/* ===== CSS Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: #333;
  background: #fff;
}

/* ===== CSS Variables ===== */
:root {
  --primary: #e60012;
  --primary-dark: #c4000f;
  --primary-light: #ff1a2e;
  --text: #1a1a1a;
  --text-secondary: #666;
  --text-muted: #999;
  --bg: #fff;
  --bg-light: #f8f9fa;
  --bg-gray: #f0f2f5;
  --border: #e8eaed;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
}

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

/* ===== Layout ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  color: var(--text);
  text-decoration: none;
}

.nav-brand svg {
  width: 32px;
  height: 32px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--primary);
  background: rgba(230,0,18,0.05);
}

.nav-link.active {
  color: var(--primary);
  background: rgba(230,0,18,0.1);
}

.nav-cta {
  margin-left: 16px;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(230,0,18,0.3);
}

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

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

.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 13px;
}

/* ===== Hero Section ===== */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(180deg, #fff 0%, var(--bg-light) 100%);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content {
  max-width: 560px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(230,0,18,0.1);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.15;
  color: var(--text);
  margin-bottom: 20px;
}

.hero-title span {
  color: var(--primary);
}

.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}

.hero-stat {
  text-align: center;
}

.hero-stat-value {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.hero-stat-label {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 6px;
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-mockup {
  width: 100%;
  max-width: 480px;
  background: #fff;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.mockup-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: var(--bg-gray);
  border-bottom: 1px solid var(--border);
}

.mockup-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.mockup-dot.r { background: #ff5f57; }
.mockup-dot.y { background: #febc2e; }
.mockup-dot.g { background: #28c840; }

.mockup-body {
  padding: 24px;
  min-height: 280px;
}

.mockup-toolbar {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.mockup-btn {
  height: 8px;
  border-radius: 4px;
  background: var(--bg-gray);
}

.mockup-btn.wide { width: 80px; }
.mockup-btn.narrow { width: 40px; }

.mockup-content {
  display: grid;
  gap: 12px;
}

.mockup-line {
  height: 12px;
  background: var(--bg-gray);
  border-radius: 6px;
}

.mockup-line.short { width: 60%; }

.mockup-card {
  margin-top: 16px;
  padding: 16px;
  background: rgba(230,0,18,0.05);
  border-radius: 8px;
  border-left: 3px solid var(--primary);
}

/* ===== Section Common ===== */
.section {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 56px;
}

.section-tag {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(230,0,18,0.1);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 16px;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 16px;
}

.section-desc {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== Features Section ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 64px;
}

.feature-card {
  padding: 32px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all 0.3s ease;
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(230,0,18,0.1);
  border-radius: 12px;
  margin-bottom: 20px;
}

.feature-icon svg {
  width: 28px;
  height: 28px;
  color: var(--primary);
}

.feature-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}

.feature-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Features Deep Dive */
.features-deep {
  display: grid;
  gap: 48px;
}

.deep-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.deep-row.reverse {
  direction: rtl;
}

.deep-row.reverse > * {
  direction: ltr;
}

.deep-content h3 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 16px;
}

.deep-content p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.deep-visual {
  background: var(--bg-light);
  border-radius: 12px;
  padding: 32px;
  min-height: 240px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.visual-bar {
  display: flex;
  align-items: center;
  gap: 12px;
}

.visual-label {
  width: 80px;
  font-size: 12px;
  color: var(--text-muted);
}

.visual-track {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.visual-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 4px;
}

/* ===== Platforms Section ===== */
.platforms {
  background: var(--bg-light);
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.platform-card {
  background: #fff;
  border-radius: 12px;
  padding: 32px 24px;
  text-align: center;
  border: 1px solid var(--border);
  transition: all 0.3s ease;
}

.platform-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.platform-card.featured {
  border-color: var(--primary);
  position: relative;
}

.platform-card.featured::before {
  content: "推荐";
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 4px 16px;
  border-radius: 0 0 8px 8px;
}

.platform-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-light);
  border-radius: 16px;
}

.platform-icon svg {
  width: 32px;
  height: 32px;
  color: var(--text);
}

.platform-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 8px;
}

.platform-version {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.platform-req {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 20px;
  padding: 8px;
  background: var(--bg-light);
  border-radius: 6px;
}

/* ===== Reviews Section ===== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  transition: all 0.3s ease;
}

.review-card:hover {
  box-shadow: var(--shadow);
}

.review-stars {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}

.review-stars svg {
  width: 18px;
  height: 18px;
  color: #ffb800;
}

.review-text {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.review-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 600;
  font-size: 14px;
}

.review-info h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.review-info span {
  font-size: 12px;
  color: var(--text-muted);
}

/* ===== Security Section ===== */
.security {
  background: var(--bg-light);
}

.security-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.security-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.security-item {
  display: flex;
  gap: 16px;
  padding: 20px;
  background: #fff;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.security-icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(230,0,18,0.1);
  border-radius: 10px;
}

.security-icon svg {
  width: 22px;
  height: 22px;
  color: var(--primary);
}

.security-item h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.security-item p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Comparison Table */
.comparison-wrap {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.comparison-header {
  padding: 20px 24px;
  background: var(--bg-gray);
  border-bottom: 1px solid var(--border);
}

.comparison-header h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
}

.comparison-table th,
.comparison-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}

.comparison-table th {
  font-weight: 600;
  color: var(--text);
  background: var(--bg-light);
}

.comparison-table td {
  color: var(--text-secondary);
}

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

.comparison-table .product-name {
  font-weight: 600;
  color: var(--text);
}

.comparison-table .highlight {
  color: var(--primary);
  font-weight: 600;
}

.comparison-table .check {
  color: #22c55e;
  font-weight: 600;
}

.comparison-table .cross {
  color: var(--text-muted);
}

/* ===== Versions Section ===== */
.versions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.version-card {
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  position: relative;
  transition: all 0.3s ease;
}

.version-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.version-card.popular {
  border-color: var(--primary);
}

.version-badge {
  position: absolute;
  top: -2px;
  right: 24px;
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 0 0 8px 8px;
}

.version-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.version-price {
  font-size: 36px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 8px;
}

.version-price span {
  font-size: 14px;
  font-weight: 400;
  color: var(--text-muted);
}

.version-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.version-features {
  list-style: none;
  margin-bottom: 28px;
}

.version-features li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-secondary);
}

.version-features li svg {
  width: 18px;
  height: 18px;
  color: var(--primary);
  flex-shrink: 0;
  margin-top: 1px;
}

/* ===== FAQ Section ===== */
.faq {
  background: var(--bg-light);
}

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

.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  transition: background 0.2s ease;
}

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

.faq-question h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  padding-right: 20px;
}

.faq-icon {
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  transition: transform 0.3s ease;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

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

.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ===== Footer ===== */
.footer {
  background: var(--text);
  color: #fff;
  padding: 40px 0;
  text-align: center;
}

.footer p {
  font-size: 13px;
  color: rgba(255,255,255,0.6);
  margin-bottom: 8px;
}

.footer p:first-child {
  font-size: 14px;
  color: rgba(255,255,255,0.8);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-content {
    max-width: 100%;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .features-grid,
  .platforms-grid,
  .reviews-grid,
  .versions-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .deep-row {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  
  .deep-row.reverse {
    direction: ltr;
  }
  
  .security-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 20px;
    gap: 4px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
  }
  
  .nav-menu.show {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-link {
    width: 100%;
    text-align: center;
    padding: 12px;
  }
  
  .nav-cta {
    margin: 12px 0 0;
    width: 100%;
  }
  
  .nav-cta .btn {
    width: 100%;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .hero {
    padding: 120px 0 60px;
  }
  
  .hero-title {
    font-size: 32px;
  }
  
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .features-grid,
  .platforms-grid,
  .reviews-grid,
  .versions-grid,
  .security-features {
    grid-template-columns: 1fr;
  }
  
  .section-title {
    font-size: 28px;
  }
  
  .comparison-table {
    font-size: 13px;
  }
  
  .comparison-table th,
  .comparison-table td {
    padding: 12px 16px;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
  }
  
  .hero-stats {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }
  
  .hero-stat-value {
    font-size: 24px;
  }
}