/* ===== 国际人app下载 - 独特视觉系统 ===== */
/* 主题：野兽派+霓虹流体+赛博网格解构 */
/* 配色：暗夜紫黑 + 酸性霓虹绿 + 熔岩橙红点缀 */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;500;700;900&display=swap');

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

:root {
  --bg-primary: #0b0a0f;
  --bg-secondary: #14121a;
  --bg-card: #1c1924;
  --text-primary: #f0edf5;
  --text-secondary: #a89fb8;
  --accent-neon: #9eff4b;
  --accent-orange: #ff6a3d;
  --accent-pink: #ff3d85;
  --border-grid: rgba(158, 255, 75, 0.15);
  --border-glow: rgba(158, 255, 75, 0.4);
  --shadow-neon: 0 0 30px rgba(158, 255, 75, 0.2);
  --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --grid-size: 60px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* ===== 背景网格解构 ===== */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--border-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-grid) 1px, transparent 1px);
  background-size: var(--grid-size) var(--grid-size);
  pointer-events: none;
  z-index: 0;
  opacity: 0.6;
}

/* ===== 容器 ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* ===== 头部 ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(11, 10, 15, 0.85);
  backdrop-filter: blur(20px) saturate(1.4);
  border-bottom: 1px solid var(--border-grid);
  transition: background 0.4s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  font-size: 1.8rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.logo:hover {
  transform: scale(1.04);
}

.logo::before {
  content: '🌐';
  font-size: 1.6rem;
  filter: hue-rotate(80deg);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.main-nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  letter-spacing: 0.3px;
  position: relative;
  padding: 4px 0;
  transition: color 0.3s ease;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-neon);
  transition: width 0.35s cubic-bezier(0.22, 1, 0.36, 1);
  box-shadow: 0 0 12px var(--accent-neon);
}

.main-nav a:hover {
  color: var(--accent-neon);
}

.main-nav a:hover::after {
  width: 100%;
}

.nav-cta {
  background: transparent;
  border: 1.5px solid var(--accent-neon);
  color: var(--accent-neon);
  padding: 8px 22px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: all 0.35s cubic-bezier(0.22, 1, 0.36, 1);
  text-transform: uppercase;
  box-shadow: 0 0 12px transparent;
}

.nav-cta:hover {
  background: var(--accent-neon);
  color: var(--bg-primary);
  box-shadow: 0 0 30px var(--accent-neon);
  transform: scale(1.05);
}

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

.menu-toggle span {
  display: block;
  width: 28px;
  height: 2.5px;
  background: var(--text-primary);
  border-radius: 4px;
  transition: all 0.3s ease;
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -20%;
  width: 70vmax;
  height: 70vmax;
  background: radial-gradient(circle at 30% 40%, rgba(158, 255, 75, 0.08), transparent 60%);
  pointer-events: none;
  animation: heroPulse 8s ease-in-out infinite alternate;
}

@keyframes heroPulse {
  0% { transform: scale(1) translate(0, 0); opacity: 0.6; }
  100% { transform: scale(1.2) translate(-40px, 30px); opacity: 1; }
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--accent-neon);
  margin-bottom: 20px;
  padding: 6px 18px;
  border: 1px solid var(--accent-neon);
  border-radius: 50px;
  background: rgba(158, 255, 75, 0.06);
  backdrop-filter: blur(4px);
}

.hero h1 {
  font-size: clamp(2.6rem, 6vw, 4.8rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.hero h1 span {
  color: var(--accent-neon);
  text-shadow: 0 0 40px rgba(158, 255, 75, 0.3);
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 480px;
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

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

.hero-image::after {
  content: '';
  display: block;
  width: 100%;
  padding-bottom: 100%;
  background: conic-gradient(from 45deg, var(--accent-neon), var(--accent-orange), var(--accent-pink), var(--accent-neon));
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.25;
  animation: rotateGlow 12s linear infinite;
}

@keyframes rotateGlow {
  0% { transform: rotate(0deg) scale(0.9); }
  50% { transform: rotate(180deg) scale(1.1); }
  100% { transform: rotate(360deg) scale(0.9); }
}

.hero-image::before {
  content: '⬇️ 国际人';
  position: absolute;
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--text-primary);
  text-shadow: 0 0 40px rgba(0,0,0,0.8);
  z-index: 2;
  letter-spacing: 6px;
  text-align: center;
  line-height: 1.2;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  border-radius: 50px;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all 0.35s cubic-bezier(0.22, 1, 0.36, 1);
  letter-spacing: 0.3px;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.1), transparent);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.btn:hover::before {
  opacity: 1;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-neon), #6bff2a);
  color: var(--bg-primary);
  box-shadow: 0 4px 24px rgba(158, 255, 75, 0.35);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 40px rgba(158, 255, 75, 0.5);
}

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

.btn-outline:hover {
  border-color: var(--accent-neon);
  color: var(--accent-neon);
  transform: translateY(-3px);
  box-shadow: 0 0 30px rgba(158, 255, 75, 0.15);
}

/* ===== 通用section ===== */
.section {
  padding: 100px 0;
  position: relative;
}

.section-label {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 5px;
  text-transform: uppercase;
  color: var(--accent-neon);
  margin-bottom: 16px;
  opacity: 0.8;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  line-height: 1.1;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.7;
}

/* ===== 卡片网格 ===== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
  margin-top: 60px;
}

.category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-grid);
  border-radius: 20px;
  padding: 40px 32px;
  transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
  position: relative;
  overflow: hidden;
}

.category-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-neon), var(--accent-orange));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

.category-card:hover::after {
  transform: scaleX(1);
}

.category-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent-neon);
  box-shadow: 0 20px 60px rgba(158, 255, 75, 0.08);
}

.card-icon {
  font-size: 2.4rem;
  margin-bottom: 20px;
  display: block;
  filter: drop-shadow(0 0 12px rgba(158, 255, 75, 0.2));
}

.category-card h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.category-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 24px;
}

.card-link {
  color: var(--accent-neon);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.85rem;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: gap 0.3s ease;
}

.card-link:hover {
  gap: 14px;
}

/* ===== Feature Block ===== */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  padding: 80px 0;
}

.feature-block:nth-child(even) {
  direction: rtl;
}

.feature-block:nth-child(even) > * {
  direction: ltr;
}

.feature-image {
  background: var(--bg-card);
  border-radius: 24px;
  padding: 40px;
  min-height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-grid);
  position: relative;
  overflow: hidden;
}

.feature-image::before {
  content: '📱';
  font-size: 5rem;
  filter: drop-shadow(0 0 30px rgba(158, 255, 75, 0.2));
}

.feature-text {
  padding: 20px 0;
}

.feature-text h3 {
  font-size: 2rem;
  font-weight: 900;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.feature-list {
  list-style: none;
  margin-top: 24px;
}

.feature-list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-grid);
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.feature-list li::before {
  content: '✦';
  color: var(--accent-neon);
  font-weight: 700;
}

/* ===== Stats Bar ===== */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding: 60px 0;
  border-top: 1px solid var(--border-grid);
  border-bottom: 1px solid var(--border-grid);
  margin: 60px 0;
}

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

.stat-number {
  font-size: 3rem;
  font-weight: 900;
  color: var(--accent-neon);
  line-height: 1;
  margin-bottom: 8px;
  text-shadow: 0 0 30px rgba(158, 255, 75, 0.2);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* ===== Content Wall ===== */
.content-wall {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 50px;
}

.content-wall-item {
  background: var(--bg-card);
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border-grid);
  transition: all 0.4s ease;
}

.content-wall-item:hover {
  transform: translateY(-6px);
  border-color: var(--accent-neon);
  box-shadow: 0 12px 40px rgba(158, 255, 75, 0.06);
}

.content-wall-item::before {
  content: '';
  display: block;
  padding-bottom: 56%;
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-card));
  background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><rect width="100" height="100" fill="none"/><text x="50" y="60" font-size="30" text-anchor="middle" fill="%239eff4b" opacity="0.15">🌍</text></svg>');
  background-size: cover;
}

.content-wall-body {
  padding: 24px;
}

.content-wall-body h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.content-wall-body p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 800px;
  margin: 50px auto 0;
}

.faq-item {
  border-bottom: 1px solid var(--border-grid);
  padding: 20px 0;
  cursor: pointer;
  transition: all 0.3s ease;
}

.faq-item summary {
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  padding: 8px 0;
  transition: color 0.3s ease;
}

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

.faq-item summary::after {
  content: '+';
  font-size: 1.6rem;
  color: var(--accent-neon);
  transition: transform 0.4s ease;
}

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

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

.faq-answer {
  padding: 16px 0 8px;
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 0.95rem;
}

/* ===== CTA Banner ===== */
.cta-banner {
  background: linear-gradient(135deg, var(--bg-card), var(--bg-secondary));
  border: 1px solid var(--accent-neon);
  border-radius: 32px;
  padding: 80px 60px;
  text-align: center;
  margin: 80px 0;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 0 60px rgba(158, 255, 75, 0.04);
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 40%, rgba(158, 255, 75, 0.03), transparent 50%);
  animation: heroPulse 10s ease-in-out infinite alternate;
}

.cta-banner h2 {
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 900;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
}

.cta-banner p {
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 32px;
  font-size: 1.05rem;
  position: relative;
  z-index: 1;
}

.cta-banner .btn {
  position: relative;
  z-index: 1;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-grid);
  padding: 60px 0 0;
  margin-top: 60px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
}

.footer-brand {
  max-width: 320px;
}

.footer-brand .logo {
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--accent-neon);
  margin-bottom: 20px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 12px;
}

.footer-col a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease;
}

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

.footer-bottom {
  border-top: 1px solid var(--border-grid);
  padding: 24px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ===== 辅助类 ===== */
.text-accent {
  color: var(--accent-neon);
}

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

.seo-description {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero p {
    margin: 0 auto 36px;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    order: -1;
    max-width: 400px;
    margin: 0 auto;
  }

  .feature-block {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .feature-block:nth-child(even) {
    direction: ltr;
  }

  .feature-list {
    text-align: left;
    max-width: 500px;
    margin: 24px auto 0;
  }

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

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

@media (max-width: 768px) {
  .header-inner {
    height: 64px;
  }

  .main-nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(11, 10, 15, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 32px 24px;
    gap: 24px;
    transform: translateY(-120%);
    opacity: 0;
    transition: all 0.5s cubic-bezier(0.22, 1, 0.36, 1);
    border-bottom: 1px solid var(--border-grid);
    pointer-events: none;
  }

  .main-nav.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .menu-toggle {
    display: flex;
  }

  .menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

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

  .menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .hero {
    padding: 100px 0 60px;
  }

  .hero h1 {
    font-size: clamp(2rem, 8vw, 2.8rem);
  }

  .section {
    padding: 60px 0;
  }

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

  .content-wall {
    grid-template-columns: 1fr;
  }

  .cta-banner {
    padding: 50px 30px;
    border-radius: 20px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }

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

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .header-inner {
    padding: 0 16px;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .hero p {
    font-size: 0.95rem;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.85rem;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: stretch;
  }

  .stats-bar {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

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

  .section-title {
    font-size: 1.6rem;
  }

  .cta-banner {
    padding: 40px 20px;
  }

  .cta-banner h2 {
    font-size: 1.6rem;
  }
}