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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background: #f5f5f5;
}

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

/* 导航栏 */
.navbar {
  background: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-logo {
  width: 40px;
  height: 40px;
}

.nav-title {
  font-size: 20px;
  font-weight: bold;
  color: #58A352;
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-links a {
  text-decoration: none;
  color: #666;
  font-size: 16px;
  transition: color 0.3s;
}

.nav-links a:hover {
  color: #4CAF50;
}

/* 主横幅 */
.hero {
  background: linear-gradient(135deg, #4CAF50 0%, #58A352 100%);
  color: white;
  padding: 100px 20px;
  text-align: center;
}

.hero-logo {
  width: 150px;
  height: 150px;
  margin-bottom: 20px;
  filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.2));
}

.hero h1 {
  font-size: 48px;
  margin-bottom: 15px;
}

.hero-subtitle {
  font-size: 24px;
  margin-bottom: 10px;
  opacity: 0.95;
}

.hero-description {
  font-size: 18px;
  margin-bottom: 30px;
  opacity: 0.9;
}

.btn-primary {
  display: inline-block;
  padding: 15px 40px;
  background: white;
  color: #4CAF50;
  text-decoration: none;
  border-radius: 30px;
  font-size: 18px;
  font-weight: bold;
  transition: all 0.3s;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* 功能特性 */
.features {
  padding: 80px 20px;
  background: white;
}

.features h2 {
  text-align: center;
  font-size: 36px;
  color: #333;
  margin-bottom: 50px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.feature-card {
  background: #f9f9f9;
  padding: 30px;
  border-radius: 10px;
  text-align: center;
  transition: all 0.3s;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.feature-icon {
  font-size: 50px;
  margin-bottom: 15px;
}

.feature-card h3 {
  font-size: 22px;
  color: #4CAF50;
  margin-bottom: 10px;
}

.feature-card p {
  color: #666;
  font-size: 16px;
}

/* 下载区域 */
.download {
  padding: 80px 20px;
  background: linear-gradient(135deg, #f5f5f5 0%, #e8f5e9 100%);
  text-align: center;
}

.download h2 {
  font-size: 36px;
  color: #333;
  margin-bottom: 15px;
}

.download-subtitle {
  font-size: 18px;
  color: #666;
  margin-bottom: 40px;
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.btn-download {
  display: inline-block;
  padding: 15px 40px;
  background: #4CAF50;
  color: white;
  text-decoration: none;
  border-radius: 30px;
  font-size: 18px;
  font-weight: bold;
  transition: all 0.3s;
  box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

.btn-download:hover {
  background: #45a049;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
}

.version-info {
  color: #999;
  font-size: 14px;
}

/* 用户留言 */
.feedback {
  padding: 80px 20px;
  background: white;
}

.feedback h2 {
  text-align: center;
  font-size: 36px;
  color: #333;
  margin-bottom: 20px;
}

.feedback-count {
  text-align: center;
  font-size: 18px;
  color: #666;
  margin-bottom: 30px;
}

.feedback-count span {
  color: #4CAF50;
  font-weight: bold;
  font-size: 24px;
}

.feedback-form {
  max-width: 600px;
  margin: 0 auto;
}

#messageInput {
  width: 100%;
  min-height: 120px;
  padding: 15px;
  border: 2px solid #ddd;
  border-radius: 10px;
  font-size: 16px;
  font-family: inherit;
  resize: vertical;
  transition: border-color 0.3s;
}

#messageInput:focus {
  outline: none;
  border-color: #4CAF50;
}

.char-count {
  text-align: right;
  color: #999;
  font-size: 14px;
  margin: 5px 0 15px;
}

.btn-submit {
  width: 100%;
  padding: 15px;
  background: #4CAF50;
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 18px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s;
}

.btn-submit:hover {
  background: #45a049;
}

.btn-submit:disabled {
  background: #ccc;
  cursor: not-allowed;
}

.submit-message {
  margin-top: 15px;
  padding: 10px;
  border-radius: 5px;
  text-align: center;
  font-size: 14px;
  display: none;
}

.submit-message.success {
  background: #d4edda;
  color: #155724;
  display: block;
}

.submit-message.error {
  background: #f8d7da;
  color: #721c24;
  display: block;
}

/* 页脚 */
.footer {
  background: #333;
  color: white;
  padding: 30px 20px;
  text-align: center;
}

.footer p {
  margin: 5px 0;
  opacity: 0.8;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .nav-links {
    gap: 15px;
  }

  .nav-links a {
    font-size: 14px;
  }

  .hero h1 {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 18px;
  }

  .features h2,
  .download h2,
  .feedback h2 {
    font-size: 28px;
  }

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

  .download-buttons {
    flex-direction: column;
    align-items: center;
  }
}