body { 
  font-family: "Segoe UI", Roboto, "Helvetica Neue", sans-serif; 
  margin: 0; 
  padding: 40px 20px; 
  line-height: 1.6; 
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%); 
  color: #2c3e50; 
  min-height: 100vh;
}
.container { 
  max-width: 800px; 
  margin: 0 auto; 
  background: #ffffff; 
  padding: 40px; 
  border-radius: 12px; 
  box-shadow: 0 10px 30px rgba(0,0,0,0.1); 
}
h1, h2, h3 { 
  color: #1a252f; 
  margin-top: 0;
  font-weight: 600;
}
.btn { 
  display: inline-block; 
  padding: 12px 20px; 
  background: #3498db; 
  color: white; 
  text-decoration: none; 
  border-radius: 6px; 
  border: none; 
  cursor: pointer; 
  font-weight: 500;
  transition: all 0.3s ease;
}
.btn:hover {
  background: #2980b9;
  transform: translateY(-2px);
  box-shadow: 0 4px 10px rgba(52, 152, 219, 0.3);
}
.btn-danger { background: #e74c3c; }
.btn-danger:hover { background: #c0392b; box-shadow: 0 4px 10px rgba(231, 76, 60, 0.3); }
.btn-secondary { background: #95a5a6; }
.btn-secondary:hover { background: #7f8c8d; box-shadow: 0 4px 10px rgba(149, 165, 166, 0.3); }
form { margin-bottom: 25px; }
input[type="text"], input[type="password"], input[type="file"] { 
  width: 100%; 
  padding: 12px; 
  margin: 10px 0 20px 0; 
  border: 1px solid #dfe6e9; 
  border-radius: 6px; 
  box-sizing: border-box; 
  transition: border 0.3s ease;
}
input[type="text"]:focus, input[type="password"]:focus {
  border-color: #3498db;
  outline: none;
  box-shadow: 0 0 0 3px rgba(52,152,219,0.2);
}
.card { 
  border: 1px solid #f1f2f6; 
  padding: 20px; 
  margin-bottom: 20px; 
  border-radius: 10px; 
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  background: #f8f9fa;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}
.card img { max-width: 150px; border-radius: 8px; }
.actions { display: flex; gap: 12px; }
iframe { width: 100%; height: 80vh; border: none; border-radius: 8px; box-shadow: inset 0 2px 10px rgba(0,0,0,0.05); }
.error { color: #e74c3c; margin-bottom: 15px; font-weight: 500; background: #fadbd8; padding: 10px; border-radius: 6px; }