/* Box-sizing fix for layout consistency */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --primary: #20c997;
  --teal-hover: #138d75;
  --navy: #001f3f;
  --navy-dark: #001737;
  --light: #f4f4f4;
  --white: #ffffff;
  --muted: #aaa;
  --dark-bg: #1f1f1f;
  --dark-card: #2c2c2c;
  --light-text: #f0f0f0;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background-color: var(--light);
  color: #333;
  margin: 0;
  padding: 2rem;
  transition: all 0.3s ease;
}

body.dark {
  background-color: var(--dark-bg);
  color: var(--light-text);
}

.container {
  max-width: 500px;
  margin: auto;
  background: var(--white);
  padding: 2rem;
  border-radius: 1rem;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
  box-sizing: border-box;
}

body.dark .container {
  background: var(--dark-card);
}

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

.gradient {
  background: linear-gradient(90deg, #20c997, #001f3f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 800;
  font-size: 1.8rem;
}

.input-group {
  margin-bottom: 1rem;
}

label {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid #ccc;
  font-size: 1rem;
  box-sizing: border-box;
}

input:focus {
  border-color: var(--primary);
  outline: none;
}

.btn {
  width: 100%;
  padding: 0.75rem;
  margin-top: 1rem;
  background-color: var(--primary);
  border: none;
  border-radius: 0.5rem;
  color: white;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s;
  box-sizing: border-box;
}

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

.btn.secondary {
  background: var(--navy);
  margin-top: 0.5rem;
}

.btn.secondary:hover {
  background: var(--navy-dark);
}

.result-card {
  margin-top: 2rem;
  background: var(--light);
  padding: 1rem;
  border-radius: 0.5rem;
  text-align: center;
}

body.dark .result-card {
  background: var(--dark-card);
}

.result-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
  flex-direction: column;
}

@media (min-width: 480px) {
  .result-actions {
    flex-direction: row;
    justify-content: center;
  }
}

.hidden {
  display: none;
}

@media (max-width: 600px) {
  .container {
    padding: 1rem;
  }

  .gradient {
    font-size: 1.4rem;
  }
}