:root {
  --bg-color: #121212;
  --card-bg: #1e1e1e;
  --primary-color: #66c0f4;
  --secondary-color: #4d9ece;
  --text-color: #e0e0e0;
  --muted-text: #a0a0a0;
  --success-color: #4BB543;
  --input-bg: #2c2c2c;
  --input-border: #444444;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.tagline {
  color: var(--muted-text);
  font-style: italic;
}

h2 {
  color: var(--primary-color);
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
}

.card {
  background-color: var(--card-bg);
  border-radius: 10px;
  padding: 2rem;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  margin-bottom: 2rem;
  transition: transform 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
}

.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

label i {
  margin-right: 0.5rem;
  color: var(--primary-color);
}

input {
  width: 100%;
  padding: 0.8rem;
  border-radius: 6px;
  border: 1px solid var(--input-border);
  background-color: var(--input-bg);
  color: var(--text-color);
  font-size: 1rem;
  transition: all 0.3s ease;
}

input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px rgba(102, 192, 244, 0.2);
}

input::placeholder {
  color: var(--muted-text);
  opacity: 0.7;
}

.btn-submit {
  width: 100%;
  padding: 1rem;
  background-color: var(--primary-color);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.3s ease;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
}

.btn-submit:hover {
  background-color: var(--secondary-color);
}

.response-container {
  text-align: center;
  min-height: 50px;
  margin-bottom: 1rem;
}

#response {
  padding: 1rem;
  font-weight: 600;
  color: var(--success-color);
  opacity: 0;
  transition: opacity 0.5s ease;
}

#response.visible {
  opacity: 1;
}

footer {
  text-align: center;
  color: var(--muted-text);
  font-size: 0.9rem;
  margin-top: 2rem;
}

/* For mobile devices */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }
  
  .card {
    padding: 1.5rem;
  }
  
  h1 {
    font-size: 2rem;
  }
}