/* ===== 全局样式 ===== */
:root {
  --primary-color: #667eea;
  --secondary-color: #764ba2;
  --accent-color: #f093fb;
  --bg-dark: #0a0e27;
  --bg-darker: #050816;
  --bg-card: rgba(15, 23, 42, 0.8);
  --text-primary: #ffffff;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: rgba(148, 163, 184, 0.1);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 30px rgba(102, 126, 234, 0.3);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-darker);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 粒子背景 ===== */
#particles-js {
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  z-index: -1;
  background: linear-gradient(135deg, #0a0e27 0%, #1a1f3a 50%, #0a0e27 100%);
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 14, 39, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.navbar.scrolled {
  background: rgba(10, 14, 39, 0.98);
  box-shadow: var(--shadow-md);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  box-shadow: var(--shadow-glow);
}

.logo-text {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-menu a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  transition: width 0.3s ease;
}

.nav-menu a:hover {
  color: var(--text-primary);
}

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

.download-btn-nav {
  padding: 10px 24px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border: none;
  border-radius: 8px;
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.download-btn-nav:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

/* ===== 英雄区域 ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 120px 24px 60px;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 1200px;
  text-align: center;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(102, 126, 234, 0.1);
  border: 1px solid rgba(102, 126, 234, 0.3);
  border-radius: 50px;
  color: var(--primary-color);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 32px;
  animation: float 3s ease-in-out infinite;
}

.badge-pulse {
  width: 8px;
  height: 8px;
  background: var(--primary-color);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(1.2);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.hero-title {
  font-size: clamp(48px, 8vw, 96px);
  font-weight: 900;
  margin-bottom: 24px;
  line-height: 1.1;
}

.gradient-text {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradient-shift 5s ease infinite;
  background-size: 200% 200%;
}

@keyframes gradient-shift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.hero-subtitle {
  font-size: clamp(20px, 3vw, 32px);
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-weight: 600;
}

.hero-description {
  font-size: clamp(16px, 2vw, 20px);
  color: var(--text-muted);
  margin-bottom: 48px;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin-bottom: 80px;
  flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
  padding: 16px 40px;
  font-size: 18px;
  font-weight: 600;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  transition: all 0.3s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(102, 126, 234, 0.6);
}

.btn-secondary {
  background: rgba(102, 126, 234, 0.1);
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
  background: rgba(102, 126, 234, 0.2);
  transform: translateY(-4px);
}

.btn-icon {
  font-size: 20px;
}

.hero-stats {
  display: flex;
  gap: 64px;
  justify-content: center;
  flex-wrap: wrap;
}

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

.stat-number {
  font-size: 48px;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.stat-label {
  color: var(--text-muted);
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ===== 3D 代码方块 ===== */
.hero-visual {
  position: absolute;
  right: -100px;
  top: 50%;
  transform: translateY(-50%);
  opacity: 0.2;
}

.code-cube {
  width: 300px;
  height: 300px;
  position: relative;
  transform-style: preserve-3d;
  animation: rotateCube 20s infinite linear;
}

@keyframes rotateCube {
  0% {
    transform: rotateX(0deg) rotateY(0deg);
  }
  100% {
    transform: rotateX(360deg) rotateY(360deg);
  }
}

.cube-face {
  position: absolute;
  width: 300px;
  height: 300px;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.3), rgba(118, 75, 162, 0.3));
  border: 2px solid rgba(102, 126, 234, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  font-weight: 900;
  color: white;
  backdrop-filter: blur(10px);
}

.cube-face.front { transform: translateZ(150px); }
.cube-face.back { transform: rotateY(180deg) translateZ(150px); }
.cube-face.right { transform: rotateY(90deg) translateZ(150px); }
.cube-face.left { transform: rotateY(-90deg) translateZ(150px); }
.cube-face.top { transform: rotateX(90deg) translateZ(150px); }
.cube-face.bottom { transform: rotateX(-90deg) translateZ(150px); }

/* ===== 滚动指示器 ===== */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
  animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
  0%, 100% {
    transform: translateX(-50%) translateY(0);
  }
  50% {
    transform: translateX(-50%) translateY(-10px);
  }
}

.mouse {
  width: 28px;
  height: 42px;
  border: 2px solid var(--primary-color);
  border-radius: 14px;
  margin: 0 auto 12px;
  position: relative;
}

.mouse::before {
  content: '';
  width: 4px;
  height: 8px;
  background: var(--primary-color);
  border-radius: 2px;
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  animation: scroll 2s ease-in-out infinite;
}

@keyframes scroll {
  0% {
    opacity: 1;
    top: 8px;
  }
  100% {
    opacity: 0;
    top: 24px;
  }
}

.scroll-indicator p {
  color: var(--text-muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

/* ===== 区块标题 ===== */
.section-header {
  text-align: center;
  margin-bottom: 80px;
}

.section-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 900;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  font-size: clamp(16px, 2vw, 20px);
  color: var(--text-muted);
}

/* ===== 功能特性 ===== */
.features {
  padding: 120px 24px;
  position: relative;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 32px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 40px;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

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

.feature-icon {
  margin-bottom: 24px;
}

.icon-wrapper {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.2), rgba(118, 75, 162, 0.2));
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 40px;
  transition: all 0.3s ease;
}

.feature-card:hover .icon-wrapper {
  transform: scale(1.1) rotate(5deg);
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.3), rgba(118, 75, 162, 0.3));
}

.feature-card h3 {
  font-size: 24px;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 20px;
}

.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature-list li {
  color: var(--text-muted);
  font-size: 14px;
  position: relative;
  padding-left: 24px;
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--primary-color);
  font-weight: bold;
}

/* ===== 技术栈 ===== */
.tech-stack {
  padding: 120px 24px;
  background: rgba(15, 23, 42, 0.5);
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
}

.tech-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 32px 24px;
  text-align: center;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.tech-item:hover {
  transform: translateY(-8px) scale(1.05);
  border-color: var(--primary-color);
  box-shadow: var(--shadow-glow);
}

.tech-logo {
  font-size: 48px;
  margin-bottom: 16px;
  filter: grayscale(100%);
  transition: filter 0.3s ease;
}

.tech-item:hover .tech-logo {
  filter: grayscale(0%);
}

.tech-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-secondary);
  transition: color 0.3s ease;
}

.tech-item:hover .tech-name {
  color: var(--text-primary);
}

/* ===== 截图展示 ===== */
.screenshots {
  padding: 120px 24px;
}

.screenshots-carousel {
  max-width: 1000px;
  margin: 0 auto;
}

.screenshot-item {
  border-radius: 20px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.screenshot-placeholder {
  background: var(--bg-dark);
  padding: 40px;
  border-radius: 20px;
  border: 1px solid var(--border-color);
}

.placeholder-content {
  background: linear-gradient(135deg, #1a1f3a 0%, #0f172a 100%);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.mock-window {
  background: #0f172a;
}

.mock-titlebar {
  background: rgba(15, 23, 42, 0.8);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border-color);
}

.mock-buttons {
  display: flex;
  gap: 8px;
}

.mock-buttons span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--text-muted);
}

.mock-buttons span:nth-child(1) { background: #ff5f56; }
.mock-buttons span:nth-child(2) { background: #ffbd2e; }
.mock-buttons span:nth-child(3) { background: #27c93f; }

.mock-title {
  color: var(--text-muted);
  font-size: 12px;
  flex: 1;
  text-align: center;
}

.mock-content {
  display: flex;
  height: 400px;
}

.mock-sidebar {
  width: 200px;
  background: rgba(10, 14, 39, 0.8);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-right: 1px solid var(--border-color);
}

.mock-menu-item {
  padding: 12px 16px;
  border-radius: 8px;
  color: var(--text-muted);
  font-size: 14px;
  transition: all 0.3s ease;
}

.mock-menu-item.active {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
}

.mock-main {
  flex: 1;
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.mock-card {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
}

.mock-card-title {
  height: 20px;
  width: 120px;
  background: linear-gradient(90deg, var(--primary-color), transparent);
  border-radius: 4px;
  margin-bottom: 16px;
}

.mock-card-text {
  height: 12px;
  background: linear-gradient(90deg, var(--text-muted), transparent);
  border-radius: 4px;
  margin-bottom: 8px;
}

.mock-card-text.short {
  width: 60%;
}

.mock-button {
  width: 120px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 8px;
  margin-top: 16px;
}

.mock-stats {
  display: flex;
  gap: 16px;
}

.mock-stat {
  flex: 1;
  height: 80px;
  background: rgba(102, 126, 234, 0.1);
  border: 1px solid rgba(102, 126, 234, 0.3);
  border-radius: 12px;
}

.screenshot-caption {
  text-align: center;
  margin-top: 24px;
  color: var(--text-muted);
  font-size: 16px;
}

/* ===== 下载区域 ===== */
.download {
  padding: 120px 24px;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
  position: relative;
  overflow: hidden;
}

.download::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(102, 126, 234, 0.2) 0%, transparent 70%);
  animation: rotate 20s linear infinite;
}

.download-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.download-title {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 900;
  margin-bottom: 16px;
}

.download-subtitle {
  font-size: 20px;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.download-features {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 32px;
}

.download-feature {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 16px;
  color: var(--text-secondary);
}

.check-icon {
  width: 24px;
  height: 24px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
  font-size: 14px;
}

.version-info {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  backdrop-filter: blur(10px);
}

.version-badge {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.version-label {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
}

.version-number {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-color);
}

.version-date, .version-size {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 4px;
}

.download-actions {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.download-card {
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 40px;
  text-align: center;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

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

.os-icon {
  margin-bottom: 24px;
}

.os-icon svg {
  color: var(--primary-color);
  filter: drop-shadow(0 4px 12px rgba(102, 126, 234, 0.3));
}

.download-card h3 {
  font-size: 28px;
  margin-bottom: 8px;
}

.os-support {
  color: var(--text-muted);
  margin-bottom: 32px;
}

.btn-download {
  width: 100%;
  padding: 20px 32px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border: none;
  border-radius: 12px;
  color: white;
  font-size: 18px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
}

.btn-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(102, 126, 234, 0.6);
}

.download-icon {
  font-size: 24px;
  animation: bounce-download 2s ease-in-out infinite;
}

@keyframes bounce-download {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-4px);
  }
}

.download-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
}

.download-main {
  font-size: 18px;
  font-weight: 600;
}

.download-sub {
  font-size: 13px;
  opacity: 0.8;
  font-weight: 400;
}

.download-alternatives {
  margin-top: 20px;
  display: flex;
  justify-content: center;
  gap: 16px;
  align-items: center;
}

.alt-link {
  color: var(--primary-color);
  text-decoration: none;
  font-size: 14px;
  transition: all 0.3s ease;
}

.alt-link:hover {
  color: var(--accent-color);
}

.separator {
  color: var(--text-muted);
}

.system-requirements {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  backdrop-filter: blur(10px);
}

.system-requirements h4 {
  font-size: 20px;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.system-requirements ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.system-requirements li {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

.system-requirements strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ===== 关于部分 ===== */
.about {
  padding: 120px 24px;
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  max-width: 1200px;
  margin: 0 auto;
}

.about-description {
  color: var(--text-secondary);
  font-size: 18px;
  line-height: 1.8;
  margin-bottom: 24px;
}

.about-description strong {
  color: var(--primary-color);
  font-weight: 600;
}

.about-stats {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 40px;
}

.about-stat {
  display: flex;
  gap: 20px;
  align-items: center;
}

.stat-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.2), rgba(118, 75, 162, 0.2));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
}

.stat-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.stat-desc {
  color: var(--text-muted);
  font-size: 14px;
}

.about-features {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.about-feature-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.about-feature-item:hover {
  border-color: var(--primary-color);
  transform: translateX(8px);
}

.about-feature-item h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.about-feature-item p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== 页脚 ===== */
.footer {
  background: rgba(10, 14, 39, 0.8);
  border-top: 1px solid var(--border-color);
  padding: 80px 24px 32px;
  backdrop-filter: blur(10px);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 64px;
  max-width: 1200px;
  margin: 0 auto 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 24px;
  font-weight: 700;
}

.footer-description {
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-social {
  display: flex;
  gap: 16px;
}

.social-link {
  width: 40px;
  height: 40px;
  background: rgba(102, 126, 234, 0.1);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: all 0.3s ease;
}

.social-link:hover {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  border-color: transparent;
  transform: translateY(-4px);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-column h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.footer-column ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-column a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  transition: all 0.3s ease;
}

.footer-column a:hover {
  color: var(--primary-color);
  padding-left: 8px;
}

.footer-bottom {
  text-align: center;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 14px;
}

/* ===== 回到顶部按钮 ===== */
.back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border: none;
  border-radius: 50%;
  color: white;
  font-size: 24px;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .download-content,
  .about-content {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-visual {
    display: none;
  }

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

@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }

  .hero {
    padding: 100px 24px 40px;
  }

  .hero-buttons {
    flex-direction: column;
  }

  .btn-primary, .btn-secondary {
    width: 100%;
    justify-content: center;
  }

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

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

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

  .mock-content {
    height: 300px;
  }

  .mock-sidebar {
    width: 150px;
  }
}

/* ===== AOS 动画（可选） ===== */
[data-aos] {
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

[data-aos].aos-animate {
  opacity: 1;
}

[data-aos="fade-up"] {
  transform: translateY(15px);
}

[data-aos="fade-up"].aos-animate {
  transform: translateY(0);
}

[data-aos="zoom-in"] {
  transform: scale(0.9);
}

[data-aos="zoom-in"].aos-animate {
  transform: scale(1);
}