .stat-icon {
    font-size: 32px;
  }

  .stat-value {
    font-size: 24px;
  }

  .grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 16px;
  }

  .pricing-table {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 24px;
  }

  .testimonials .testimonial-grid {
    grid-template-columns: 1fr;
  }
}

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

  .container {
    padding: 0 16px;
  }
}

/* ========== Hero 背景装饰 ========== */
.hero {
  position: relative;
  overflow: hidden;
}

.hero-bg-decoration {
  position: absolute;
  inset: 0;
  background: 
    radial-gradient(circle at 20% 30%, rgba(79, 70, 229, 0.15), transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.15), transparent 50%);
  pointer-events: none;
  z-index: 0;
}

.hero .container {
  position: relative;
  z-index: 1;
}

/* ========== 导航栏滚动固定效果 ========== */
.nav {
  transition: all 0.3s ease;
}

.nav.scrolled {
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(20px);
  padding: 12px 20px;
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  margin-top: 8px;
}

/* ========== 套餐卡片推荐标签 ========== */
.card {
  position: relative;
}

.card-badge {
  position: absolute;
  top: -12px;
  right: 20px;
  background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  color: #fff;
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.4);
  z-index: 10;
}

/* ========== 客户评价星级评分 ========== */
.testimonial-rating {
  color: #fbbf24;
  font-size: 16px;
  margin-bottom: 8px;
  letter-spacing: 2px;
}

/* ========== FAQ 优化样式 ========== */
.faq-list details {
  margin-bottom: 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 0;
  background: #fff;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-list details:hover {
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.1);
}

.faq-list details[open] {
  border-color: var(--primary);
  box-shadow: 0 4px 16px rgba(79, 70, 229, 0.15);
}

.faq-list details summary {
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  color: var(--text);
  list-style: none;
  position: relative;
  transition: color 0.2s ease;
  user-select: none;
}

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

.faq-list details summary::after {
  content: '+';
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 24px;
  font-weight: 300;
  color: var(--primary);
  transition: transform 0.3s ease;
}

.faq-list details[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

.faq-list details summary:hover {
  color: var(--primary);
}

.faq-list details p {
  padding: 0 24px 24px 24px;
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
  font-size: 15px;
  animation: fadeIn 0.3s ease;
}

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

/* ========== Footer 优化 ========== */
.footer {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: rgba(248, 250, 252, 0.8);
  padding: 60px 0 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  font-size: 20px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
}

.footer-section h4 {
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 16px;
}

.footer-section p {
  color: rgba(248, 250, 252, 0.7);
  line-height: 1.6;
  font-size: 14px;
  margin: 0;
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section ul li {
  margin-bottom: 12px;
  font-size: 14px;
}

.footer-section ul li a {
  color: rgba(248, 250, 252, 0.7);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-section ul li a:hover {
  color: #fff;
  padding-left: 4px;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  flex-wrap: wrap;
  gap: 16px;
}

.footer-bottom p {
  margin: 0;
  font-size: 14px;
  color: rgba(248, 250, 252, 0.6);
}

.footer-links {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}

.footer-links a {
  color: rgba(248, 250, 252, 0.7);
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: #fff;
}

.footer-links span {
  color: rgba(248, 250, 252, 0.4);
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary) 0%, #6366f1 100%);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(79, 70, 229, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 999;
}

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

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(79, 70, 229, 0.5);
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
}

.back-to-top:active {
  transform: translateY(-2px);
}

.back-to-top svg {
  transform: rotate(-90deg);
}

/* ========== 表单输入框优化 ========== */
form input {
  width: 100%;
  margin-top: 6px;
  padding: 14px 16px;
  border-radius: 10px;
  border: 2px solid var(--border);
  font-size: 15px;
  transition: all 0.3s ease;
  background: #fff;
}

form input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
  transform: translateY(-1px);
}

form input::placeholder {
  color: #9ca3af;
}

/* ========== 响应式优化 ========== */
@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .back-to-top {
    bottom: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
  }

  .card-badge {
    top: -10px;
    right: 16px;
    padding: 4px 12px;
    font-size: 11px;
  }
}

@media (max-width: 480px) {
  .footer-content {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}