/* ===========================
   Zoom Earth 介绍页样式
   =========================== */

:root {
  --bg-deep: #060f24;
  --bg-base: #0a1428;
  --bg-elevated: #0e1d3a;
  --bg-card: rgba(255, 255, 255, 0.05);
  --bg-card-hover: rgba(94, 195, 255, 0.08);
  --primary: #1e7fd6;
  --primary-dark: #0a4a8f;
  --accent: #5ec3ff;
  --accent-warm: #ffd93d;
  --accent-fire: #ff8c42;
  --text: #ffffff;
  --text-soft: #cfe5f7;
  --text-muted: #8fb3d6;
  --border: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(94, 195, 255, 0.25);
  --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(94, 195, 255, 0.2);
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;
  --max-width: 1200px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text-soft);
  background: var(--bg-base);
  background-image:
    radial-gradient(ellipse 80% 60% at 80% 0%, rgba(30, 127, 214, 0.25), transparent 60%),
    radial-gradient(ellipse 70% 50% at 0% 30%, rgba(94, 195, 255, 0.12), transparent 60%),
    linear-gradient(180deg, var(--bg-deep) 0%, var(--bg-base) 50%, var(--bg-deep) 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

img,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #ffffff;
}

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4 {
  color: var(--text);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* ===========================
   布局容器
   =========================== */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 96px 0;
  position: relative;
}

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

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 6px 14px;
  border: 1px solid var(--border-accent);
  border-radius: 999px;
  margin-bottom: 20px;
  background: rgba(94, 195, 255, 0.06);
}

.section-head h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 16px;
}

.section-head p {
  font-size: 1.0625rem;
  color: var(--text-muted);
}

/* ===========================
   顶部导航
   =========================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(6, 15, 36, 0.72);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.01em;
}

.brand img {
  width: 36px;
  height: 36px;
}

.brand small {
  display: block;
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-soft);
  font-size: 0.9375rem;
  font-weight: 500;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.25s ease;
}

.nav-links a:hover::after,
.nav-links a[aria-current="page"]::after {
  width: 100%;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  background: var(--accent);
  color: var(--bg-deep);
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: 999px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.nav-cta:hover {
  color: var(--bg-deep);
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.2s ease;
}

/* ===========================
   Hero
   =========================== */

.hero {
  position: relative;
  padding: 80px 0 64px;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-content .eyebrow {
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.5rem, 5.5vw, 4.25rem);
  line-height: 1.08;
  margin-bottom: 24px;
}

.hero h1 .grad {
  background: linear-gradient(120deg, var(--accent) 0%, #ffffff 50%, var(--accent-warm) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.hero p.lead {
  font-size: 1.1875rem;
  color: var(--text-soft);
  max-width: 560px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 40px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 1rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-deep);
  box-shadow: 0 10px 30px rgba(94, 195, 255, 0.3);
}

.btn-primary:hover {
  color: var(--bg-deep);
  transform: translateY(-2px);
  box-shadow: 0 14px 40px rgba(94, 195, 255, 0.45);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--border-accent);
}

.btn svg {
  width: 20px;
  height: 20px;
}

.hero-stats {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
}

.hero-stat .num {
  font-size: 1.875rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1;
}

.hero-stat .label {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 6px;
}

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

.hero-visual .earth {
  width: 100%;
  max-width: 520px;
  filter: drop-shadow(0 30px 60px rgba(30, 127, 214, 0.4));
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-16px); }
}

/* ===========================
   信任徽章
   =========================== */

.trust {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.trust-row {
  display: flex;
  align-items: center;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 24px;
  text-align: center;
}

.trust-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.trust-item .src {
  font-size: 0.8125rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.trust-item .desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  opacity: 0.7;
}

/* ===========================
   功能卡片网格
   =========================== */

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: transform 0.25s ease, border-color 0.25s ease, background 0.25s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-accent), transparent);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-card .icon {
  width: 64px;
  height: 64px;
  margin-bottom: 22px;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.feature-card .tag {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--accent);
  background: rgba(94, 195, 255, 0.1);
  padding: 4px 10px;
  border-radius: 999px;
  font-weight: 500;
}

/* ===========================
   功能详情（图文交替）
   =========================== */

.feature-detail {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  margin-bottom: 96px;
}

.feature-detail:last-child {
  margin-bottom: 0;
}

.feature-detail.reverse {
  direction: rtl;
}

.feature-detail.reverse > * {
  direction: ltr;
}

.feature-detail .content h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  margin-bottom: 16px;
}

.feature-detail .content p {
  font-size: 1.0625rem;
  color: var(--text-soft);
  margin-bottom: 20px;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: 24px;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  color: var(--text-soft);
  font-size: 0.9375rem;
}

.feature-list li::before {
  content: "";
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 3px;
  border-radius: 50%;
  background: rgba(94, 195, 255, 0.15) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%235ec3ff' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'><polyline points='20 6 9 17 4 12'/></svg>") center/14px no-repeat;
}

.feature-detail .visual {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 320px;
  position: relative;
  overflow: hidden;
}

.feature-detail .visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 50%, rgba(94, 195, 255, 0.08), transparent 70%);
  pointer-events: none;
}

.feature-detail .visual img {
  max-width: 240px;
  position: relative;
  z-index: 1;
}

/* ===========================
   数据统计
   =========================== */

.stats {
  background: linear-gradient(180deg, transparent, rgba(30, 127, 214, 0.06), transparent);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

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

.stat-item .num {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  background: linear-gradient(120deg, var(--accent), #ffffff);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  line-height: 1;
}

.stat-item .label {
  margin-top: 12px;
  font-size: 0.9375rem;
  color: var(--text-muted);
}

/* ===========================
   下载区域
   =========================== */

.download {
  text-align: center;
}

.download-card {
  background: linear-gradient(135deg, rgba(30, 127, 214, 0.15), rgba(94, 195, 255, 0.08));
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
  padding: 64px 40px;
  position: relative;
  overflow: hidden;
}

.download-card::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -10%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(94, 195, 255, 0.15), transparent 60%);
  pointer-events: none;
}

.download-card h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.75rem);
  margin-bottom: 16px;
  position: relative;
}

.download-card p {
  font-size: 1.0625rem;
  color: var(--text-soft);
  max-width: 560px;
  margin: 0 auto 36px;
  position: relative;
}

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

.store-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 24px;
  background: #ffffff;
  color: #000000;
  border-radius: 14px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.store-btn:hover {
  color: #000000;
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.3);
}

.store-btn.dark {
  background: #000000;
  color: #ffffff;
}

.store-btn.dark:hover {
  color: #ffffff;
}

.store-btn svg {
  width: 28px;
  height: 28px;
}

.store-btn .store-text small {
  display: block;
  font-size: 0.6875rem;
  font-weight: 400;
  opacity: 0.8;
}

.store-btn .store-text strong {
  font-size: 1.0625rem;
  display: block;
  line-height: 1.2;
}

.download-meta {
  margin-top: 28px;
  font-size: 0.8125rem;
  color: var(--text-muted);
  position: relative;
}

/* ===========================
   FAQ
   =========================== */

.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item[open] {
  border-color: var(--border-accent);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  cursor: pointer;
  font-weight: 600;
  color: var(--text);
  font-size: 1.0625rem;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--accent);
  font-weight: 300;
  transition: transform 0.25s ease;
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item .answer {
  padding: 0 24px 22px;
  color: var(--text-soft);
  font-size: 0.9375rem;
}

/* ===========================
   Footer
   =========================== */

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-deep);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand .brand {
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 18px;
  font-weight: 600;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col a {
  color: var(--text-soft);
  font-size: 0.9375rem;
}

.footer-col a:hover {
  color: var(--accent);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.footer-bottom a {
  color: var(--text-muted);
}

.footer-bottom a:hover {
  color: var(--accent);
}

/* ===========================
   通用工具
   =========================== */

.text-center { text-align: center; }
.mt-40 { margin-top: 40px; }

/* ===========================
   响应式
   =========================== */

@media (max-width: 960px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .hero-content .eyebrow,
  .hero-actions,
  .hero-stats {
    justify-content: center;
  }

  .hero p.lead {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-visual .earth {
    max-width: 360px;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-detail,
  .feature-detail.reverse {
    grid-template-columns: 1fr;
    gap: 32px;
    direction: ltr;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
  }

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

@media (max-width: 720px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    padding: 8px 24px 16px;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    padding: 14px 0;
    border-bottom: 1px solid var(--border);
  }

  .nav-links a:last-child {
    border-bottom: none;
  }

  .nav-cta {
    margin-top: 12px;
    justify-content: center;
  }

  .nav-toggle {
    display: flex;
  }

  .section {
    padding: 64px 0;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .download-card {
    padding: 40px 24px;
  }

  .store-btn {
    width: 100%;
    justify-content: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}