/* ============================================================
   德扑圈 - 共享样式表
   SaaS风格: 干净留白、大圆角、微阴影
   主色调: blue-600
   ============================================================ */

/* --- CSS Variables --- */
:root {
  --primary: #2563EB;
  --primary-dark: #1D4ED8;
  --primary-light: #3B82F6;
  --primary-50: #EFF6FF;
  --primary-100: #DBEAFE;
  --primary-600: #2563EB;
  --primary-700: #1D4ED8;
  --text-dark: #111827;
  --text-gray: #6B7280;
  --text-light: #9CA3AF;
  --bg-white: #FFFFFF;
  --bg-light: #F9FAFB;
  --bg-gray: #F3F4F6;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.04);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Base Reset & Typography --- */
html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  color: var(--text-dark);
  background: var(--bg-white);
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-md);
  padding: 10px 0;
}

.navbar .logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: #fff;
  text-decoration: none;
  letter-spacing: -0.5px;
  transition: var(--transition);
}

.navbar.scrolled .logo {
  color: var(--primary-600);
}

.navbar .nav-link {
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  text-decoration: none;
}

.navbar .nav-link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.15);
}

.navbar.scrolled .nav-link {
  color: var(--text-gray);
}

.navbar.scrolled .nav-link:hover {
  color: var(--primary-600);
  background: var(--primary-50);
}

.navbar .nav-link.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.2);
}

.navbar.scrolled .nav-link.active {
  color: var(--primary-600);
  background: var(--primary-100);
}

/* Mobile menu button */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 8px;
  transition: var(--transition);
}

.navbar.scrolled .mobile-menu-btn {
  color: var(--primary-600);
}

/* Mobile menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.mobile-menu.open {
  display: block;
  opacity: 1;
}

.mobile-menu-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: 280px;
  height: 100%;
  background: #fff;
  padding: 80px 24px 24px;
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu.open .mobile-menu-panel {
  transform: translateX(0);
}

.mobile-menu-panel a {
  display: block;
  padding: 14px 16px;
  color: var(--text-dark);
  font-weight: 500;
  font-size: 1.05rem;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.mobile-menu-panel a:hover,
.mobile-menu-panel a.active {
  color: var(--primary-600);
  background: var(--primary-50);
}

.mobile-menu-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-gray);
  cursor: pointer;
  padding: 8px;
}

/* --- Hero Section --- */
.hero-section {
  position: relative;
  background: linear-gradient(135deg, #1E3A8A 0%, #2563EB 40%, #3B82F6 70%, #60A5FA 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-section::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(255,255,255,0.05) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: #fff;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  color: #fff;
  line-height: 1.15;
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: rgba(255, 255, 255, 0.85);
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-image {
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  transition: transform 0.5s ease;
}

.hero-image:hover {
  transform: translateY(-8px) scale(1.02);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}

.btn-primary {
  background: #fff;
  color: var(--primary-600);
  box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2);
  background: #f0f7ff;
}

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: #fff;
  transform: translateY(-2px);
}

.btn-download {
  background: var(--primary-600);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.btn-download:hover {
  background: var(--primary-700);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-lg {
  padding: 16px 40px;
  font-size: 1.1rem;
}

/* --- Section Common --- */
.section-padding {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-badge {
  display: inline-block;
  background: var(--primary-50);
  color: var(--primary-600);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 16px;
  line-height: 1.2;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-gray);
  max-width: 600px;
  margin: 0 auto;
}

.bg-light {
  background: var(--bg-light);
}

/* --- Feature Cards --- */
.feature-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid #F3F4F6;
  transition: var(--transition);
  height: 100%;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-100);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--primary-50);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--primary-600);
  margin-bottom: 20px;
  transition: var(--transition);
}

.feature-card:hover .feature-icon {
  background: var(--primary-600);
  color: #fff;
  transform: scale(1.08);
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-dark);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-gray);
  line-height: 1.7;
}

/* --- Stats Section --- */
.stats-section {
  background: linear-gradient(135deg, #1E3A8A 0%, #2563EB 100%);
  padding: 80px 0;
}

.stat-item {
  text-align: center;
  padding: 24px;
}

.stat-number {
  font-size: 3rem;
  font-weight: 800;
  color: #fff;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-plus {
  font-size: 1.8rem;
  font-weight: 700;
  color: #60A5FA;
}

.stat-label {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.75);
  font-weight: 500;
}

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

.faq-item {
  background: #fff;
  border: 1px solid #E5E7EB;
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: var(--primary-200);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-dark);
  text-align: left;
  gap: 16px;
  transition: var(--transition);
}

.faq-question:hover {
  color: var(--primary-600);
}

.faq-question i {
  font-size: 0.85rem;
  color: var(--text-light);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-question i {
  transform: rotate(180deg);
  color: var(--primary-600);
}

.faq-item.active {
  border-color: var(--primary-200);
  box-shadow: var(--shadow-md);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-gray);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* --- CTA Section --- */
.cta-section {
  background: linear-gradient(135deg, #2563EB 0%, #1D4ED8 100%);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: -80px;
  right: -80px;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  border-radius: 50%;
}

.cta-section h2 {
  font-size: 2.2rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
}

.cta-section p {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 32px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* --- Footer --- */
.footer {
  background: var(--text-dark);
  color: rgba(255, 255, 255, 0.6);
  padding: 60px 0 30px;
}

.footer h5 {
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 20px;
}

.footer a {
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.9rem;
}

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

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

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 40px;
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
}

/* --- Page Header (for sub-pages) --- */
.page-header {
  background: linear-gradient(135deg, #1E3A8A 0%, #2563EB 40%, #3B82F6 100%);
  padding: 140px 0 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: -60px;
  right: -60px;
  width: 250px;
  height: 250px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.page-header h1 {
  font-size: 3rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
}

.page-header p {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.8);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Download Cards --- */
.download-card {
  background: #fff;
  border-radius: var(--radius-xl);
  padding: 40px 32px;
  box-shadow: var(--shadow-md);
  border: 1px solid #F3F4F6;
  text-align: center;
  transition: var(--transition);
  height: 100%;
  position: relative;
  overflow: hidden;
}

.download-card.featured {
  border: 2px solid var(--primary-600);
  box-shadow: var(--shadow-xl);
}

.download-card.featured::before {
  content: '推荐';
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--primary-600);
  color: #fff;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
}

.download-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.download-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--primary-50);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  color: var(--primary-600);
  margin: 0 auto 20px;
}

.download-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.download-card .version {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 16px;
}

.download-card .file-info {
  font-size: 0.85rem;
  color: var(--text-gray);
  margin-bottom: 24px;
  padding: 10px 16px;
  background: var(--bg-gray);
  border-radius: var(--radius-sm);
  display: inline-block;
}

/* --- Club Cards --- */
.club-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid #F3F4F6;
  transition: var(--transition);
  height: 100%;
  text-align: center;
}

.club-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-200);
}

.club-card .club-badge {
  display: inline-block;
  background: linear-gradient(135deg, #F59E0B, #EF4444);
  color: #fff;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.club-card h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.club-card .club-stats {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin: 16px 0;
  font-size: 0.85rem;
  color: var(--text-gray);
}

.club-card .club-stats span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.club-card .club-stats i {
  color: #F59E0B;
}

/* --- Steps / Process --- */
.step-list {
  counter-reset: step;
}

.step-item {
  display: flex;
  gap: 24px;
  margin-bottom: 40px;
  counter-increment: step;
}

.step-number {
  width: 52px;
  height: 52px;
  min-width: 52px;
  border-radius: 50%;
  background: var(--primary-50);
  color: var(--primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 800;
}

.step-content h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.step-content p {
  color: var(--text-gray);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* --- Advantages List --- */
.advantage-item {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid #F3F4F6;
}

.advantage-item:last-child {
  border-bottom: none;
}

.advantage-icon {
  width: 44px;
  height: 44px;
  min-width: 44px;
  border-radius: var(--radius-sm);
  background: var(--primary-50);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary-600);
  font-size: 1.1rem;
}

.advantage-content h5 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.advantage-content p {
  font-size: 0.9rem;
  color: var(--text-gray);
}

/* --- Scroll Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary-600);
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: var(--transition);
  z-index: 900;
}

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

.back-to-top:hover {
  background: var(--primary-700);
  transform: translateY(-4px);
}

/* --- Install Tutorial --- */
.tutorial-step {
  display: flex;
  gap: 20px;
  padding: 24px;
  background: #fff;
  border-radius: var(--radius-md);
  border: 1px solid #F3F4F6;
  margin-bottom: 16px;
  transition: var(--transition);
}

.tutorial-step:hover {
  border-color: var(--primary-100);
  box-shadow: var(--shadow-md);
}

.tutorial-step-num {
  width: 40px;
  height: 40px;
  min-width: 40px;
  border-radius: var(--radius-sm);
  background: var(--primary-600);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.tutorial-step-content h5 {
  font-weight: 700;
  margin-bottom: 4px;
}

.tutorial-step-content p {
  color: var(--text-gray);
  font-size: 0.9rem;
  margin: 0;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 2.8rem;
  }

  .section-title {
    font-size: 2rem;
  }

  .page-header h1 {
    font-size: 2.2rem;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .section-padding {
    padding: 64px 0;
  }

  .section-title {
    font-size: 1.7rem;
  }

  .page-header {
    padding: 120px 0 48px;
  }

  .page-header h1 {
    font-size: 1.8rem;
  }

  .mobile-menu-btn {
    display: block;
  }

  .desktop-nav {
    display: none !important;
  }

  .btn-lg {
    padding: 14px 28px;
    font-size: 1rem;
  }

  .stat-number {
    font-size: 2.2rem;
  }

  .step-item {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }

  .step-number {
    margin: 0 auto;
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 1.8rem;
  }

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

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

  .feature-card {
    padding: 24px 20px;
  }

  .download-card {
    padding: 28px 20px;
  }
}