/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  color: #1a1a2e;
  background: #fff;
}
img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* ===== VARIABLES ===== */
:root {
  --orange: #f97316;
  --orange-dark: #ea580c;
  --orange-hover: #fb923c;
  --blue-dark: #0a1628;
  --blue-mid: #0d2244;
  --blue-light: #1a3a6e;
  --max-w: 1200px;
}

/* ===== CONTAINER ===== */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== BUTTONS ===== */
.btn-orange {
  display: inline-block;
  background: linear-gradient(135deg, var(--orange), var(--orange-dark));
  color: #fff;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  border: none;
  transition: all 0.25s ease;
  text-align: center;
}
.btn-orange:hover {
  background: linear-gradient(135deg, var(--orange-hover), var(--orange));
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(249,115,22,0.4);
}
.btn-lg { padding: 14px 36px; font-size: 16px; }
.btn-md { padding: 12px 32px; font-size: 15px; }
.btn-outline {
  display: inline-block;
  border: 2px solid var(--orange);
  color: var(--orange);
  background: transparent;
  padding: 10px 28px;
  border-radius: 4px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.25s ease;
}
.btn-outline:hover { background: var(--orange); color: #fff; }

/* ===== ANIMATIONS ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(32px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-14px); }
}
@keyframes progressFill {
  from { width: 0%; }
  to   { width: 100%; }
}
.animate-fade-in-up { animation: fadeInUp 0.8s ease forwards; }
.animate-float      { animation: float 4s ease-in-out infinite; }

/* ===== HEADER ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: #fff;
  box-shadow: 0 1px 8px rgba(0,0,0,0.08);
}
.header-inner {
  display: flex;
  align-items: center;
  height: 64px;
  gap: 32px;
}
.logo-link { flex-shrink: 0; }
.logo-img { height: 36px; width: auto; }
.main-nav {
  display: flex;
  gap: 28px;
  flex: 1;
  justify-content: center;
}
.main-nav a {
  font-size: 14px;
  font-weight: 500;
  color: #374151;
  transition: color 0.2s;
}
.main-nav a:hover { color: #2563eb; }
.header-cta { padding: 9px 22px; font-size: 14px; flex-shrink: 0; }
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  margin-left: auto;
}
.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: #374151;
  border-radius: 2px;
  transition: all 0.3s;
}
.mobile-nav {
  display: none;
  flex-direction: column;
  background: #fff;
  border-top: 1px solid #f0f0f0;
  padding: 12px 24px 16px;
  gap: 4px;
}
.mobile-nav.open { display: flex; }
.mobile-nav-link {
  padding: 10px 0;
  font-size: 15px;
  color: #374151;
  border-bottom: 1px solid #f5f5f5;
}
.mobile-nav-cta { margin-top: 12px; text-align: center; padding: 12px; }

/* ===== HERO ===== */
.hero-section {
  position: relative;
  min-height: 480px;
  display: flex;
  align-items: center;
  margin-top: 64px;
  overflow: hidden;
}
.hero-bg-img {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.hero-inner {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  padding-top: 60px;
  padding-bottom: 60px;
}
.hero-text { flex: 0 0 480px; max-width: 480px; }
.hero-text h1 {
  font-size: 38px;
  font-weight: 700;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 20px;
}
.hero-text p {
  font-size: 14px;
  color: rgba(255,255,255,0.85);
  line-height: 1.8;
  margin-bottom: 32px;
}
.hero-visual { flex: 0 0 auto; max-width: 520px; }
.hero-visual img { width: 100%; }

/* ===== FEATURE SECTION ===== */
.feature-section {
  padding: 72px 0;
  background: #fff;
}
.feature-inner {
  display: flex;
  gap: 48px;
  align-items: flex-start;
}
.feature-left {
  flex: 0 0 240px;
  text-align: center;
}
.feature-left h2 {
  font-size: 22px;
  font-weight: 700;
  color: #1a1a2e;
  margin-bottom: 24px;
  text-align: left;
}
.feature-logo-wrap {
  background: #f8fafc;
  border-radius: 12px;
  padding: 24px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.feature-logo-wrap img { width: 120px; height: auto; }
.feature-right { flex: 1; }
.feature-right p {
  font-size: 14px;
  color: #4b5563;
  line-height: 1.8;
  margin-bottom: 16px;
}
.feature-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 28px;
}
.feature-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 20px 12px;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  font-size: 13px;
  color: #374151;
  font-weight: 500;
  text-align: center;
  transition: all 0.25s;
  cursor: default;
}
.feature-card:hover {
  border-color: #2563eb;
  box-shadow: 0 4px 16px rgba(37,99,235,0.1);
  transform: translateY(-2px);
}
.feature-icon {
  width: 40px;
  height: 40px;
  color: #2563eb;
}
.feature-icon svg { width: 100%; height: 100%; }

/* ===== DOWNLOAD GUIDE ===== */
.download-section {
  padding: 72px 0 80px;
  background: #f8fafc;
}
.section-title {
  font-size: 28px;
  font-weight: 700;
  color: #1a1a2e;
  text-align: center;
  margin-bottom: 36px;
}

/* Tab 导航 */
.tab-nav {
  display: flex;
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid #e5e7eb;
  background: #fff;
  max-width: 100%;
}
.tab-btn {
  flex: 1;
  padding: 14px 20px;
  font-size: 15px;
  font-weight: 500;
  color: #6b7280;
  background: #fff;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  border-right: 1px solid #e5e7eb;
  position: relative;
}
.tab-btn:last-child { border-right: none; }
.tab-btn:hover { color: #2563eb; background: #f0f4ff; }
.tab-btn.active {
  background: #2563eb;
  color: #fff;
  font-weight: 600;
}

/* 进度条 */
.tab-progress-bar {
  height: 3px;
  background: #e5e7eb;
  border-radius: 0 0 2px 2px;
  overflow: hidden;
  margin-bottom: 32px;
}
.tab-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--orange);
  border-radius: 2px;
}
.tab-progress-fill.running {
  animation: progressFill 5s linear forwards;
}

/* Tab 面板 */
.tab-panels { position: relative; }
.tab-panel {
  display: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.tab-panel.active {
  display: block;
  opacity: 1;
}
.panel-inner {
  display: flex;
  gap: 48px;
  align-items: center;
  background: #fff;
  border-radius: 12px;
  padding: 40px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
}
.panel-img {
  flex: 0 0 420px;
  max-width: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.panel-img img { width: 100%; height: auto; }
.panel-content { flex: 1; }
.panel-content h3 {
  font-size: 22px;
  font-weight: 700;
  color: #1a1a2e;
  margin-bottom: 20px;
}
.panel-list { margin-bottom: 28px; }
.panel-list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: #4b5563;
  line-height: 1.8;
  margin-bottom: 8px;
}
.panel-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--orange);
  font-weight: 700;
}

/* ===== CTA SECTION ===== */
.cta-section {
  position: relative;
  padding: 72px 0;
  overflow: hidden;
}
.cta-bg-img {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.cta-inner {
  position: relative;
  z-index: 2;
  text-align: center;
}
.cta-inner h2 {
  font-size: 26px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 48px;
}
.cta-layout {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 40px;
}
.cta-features { display: flex; flex-direction: column; gap: 16px; }
.cta-features-left { align-items: flex-end; }
.cta-features-right { align-items: flex-start; }
.cta-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255,255,255,0.12);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 24px;
  padding: 10px 20px;
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
}
.cta-feature-item .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  flex-shrink: 0;
}
.cta-visual {
  flex: 0 0 220px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.cta-visual img { width: 200px; height: auto; }
.cta-btn { min-width: 220px; }

/* ===== FAQ ===== */
.faq-section {
  padding: 72px 0 80px;
  background: #fff;
}
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 32px;
}
.faq-item {
  border-bottom: 1px solid #e5e7eb;
}
.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 0;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-size: 15px;
  font-weight: 500;
  color: #1a1a2e;
  transition: color 0.2s;
}
.faq-question:hover { color: #2563eb; }
.faq-question span { flex: 1; }
.faq-arrow {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: #6b7280;
  transition: transform 0.3s ease;
}
.faq-item.open .faq-arrow { transform: rotate(180deg); }
.faq-item.open .faq-question { color: #2563eb; }
.faq-answer {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.35s ease, padding 0.35s ease;
}
.faq-answer p {
  font-size: 14px;
  color: #4b5563;
  line-height: 1.8;
  padding-bottom: 16px;
}
.faq-item.open .faq-answer { max-height: 200px; }

/* ===== FOOTER ===== */
.site-footer {
  background: #f8fafc;
  border-top: 1px solid #e5e7eb;
  padding: 32px 0;
  text-align: center;
}
.footer-inner { display: flex; flex-direction: column; gap: 12px; align-items: center; }
.footer-disclaimer { font-size: 13px; color: #6b7280; }
.footer-risk { font-size: 12px; color: #9ca3af; max-width: 800px; line-height: 1.7; }
.footer-links {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: #9ca3af;
}
.footer-links a { color: #6b7280; transition: color 0.2s; }
.footer-links a:hover { color: #2563eb; }
.footer-copy { font-size: 12px; color: #9ca3af; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .hero-text { flex: 0 0 400px; max-width: 400px; }
  .hero-text h1 { font-size: 30px; }
  .feature-cards { grid-template-columns: repeat(2, 1fr); }
  .panel-img { flex: 0 0 320px; max-width: 320px; }
  .cta-layout { gap: 24px; }
}

@media (max-width: 768px) {
  .main-nav, .header-cta { display: none; }
  .mobile-menu-btn { display: flex; }
  .hero-inner { flex-direction: column; text-align: center; padding-top: 40px; padding-bottom: 40px; }
  .hero-text { flex: none; max-width: 100%; }
  .hero-text h1 { font-size: 26px; }
  .hero-visual { max-width: 100%; }
  .feature-inner { flex-direction: column; }
  .feature-left { width: 100%; text-align: center; }
  .feature-left h2 { text-align: center; }
  .feature-cards { grid-template-columns: repeat(2, 1fr); }
  .panel-inner { flex-direction: column; padding: 24px; }
  .panel-img { flex: none; max-width: 100%; }
  .cta-layout { flex-direction: column; }
  .cta-features-left, .cta-features-right { align-items: center; }
  .faq-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero-text h1 { font-size: 22px; }
  .section-title { font-size: 22px; }
  .feature-cards { grid-template-columns: repeat(2, 1fr); }
  .tab-btn { font-size: 13px; padding: 12px 8px; }
}