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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f0f2f5;
  color: #5a7c7a;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

nav {
  background-color: #2c3e50;
  padding: 1.5rem;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-title {
  color: white;
  font-size: 1.5rem;
  font-weight: bold;
  text-decoration: none;
}

header {
  text-align: center;
  padding: 60px 20px 20px;
  background-color: #e9ecef;
  margin-bottom: 40px;
}

header h1 {
  font-size: 3rem;
  color: #2c3e50;
  margin-bottom: 10px;
}

header p {
  font-size: 1.2rem;
  color: #555;
  margin-bottom: 30px;
}

.button-container {
  text-align: center;
  margin-bottom: 50px;
}

.download-button {
  background-color: white;
  color: #007bff;
  padding: 15px 30px;
  border: 2px solid #007bff;
  border-radius: 10px;
  font-size: 18px;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.05);
  transition: background-color 0.3s, color 0.3s, transform 0.2s;
  display: inline-block;
}

.download-button:hover {
  background-color: #007bff;
  color: white;
  transform: scale(1.05);
}

.download-button-mini {
  background-color: #007bff;
  color: #ffffff;
  padding: 8px 16px;
  border-radius: 10px;
  font-size: 14px;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.05);
  transition: background-color 0.3s, color 0.3s, transform 0.2s;
  display: inline-block;
}

.download-button-mini:hover {
  background-color: #007bff;
  color: white;
  transform: scale(1.02);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.main-content {
  padding: 60px 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4rem;
  background-color: #ffffff;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  border-radius: 20px;
  margin: 0 auto 80px;
  width: 90%;
  max-width: 1300px;
}

.box {
  background-color: #ffffff;
  border: 1px solid #ddd;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.08);
  padding: 30px 20px;
  flex: 1 1 300px;
  max-width: 350px;
  text-align: center;
  transition: transform 0.3s, box-shadow 0.3s;
}

.box:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
}

.box h3 {
  font-size: 1.8rem;
  color: #2c3e50;
  margin-bottom: 20px;
}

.box p {
  font-size: 1rem;
  color: #555;
  line-height: 1.5;
}
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.hidden {
  display: none;
}

.spinner {
  border: 8px solid #f3f3f3;
  border-top: 8px solid #3498db;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0%   { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}


/* Responsive */
@media (max-width: 768px) {
  header {
    padding: 40px 10px 20px;
  }
  header h1 {
    font-size: 2.2rem;
  }
  .main-content {
    padding: 40px 10px;
    gap: 2rem;
  }
}